estimation of flood-frequency discharges for rural ... · estimation of flood-frequency discharges...

U.S. Department of the InteriorU.S. Geological Survey

Scientific Investigations Report 2010–5033

Prepared in cooperation with the West Virginia Department of Transportation, Division of Highways

Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia


By Jeffrey B. Wiley and John T. Atkins, Jr.

Prepared in cooperation with the West Virginia Department of Transportation, Division of Highways


U.S. Department of the InteriorU.S. Geological Survey

U.S. Department of the InteriorKEN SALAZAR, Secretary

U.S. Geological SurveyMarcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2010

For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS

For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod

To order this and other USGS information products, visit http://store.usgs.gov

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report.

Suggested citation:Wiley, J.B., and Atkins, J.T., Jr., 2010, Estimation of flood-frequency discharges for rural, unregulated streams in West Virginia: U.S. Geological Survey Scientific Investigations Report 2010–5033, 78 p.

ISBN 978-1-4113-2769-6

iii

Contents

Abstract ...........................................................................................................................................................1Introduction.....................................................................................................................................................1

Regional Historical Floods ...................................................................................................................1Description of Study Area ...................................................................................................................4Previous Studies ...................................................................................................................................4This Study ...............................................................................................................................................6

Development of Flood-Frequency Discharge Equations .........................................................................7Peak Discharges ...................................................................................................................................7Basin Characteristics ...........................................................................................................................7Correlation of Basin Characteristics .................................................................................................9West Virginia Skew Coefficients ........................................................................................................9Flood-Frequency Discharges ............................................................................................................10Regional Regression of Flood-Frequency Discharges .................................................................11Accuracy of Flood-Frequency Discharge Equations ....................................................................14

Procedures For Estimating Flood-Frequency Discharges ....................................................................15At a Streamgage Station ...................................................................................................................15At an Ungaged Location ....................................................................................................................15

Upstream From a Streamgage Station ...................................................................................18Downstream From a Streamgage Station .............................................................................18Between Streamgage Stations ...............................................................................................18

Hydrologic Conditions Change Linearly between Streamgage Stations ................19Hydrologic Conditions Change Linearly to the Regional Hydrologic Conditions

between Streamgage Stations .........................................................................19Not on the Same Stream as a Streamgage Station .............................................................20

Example Applications .........................................................................................................................20Limitations of Procedures for Estimating Flood-Frequency Discharges ...................................21

Summary........................................................................................................................................................21References Cited..........................................................................................................................................22Appendix 1. Matrices Used to Compute Individual Standard Errors of Prediction ..........................78

iv

Figures 1–4. Map showing— 1. Selected streams used for identifying regional extent of historic floods

in West Virginia ....................................................................................................................2 2. Appalachian Plateaus, Valley and Ridge, and Blue Ridge Physiographic

Provinces, and Climatic Divide in West Virginia .............................................................5 3. The 290 U.S. Geological Survey streamgage stations in West Virginia and

adjacent states considered in the estimation of flood-frequency discharges in West Virginia. ...................................................................................................................8

4. The Eastern Panhandle, Central Mountains, and Western Plateaus Regions of West Virginia for which equations for estimation of flood frequency discharges were developed in this study ......................................................................12

5–7. Graph showing— 5. Range of differences of the individual standard errors of the prediction from

the average prediction errors for the indicated drainage areas ...............................14 6. LOESS curves of the absolute difference between the 100-year flood

discharges determined at streamgage stations and values estimated from the (1) drainage-area ratio method and (2) regional equations, in relation to the ratios of the drainage areas ......................................................................................17

7. LOESS curves of the absolute difference between the 1.1- through 500-year flood discharges determined at streamgage stations and values estimated from the (1) drainage-area ratio method and (2) regional equations, in relation to the ratios of the drainage areas .................................................................................17

Tables 1. Identification numbers, station numbers, streamgage-station names, and skew

coefficients and statistics for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states ................................25

2. Flood-frequency statistics and drainage areas for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states ............................................................................................................................................36

3. Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states .................46

4. Equations used to estimate selected flood-frequency discharges for streams in the Eastern Panhandle, Central Mountains, and Western Plateaus Regions of West Virginia ...........................................................................................................................13

5. Description of the 88 pairs of U.S. Geological Survey streamgage stations in West Virginia and adjacent states that were evaluated to quantify “near” for application of the drainage-area ratio method in this study ...............................................73

6. Values of the exponent, and upstream and downstream limits of the drainage- area ratios used to quantify the definition of “near” for estimating selected flood-frequency discharges for ungaged locations in West Virginia ................................16

v

Conversion Factors, Datums, Acronyms, and Abbreviations

Multiply By To obtainLength

inch (in.) 2.54 centimeter (cm)foot (ft) 0.3048 meter (m)mile (mi) 1.609 kilometer (km)

Areasquare mile (mi2) 2.590 square kilometer (km2)

Flow ratecubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s)cubic foot per second per square

mile [(ft3/s)/mi2] 0.01093 cubic meter per second per square

kilometer [(m3/s)/km2]

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 (NAVD 88).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Altitude, as used in this report, refers to distance above the vertical datum.

AcronymsGLSNet USGS software for computing generalized least-square regressionLOESS Locally weighted regressionPeakFQ USGS software for computing flood-frequency discharges S-PLUS Commercially available software for computing statistics USGS U. S. Geological SurveySWSTAT USGS software for computing surface-water statistics

AbbreviationsAOP Annual-occurrence probability AU Drainage area at the location of the unknown flood-frequency dischargeAK Drainage area at the location of the known flood-frequency dischargeAUS Drainage area at the upstream locationADS Drainage area at the downstream locationAOP Annual-occurrence probabilityDRNAREA Drainage area EX Exponent for drainage-area ratios

vi

EY Equivalent years of recordK Frequency factor MSE Mean-square error N Number of years of peak-discharge record Q DischargeQDS Flood-frequency discharge at the downstream location QK Known flood-frequency dischargeQKE Regional equation evaluated at the location of the known flood-frequency dischargeQr Flood-frequency discharge determined from the appropriate regional equationQs Flood-frequency discharge determined from systematic and historical recordQU Unknown flood-frequency dischargeQUE Regional equation evaluated at the location of the unknown flood-frequency dischargeQUS Flood-frequency discharge at the upstream location Qw Discharge weighted by number of years of peak-discharge record at the gaging station and equivalent years of record for the appropriate regional equationQ(n) Discharge for the n-year recurrence intervalRDS Downstream limit of the ratio of drainage areas RU/K Ratio of the drainage area at the location of the unknown flood-frequency discharge to the drainage area at the location of the known flood-frequency discharge RUS Upstream limit of the ratio of drainage areasSP Standard deviation of the log10-transformed annual peak dischargesX Log10-transformed annual peak dischargesXmean Mean of the log10-transformed annual peak discharges


By Jeffrey B. Wiley And John T. Atkins, Jr.

IntroductionMany engineering projects are built within or adjacent to

flood-prone areas. Information on past flooding and estimates of the magnitude and frequency of potential future floods are critical to the safe and economical design of hydraulic struc-tures such as bridges, culverts, dams, flood dikes, and levees.

Regional Historical Floods

Before 1930, neither floods nor streamflow in West Virginia were systematically documented. Since 1930, data on regional flooding has been collected as part of the operation of a statewide streamgaging network supported by State and Federal funding. Local floods in small, ungaged watersheds remain only sparsely quantified. Major regional floods affect-ing parts of West Virginia occurred in 1844, 1877, 1878, 1888, 1889, 1912, 1918, 1932, 1936, 1949, 1963, 1967, 1977, 1984, 1985, and 1996. For floods prior to 1930, the regional extent is not defined, but rivers other than those identified in West Virginia may have been affected. Locations of selected West Virginia streams are shown in figure 1. A list of flood dates with a brief description of the flood and the report that docu-ments the flood follows.

• July 1844: Flooding on the Cheat River was docu-mented by Speer and Gamble (1965, p. 148). This flood was about equal in magnitude to those in July 1888 and May 1996.

• November 1877: Flooding on the South Branch Potomac River was documented by Tice (1968, p. 488, 490). This flood was about equal in magnitude to those in March 1936 and September 1996.

• September 1878: Flooding on the New River was documented by Speer and Gamble (1965, p. 284–288).

AbstractFlood-frequency discharges were determined for 290

streamgage stations having a minimum of 9 years of record in West Virginia and surrounding states through the 2006 or 2007 water year. No trend was determined in the annual peaks used to calculate the flood-frequency discharges.

Multiple and simple least-squares regression equations for the 100-year (1-percent annual-occurrence probability) flood discharge with independent variables that describe the basin characteristics were developed for 290 streamgage stations in West Virginia and adjacent states. The regression residuals for the models were evaluated and used to define three regions of the State, designated as Eastern Panhandle, Central Mountains, and Western Plateaus. Exploratory data analysis procedures identified 44 streamgage stations that were excluded from the development of regression equations representative of rural, unregulated streams in West Virginia. Regional equations for the 1.1-, 1.5-, 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year flood discharges were determined by generalized least-squares regression using data from the remaining 246 streamgage stations. Drainage area was the only significant independent variable determined for all equa-tions in all regions.

Procedures developed to estimate flood-frequency dis-charges on ungaged streams were based on (1) regional equa-tions and (2) drainage-area ratios between gaged and ungaged locations on the same stream. The procedures are applicable only to rural, unregulated streams within the boundaries of West Virginia that have drainage areas within the limits of the stations used to develop the regional equations (from 0.21 to 1,461 square miles in the Eastern Panhandle, from 0.10 to 1,619 square miles in the Central Mountains, and from 0.13 to 1,516 square miles in the Western Plateaus). The accuracy of the equations is quantified by measuring the average predic-tion error (from 21.7 to 56.3 percent) and equivalent years of record (from 2.0 to 70.9 years).

2 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

OHIO

PENNSYLVANIA

MARYLAND

VIRGINIA

KENTUCKY

Rive

r

Potomac River

South

Bra

nch

North B

ranchRi

ver

Oh io River

New River

Greenb

rier R

iver

Gu y andotte R

i ver

Tug Fo r k R i v e r

Ka n awha R iver

Elk Ri v

er

Little K ana w h a River

Cheat River

Tygart Valley River

Monon

gahe

la

G auley R ive

r

Big

Sand

y78°W81°W

40°N

38°N

0 20 40 60 MILES

0 20 40 60 KILOMETERS

EXPLANATIONState boundary

Major stream

Base from U.S. Geological Survey 1:100,000 digital line graphics. Universal Transverse Mercator projection, zone 17, NAD 83.

Figure 1. Selected streams used for identifying regional extent of historic floods in West Virginia.

Introduction 3

• July 1888: Flooding on the Monongahela River was documented by Speer and Gamble (1965, p. 121, 138, 146–149). This flood was about equal in magnitude to those in July 1844 on the Cheat River and May 1996 on the Cheat and upper Monongahela Rivers.

• May–June 1889: Flooding on the North Branch Potomac River was documented by Tice (1968, p. 480, 490, 494, 497). This flood was about equal in magni-tude to those in March 1936 and September 1996.

• July 1912: Flooding on the Tygart Valley River was documented by Speer and Gamble (1965, p. 118, 121, 127–128).

• March 1918: Flooding on the Greenbrier and Gauley Rivers was documented by Speer and Gamble (1965, p. 298, 310).

• February 1932: Flooding on the Tygart Valley, Green-brier, and Gauley Rivers was documented by Speer and Gamble (1965, p. 119, 121, 129, 295, 298, 304, 307, 310).

• March 1936: Flooding was documented on the Potomac and Cheat Rivers. This flood, which was documented by Grover (1937) as having a regional extent including the upper Ohio, Potomac, and James Rivers (the James River in Virginia), was caused by four separate cyclonic storms passing over the northeastern United States, resulting in multiple peak discharges and superposition of later peak discharges on earlier peak discharges. This flood was about equal in magnitude to those in November 1877 on the South Branch Potomac River, May through June 1889 on the North Branch Potomac River, and September 1996 on the upper Potomac River (both North and South Branch).

• June 1949: Flooding on the South Branch Potomac River was documented by Tice (1968, p. 483–488).

• March 1963: Flooding was documented on the Big Sandy (including the Tug Fork in West Virginia), Guy-andotte, Little Kanawha, Cheat, and Greenbrier Rivers. This flood, which was documented by Barnes (1964) as having affected the western slopes of the Appala-chian Mountains from Alabama to West Virginia, was caused by three separate frontal storms in which rain fell on a snowpack and was followed by two additional storms.

• March 1967: Flooding was documented on the Kanawha and Monongahela Rivers. This flood was caused by 4 to 5 in. of rainfall over 3 days, augmented by runoff from melting snow (U.S. Geological Survey, 1991).

• April 1977: Flooding was documented on the Tug Fork and Guyandotte Rivers. This flood was documented by Runner (1979) and Runner and Chin (1980) as having affected northeastern Tennessee, southwestern Vir-ginia, eastern Kentucky, and southern West Virginia. This flood resulted from a frontal storm that moved southeastward through the region, became stationary, then moved slowly northwestward drawing a warm moist maritime airmass from the Gulf of Mexico and combining to produce heavy rainfall. The highest peak discharges ever recorded on the Tug Fork and Guyan-dotte Rivers resulted from this storm.

• May 1984: Flooding was documented on the Tug Fork and Guyandotte Rivers (U.S. Geological Survey, 1991).

• November 1985: Flooding was documented on the Monongahela, Potomac, upper Little Kanawha, upper Elk, and upper Greenbrier Rivers. This flood was documented by Lescinsky (1987) and Carpenter (1990) as having affected eastern West Virginia, western and northern Virginia, southwestern Pennsylvania, and western Maryland. This flood resulted from a complex sequence of meteorological events. Hurricane Juan moved from the Gulf of Mexico through southern Mississippi, ultimately causing precipitation as far north as Michigan and generating less than 2 in. of rainfall in West Virginia. This rainfall was caused by a second low pressure system that developed from the hurricane remnants. The low pressure developed near the Tennessee-North Carolina border and trav-eled rapidly eastward to the Atlantic Ocean. A third low pressure system moved from the Gulf of Mexico into the Florida panhandle then moved slowly up the east coast of the United States, resulting in additional rainfall in West Virginia of up to 9 in. The highest peak discharges ever recorded on the upper Monongahela and Potomac Rivers resulted from this flood.

• January 1996: About 2 in. of rain fell on a 3 to 4 ft snowpack, resulting in flooding in the upper Potomac, upper Cheat, upper Elk, and Greenbrier Rivers.

• May 1996: A frontal storm caused flooding on the Cheat and upper Monongahela Rivers that was about equal in magnitude to flooding on the Cheat River in July 1844 and July 1888.

• September 1996: Tropical storm Fran caused regional flooding on the upper Potomac River. This flood was about equal in magnitude to that in November 1877 on the South Branch Potomac River, to that in May through June 1889 on the North Branch Potomac River, and to that in March 1936 on the upper Potomac River.


Description of Study Area

West Virginia can be differentiated into three phys-iographic provinces, the Appalachian Plateaus, Valley and Ridge, and Blue Ridge (Fenneman, 1938) (fig. 2). The move-ment of air masses across the State allows identification of two climatic regions, separated by a line defined as the Climatic Divide (Wiley, 2008) (fig. 1).

Generally, the part of the State west of the Climatic Divide is in the Appalachian Plateaus Physiographic Province, where altitudes range from about 2,500 to 4,861 ft (NAVD88) at Spruce Knob along the Climatic Divide to about 550 to 650 ft along the Ohio River. The part of West Virginia east of the Climatic Divide is in the Valley and Ridge Physiographic Province, except for the extreme eastern tip of the State, which is in the Blue Ridge Physiographic Province. Altitudes decrease eastward from the Climatic Divide to 274 ft at Harp-ers Ferry in the Eastern Panhandle (U.S. Geological Survey, 1990, 2006; National Oceanic and Atmospheric Administra-tion, 2006a).

The Appalachian Plateaus Physiographic Province con-sists of consolidated, mostly noncarbonate sedimentary rocks that have a gentle slope from southeast to northwest near the Climatic Divide and are nearly flat-lying along the Ohio River. One exception is in the northeastern area of the province (west of the Climatic Divide), where the rocks are gently folded and some carbonate rock crops out (Fenneman, 1938). The rocks in the Appalachian Plateaus Physiographic Province have been eroded to form steep hills and deeply incised valleys; drainage patterns are dendritic.

The Valley and Ridge Physiographic Province in West Virginia consists of consolidated carbonate and noncarbon-ate sedimentary rocks that are folded sharply and extensively faulted (Fenneman, 1938). Northeast-trending valleys and ridges parallel the Climatic Divide; drainage patterns are trellis.

The Blue Ridge Physiographic Province within West Vir-ginia consists predominantly of metamorphosed sandstone and shale (Fenneman, 1938). The province has high relief between mountains and wide valleys that parallel the Climatic Divide.

The climate of West Virginia is primarily continental, with mild summers and cold winters. Major weather systems generally approach from the west and southwest, although polar continental air masses of cold, dry air that approach from the north and northwest are not unusual. Air masses from the Atlantic Ocean sometimes affect the area east of the Climatic Divide and less frequently affect the area west of the Climatic Divide. Generally, tropical continental masses of hot, dry air from the southwest affect the climate west of the Climatic Divide. Tropical maritime masses of warm, moist air from the Gulf of Mexico affect the climate east of the Climatic Divide more than west of the Climatic Divide. Evaporation from local and upwind land surfaces, lakes, and reservoirs also provides a source of moisture that affects the climate of the State (U.S. Geological Survey, 1991; National Oceanic and Atmospheric Administration, 2006a).

Annual precipitation averages about 42 to 45 in. state-wide with about 60 percent received from March through August. July is the wettest month, and September through November are the driest. Annual average precipitation in the State generally decreases northwestward from about 50 to 60 in. along the Climatic Divide to about 40 in. along the Ohio River, and increases from about 30 to 35 in. east of the Climatic Divide to about 40 in. in the extreme eastern tip of the State. Greater precipitation along and west of the Cli-matic Divide is a consequence of the higher elevations along the Divide and the general movement of weather systems approaching from the west and southwest. Annual average snowfall follows the general pattern of annual average pre-cipitation, decreasing northwestward from about 36 to 100 in. along the Climatic Divide to about 20 to 30 in. along the Ohio River. Annual average snowfall ranges from 24 to 36 in. east of the Climatic Divide (U.S. Geological Survey, 1991; Natural Resources Conservation Service, 2006; National Oceanic and Atmospheric Administration, 2006a, 2006b).

Flooding across large drainage areas results from regional climatic events like frontal systems in winter and early spring, rainfall on snowpack in early spring, and tropical cyclones (hurricanes and tropical storms) in late summer or early fall. Generally, the most severe flooding across small drainage areas results from local intense thunderstorms in late spring through summer (Doll and others, 1963).

Previous Studies

Flood-frequency studies completed by Wiley and oth-ers (2000, 2002) used data for peak discharges from 267 rural, unregulated streamgage stations in West Virginia and adjacent states. Simple and multiple least-squares regression models were used to determine three regions in the State and to develop initial estimating equations with drainage area as the only significant independent variable. The final estimat-ing equations were determined for the 1.1-, 1.2-, 1.3-, 1.4-, 1.5-, 1.6-, 1.7-, 1.8-, 1.9-, 2-, 2.5-, 3-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year flood discharges using a generalized least-squares regression model (Stedinger and Tasker, 1985; Tasker and Stedinger, 1989).

New procedures for transferring the flood-frequency discharges determined by Wiley and others (2000, 2002) to ungaged locations were presented by Wiley (2008, Appendix 1). These methods incorporated a comparison of discharge estimates determined using drainage-area ratios to discharge estimates determined by application of the flood-fre-quency equations. This current study repeats that analysis and supersedes the results presented in Wiley (2008, Appendix 1).

Atkins and others (2009) determined generalized skew coefficients applicable to West Virginia (WV skew) for use in determining flood-frequency discharges at streamgage sta-tions. The WV skew coefficients supersede the United States skew coefficients (U.S. skew) determined by the Interagency Advisory Committee on Water Data (1982). Analysis of

Introduction 5

VALLEY A

ND RID

GE

A P P A L A C H I A N PL AT E A U S

BLUERIDGE

Elkins

Beckley

SpruceKnob

Wheeling

Morgantown

HuntingtonCharleston

Harpers Ferry

OHIO

PENNSYLVANIA

MARYLAND

VIRGINIA

KENTUCKY

78°W81°W

40°N

38°N

0 20 40 60 MILES



Geographic location

Cl i m

a t i c Di v i d e

Base from U.S. Geological Survey 1:100,000 digital line graphics. Universal Transverse Mercator projection, zone 17, NAD 83.

Physiographic provinces from Fenneman, 1938

Figure 2. Appalachian Plateaus, Valley and Ridge, and Blue Ridge Physiographic Provinces, and Climatic Divide in West Virginia.


discharges at 147 rural, unregulated streams in West Virginia and adjacent states with streamgage stations followed guide-lines established by the Interagency Advisory Committee on Water Data (1982), except that streamgage stations having 50 or more years of record were used instead of those with the recommended 25 years of record. The increased record length of 50 years was determined to be statistically significant when compared to the recommended 25 years. The generalized-skew analysis considered contouring, averaging, and regres-sion of station skews; the best method was determined to be that with the smallest mean-square error (MSE). The con-touring of station skews was found to be the best method for determining generalized skew for West Virginia, with a MSE of 0.2174 (Atkins and others, 2009). The MSE of 0.2174 is a significant improvement (28 percent reduction) over the MSE of 0.3025 for the U.S. skew, presented by the Interagency Advisory Committee on Water Data (1982).

Flood-frequency studies completed by Frye and Run-ner (1969, 1970, 1971) and Runner (1980a and b) for West Virginia lacked data on peak discharges at streamgage stations having drainage areas less than 50 mi2. These studies found that the lack of data for small drainage areas could be over-come by (1) not using the flood-frequency estimating methods for small drainage areas, (2) limiting the flood-frequency discharge estimates to small recurrence intervals, (3) increas-ing the record lengths for small drainages by using a rainfall-runoff model, or (4) using a composite analysis of long-term data (primarily stations with a minimum of 40 years of record) with an analysis of long-term data combined with short-term data for small drainage areas.

Frye and Runner (1969) estimated flood-frequency discharges for rural, unregulated streams in West Virginia by using equations presented in U.S. Geological Survey Water Supply Papers 1672 (Tice, 1968) and 1675 (Speer and Gamble, 1965). The nationwide flood-frequency discharge equations in these publications were developed for regional or major river basins. The authors suggested that the equations only be used for drainage areas greater than 50 mi2 in the Ohio River Basin and greater than 30 mi2 in the Potomac River Basin.

Frye and Runner (1970) presented a method for estimat-ing flood-frequency discharges using an analytical technique similar to that proposed by Benson (1962). Peak-discharge data from streamgage stations on rural, unregulated streams in West Virginia with a minimum of 10 years of record were analyzed. The authors suggested that the analytical techniques be used only for drainage areas greater than 50 mi2 because adequate data were not available.

Frye and Runner (1971) presented a method for esti-mating the 2-, 5-, and 10-year flood discharges for rural, unregulated streams in the Ohio River Basin of West Virginia. Data from a network of small streams with an average record length of 6 years were correlated with long-term data from streamgage stations to estimate additional years of peak dis-charges. The equations were applicable only to streams with drainage areas between 1 and 50 mi2.

Runner (1980a) presented equations for estimating the 2-, 5-, 10-, 25-, 50-, 100-, and 500-year flood discharges for rural, unregulated streams in West Virginia. The estimating equa-tions were used only for drainage areas of 0.3 to 2,000 mi2. The flood-frequency discharges in this study were made using methods recommended by the Interagency Advisory Commit-tee on Water Data (1976), including adjustments to station-frequency determinations by applying weighted regional and station skews. The peak-discharge data from 170 streamgage stations included data from Maryland and Virginia. Records of peak discharges for 15 stations with small drainage areas (ranging from 1.8 to 12.2 mi2) were synthesized to greater than 40 years of record (Runner, 1980b) by use of a rainfall-runoff model developed by Dawdy and others (1972). On the basis of regression analyses using 12 basin characteristics as indepen-dent variables, regional flood-frequency discharge equations were developed separately for stations with more than 40 years of record (including 15 small drainage-area streamgage stations for which at least 40-year records were estimated) and for all 170 stations. Three regions were delineated using an analysis of the regression residuals, and drainage area was determined to be the only statistically significant independent variable. A composite of the equations for stations with greater than 40 years of record and all 170 streamgage stations was determined.

This Study

To provide flood-related information and estimates needed for the design of structures that will meet existing or proposed safety standards, yet not incur excessive costs because of overdesign, the U.S. Geological Survey (USGS), in cooperation with the West Virginia Department of Transpor-tation, Division of Highways, revised previously developed equations for estimating the magnitude and frequency of flood discharges on rural, unregulated streams in West Virginia. The results of this study supersede those published by Wiley and others (2000, 2002).

This report presents newly revised equations for estimat-ing the discharges of the 1.1-, 1.5-, 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence interval floods (flood-frequency discharges) on rural, unregulated streams in West Virginia. A flood frequency is the reciprocal of the annual-occurrence probability (AOP), in percent, where the 100-year flood fre-quency is equal to the 1-percent AOP. This report documents the information used to estimate flood-frequency discharges and includes a list of regional floods in West Virginia; a discussion of climatic conditions affecting flooding; a presen-tation of results from previous studies; and an inventory of data sources containing peak discharges, basin characteristics, and skew coefficients. The statistical methods are described, including an accounting of error, which provides project designers with the associated uncertainty of flood discharge estimates determined from applying flood-frequency discharge equations to West Virginia streams.

Development of Flood-Frequency Discharge Equations 7

Development of Flood-Frequency Discharge Equations

Annual peak discharge data, basin characteristics data, and generalized West Virginia skew coefficients for 290 streamgages on rural, unregulated streams in West Virginia and adjacent states were analyzed to determine regional equa-tions to be used to estimate the magnitude of flood discharges for selected recurrence intervals. Basin characteristics, gener-alized West Virginia skew coefficients, and flood-frequency discharges for streamgage stations in adjacent states developed for this study do not supersede values used by adjacent states. The equations for the 100-year recurrence interval (1-percent AOP) flood discharges were regionalized by plotting the areal distribution of residuals determined by use of multiple and simple least-squares regression models. Independent variables describe basin characteristics (such as drainage area, mean annual precipitation, and percent forest cover) for each station location. Areal distributions of residual plots from regres-sions of the 100-year discharges were used to select stations in adjacent states to represent flood discharges expected in West Virginia and to determine regional boundaries. The initial regional equations for the selected recurrence intervals were derived with the use of multiple and simple least-square regression models and by determining the significance of inde-pendent variables. The final regional equations were derived with the use of a generalized least-square regression model and independent variables from the initial regional equations.

Peak Discharges

Annual peak discharges at 290 streamgage stations on rural, unregulated streams with a minimum of 9 years of record through the 2007 water year (the period beginning October 1 of the previous year through September 30 of the indicated year) in West Virginia and through the 2006 (2007 for some stations in Maryland) water year for stations in adjacent states were available for this study (fig. 3; table 1, at end of this report). Guidelines established by the Inter-agency Advisory Committee on Water Data (1982) required that streamgage used in the analysis have a minimum of 10 years of record, but stations with 9 years of record were accepted because the addition of six stations with drainage areas less than 30 mi2 was considered more beneficial to this study than adhering to the 10-year guideline. Annual-peak-discharge data are maintained in the U.S. Geological Sur-vey’s “Peak File” database available on the World Wide Web from the USGS United States NWIS-W Data Retrieval site (http://waterdata.usgs.gov/).

Peak discharges at the streamgage station Cheat River at Rowlesburg, identification number (ID) 121 in fig. 3 and streamgage station number (streamgage) 03070000 in table 1, are from a combination of records that include and exclude flow from the tributary stream Saltlick Creek. Peak-discharge

data collected at Rowlesburg prior to the flood of November 5, 1985, include flow from Saltlick Creek for a drainage area of 974 mi2. Peak-discharge data collected at Rowlesburg from Novem ber 6, 1985, through September 30, 1996, exclude flow from Saltlick Creek for a drainage area of 939 mi2. Streamgage station ratings (relations between stream stage and discharge) were dif ficult to define accurately after Novem-ber 5, 1985, because they were affected by scour throughout the range of stage. Peak discharges were not adjusted for the 4-percent differ ence in drainage area (typically necessary when records are combined) because the rating defi nition dif-ficulties resulted in peak discharges with much greater than 4 percent uncertainties.

Peak discharges at the streamgage station Right Fork Holly River at Guardian (ID 229 and streamgage 03195100) for the 1979 to 1982 water years, and peak discharges at the station Left Fork Holly River near Replete (ID 230 and streamgage 03195250) for the 1979 to 1982 and 1987 to 2007 water years were pro vided by the U.S. Army Corps of Engi-neers, Huntington District (Phillip E. Anderson, oral and writ-ten commun., 1997 and 1998; Charlotte L. Hazelett, written commun., 2007).

Peak discharges at the streamgage station Fernow Water-shed Number Four near Hendricks (ID 113 and streamgage 03067100) for the 1952 to 2006 water years were provided by the U.S. Forest Service, Fernow Experimental Forest (Fred-erica Wood, written commun., 2006 and 2007). No data were available for the 2007 water year at the time of this study.

Peak discharge records for the streamgage station Elk River below Webster Springs (ID 227 and streamgage 03194700) were lengthened using records for the station Elk River at Centralia (ID 228 and streamgage 03195000). Peak discharges at the station Twelvepole Creek below Wayne (ID 266 and streamgage 03207020) were lengthened using records for the station Twelvepole Creek at Wayne (ID 265 and streamgage 03207000). Peak discharges at the station Tug Fork at Kermit (ID 285 and streamgage 03214500) were lengthened using records for Tug Fork near Kermit (ID 284 and streamgage 03214000). Peak discharges at the station New River at Fayette (ID 207 and streamgage 03186000) were lengthened using records for New River at Caperton (ID 206 and streamgage 03185500); and peak discharges at the station Cheat River near Pisgah (ID 123 and streamgage 03071000) were lengthened using records for Cheat River near Mor-gantown (ID 124 and streamgage 03071500). Records were lengthened by estimating discharges using drainage-area ratios; the stations used to lengthen records were not consid-ered in the regression analysis.

Basin Characteristics

Characteristics of the basins draining to the 290 streamgage stations on rural, unregulated streams in West Virginia and adjacent states (Paybins, 2008) were available for use as independent variables in the regression analysis.


OHIO

PENNSYLVANIA

MARYLAND

VIRGINIA

KENTUCKY

78°W81°W

40°N

38°N

0 20 40 60 MILES



County boundary

Major stream

Streamgage station and identification number212

Base from U.S. Geological Survey 1:100,000 digital line graphics for state boundaries and streams and from the West Virginia Department of Environmental Protection 1:24,000 digital data for county boundaries. Universal Transverse Mercator projection, zone 17, NAD 83.

9

865

321

99

98

9796 95

9493

92

91

90

89

87

8685

84

83

8281

80

79

7877

76

75

74

7372

71

7069

6867

66

65

6463

62

616059

5857

56

5554

53 525150

4948

47

46

45

44

43

4241

39, 40

38

37

35,363433

32

31

3029

2827

26

23

2221

19, 20

18

1716

1514

13

1211

10

290

289

288

287

286

285284

283

282281

280279

278277

275274

273

272

271270

269268267

266265

264

263

262

261260

259

258

257256

255254

253

252 251

250

249

248

247 246245

244

243242241 240

239

238

237

236

235

234

233

232231

230229228

226

225

224

223222 221 220

219218

217216

214213

212

211 210

209 208

207206

205204

203 202

201200

199198

197

196

195194

193

192

191190189

188

186

185

184

183

182181

180179

178

177

176

175

174

173172

171170

169168

167166

165

164

163162

160

159

158

157156

155154

153

149, 150, 151, 152

148

147 146

145144143

142141

139, 140 138

137

136

135

134

133

132

131130

129

128127

126125

124

123122

121120

119118

116115

114

113

112 111

109

108

106

105104

103102

101

4, 7

88

24, 25

276

227

215

187

161

117 110

107

100

Figure 3. The 290 U.S. Geological Survey streamgage stations in West Virginia and adjacent states considered in the estimation of flood-frequency discharges in West Virginia. (Identification numbers are cross-references with streamgage-station names and numbers in table 1.)


The 36 basin characteristics evaluated for use in this study are the following: drainage area (DRNAREA), in mi2 (Mathes, 1977; Wilson, 1979; Mathes and others, 1982; Preston and Mathes, 1984; Stew art and Mathes, 1995; Wiley, 1997; Wiley and others, 2007); latitude of the basin centroid, in decimal degrees; longitude of the basin centroid, in decimal degrees; basin perimeter, in mi; basin slope, in ft/mi; basin relief, in ft; basin orientation, in degrees; channel length, in mi; valley length, in mi; channel slope, in ft/mi; stream length, in mi; mean basin elevation, in ft; 24-hour 2-year rainfall, in inches; annual precipitation, in inches; January minimum temperature, in degrees Fahrenheit; annual snow depth, in inches; forest cover, in percent; grassland cover, in percent; barren land cover, in percent; urban land cover, in percent; wetland cover, in percent; open-water cover, in percent; agriculture cover, in percent; impervious cover, in percent; basin width, in mi; shape factor, dimensionless; elongation ratio, dimensionless; rotundity of basin, dimensionless; compactness ratio, dimen-sionless; relative relief, in ft/mi; sinuosity ratio, dimensionless; stream density, in mi/mi2; channel maintenance, in mi2/mi; slope proportion, dimensionless; ruggedness number, in ft/mi; and slope ratio, dimensionless.

Correlation of Basin Characteristics

The basin characteristics were log10 transformed and evaluated for linear correlation by using a Pearson coefficient, or Pearson’s r (Helsel and Hirsch, 2002). The numeral one was added to values of grassland cover, barren land cover, urban land cover, wetland cover, open-water cover, agriculture cover, and impervious cover to ensure that values were greater than zero for log10 transformation. To decrease values for regres-sion analysis, 77 was subtracted from longitude of the basin centroid, and 37 was subtracted from latitude of the basin centroid.

Basin characteristics were considered highly correlated where the absolute value of the Pearson coefficient was greater than or equal to 0.80. The following characteristics were highly correlated within each group: drainage area, basin perimeter, channel length, valley length, basin width, stream length, compactness ratio, and slope proportion; channel slope, relative relief, and slope ratio; shape factor, elongation ratio, and rotundity of basin; basin relief and ruggedness number; valley length and basin relief; and urban land cover and imper-vious cover.

The Pearson coefficient was equal to the numeral one (singularity) for some combinations of basin characteristics including stream density and channel maintenance; shape factor, elongation ratio, and rotundity of basin; drainage area, basin width, shape factor, and rotundity of basin; and stream length, compactness ratio, relative relief, stream density, and ruggedness number. The characteristics elongation ratio, rotundity of basin, channel maintenance, and basin width

were removed from consideration for regression because of singularity.

The number of basin characteristics considered for regression was reduced from 36 to 32 with the removal of the characteristics because of singularity. Additional characteris-tics having singularity were removed if they became signifi-cant in the regression analysis.

West Virginia Skew Coefficients

Atkins and others (2009) determined generalized skew coefficients applicable to West Virginia, the WV skew, to supersede the U.S. skew presented by the Interagency Advi-sory Committee on Water Data (1982) (table 1, at the end of this report). The generalized skew coefficient is a regional measure (of individual streamgage-station skews) of the fit-ness of annual-peak discharges to a Pearson Type III prob-ability curve. The WV skew coefficients used in this current study do not supersede values used for studies in adjacent states but are applicable only to analyses in West Virginia. The difference between the WV- and U.S.-skew coefficients (WV skew minus U.S. skew) ranged from -0.493, unitless, for Brier Creek at Fanrock (ID 255 and streamgage 03202480) to 0.491, unitless, for Dry Fork at Hendricks (ID 110 and streamgage 03065000).

A direct relation was not observed between the differ-ence between the WV- and U.S.-skew coefficients and the difference between the flood-frequency discharge calculations made using the WV- and U.S.-skew coefficients. (Skew coef-ficients are weighted and adjusted using systematic years of record, systematic skews, low- and high-outlier criterion, and historic years to determine flood frequencies.) The 100-year flood discharges determined in this study using the WV skew were compared to the 100-year flood discharges calculated using the U.S. skew. The differences in the 100-year flood discharges (discharge using WV skew minus discharge using U.S. skew, divided by discharge using WV skew, times 100) ranged from -23.8 percent for Marsh Fork at Maben (ID 253 and streamgage 03202245) to 13.3 percent for Job Run near Wymer (ID 109 and streamgage 03063950). An area of large negative differences was observed for the headwaters of the Coal, Guyandotte, and Tug Fork Rivers near the southern border of the State, and an area of large positive differences was observed for the headwaters of the South Branch Potomac River near the eastern border of the State. The difference for Brier Creek at Fanrock (ID 255 and streamgage 03202480) is -14.3 percent (-0.493, unitless, difference in skews discussed above), and the difference for Dry Fork at Hendricks (ID 110 and streamgage 03065000) is 3.8 percent (the 0.491, unitless, difference in skews discussed above); these streamgage sta-tions are located near the southern and north-central areas of the State, respectively.


Flood-Frequency Discharges

The flood-frequency discharges at the 290 streamgage stations on rural, unregulated streams were determined fol-lowing the guidelines established by the Interagency Advisory Committee on Water Data (1982). The U.S. Geological Survey computer program PeakFQ (Flynn and others, 2006) was used to compute the flood-frequency discharges. In the analysis of flood-frequency discharges for adjacent states, information from previous studies was used (Bisese, 1995; Dillow, 1996; Stuckey and Reed, 2000; Hodgkins and Martin, 2003; and Koltun, 2003) as a reference for determining flood-frequency discharges calculated with the WV skew for use in this current study.

The log10-transformed systematic (continuous record or broken record that can be statistically treated as a continu-ous record) annual-peak series for each streamgage station was fitted to the Pearson Type III probability curve. Regional general skew (WV skew) was obtained from the map devel-oped by Atkins and others (2009). Regional general skew is weighted with station skew to determine a final adjustment to the Pearson Type III probability curve. Additionally, high-outlier, low-outlier, and historical peak assessments were made to adjust the annual-peak series. Mixed populations, such as floods from snowmelt and those from tropical storms or hurricanes, were not analyzed separately. Selected statis-tics from the flood-frequency discharge analyses for the 290 streamgage stations in West Virginia and adjacent states are listed in table 2 (at the end of this report). Flood-frequency discharges determined following the guidelines established by the Interagency Advisory Committee on Water Data (1982) for 10 recurrence intervals for the 290 streamgage stations in West Virginia and adjacent states are identified as Qs in table 3 (also at the end of this report); the 10 recurrence intervals are the 1.1- (90-percent AOP), 1.5- (67-percent AOP), 2- (50-percent AOP), 5- (20-percent AOP), 10- (10-percent AOP), 25- (4-per-cent AOP), 50- (2-percent AOP), 100- (1-percent AOP), 200- (0.5-percent AOP), and 500-year (0.2-percent AOP).

The PeakFQ computer program does not output flood-fre-quency discharges for all the recurrence intervals needed for this study. However, subroutines within PeakFQ (the HARTIV subroutine with related subroutines and functions, originally developed by Kirby, 1980) were used to calculate the needed flood-frequency discharges. The 1.1-year and sometimes the 1.5-year flood discharges were computed for 15 streamgage stations using the PeakFQ subroutines; these discharges are footnoted in table 3 (at the end of this report). The identified subroutines within PeakFQ do not calculate discharge directly, but determine a frequency factor (K or “the K value”) that is used to calculate the discharge. A short Fortran computer pro-gram (Wiley and others, 2002, Appendix 1) was used to calcu-late all the frequency factors using the Bulletin-17B weight-ing procedures and the WV skew (Atkins and others, 2009) (table 1, at the end of this report). The short computer program uses the current versions of computer subroutines contained in a library of USGS water-resources application programs (U.S.

Geological Survey, 2001). The frequency factors are used to determine discharge by computing the antilog of discharge from the following modified equation (Interagency Advisory Committee on Water Data, 1982, equation 1, p. 9):

Log10 Q = Xmean + KSP , (1)

where

Xmean = ∑ X / N, (2)

where X is the log10-transformed annual peak

discharges (Bulletin-17B adjusted), in ft3/s; and

N is the number of years of peak-discharge record, unitless;

K is the frequency factor, unitless; and SP is the standard deviation of the log10-

transformed annual peak discharges (Bulletin-17B adjusted), in ft3/s:

[∑ (X – Xmean)2 / (N – 1)]0.5. (3)

Typically, the magnitude of a flood-frequency discharge increases with increasing drainage area. For floods with recur-rence intervals greater than 10 years, however, the flood-fre-quency discharges calculated for the streamgage station Tygart Valley River near Dailey (ID 83 and streamgage 03050000) are greater than those for the station Tygart Valley River near Elkins (ID 84 and streamgage 03050500), although the drainage area for Tygart Valley River near Dailey (185 mi2) is smaller than the drainage area for Tygart Valley River near Elkins (271 mi2) (tables 2 and 3, at the end of this report). This inconsistency may be due to the wide floodplain along the river between Daily and Elkins, which contrasts with the more mountainous and narrower floodplains upstream from Daily and, therefore, increases the stream storage and attenuates the flood peak. The inconsistency also may occur because the frequency analysis for each station is based on different time periods, thus creating a time-sampling error.

Wiley and others (2000) investigated data for the streamgage station Poplar Fork at Teays (ID 248 and streamgage 03201410) for nonhomogeneity. The study concluded that the data for the period 1967 to 1978 indicate annual peaks were higher than those for 1992 to 1997, but collection of additional years of record would be necessary to resolve the question of nonhomogeneity. This current study determined that nonhomogeneity exists between the periods 1967 to 1978 and 1992 to 2007. It is hypothesized that exces-sive runoff from nearby impervious areas resulted in higher annual peaks for the period 1967 to 1978. The excessive run-off no longer affects annual peaks since the streamgage station was moved to a location upstream from the nearby impervious areas for the period 1992 to 2007. The flood-frequency dis-charges for Popular Fork at Teays were determined using only


annual peaks for the period 1992 to 2007 because they better represent a rural, unregulated stream.

The randomness of the systematic annual-peak series was statistically tested to detect a trend using Kendall’s test for correlation (Kendall, 1975; Hirsch and others, 1982). The computer program SWSTAT (Surface Water STATistics), ver-sion 4.1, dated February 25, 2002, (Lumb and others, 1990; A.M. Lumb, W.O. Thomas, Jr., and K.M. Flynn, USGS, writ-ten commun., titled “Users manual for SWSTAT, a computer program for interactive computation of surface-water statis-tics,” June 15, 1995) was used to calculate Kendall’s tau and the level of significance (the probability or p-value). For the Kendall’s test for correlation, the hypothesis that there is no trend is tested. If the hypothesis fails to attain a particular level of significance, the hypothesis of no trend is rejected. For this study, the particular level of significance selected was 0.05, so a trend is determined for an annual-peak series if the level of significance is less than 0.05. Kendall’s tau and the level of significance were determined for the annual-peak series of 246 streamgage stations (44 stations were eliminated from consideration as part of the regression analysis discussed later in this report) in West Virginia (table 2). Streamgage stations were further limited to the 125, those with a minimum of 30 years of record, to eliminate affects that might be due to natural climatic variations (U.S. Geological Survey, 2005). The annual-peak series for 12 streamgage stations (about 10 percent of the 125 stations) indicated a trend, 7 positive and 5 negative. If chance were the only factor, 6 streamgage sta-tions would be expected to indicate a trend (about 5 percent of the 125 stations). Statistics indicate trends at twice as many streamgage stations as would be expected by chance, but the trends were nearly equally divided between stations with posi-tive and negative values. Therefore, no significance could be determined for the trends indicated at the 12 stations.

Regional Regression of Flood-Frequency Discharges

Regression models with the 10 log10-transformed flood-frequency discharges as dependent variables and the 36 log10-transformed basin characteristics as potential indepen-dent variables were evaluated. The flood-frequency equations for the 100-year recurrence interval (1-percent AOP) were regionalized by plotting the areal distribution of residuals from the application of multiple and simple least-squares regres-sion models. Regional regression procedures were performed using the computer program S-PLUS 7.0 (Insightful Corpora-tion, 2005), a commercially available statistical computing package. Areal distributions of residual plots indicated three regions—Eastern Panhandle, Central Mountains, and West-ern Plateaus—with drainage area (DRNAREA) as the only significant independent variable (fig. 4). Initial equations for all flood-frequency discharges were determined using the regions determined by analysis of the 100-year flood, and the outcomes of all equations identified DRNAREA as the only significant independent variable. (A regional analysis of the

2-year floods agreed with the regional divisions determined by analysis of the 100-year floods.) The final regional equations were then developed from application of a generalized least-square (GLS) regression model (Stedinger and Tasker, 1985; Tasker and Stedinger, 1989) (U.S. Geological Survey com-puter program GLSNet, version 4.0) for the three regions with DRNAREA as the only independent variable (table 4).

The three regions—Eastern Panhandle, Central Moun-tains, and Western Plateaus (fig. 4)—are separated by topo-graphic features. The boundary between the Eastern Panhandle and Central Mountains Regions follows the Potomac River Basin boundary. The Central Mountains Region (from north-east to southwest) contains the drainage areas of the Cheat River, Tygart Valley River (including the Buckhannon River), Elk River upstream from the confluence of Birch River, and the New and Gauley Rivers upstream of the Kanawha River. The Western Plateaus Region encompasses the remainder of the State.

Forty-four streamgage stations were removed from the regression analysis (table 1, at the end of this report), including 12 stations in West Virginia. Thirty-two stations in adjacent states were removed primarily because residual plots indicated that the stations were not representative of flows expected in West Virginia, except for Potomac River at Hancock (ID 34 and streamgage 01613000), Shepherd-stown (ID 44 and streamgage 01618000), and Point Of Rocks (ID 70 and streamgage 01638500) in Maryland where the flood-frequency discharges at these streamgage stations with large drainage areas (4,075 to 9,651 mi2) leveraged the regional regression equations, resulting in greater estimation errors for small drainage areas. The 12 streamgage stations removed from the regression analysis in West Virginia are Tuscarora Creek above Martinsburg (ID 42 and streamgage 01617000) because the station was located in a karst area of the State (equations developed in this current study are not applicable to karst areas of the state); Elk River at Centralia (ID 228 and streamgage 03195000) because the peak record for this station was used to lengthen the record for Elk River below Webster Springs (ID 227 and streamgage 03194700); Twelvepole Creek at Wayne (ID 265 and streamgage 03207000) because the peak record for this station was used to lengthen the record for Twelvepole Creek below Wayne (ID 266 and streamgage 03207020); Tug Fork near Kermit (ID 284 and streamgage 03214000) because the peak record for this station was used to lengthen the record for Tug Fork at Kermit (ID 285 and streamgage 03214500); New River at Caperton (ID 206 and streamgage 03185500) because the peak record for this station was used to lengthen the record for New River at Fayette (ID 207 and streamgage 03186000); Cheat River near Morgantown (ID 124 and streamgage 03071500) because the peak record for this station was used to lengthen the record for Cheat River near Pisgah (ID 123 and streamgage 03071000); and Potomac River at Paw Paw (ID 28 and streamgage 01610000), Shenandoah River at Millville (ID 66 and streamgage 01636500), New River at Bluestone Dam (ID 188 and streamgage 03180000), New River at


OHIO

PENNSYLVANIA

MARYLAND

VIRGINIA

KENTUCKY

78°W81°W

40°N

38°N

0 20 40 60 MILES


EXPLANATIONEastern-Panhandle Region

Central-Mountains Region

Western-Plateaus Region

State boundary

County boundary

Major stream

Base from U.S. Geological Survey 1:100,000 digital line graphics for state boundaries and streams and from the West Virginia Department of Environmental Protection 1:24,000 digital data for county boundaries. Universal Transverse Mercator projection, zone 17, NAD 83.

Randolph

Kanawha

Greenbrier

Hardy

Fayette

Preston

Grant

Pocahontas

Raleigh

Boone

Roane

Wayne

Nicholas

Clay

Logan

Pendleton

Webster

MasonBraxton

Wood

Lewis

Mingo

RitchieTucker

Monroe

Jackson

Hampshire

Mercer

Lincoln

Wetzel

Wirt

Wyoming

McDowell

Tyler

UpshurGilmer

Harrison

Putnam

Cabell

Marion

Barbour

Mineral

Summers

Berkeley

Marshall

Calhoun

MonongaliaMorgan

Taylor

Ohio

DoddridgeJefferson

Pleasants

Brooke

Hancock

Figure 4. The Eastern Panhandle, Central Mountains, and Western Plateaus Regions of West Virginia for which equations for estimation of flood frequency discharges were developed in this study.


Table 4. Equations used to estimate selected flood-frequency discharges for streams in the Eastern Panhandle, Central Mountains, and Western Plateaus Regions of West Virginia.

[PK(n_n), peak discharge in cubic feet per second for the (n.n)-year recurrence interval; PK(n), peak discharge in cubic feet per second for the (n)-year recur-rence interval; %, percent; AOP, annual-occurrence probability; DRNAREA, drainage area in square miles]

EquationStandard error of the model,

in percent

Average standard error of sampling,

in percent

Average prediction error,

in percent

Equivalent years of record, unitless

Eastern Panhandle Region (Range in DRNAREA from 0.21 to 1,461 for 57 streamgage stations)

PK1_1(90%AOP) = 29.6 DRNAREA 0.818 43.4 10.3 44.8 3.4

PK1_5(67%AOP) = 46.4 DRNAREA 0.828 35.7 8.9 36.9 3.3

PK2(50%AOP) = 59.8 DRNAREA 0.832 32.1 8.6 33.4 4.1

PK5(20%AOP) = 105 DRNAREA 0.838 25.6 8.9 27.2 10.6

PK10(10%AOP) = 145 DRNAREA 0.842 22.5 9.5 24.5 19.1

PK25(4%AOP) = 204 DRNAREA 0.848 19.7 10.3 22.4 34.1

PK50(2%AOP) = 254 DRNAREA 0.852 18.6 11.1 21.7 46.1

PK100(1%AOP) = 307 DRNAREA 0.855 18.3 11.6 21.7 56.7

PK200(0.5%AOP) = 365 DRNAREA 0.859 18.4 12.4 22.4 64.7

PK500(0.2%AOP) = 447 DRNAREA 0.864 19.4 13.5 23.8 70.9

Central Mountains Region (Range in DRNAREA from 0.10 to 1,619 for 83 streamgage stations)

PK1_1(90%AOP) = 33.4 DRNAREA 0.914 40.0 8.3 41.0 2.4

PK1_5(67%AOP) = 53.8 DRNAREA 0.887 34.6 7.3 35.4 2.0

PK2(50%AOP) = 69.4 DRNAREA 0.873 33.4 7.3 34.2 2.1

PK5(20%AOP) = 116 DRNAREA 0.845 34.1 8.0 35.1 3.2

PK10(10%AOP) = 153 DRNAREA 0.831 36.3 8.6 37.4 4.0

PK25(4%AOP) = 206 DRNAREA 0.816 39.9 9.8 41.2 4.8

PK50(2%AOP) = 250 DRNAREA 0.807 42.9 10.6 44.4 5.3

PK100(1%AOP) = 297 DRNAREA 0.800 46.2 11.3 47.9 5.6

PK200(0.5%AOP) = 347 DRNAREA 0.793 49.7 12.0 51.5 5.9

PK500(0.2%AOP) = 420 DRNAREA 0.785 54.3 13.1 56.3 6.1

Western Plateaus Region (Range in DRNAREA from 0.13 to 1,516 for 106 streamgage stations)

PK1_1(90%AOP) = 56.9 DRNAREA 0.763 38.2 7.6 39.1 3.8

PK1_5(67%AOP) = 97.8 DRNAREA 0.741 33.4 6.5 34.1 2.8

PK2(50%AOP) = 129 DRNAREA 0.730 31.6 6.1 32.2 2.8

PK5(20%AOP) = 221 DRNAREA 0.710 29.3 6.5 30.0 4.4

PK10(10%AOP) = 292 DRNAREA 0.699 28.9 6.5 29.7 5.9

PK25(4%AOP) = 391 DRNAREA 0.688 29.4 7.3 30.3 7.9

PK50(2%AOP) = 472 DRNAREA 0.681 30.2 7.6 31.3 9.1

PK100(1%AOP) = 557 DRNAREA 0.674 31.4 8.0 32.5 10.1

PK200(0.5%AOP) = 647 DRNAREA 0.668 32.7 8.3 33.9 10.8

PK500(0.2%AOP) = 775 DRNAREA 0.661 34.8 8.9 36.1 11.4


Hinton (ID 203 and streamgage 03184500), New River at Fay-ette (ID 207 and streamgage 03186000), and Kanawha River at Kanawha Falls (ID 224 and streamgage 03193000) because the flood-frequency discharges at these stations with large drainage areas (4,602 to 8,371 mi2) leveraged the regional regression equations, resulting in greater estimation errors for small drainage areas.

Accuracy of Flood-Frequency Discharge Equations

The accuracy of equations used to estimate discharge is quantified by calculating the average prediction error (Tasker and Stedinger, 1989; Hodge and Tasker, 1995) and equivalent years of record (Hardison, 1969, 1971). Average prediction error is the square root of the sum of the squared standard error of the model (the portion of the total error due to an imperfect model) and the average squared standard error of sampling (the portion of the total error due to estimating model parameters from a sample), in log units. The average prediction errors range from 21.7 to 56.3 percent (table 4). The average prediction error is within 3.4 percentage points of the standard error of the model for all regression equa-tions, indicating that addition of the average standard error of sampling to the standard error of the model accounts for very little additional unexplained variance of the flood-frequency discharge estimate.

Also, the average prediction error is the square root of the average of individual squared standard errors of predic-tion. Individual standard errors of prediction for the regres-sion equations shown in table 4 were computed over the entire range of applicable drainage areas and compared to the average prediction errors (fig. 5). The x-axis of figure 5 is not to scale because the minimum and maximum drainage areas are unequal among regions. The individual standard errors of prediction were computed using the matrices presented in Appendix 1 and methods described by Hodge and Tasker (1995, p. 37–42), Wiley and others (2000, Appendix 1), Wiley and others (2002, Appendix 2), and Koltun (2003, Appendix A). The individual standard errors of prediction increase for drainage areas less than and greater than about 100 mi2 (where the individual standard errors are 1.0 percent-age point less than average prediction error) for all regression equations. The maximum individual standard errors of predic-tion for the maximum drainage areas are within 0.5 percent-age point of the average standard error of prediction for all regression equations. The maximum individual standard errors of prediction for the minimum drainage areas are less than 5.8 percentage points greater than the average prediction error for all regression equations. The individual standard errors of prediction are about equal (within 0.3 percentage point) to the average prediction error at 10 mi2 for all regression equations. In summary, the individual standard errors of prediction are within 1.0 percentage point of the average prediction error for drainage areas greater than 10 mi2, and the individual standard

errors of prediction increase to a maximum of 5.8 percentage points greater than the average standard error of prediction for the minimum drainage areas.

It is not necessary to compute the individual standard errors of prediction when using the regression equations developed in this study for drainage areas greater than or equal to about 10 mi2 because the differences between the individual standard errors of prediction and average prediction error are insignificant (within 1.0 percentage point). Also, it is not nec-essary to compute the individual standard errors of prediction for drainage areas less than about 10 mi2 if an additional error of up to 5.8 percentage points (the maximum of individual standard errors of prediction for the minimum drainage areas) is acceptable for the particular application.

Equivalent years of record (table 4) is an estimate of the number of systematic years of record that must be collected at a streamgage station to calculate flood-frequency discharges with an accuracy equal to that of the regional equation. The equivalent years of record ranged from 2.0 to 70.9 years. The equivalent years of record is not a direct measurement of accuracy between equations of flood-frequency discharges. A comparison of the equation for PK1_1 (90% AOP) to that for PK25 (4% AOP) in the Eastern Panhandle Region shows that the equivalent years of record increased 10 times (3.4 to 34.1), but the average prediction error decreased only by half (44.8 to 22.4). Equivalent years of record is a weighting factor that is applied when determining flood-frequency discharges at streamgage stations.

The high values for the equivalent years of record in the Eastern Panhandle Region are atypical compared to values for flood-frequency equations in surrounding states and the previous study in West Virginia. The atypical high values are probably due to (1) a good correlation with the distance

6

4

2

0

-2

-4

-6

DIFF

EREN

CES,

IN P

ERCE

NT

DRAINAGE AREA, IN SQUARE MILES

Regionalminimum

Regionalmaximum

10 100

NOT TO SCALE

Figure 5. Range of differences (shaded) of the individual standard errors of the prediction from the average prediction errors for the indicated drainage areas. The graph represents all regional equations.

Procedures For Estimating Flood-Frequency Discharges 15

between stations for weighting in the GLS regression com-pared to the correlations for other regions in this study; (2) unusually low residuals for short-term streamgage stations (less than 15 years) that have small drainage areas (less than 5 mi2) compared to residuals for other regions in this study, the previous study in West Virginia, and regression studies for other hydrologic statistics conducted by the authors; and (3) the longer average record length for stations in the Eastern Panhandle Region (41) compared to average record lengths in the Central Mountains (39) and Western Plateaus (33).

Procedures For Estimating Flood-Frequency Discharges

Estimating procedures for the 1.1- (90-percent AOP), 1.5- (67-percent AOP), 2- (50-percent AOP), 5- (20-percent AOP), 10- (10-percent AOP), 25- (4-percent AOP), 50- (2-percent AOP), 100- (1-percent AOP), 200- (0.5-percent AOP), and 500-year (0.2-percent AOP) flood discharges were devel-oped for streamgage stations and ungaged locations in West Virginia.

At a Streamgage Station

A flood-frequency discharge at a streamgage station is determined by reading the weighted (Qw) value directly from table 3 (at the end of this report). This discharge was calculated by weighting (1) the discharge determined from the systematic and historical record (Qs in table 3), using the guidelines established by the Interagency Advisory Committee on Water Data (1982) with the WV skew, and (2) the discharge determined by the appropriate regional regression equation (Qr in table 3). The weighting technique considers (1) the number of years of peak-discharge record which equals the number of years of systematic record, plus the number of histori-cal peaks, minus the number of high-outlier peaks (values from table 2, at the end of this report), and (2) the number of equivalent years of record (an estimate given in table 4 of the number of systematic years of record for a streamgage station necessary to calculate flood-frequency discharges with an accuracy equal to that of the regional regression equation). The following equation was used.

Qw = (Qs N + Qr EY) / (N + EY) , (4)

where Qw is the weighted discharge, in ft3/s; Qs is the flood-frequency discharge determined

from the systematic and historical record using the guidelines established by the Interagency Advisory Committee on Water Data (1982), in ft3/s;

Qr is the flood-frequency discharge determined from the appropriate regional equation, in ft3/s;

N is the number of years of peak-discharge record, unitless; and

EY is the equivalent years of record, unitless.

No weighted value was calculated for one of the two streamgage stations on the same stream that were combined into a single time-series record; the flood-frequency discharge near (at) the streamgage station without a weighted value is to be determined using procedures for an ungaged location. No weighted value was calculated for Tuscarora Creek above Martinsburg (ID 42 and streamgage 01617000) because the streamgage station is located in a karst area of the State; the frequency discharge of the systematic record (Qs) is to be used at this station.

At an Ungaged Location

Four different procedures are used to determine a flood-frequency discharge at an ungaged location (1) when the ungaged location is upstream from a streamgage sta-tion, (2) when the ungaged location is downstream from a streamgage station, (3) when the ungaged location is between two streamgage stations on the same stream, and (4) when the ungaged location is not on the same stream as a streamgage station. Two locations were considered to be on the same stream when the stream path from the downstream location to the basin divide followed the stream segment with the largest drainage area at each stream confluence and passed through the upstream location.

It is necessary to determine if the ungaged location is near a streamgage station, and arithmetic methods are used to quantify the definition of “near.” A drainage-area-ratio method for estimating statistics at ungaged locations has been used by several researchers, including Hayes (1991), Ries and Friesz (2000), Flynn (2003), and Wiley (2008). The ratio of the drainage areas (RU/K) is defined as the ratio of the drain-age area where the flood-frequency discharge is unknown (AU) to the drainage area where the flood-frequency discharge is known (AK). These researchers use arithmetic methods for determining the upstream and downstream limits of the range of drainage-area ratios over which flood-frequency discharges can be accurately estimated from those at a streamgage station using an equation similar to the following:

QU = QK (RU/K)EX , (5)

where QU is the unknown flood-frequency discharge, in

ft3/s; QK is the known flood-frequency discharge, in

ft3/s;


RU/K is the ratio of the drainage area at the location of the unknown flood-frequency discharge (AU) to the drainage area at the location of the known flood-frequency discharge (AK), unitless; and

EX is the exponent for the particular flood-frequency discharge, unitless.

The 1.1-, 1.5-, 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year flood discharges at 88 pairs of streamgage stations located on the same stream in West Virginia and adjacent states (table 5, at the end of this report) were evaluated to quantify “near” for application of the drainage-area-ratio method in this study. Two computations, one upstream and one downstream, were made for each pair of stations. Ratios of the drainage areas for the 176 computations ranged from 0.038 to 26.4. Equation 5 was solved for the exponent (EX) as the dependent variable:

Log10 (QU / QK) = EX (Log10 (RU/K)) . (6)

The exponent was evaluated for the 88 pairs of streamgage stations for each flood-frequency discharge using simple linear regression with no intercept (regression line goes through the graph origin). The values of the exponent (EX) for the flood-frequency discharges ranged from 0.68 to 0.79 (table 6).

The upstream and downstream limits for application of drainage-area ratios used to quantify the definition of “near” were determined by plotting the x-axis as the drainage-area ratios and the y-axis as the absolute percent differences between the flood-frequency discharges at the streamgage station (Qw) and the flood-frequency discharges estimated by applying (1) the drainage-area-ratio method and (2) the regional equations (Qr). S-PLUS 7.0 was used to construct locally weighted regression (LOESS) curves (a data-smooth-ing technique) through differences between flood-frequency discharges computed from streamgage-station records and the estimated values (selected LOESS parameters were “span = 0.5; degree = one, locally linear fitted; family = Symmetric, no feature for handling outlier distortions, strictly applying locally linear fitting”). The absolute percent differences for estimates of the 100-year flood made by applying the drain-age-area-ratio method are lower than the estimates made by applying the regional equation at drainage-area ratios greater than about 0.40 (fig. 6). Similar results were determined for all flood frequencies estimated in this study, and absolute percent differences for all equations were combined to determine ratio limits applicable for all flood frequencies (fig. 7). The upstream limit used to quantify the definition of “near” for all flood frequencies was determined to be 0.40, and the down-stream limit was set to the maximum ratios studied, 26.4, because no assessment could be made for ratios greater than 26.4 (table 6).

The downstream limit of 26.4 for application of drainage-area ratios determined in this study is much greater than values determined by Hayes (1991), Ries and Friesz (2000), and Flynn (2003), probably because the streamgage stations used to compute ratios in this study were limited to those on the same stream (the stream path from the downstream loca-tion to the basin divide followed the stream segment with the largest drainage area at each stream confluence and passed through the upstream location). The downstream limit of 26.4 determined in this study is much greater than the value of 4.76 determined by Wiley (2008), but both studies used LOESS plots to set the downstream limit to the maximum ratio studied.

The upstream limit of 0.40 for application of drainage-area ratios determined in this study was equal to that deter-mined by Wiley (2008) for flood frequencies at and below the 10-year recurrence interval. The upstream limit of 0.21 for flood frequencies at and above the 25-year recurrence interval determined by Wiley (2008) is superseded by the value 0.40 determined in this study because more than three times as many pairs of stations were used to determine the value in this study (26 pairs compared to 88 pairs).

Table 6. Values of the exponent, and upstream and downstream limits of the drainage-area ratios used to quantify the definition of “near” for estimating selected flood-frequency discharges for ungaged locations in West Virginia.

[EX, exponent; RUS, upstream limit of the drainage-area ratio; RDS, down-stream limit of the drainage-area ratio; PK(n_n), peak discharge in cubic feet per second for the (n.n)-year recurrence interval; PK(n), peak discharge in cubic feet per second for the (n)-year recurrence interval; %, percent; AOP, annual-occurrence probability]

Statistic EX RUS RDS

PK1_1(90%AOP) 0.79 0.40 26.4

PK1_5(67%AOP) .76 .40 26.4

PK2(50%AOP) .75 .40 26.4

PK5(20%AOP) .73 .40 26.4

PK10(10%AOP) .72 .40 26.4

PK25(4%AOP) .71 .40 26.4

PK50(2%AOP) .70 .40 26.4

PK100(1%AOP) .70 .40 26.4

PK200(0.5%AOP) .69 .40 26.4

PK500(0.2%AOP) .68 .40 26.4


Upstream limit of the drainage-area ratios used to quantify the definition of "near" for estimating statistics is 0.40

Drainage-area ratiosRegional equations

0.0 0.1 1.0 10.0 100.0

RATIO OF DRAINAGE AREAS, UNITLESS

50

100

150

200

ABSO

LUTE

DIF

FERE

NCE

, IN

PER

CEN

T

0

Figure 6. LOESS curves of the absolute difference between the 100-year (1-percent annual-occurrence probability) flood discharges determined at streamgage stations and values estimated from the (1) drainage-area ratio method and (2) regional equations, in relation to the ratios of the drainage areas.

0.01 0.10 1.00 10.00 100.00

RATIO OF DRAINAGE AREAS, UNITLESS

0

50

100

150

200

ABSO

LUTE

DIF

FERE

NCE

, IN

PER

CEN

T

Drainage-area ratiosRegional equations

Upstream limit of the drainage-area ratios used to quantify the definition of "near" for estimating statistics is 0.40

Figure 7. LOESS curves of the absolute difference between the 1.1- through 500-year (90- through 0.2-percent annual-occurrence probabilities) flood discharges determined at streamgage stations and values estimated from the (1) drainage-area ratio method and (2) regional equations, in relation to the ratios of the drainage areas.


Upstream From a Streamgage Station This procedure is used when there is a streamgage station

downstream from the ungaged location but none upstream on the same stream. The hydrologic assumption for this circumstance is that the conditions affecting flood-frequency discharges, such as land cover, basin topography, and climatic conditions, are unchanged upstream from the streamgage sta-tion. Mathematically, the values of flood-frequency discharges are proportioned by drainage area. It is suggested that a streamgage be established when RU/K is less than or equal to the upstream limit of the ratio of drainage areas (RUS) (table 6). The following equation is used to estimate flood-frequency discharges:

QU = QK (RU/K)EX , (7)

where QU is the unknown flood-frequency discharge,

in ft3/s; QK is the known flood-frequency discharge

(table 3), in ft3/s; RU/K is the ratio of the drainage area at the location

of the unknown flood-frequency discharge (AU) to the drainage area at the location of the known flood-frequency discharge (AK), unitless; and

EX is the exponent for the particular flood-frequency discharge (table 6), unitless.

In this method, it is not assumed that the conditions affecting flood-frequency discharges change in the upstream direction toward the regional tendency. The critical situation for this assumption is where the unknown location approaches the headwaters of a stream. This assumption might be accept-able if the flood-frequency discharge at the known location is less than that estimated by applying the regional equation at the known location because the upstream estimate of the flood-frequency discharge would be greater, and therefore, more conservative from a flood inundation perspective than that determined using the method presented. However, this assumption would be unacceptable if the flood-frequency discharge at the known location is greater than that estimated by applying the regional equation because the upstream estimate of flood-frequency discharge would be less than that determined using the method presented, thus requiring an assumption of reducing unit inflow. The method presented would require establishing a streamgage station in order to reduce unit inflow when the known flood-frequency discharge is greater than that estimated using the regional equation.

Downstream From a Streamgage StationThis procedure is used when there is a streamgage station

upstream from the ungaged location but none downstream on the same stream. The hydrologic assumption for this

circumstance is that the conditions affecting flood-frequency discharges at the streamgage station change, in the down-stream direction, toward those of the regional tendency. The conditions affecting flood-frequency discharges in the vicinity of the streamgage station could be atypical impervious land cover, unusual basin slope, uncommon basin orientation, or diversion of storm runoff that likely would not significantly affect flood-frequency discharges if the drainage area were larger and, therefore, conditions were more similar to the regional tendency. Mathematically, the value of a flood-fre-quency discharge is changed to that estimated by applying the regional equation as RU/K approaches the downstream limit of the ratio of drainage areas (RDS) (table 6). It is suggested that a streamgage be established when RU/K is greater than or equal to RDS . The flood-frequency discharge is estimated by apply-ing the regional equation when RU/K is greater than or equal to RDS , and the following equation is used to estimate the flood-frequency discharge when RU/K is less than RDS :

QU = QUE + (QK – QKE) (RDS – RU/K) / (RDS – 1) , (8)

when

RU/K < RDS ; and

where QU is the unknown flood-frequency discharge,

in ft3/s; QUE is the regional equation (table 4) evaluated

at the location of the unknown flood-frequency discharge, in ft3/s;

QK is the known flood-frequency discharge (table 3), in ft3/s;

QKE is the regional equation (table 4) evaluated at the location of the known flood-frequency discharge, in ft3/s;

RDS is the downstream limit of the ratio of drainage areas (table 6), unitless; and

RU/K is the ratio of the drainage area at the location of the unknown flood-frequency discharge (AU) to the drainage area at the location of the known flood-frequency discharge (AK), unitless.

Between Streamgage Stations This procedure is used when there are streamgage sta-

tions both upstream and downstream from the ungaged loca-tion on the same stream. The hydrologic assumption for this circumstance is that the conditions affecting flood-frequency discharges are changing on the basis of the relation between the flood-frequency discharges at the streamgage stations, the ratios of the drainage areas, and differences between regional hydrologic conditions and those that affect flood-frequency discharges at the stations. It is suggested that a streamgage be established when RU/K is greater than RDS and less than RUS ,


and when one of the values of the flood-frequency discharge at the upstream and downstream locations is greater than, and one of the values is less than, that estimated by applying the regional equation. Two alternative hydrologic assumptions are described in detail below.

Hydrologic Conditions Change Linearly between Streamgage Stations

This hydrologic assumption is that the conditions affect-ing flood-frequency discharges at the upstream streamgage sta-tion change linearly with drainage area to those at the down-stream location when (1) both streamgage stations are near the ungaged location, or (2) both streamgage stations are not near the ungaged location, but the hydrologic conditions affecting flood-frequency discharges at the stations and ungaged loca-tion are consistent. The conditions affecting flood-frequency discharges between the upstream and downstream locations are well defined by streamgage stations when both are near the ungaged location; the conditions affecting flood-frequency discharges are consistent from the upstream to the downstream location when neither is near the ungaged location and the conditions at both stations are more similar to each other than to the regional hydrologic conditions. Mathematically, the value of flood-frequency discharges changes linearly with respect to drainage area from the upstream to the downstream value when (1) RU/K is less than RDS at the upstream location and RU/K is greater than RUS at the downstream location; or (2) RU/K is greater than or equal to RDS at the upstream location, RU/K is less than or equal to RUS at the downstream location, and the discharges of the flood frequencies at the upstream and downstream locations are both greater than or both less than those estimated by applying the regional equation. The follow-ing equation is used to estimate the flood-frequency discharge under the limitations described above:

QU = [QUS (ADS – AU) + QDS (AU – AUS)] / (ADS – AUS) , (9)

when

RU/K < RDS at upstream location and RU/K > RUS at downstream location,

or when

RU/K ≥ RDS at upstream location and RU/K ≤ RUS at downstream location; and

QKE at the upstream location > QUS and QKE at the downstream location > QDS or

QKE at the upstream location < QUS and QKE at the downstream location < QDS ; and


ft3/s; QUS is the flood-frequency discharge at the

upstream location (table 3), in ft3/s; QDS is the flood-frequency discharge at the

downstream location (table 3), in ft3/s; QKE is the regional equation evaluated at the

location of the known flood-frequency discharge, in ft3/s;

AU is the drainage area at the location of the unknown flood-frequency discharge, in mi2;

AUS is the drainage area at the upstream location (table 2), in mi2;

ADS is the drainage area at the downstream location (table 2), in mi2;

RUS is the upstream limit of the ratio of drainage areas (table 5), unitless; and

RDS is the downstream limit of the ratio of drainage areas (table 5), unitless.

Hydrologic Conditions Change Linearly to the Regional Hydrologic Conditions between Streamgage Stations

This hydrologic assumption is that the conditions affect-ing flood-frequency discharges at the streamgage station change linearly with drainage area to those represented by the regional equation when neither streamgage station is near the ungaged location and the hydrologic conditions affecting flood-frequency discharges at the two stations are inconsistent. The conditions affecting flood discharges can vary greatly as a result of factors such as (1) significant changes in land cover, basin topography, or climatic conditions; (2) input from a tributary stream that is hydrologically different from the stream on which the streamgage station is located or from regional hydrologic conditions; or (3) transfer of storm runoff into or out of the basin. Mathematically, the hydrologic condi-tions are inconsistent if one of the flood-frequency discharges at the upstream and downstream locations is greater than and one of the flood-frequency discharges is less than those esti-mated by applying the regional equation—that is, the flood-frequency discharge changes from a value greater than the flood-frequency discharge estimated by applying the regional equation at the upstream location to a value equal to the flood-frequency discharge estimated from the regional equation, and then to a value less than the flood-frequency discharge estimated from the regional equation at the downstream loca-tion, or the reverse. The regional equation (table 4) is applied to estimate the flood-frequency discharge if RU/K is greater than or equal to RDS at the upstream location and RU/K is less than or equal to RUS at the downstream location. Equation 8 presented in the section “Downstream from a Streamgage Station” is used to estimate the flood-frequency discharge if RU/K is less than RDS at the upstream location and RU/K is less than or equal


to RUS at the downstream location. The following equation is used to estimate the flood-frequency discharge if RU/K is greater than or equal to RDS at the upstream location and RU/K is greater than RUS at the downstream location:

QU = QUE + (QK – QKE) (RU/K – RUS) / (1 – RUS) , (10)

when

RU/K ≥ RDS at upstream location and RU/K > RUS at downstream location, and


ft3/s; QUE is the regional equation (table 4) evaluated

at the location of the unknown flood-frequency discharge, in ft3/s;

QK is the known flood-frequency discharge (table 3), in ft3/s;

QKE is the regional equation (table 4) evaluated at the location of the known flood-frequency discharge, in ft3/s;

RDS is the downstream limit of the ratio of drainage areas (table 5), unitless;

RUS is the upstream limit of the ratio of drainage areas (table 5), unitless; and

RU/K is the ratio of the drainage area at the location of the unknown flood-frequency discharge (AU) to the drainage area at the location of the known flood-frequency discharge (AK), unitless.

Not on the Same Stream as a Streamgage Station

This procedure is used when there is no streamgage sta-tion on the same stream as the ungaged location. The hydro-logic assumption for this circumstance is that the conditions affecting flood-frequency discharges are those represented by the regional equation. A streamgage station could be estab-lished when there is no streamgage station on the same stream as the ungaged location. Mathematically, the flood-frequency discharge is estimated by applying the regional equation (table 4).

Example Applications

Estimates of flood-frequency discharges are made by directly reading from table 3 when the location of interest is at a streamgage station, or using one of the four procedures at an ungaged location: (1) when the ungaged location is upstream from a streamgage station, (2) when the ungaged location is downstream from a streamgage station, (3) when the ungaged location is between two streamgage stations on the same

stream, and (4) when the ungaged location is not on the same stream as a streamgage station.

• At a streamgage station: A flood-frequency discharge for a streamgage station is determined by reading the weighted (Qw) value from table 3. For example, the 500-year flood discharge (PK500, 0.2-percent AOP) at the streamgage station Big Coal River at Ash-ford (ID 238 and streamgage 03198500) is given as 50,300 ft3/s.

• Upstream from a streamgage station: The 50-year flood discharge (PK50, 2-percent AOP) for the South Fork South Branch Potomac River just downstream from the confluence of George Run in Pendleton County (Sugar Grove 7½-minute U.S. Geological Survey topographic map) and upstream from the streamgage station at Brandywine (ID 19 and streamgage 01607500) can be calculated using equa-tion 7. The known 50-year flood discharge (QK) at the Brandywine streamgage station is 18,600 ft3/s (the value for Qw from table 3). The drainage area at the unknown location (AU) is 84.56 mi2 (Wiley and oth-ers, 2007, p. 29), and the drainage area at the known location (AK) is 103 mi2 (table 2). The exponent (EX) for the 50-year flood discharge is 0.70 (table 6). RU/K (which equals AU / AK) is calculated to be 0.82, which is greater than the upstream limit of the ratio of drain-age areas, 0.40 (RUS from table 6), indicating that the installation of a streamgage station is not suggested. The 50-year flood discharge of the South Fork South Branch Potomac River just downstream from the con-fluence of George Run is calculated from equation 7 to be 16,200 ft3/s.

• Downstream from a streamgage station: The 2-year flood discharge (PK2, 50-percent AOP) for Sand Run just downstream from the confluence of Laurel Fork in Upshur County (Century 7½-minute U.S. Geologi-cal Survey topographic map) and downstream from the streamgage station near Buckhannon (ID 90 and streamgage 03052500) can be calculated using equa-tion 8. (No other streamgage station is present down-stream from Sand Run near Buckhannon on the same stream.) The known 2-year flood discharge (QK) at the Buckhannon streamgage station is 794 ft3/s (the value for Qw from table 3). The drainage area at the unknown location (AU) is 27.56 mi2 (Stewart and Mathes, 1995, p. 19), and the drainage area at the known location (AK) is 14.3 mi2 (table 2). The result of the regional equation calculation at the unknown location (QUE) is 1,260 ft3/s (Central Mountains Region determined from fig. 4, equation from table 4) and for the known location (QKE) is 708 ft3/s. RU/K (which equals AU / AK) was calculated to be 1.93, which is less than the downstream limit of the ratio of drainage areas, 26.4 (RDS from table 6). The drainage areas are within the

Summary 21

limits of the regional equation from 0.10 to 1,619 mi2 (table 4), indicating that the procedure is valid and that the installation of a streamgage station is not sug-gested. The 2-year flood discharge of Sand Run just downstream from the confluence of Laurel Fork was calculated from equation 8 to be 1,340 ft3/s.

• Between two streamgage stations on the same stream: The 100-year flood discharge (PK100, 1-percent AOP) for the Greenbrier River just down-stream from the confluence of Wolf Creek in Mon-roe County (Alderson 7½-minute U.S. Geological Survey topographic map), downstream from the streamgage station at Alderson (ID 198 and streamgage 03183500), and upstream from the streamgage station at Hilldale (ID 201 and streamgage 03184000) can be calculated using equation 9. The upstream 100-year flood discharge (QUS) at the Alderson streamgage station is 80,400 ft3/s, and the downstream 100-year flood discharge (QDS) at the Hilldale streamgage sta-tion is 85,400 ft3/s (the values for Qw from table 3). The drainage area at the unknown location (AU) is 1,535.79 mi2 (Mathes and others, 1982, p. 55), the upstream drainage area at the Alderson streamgage station (AUS) is 1,364 mi2 (table 2), and the downstream drainage area at the Hilldale gaging station (ADS) is 1,619 mi2. RU/K (which equals AU / AK) at the upstream location was calculated to be 1.13, which is less than the downstream limit of the ratio of drainage areas, 26.4 (RDS from table 6). RU/K at the downstream loca-tion was calculated to be 0.95, which is greater than the upstream limit of the ratio of drainage areas, 0.40 (RUS table 6), indicating that the procedure is valid and that installation of a streamgage is not suggested. The 100-year flood discharge of the Greenbrier River just downstream from the confluence of Wolf Creek was calculated from equation 9 to be 83,800 ft3/s.

• Not on the same stream as a streamgage station: The 10-year flood discharge (PK10, 10-percent AOP) for Fishing Creek just downstream from the confluence of North and South Forks of Fishing Creek in Wetzel County (Pine Grove 7½-minute U.S. Geological Survey topographic map) can be calculated from the regional equation. (There are no streamgage stations on Fishing Creek or South Fork Fishing Creek that could have been on the same stream.) The streams are in the Western Plateaus Region (fig. 4), and the drainage area is 113.92 mi2 (Wiley, 1997, page 30). The drain-age area is within the limits of the regional equation from 0.13 to 1,516 mi2 (table 4), indicating that the procedure is valid, but that installation of a streamgage station could improve the estimate. The 10-year flood discharge was calculated from the regression equa-tion for the Western Plateaus Region (table 4) to be 8,000 ft3/s.

Limitations of Procedures for Estimating Flood-Frequency Discharges

Procedures developed in this study are applicable only to rural, unregulated streams located within the boundaries of West Virginia. Procedures also are limited to the range of drainage areas used to develop the equations—from 0.21 to 1,461 mi2 in the Eastern Panhandle Region, from 0.10 to 1,619 mi2 in the Central Mountains Region, and from 0.13 to 1,516 mi2 in the Western Plateaus Region. The procedures are not meant to be applied to urban areas with paved surfaces, concrete channels, or culverts that substantially increase runoff or decrease infiltration. The procedures are not meant to be applied to streams regulated by dams or with large lakes and ponds that substantially retain runoff. Procedures are not applicable to heavily mined areas if excessive runoff is diverted into or outside the basin, retained along strip benches, or retained underground. Procedures are not applicable to karst areas if excessive runoff is diverted into, outside, or deep within the basin through solution channels or other cavities in carbonate (limestone and dolomite) rocks. Jones (1997) describes the locations of karst areas in eastern coun-ties of West Virginia, including parts of Monongalia, Preston, Barbour, Tucker, Grant, Mineral, Hardy, Hampshire, Morgan, Berkeley, Jefferson, Randolph, Pendleton, Pocahontas, Green-brier, Summers, Monroe, and Mercer (counties are shown in fig. 4).

SummaryFlood-frequency discharges were determined for 290

streamgage stations on rural, unregulated streams in West Virginia and adjacent states that have a minimum of 9 years of record through the 2006 or 2007 water year. This study was conducted by the USGS, in cooperation with the West Virginia Department of Transportation, Division of Highways. West Virginia skew coefficients were used instead of the United States skew coefficients used in previous studies in West Virginia. Flood-frequency discharges and skew coefficients for stations in adjacent states are applicable only for determining estimates in West Virginia and do not supersede values used in the adjacent states.

The results of a correlation analysis of 36 log10-trans-formed basin characteristics available for the 290 streamgage stations reduced the number of characteristics to 32 for con-sideration as independent variables in the regression analy-sis. Elongation ratio (ER), rotundity of basin (RB), channel maintenance (CM), and basin width (BW) were removed from consideration as independent variables because the Pearson’s coefficient was equal to 1 (singularity) for this group of basin characteristics.

Regression analysis was conducted using log10-trans-formed flood-frequency discharges as dependent variables and log10-transformed basin characteristics as independent


variables for 246 streamflow stations. Forty-four stream-flow stations were excluded from the analysis because the (1) peak data were used to lengthen records for other nearby streamgage stations, (2) station is located in a karst area, (3) plot of the regression residual indicated the station was not representative of West Virginia, and (4) station has a large drainage area and leveraged the regression equation, affecting estimates for small drainage areas. Residuals from multiple and simple least-squares regression models of the 100-year (1-percent AOP) flood discharge with independent variables describing the basin characteristics were used to determine drainage area as the only significant independent variable and to delineate boundaries of three regions in West Virginia—Eastern Panhandle, Central Mountains, and Western Plateaus. Regional equations for the 1.1- (90-percent AOP), 1.5- (67-percent AOP), 2- (50-percent AOP), 5- (20-percent AOP), 10- (10-percent AOP), 25- (4-percent AOP), 50- (2-percent AOP), 100- (1-percent AOP), 200- (0.5-percent AOP), and 500-year (0.2-percent AOP) flood discharges were determined by executing a generalized least-squares regression model. Drainage area was the only significant independent variable determined for all equations in all regions.

The 246 streamgage stations were reduced to 125 for consideration in the trend analysis. For the trend analysis, streamgage stations with a minimum of 30 years of record were considered in order to eliminate effects that might be due to climate variability. Twelve streamgage stations indicated a trend, twice as many as would be expected by chance, but the stations were about equally divided between those having a positive trend and those having a negative trend. No signifi-cance was determined for the streamgage stations having a trend.

The accuracy of estimating equations was quantified by measuring the average prediction error and equivalent years of record. The average prediction error ranged from 21.7 to 56.3 percent, and the equivalent years of record ranged from 2.0 to 70.9 years.

Procedures for estimating flood-frequency discharges at a streamgage station and at an ungaged location are presented in the text of this report. The procedures for an ungaged location include a combination of (1) estimates based on drainage-area ratios between stations and ungaged locations on the same stream and (2) estimates from regional equations. Examples of the procedures are presented in the text.

Equations developed in this study are applicable only to rural, unregulated streams located within the boundaries of West Virginia. Equation application is limited to the range of drainage areas used in equation development—from 0.21 to 1,461 mi2 in the Eastern Panhandle Region, from 0.10 to 1,619 mi2 in the Central Mountains Region, and from 0.13 to 1,516 mi2 in the Western Plateaus Region. The authors suggest using caution in evaluating the results if the equations are applied to heavily mined or karst areas.

References Cited

Atkins, J.T., Jr., Wiley, J.B., and Paybins, K.S., 2009, Gen-eralized skew coefficients of annual peak flows for rural, unregulated streams in West Virginia: U.S. Geological Survey Open-File Report 2008–1304, 13 p.

Barnes, H.H., Jr., 1964, Floods of March 1963, Alabama to West Virginia: U.S. Geological Survey Open-File Report 63-8, 44 p.

Benson, M.A., 1962, Factors influencing the occurrence of floods in a humid region of diverse terrain: U.S. Geological Survey Water-Supply Paper 1580-B, 64 p.

Bisese, J.A., 1995, Methods for estimating magnitude and frequency of peak discharges of rural, unregulated streams in Virginia: U.S. Geological Survey Water-Resources Inves-tigations Report 94-4148, 70 p.

Carpenter, D.H., 1990, Floods in West Virginia, Virginia, Pennsylvania, and Maryland, November 1985: U.S. Geological Survey Water-Resources Investigations Report 88-4213, 86 p.

Dawdy, D.R., Lichty, R.W., and Bergmann, J.M., 1972, A rainfall-runoff simulation model for estimation of flood peaks for small drainage basins: U.S. Geological Survey Professional Paper 506-B, 28 p.

Dillow, J.A., 1996, Technique for estimating magnitude and frequency of peak flows in Maryland: U.S. Geological Sur-vey Water-Resources Investigations Report 95-4154, 55 p.

Doll, W.C., Meyer, Gerald, and Archer, R.J., 1963, Water Resources of West Virginia: Charleston, WV, West Vir-ginia Department of Natural Resources, Division of Water Resources, 134 p.

Fenneman, N.M., 1938, Physiography of Eastern United States: New York, McGraw-Hill, 714 p.

Flynn, K.M., Kirby, W.H., and Hummel, P.R., 2006, User’s manual for program PeakFQ annual flood-frequency analy-sis using Bulletin 17B guidelines: U.S. Geological Survey Techniques and Methods bk 4, chap. B4, 42 p.

Flynn, R.H., 2003, Development of regression equations to estimate flow durations and low-flow-frequency statistics in New Hampshire streams: U.S. Geological Survey Water-Resources Investigations Report 02-4298, 66 p.

Frye, P.M., and Runner, G.S., 1969, Procedure for estimating magnitude and frequency of floods in West Virginia: West Virginia State Road Commission design directive, 10 p.

Frye, P.M., and Runner, G.S., 1970, A proposed streamflow data program for West Virginia: U.S. Geological Survey Open-File Report, 38 p.

References Cited 23

Frye, P.M., and Runner, G.S., 1971, A preliminary report on small streams flood frequency in West Virginia: West Vir-ginia Department of Highways design directive, 9 p.

Grover, N.C., 1937, The floods of March 1936, Part 3, Potomac, James, and upper Ohio Rivers: U.S. Geological Survey Water-Supply Paper 800, 351 p.

Hardison, C.H., 1969, Accuracy of streamflow characteris-tics: U.S. Geological Survey Professional Paper 650-D, p. D210–D214.

Hardison, C.H., 1971, Predictive error of streamflow charac-teristics at ungaged sites: U.S. Geological Survey Profes-sional Paper 750-C, p. 228–236.

Hayes, D.C., 1991, Low-flow characteristics of streams in Virginia: U.S. Geological Survey Water-Supply Paper 2374, 69 p.

Helsel, D.R., and Hirsch, R.M., 2002, Statistical methods in water resources: U.S. Geological Survey Techniques of Water-Resources Investigations Report, bk 4, chap. A3, 510 p.

Hirsch, R.M., Slack, J.R., and Smith, R.A., 1982, Techniques of trend analysis for monthly water quality data: Water Resources Research, v. 18, no. 1, p. 107–121.

Hodge, S.A., and Tasker, G.D., 1995, Magnitude and fre-quency of floods in Arkansas: U.S. Geological Survey Water-Resources Investigations Report 95-4224, 52 p.

Hodgkins, G.A., and Martin, G.R., 2003, Estimating the mag-nitude and frequency of peak flows for streams in Kentucky for selected recurrence intervals: U.S. Geological Survey Water-Resources Investigations Report 03-4180, 68 p.

Insightful Corporation, 2005, S-PLUS 7.0 Professional edi-tion software for Windows: Seattle, Washington, Insightful Corporation.

Interagency Advisory Committee on Water Data, 1976, Guide-lines for determining flood flow frequency: Water Resources Council Bulletin 17, 26 p.

Interagency Advisory Committee on Water Data, 1982, Guide-lines for determining flood flow frequency: Water Resources Council Bulletin 17B, 28 p.

Jones, W.K., 1997, Karst hydrology of West Virginia: Charles Town, WV, Karst Waters Institute, Inc., Special Publication 4, 111 p.

Kendall, M.G., 1975, Rank correlation methods (4th ed.): London, Charles Griffin, 202 p.

Kirby, W., 1980, Computer routines for probability distribu-tions, random numbers, and related functions: U.S. Geologi-cal Survey Open-File Report 80-448, 61 p.

Koltun, G.F., 2003, Techniques for estimating flood-peak dis-charges of rural, unregulated streams in Ohio: U.S. Geologi-cal Survey Water-Resources Investigations Report 03-4164, 75 p.

Lescinsky, J.B., 1987, Flood of November 1985 in West Vir-ginia, Pennsylvania, Maryland, and Virginia: U.S. Geologi-cal Survey Open-File Report 86-486, 33 p.

Lumb, A.M., Kittle, J.L., Jr., and Flynn, K.M., 1990, Users manual for ANNIE, computer program for interactive hydrologic analysis and data management: U.S. Geological Survey Water-Resources Investigations Report 89-4080, 236 p.

Mathes, M.V, Jr., 1977, Drainage areas of the Guyandotte River Basin, West Virginia: U.S. Geological Survey Open-File Report 77-801, 56 p.

Mathes, M.V., Kirby, J.R., Payne, D.D., and Shultz, R.A., 1982, Drainage areas of the Kanawha River Basin, West Virginia: U.S. Geological Survey Open-File Report 82-351, 222 p.

National Oceanic and Atmospheric Administration, 2006a, Climate of West Virginia, accessed September 30, 2006, at http://cdo.ncdc.noaa.gov/climatenormals/clim60/states/Clim_WV_01.pdf.

National Oceanic and Atmospheric Administration, 2006b, Total precipitation in inches by month for climate divisions, accessed September 30, 2006, at http://www.cdc.noaa.gov/USclimate/pcp.state.19712000.climo.html.

Natural Resources Conservation Service, 2006, West Virginia Precipitation data/maps, accessed September 30, 2006, at http://www.ncgc.nrcs.usda.gov/products/datasets/climate/data/precipitation-state/wv.html.

Paybins, K.S., 2008, Basin characteristics for selected streamflow-gaging stations in and near West Virginia: U.S. Geological Survey Open-File Report 2008–1087, 9 p. (Also available at http://pubs.er.usgs.gov/usgspubs/ofr/ofr20081087.)

Preston, J.S., and Mathes, M.V., 1984, Stream drainage areas for the Little Kanawha River Basin, West Virginia: U.S. Geological Survey Open-File Report 84-861, 171 p.

Ries, K.G., III, and Friesz, P.J., 2000, Methods for estimating low-flow statistics for Massachusetts streams: U.S. Geologi-cal Survey Water-Resources Investigations Report 00-4135, 81 p.

Runner, G.S., 1979, Flood of April 1977 on the Tug Fork, Matewan to Williamson, West Virginia and Kentucky: U.S. Geological Survey Hydrologic Investigations Atlas HA-588, scale 1:12,000.


Runner, G.S., 1980a, Technique for estimating magnitude and frequency of floods in West Virginia: U.S. Geological Survey Open-File Report 80-1218, 44 p.

Runner, G.S., 1980b, Hydrologic data for Runoff studies on small drainage areas, West Virginia Department of High-ways Research Project 16: U.S. Geological Survey Open-File Report 80-560, 169 p.

Runner, G.S., and Chin, E.H., 1980, Flood of April 1977 in the Appalachian region of Kentucky, Tennessee, Virginia, and West Virginia: U.S. Geological Survey Professional Paper 1098, 43 p.

Speer, P.R., and Gamble, C.R., 1965, Magnitude and fre-quency of floods in the United States, Part 3-A, Ohio River basin except Cumberland and Tennessee River basins: U.S. Geological Survey Water-Supply Paper 1675, 630 p.

Stedinger, J.R., and Tasker, G.D., 1985, Regional hydro-logic analysis 1: ordinary, weighted, and generalized least squares compared: Water Resources Research, v. 21, no. 9, p. 1421–1432.

Stewart, D.K., and Mathes, M.V., 1995, Drainage areas of the Monongahela River Basin, West Virginia: U.S. Geological Survey Open-File Report 95-170, 79 p.

Stuckey, M.H., and Reed, L.A., 2000, Techniques for estimat-ing magnitude and frequency of peak flows for Pennsyl-vania streams: U.S. Geological Survey Water-Resources Investigations Report 00-4189, 43 p.

Tasker, G.D., and Stedinger, J.R., 1989, An operational GLS model for hydrologic regression: Journal of Hydrology, v. 111, p. 361–375.

Tice, R.H., 1968, Magnitude and frequency of floods in the United States, Part 1-B, North Atlantic Slope Basins, New York to York River: U.S. Geological Survey Water-Supply Paper 1672, 585 p.

U.S. Geological Survey, 1990, National water summary 1987—Hydrologic events and water supply and use: U.S. Geological Survey Water-Supply Paper 2350, 553 p.

U.S. Geological Survey, 1991, National water summary 1988-89—Hydrologic events and floods and droughts: U.S. Geological Survey Water-Supply Paper 2375, 591 p.

U.S. Geological Survey, 2001, Water Resources Applications Software: LIB3.2, revised June 29, 1998, accessed Novem-ber 2001, at http://water.usgs.gov/software/lib.html/.

U.S. Geological Survey, 2005, Streamflow trends in the United States: U.S. Geological Survey Fact Sheet FS2005–3017, 4 p.

U.S. Geological Survey, 2006, The National Map, accessed September 30, 2006, at http://nationalmap.gov.

Wiley, J.B., 1997, Drainage areas of West Virginia streams tributary to the Ohio River: U.S. Geological Survey Open-File Report 97-231, 70 p.

Wiley, J.B., 2008, Estimating selected annual streamflow statistics representative of 1930–2002 in West Virginia: U.S. Geological Survey Scientific Investigations Report 2008–5105, 24 p.

Wiley, J.B., Atkins, J.T., Jr., and Newell, D.A., 2002, Estimat-ing the magnitude of annual peak discharges with recur-rence intervals between 1.1 and 3.0 years for rural, unregu-lated streams in West Virginia: U.S. Geological Survey Water-Resources Investigations Report 02-4164, 73 p.

Wiley, J.B., Atkins, J.T., Jr., and Tasker, G.D., 2000, Estimat-ing magnitude and frequency of peak discharges for rural, unregulated streams in West Virginia: U.S. Geological Sur-vey Water-Resources Investigations Report 00-4080, 93 p.

Wiley, J.B., Hunt, M.L., and Stewart, D.K., 2007, Drainage areas of the Potomac River Basin, West Virginia: U.S. Geo-logical Survey Open-File Report 95-292 (3d ed.), 60 p.

Wilson, M.W., 1979, Drainage areas of the Twelvepole Creek Basin, West Virginia; Big Sandy River Basin, West Virginia; Tug Fork Basin, Virginia, Kentucky, West Virginia: U.S. Geological Survey Open-File Report 79-746, 49 p.

Table 1 25Ta

ble

1.

Iden

tifica

tion

num

bers

, sta

tion

num

bers

, stre

amga

ge-s

tatio

n na

mes

, and

ske

w c

oeffi

cien

ts a

nd s

tatis

tics

for t

he 2

90 U

.S. G

eolo

gica

l Sur

vey

stre

amga

ge s

tatio

ns o

n ru

ral,

unre

gula

ted

stre

ams

in W

est V

irgin

ia a

nd a

djac

ent s

tate

s.—

Cont

inue

d

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

N.,

Nor

th; S

., So

uth;

E.,

East

; W.,

Wes

t; R

., R

ight

; Br.,

B

ranc

h; F

k., F

ork;

Cr.,

Cre

ek; T

rib.,

Trib

utar

y; S

pgs.,

Spr

ings

; Rt.,

Rou

te; b

l, be

low

; nr,

near

; U.S

. ske

w, U

nite

d St

ates

skew

, the

skew

pre

sent

ed in

Bul

letin

-17B

by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2); W

V sk

ew, W

est V

irgin

ia sk

ew d

eter

min

ed b

y A

tkin

s and

oth

ers (

2009

); sh

adin

g in

dica

tes t

he 4

4 st

ream

gage

stat

ions

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stre

amga

ge-s

tatio

n na

me

Stat

eW

V sk

ew,

unitl

ess

U.S

. ske

w,

unitl

ess

Diff

eren

ce

betw

een

WV

and

US

skew

s,

unitl

ess

Wei

ghte

d W

V an

d st

atio

n sk

ews,

un

itles

s

Mea

n of

log 10

-tr

ansf

orm

ed

flood

-fre

quen

cy

disc

harg

es,

in c

ubic

feet

per

se

cond

Stan

dard

de

viat

ion

of lo

g 10-

tran

sfor

med

flo

od-f

requ

ency

di

scha

rges

, in

cub

ic fe

et p

er

seco

nd1

0159

5000

Nor

th B

ranc

h Po

tom

ac R

iver

at S

teye

rM

D0.

594

0.33

70.

257

0.37

63.

531

0.24

52

0159

5300

Abr

am C

reek

at O

akm

ont

WV

.523

.348

.175

1.09

33.

127

.193

301

5955

00N

orth

Br.

Poto

mac

Riv

er a

t Kitz

mill

erM

D.5

68.3

44.2

24.9

003.

914

.232

401

5960

00N

orth

Br.

Poto

mac

Riv

er a

t Blo

omin

gton

MD

.549

.351

.198

.466

3.92

4.2

595

0159

6500

Sava

ge R

iver

nea

r Bar

ton

MD

.565

.335

.230

.639

3.19

4.2

236

0159

7000

Cra

btre

e C

reek

nea

r Sw

anto

nM

D.5

43.3

34.2

09.7

222.

714

.267

701

5980

00Sa

vage

Riv

er a

t Blo

omin

gton

MD

.553

.350

.203

.628

3.56

1.2

598

0159

9000

Geo

rges

Cre

ek a

t Fra

nklin

MD

.535

.354

.181

.502

3.28

9.2

349

0159

9500

New

Cre

ek n

ear K

eyse

rW

V.4

75.3

71.1

04.0

603.

013

.302

1001

6000

00N

orth

Bra

nch

Poto

mac

Riv

er a

t Pin

toM

D.5

16.3

66.1

50.5

004.

215

.259

1101

6015

00W

ills C

reek

nea

r Cum

berla

ndM

D.5

95.3

58.2

37.7

923.

817

.255

1201

6030

00N

. Br.

Poto

mac

Riv

er n

ear C

umbe

rland

MD

.529

.365

.164

.697

4.27

0.2

1113

0160

4500

Patte

rson

Cre

ek n

ear H

eads

ville

WV

.430

.383

.047

.017

3.56

5.3

0014

0160

5500

Sout

h B

ranc

h Po

tom

ac R

iver

at F

rank

linW

V.7

00.4

19.2

81.4

503.

681

.341

1501

6057

00R

eeds

Cre

ek T

ribut

ary

near

Fra

nklin

WV

.800

.401

.399

.644

1.32

2.2

2916

0160

6000

N. F

k. S

. Br.

Poto

mac

Riv

er a

t Cab

ins

WV

.824

.389

.435

.874

3.94

2.2

5117

0160

6500

S. B

r. Po

tom

ac R

iver

nea

r Pet

ersb

urg

WV

.802

.396

.406

.719

4.14

9.2

7618

0160

6800

Bru

shy

Run

nea

r Pet

ersb

urg

WV

.689

.415

.274

.551

1.62

2.3

7719

0160

7500

S. F

k. S

. Br.

Poto

mac

R. a

t Bra

ndyw

ine

WV

.659

.433

.226

.816

3.56

0.3

2920

0160

7510

Hea

vene

r Run

nea

r Bra

ndyw

ine

WV

.715

.435

.280

.500

1.51

2.3

0721

0160

8000

S. F

k. S

. Br.

Poto

mac

R. n

ear M

oore

field

WV

.671

.423

.248

.621

3.80

5.3

1122

0160

8100

Will

iam

s Hol

low

nea

r Moo

refie

ldW

V.3

91.4

19-.0

28.1

251.

669

.142

2301

6085

00S.

Br.

Poto

mac

Riv

er n

ear S

prin

gfiel

dW

V.6

91.3

98.2

93.5

984.

385

.295

2401

6090

00To

wn

Cre

ek n

ear O

ldto

wn

MD

.510

.393

.117

.146

3.59

1.2

5525

0160

9500

Saw

pit R

un n

ear O

ldto

wn

MD

.425

.394

.031

.580

2.44

5.1

9326

0160

9650

Littl

e C

acap

on R

iver

at F

renc

hbur

gW

V.3

03.4

14-.1

11.1

983.

034

.360

2701

6098

00Li

ttle

Cac

apon

Riv

er n

ear L

evel

sW

V.3

22.4

06-.0

84.3

243.

593

.223

26 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West VirginiaTa

ble

1.

Iden

tifica

tion

num

bers

, sta

tion

num

bers

, stre

amga

ge-s

tatio

n na

mes

, and

ske

w c

oeffi

cien

ts a

nd s

tatis

tics

for t

he 2

90 U

.S. G

eolo

gica

l Sur

vey

stre

amga

ge s

tatio

ns o

n ru

ral,

unre

gula

ted

stre

ams

in W

est V

irgin

ia a

nd a

djac

ent s

tate

s.—

Cont

inue

d

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

N.,

Nor

th; S

., So

uth;

E.,

East

; W.,

Wes

t; R

., R

ight

; Br.,

B

ranc

h; F

k., F

ork;

Cr.,

Cre

ek; T

rib.,

Trib

utar

y; S

pgs.,

Spr

ings

; Rt.,

Rou

te; b

l, be

low

; nr,

near

; U.S

. ske

w, U

nite

d St

ates

skew

, the

skew

pre

sent

ed in

Bul

letin

-17B

by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2); W

V sk

ew, W

est V

irgin

ia sk

ew d

eter

min

ed b

y A

tkin

s and

oth

ers (

2009

); sh

adin

g in

dica

tes t

he 4

4 st

ream

gage

stat

ions

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stre

amga

ge-s

tatio

n na

me

Stat

eW

V sk

ew,

unitl

ess

U.S

. ske

w,

unitl

ess

Diff

eren

ce

betw

een

WV

and

US

skew

s,

unitl

ess

Wei

ghte

d W

V an

d st

atio

n sk

ews,

un

itles

s

Mea

n of

log 10

-tr

ansf

orm

ed

flood

-fre

quen

cy

disc

harg

es,

in c

ubic

feet

per

se

cond

Stan

dard

de

viat

ion

of lo

g 10-

tran

sfor

med

flo

od-f

requ

ency

di

scha

rges

, in

cub

ic fe

et p

er

seco

nd28

0161

0000

Poto

mac

Riv

er a

t Paw

Paw

WV

.457

.404

.053

.465

4.63

7.2

1429

0161

0150

Bea

r Cre

ek a

t For

est P

ark

MD

.454

.395

.059

.213

2.58

5.2

8830

0161

0155

Side

ling

Hill

Cre

ek a

t Bel

legr

ove

MD

.481

.399

.082

.169

3.56

9.3

3331

0161

0500

Cac

apon

Riv

er a

t Yel

low

Spr

ing

WV

.242

.446

-.204

.085

3.87

5.3

6232

0161

1500

Cac

apon

Riv

er n

ear G

reat

Cac

apon

WV

.306

.411

-.105

.025

4.11

5.3

1833

0161

2500

Littl

e To

nolo

way

Cre

ek n

ear H

anco

ckM

D.2

46.4

00-.1

54.2

252.

730

.271

3401

6130

00Po

tom

ac R

iver

at H

anco

ckM

D.4

35.4

07.0

28.4

944.

745

.240

3501

6131

50D

itch

Run

nea

r Han

cock

MD

.391

.412

-.021

.322

2.38

7.2

3136

0161

3160

Poto

mac

Riv

er T

ribut

ary

near

Han

cock

MD

.418

.412

.006

.519

2.03

6.1

6637

0161

3900

Hog

ue C

reek

nea

r Hay

field

VA.4

11.4

62-.0

51-.1

302.

925

.348

3801

6140

00B

ack

Cre

ek n

ear J

ones

Spr

ings

WV

.210

.445

-.235

.310

3.76

1.2

5039

0161

5000

Ope

quon

Cre

ek n

ear B

erry

ville

VA.2

52.4

88-.2

36.0

813.

388

.315

4001

6160

00A

bram

s Cre

ek n

ear W

inch

este

rVA

.211

.487

-.276

-.020

2.73

4.2

8141

0161

6500

Ope

quon

Cre

ek n

ear M

artin

sbur

gW

V.2

18.4

70-.2

52.1

573.

659

.307

4201

6170

00Tu

scar

ora

Cre

ek a

bove

Mar

tinsb

urg

WV

.243

.459

-.216

.294

2.23

5.2

5343

0161

7800

Mar

sh R

un a

t Grim

esM

D.3

06.4

81-.1

75.0

232.

012

.339

4401

6180

00Po

tom

ac R

iver

at S

heph

erds

tow

nM

D.3

18.4

90-.1

72.3

224.

837

.224

4501

6194

75D

og C

reek

Trib

utar

y ne

ar L

ocus

t Gro

veM

D.3

22.5

07-.1

85.4

171.

354

.360

4601

6195

00A

ntie

tam

Cre

ek n

ear S

harp

sbur

gM

D.3

63.4

98-.1

35.2

883.

428

.273

4701

6205

00N

orth

Riv

er n

ear S

toke

svill

eVA

.560

.471

.089

.492

2.89

4.3

9848

0162

1000

Dry

Riv

er a

t Raw

ley

Sprin

gsVA

.611

.477

.134

.911

3.39

3.2

7049

0162

1200

War

Bra

nch

near

Hin

ton

VA.5

37.4

90.0

47.4

642.

759

.273

5001

6214

00B

lack

s Run

at H

arris

onbu

rgVA

.453

.506

-.053

.585

2.69

1.1

8651

0162

1450

Bla

cks R

un T

ribut

ary

near

Har

rison

burg

VA.4

62.5

07-.0

45.7

281.

644

.253

5201

6220

00N

orth

Riv

er n

ear B

urke

tow

nVA

.550

.514

.036

.587

3.86

1.2

9153

0162

2100

Nor

th R

iver

Trib

utar

y at

Mou

nt C

raw

ford

VA.4

45.5

13-.0

68.2

431.

778

.278

5401

6223

00B

uffa

lo B

ranc

h Tr

ib. n

ear A

gust

a Sp

rings

VA.3

40.4

89-.1

49.3

201.

733

.165

Table 1 27Ta

ble

1.

Iden

tifica

tion

num

bers

, sta

tion

num

bers

, stre

amga

ge-s

tatio

n na

mes

, and

ske

w c

oeffi

cien

ts a

nd s

tatis

tics

for t

he 2

90 U

.S. G

eolo

gica

l Sur

vey

stre

amga

ge s

tatio

ns o

n ru

ral,

unre

gula

ted

stre

ams

in W

est V

irgin

ia a

nd a

djac

ent s

tate

s.—

Cont

inue

d

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

N.,

Nor

th; S

., So

uth;

E.,

East

; W.,

Wes

t; R

., R

ight

; Br.,

B

ranc

h; F

k., F

ork;

Cr.,

Cre

ek; T

rib.,

Trib

utar

y; S

pgs.,

Spr

ings

; Rt.,

Rou

te; b

l, be

low

; nr,

near

; U.S

. ske

w, U

nite

d St

ates

skew

, the

skew

pre

sent

ed in

Bul

letin

-17B

by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2); W

V sk

ew, W

est V

irgin

ia sk

ew d

eter

min

ed b

y A

tkin

s and

oth

ers (

2009

); sh

adin

g in

dica

tes t

he 4

4 st

ream

gage

stat

ions

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stre

amga

ge-s

tatio

n na

me

Stat

eW

V sk

ew,

unitl

ess

U.S

. ske

w,

unitl

ess

Diff

eren

ce

betw

een

WV

and

US

skew

s,

unitl

ess

Wei

ghte

d W

V an

d st

atio

n sk

ews,

un

itles

s

Mea

n of

log 10

-tr

ansf

orm

ed

flood

-fre

quen

cy

disc

harg

es,

in c

ubic

feet

per

se

cond

Stan

dard

de

viat

ion

of lo

g 10-

tran

sfor

med

flo

od-f

requ

ency

di

scha

rges

, in

cub

ic fe

et p

er

seco

nd55

0162

2400

Buf

falo

Bra

nch

Trib

utar

y ne

ar C

hris

tian

VA.3

78.4

92-.1

14.5

111.

760

.260

5601

6320

00N

. Fk.

She

nand

oah

R. a

t Coo

tes S

tore

VA.5

15.4

82.0

33.0

103.

909

.293

5701

6323

00Lo

ng M

eado

w n

ear B

road

way

VA.4

13.4

99-.0

86.3

952.

137

.407

5801

6329

00Sm

ith C

reek

nea

r New

Mar

ket

VA.3

82.4

96-.1

14-.0

103.

328

.373

5901

6329

50C

rook

ed R

un T

ribut

ary

near

Con

icvi

lleVA

.347

.474

-.127

.151

1.36

3.1

9860

0163

2970

Cro

oked

Run

nea

r Mou

nt Ja

ckso

nVA

.343

.482

-.139

.244

2.42

1.3

6361

0163

3000

N. F

k. S

hena

ndoa

h R

. at M

ount

Jack

son

VA.4

39.4

89-.0

50.0

404.

037

.292

6201

6335

00St

ony

Cre

ek a

t Col

umbi

a Fu

rnac

eVA

.336

.475

-.139

.300

3.32

7.2

8663

0163

3650

Pugh

s Run

nea

r Woo

dsto

ckVA

.243

.475

-.232

.224

2.05

9.3

7264

0163

4000

N. F

k. S

hena

ndoa

h R

iver

nea

r Stra

sbur

gVA

.378

.489

-.111

.416

4.07

7.3

1465

0163

4500

Ced

ar C

reek

nea

r Win

ches

ter

VA.1

99.4

76-.2

77.2

053.

524

.340

6601

6365

00Sh

enan

doah

Riv

er a

t Mill

ville

WV

.359

.515

-.156

.154

4.52

4.2

9867

0163

7000

Littl

e C

atoc

tin C

reek

at H

arm

ony

MD

.332

.522

-.190

.344

2.76

6.4

0568

0163

7500

Cat

octin

Cre

ek n

ear M

iddl

etow

nM

D.3

36.5

29-.1

93.1

413.

402

.311

6901

6384

80C

atoc

tin C

reek

at T

aylo

rsto

wn

VA.2

87.5

54-.2

67-.0

703.

584

.364

7001

6385

00Po

tom

ac R

iver

at P

oint

Of R

ocks

MD

.228

.556

-.328

.236

5.01

8.2

2871

0164

3700

Goo

se C

reek

nea

r Mid

dleb

urg

VA.2

47.5

58-.3

11.1

013.

596

.369

7201

6440

00G

oose

Cre

ek n

ear L

eesb

urg

VA.2

68.5

93-.3

25.3

413.

880

.335

7301

6441

00So

uth

Fork

Syc

olin

Cre

ek n

ear L

eesb

urg

VA.2

86.5

79-.2

93.2

282.

599

.282

7402

0095

00C

atta

il R

un n

ear B

olar

VA.3

38.4

16-.0

78.3

851.

512

.101

7502

0114

00Ja

ckso

n R

iver

nea

r Bac

ova

VA.2

38.4

13-.1

75.5

373.

584

.245

7602

0114

60B

ack

Cre

ek n

ear S

unris

eVA

.419

.405

.014

.489

3.46

9.2

2677

0201

1480

Bac

k C

r. at

Rt.

600

near

Mou

ntai

n G

rove

VA.3

44.4

04-.0

60.0

963.

643

.177

7802

0115

00B

ack

Cre

ek n

ear M

ount

ain

Gro

veVA

.258

.407

-.149

-.120

3.77

0.2

0079

0201

2500

Jack

son

Riv

er a

t Fal

ling

Sprin

gVA

.136

.417

-.281

-.260

4.00

3.2

3680

0201

2950

Swee

t Spg

s. C

r. Tr

ib. a

t Sw

eet C

hayl

beat

eVA

.003

.413

-.410

-.140

1.56

2.6

0281

0201

3000

Dun

lap

Cre

ek n

ear C

ovin

gton

VA.0

15.4

17-.4

02.0

683.

725

.254


ble

1.

Iden

tifica

tion

num

bers

, sta

tion

num

bers

, stre

amga

ge-s

tatio

n na

mes

, and

ske

w c

oeffi

cien

ts a

nd s

tatis

tics

for t

he 2

90 U

.S. G

eolo

gica

l Sur

vey

stre

amga

ge s

tatio

ns o

n ru

ral,

unre

gula

ted

stre

ams

in W

est V

irgin

ia a

nd a

djac

ent s

tate

s.—

Cont

inue

d

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

N.,

Nor

th; S

., So

uth;

E.,

East

; W.,

Wes

t; R

., R

ight

; Br.,

B

ranc

h; F

k., F

ork;

Cr.,

Cre

ek; T

rib.,

Trib

utar

y; S

pgs.,

Spr

ings

; Rt.,

Rou

te; b

l, be

low

; nr,

near

; U.S

. ske

w, U

nite

d St

ates

skew

, the

skew

pre

sent

ed in

Bul

letin

-17B

by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2); W

V sk

ew, W

est V

irgin

ia sk

ew d

eter

min

ed b

y A

tkin

s and

oth

ers (

2009

); sh

adin

g in

dica

tes t

he 4

4 st

ream

gage

stat

ions

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stre

amga

ge-s

tatio

n na

me

Stat

eW

V sk

ew,

unitl

ess

U.S

. ske

w,

unitl

ess

Diff

eren

ce

betw

een

WV

and

US

skew

s,

unitl

ess

Wei

ghte

d W

V an

d st

atio

n sk

ews,

un

itles

s

Mea

n of

log 10

-tr

ansf

orm

ed

flood

-fre

quen

cy

disc

harg

es,

in c

ubic

feet

per

se

cond

Stan

dard

de

viat

ion

of lo

g 10-

tran

sfor

med

flo

od-f

requ

ency

di

scha

rges

, in

cub

ic fe

et p

er

seco

nd82

0201

4000

Potts

Cre

ek n

ear C

ovin

gton

VA.0

01.4

25-.4

24-.1

303.

595

.241

8303

0500

00Ty

gart

Valle

y R

iver

nea

r Dai

ley

WV

.546

.320

.226

.334

3.84

1.1

7084

0305

0500

Tyga

rt Va

lley

Riv

er n

ear E

lkin

sW

V.5

87.3

06.2

81.4

713.

874

.137

8503

0506

50U

nnam

ed R

un a

t Gilm

anW

V.6

08.3

06.3

02.7

581.

700

.284

8603

0510

00Ty

gart

Valle

y R

iver

at B

elin

gton

WV

.579

.284

.295

.291

4.01

6.1

3987

0305

1500

Mid

dle

Fork

Riv

er a

t Mid

vale

WV

.424

.276

.148

.278

3.69

5.1

9988

0305

2000

Mid

dle

Fork

Riv

er a

t Aud

raW

V.4

12.2

65.1

47.2

313.

789

.177

8903

0523

40M

ud L

ick

Run

nea

r Buc

khan

non

WV

.124

.246

-.122

.221

2.19

7.1

9190

0305

2500

Sand

Run

nea

r Buc

khan

non

WV

.274

.265

.009

.356

2.91

6.2

4391

0305

3500

Buc

khan

non

Riv

er a

t Hal

lW

V.2

49.2

57-.0

08-.2

103.

870

.141

9203

0545

00Ty

gart

Valle

y R

iver

at P

hilli

piW

V.4

32.2

51.1

81.2

344.

355

.152

9303

0550

20B

onic

a R

un o

n U

.S. 2

50 n

ear P

hilli

piW

V.3

61.2

60.1

01.0

701.

828

.263

9403

0550

40B

onic

a R

un o

n R

oute

38

near

Phi

llipi

WV

.363

.259

.104

.352

2.33

3.2

7195

0305

6250

Thre

e Fo

rk C

reek

nea

r Gra

fton

WV

.375

.227

.148

.284

3.68

3.1

7696

0305

6500

Tyga

rt Va

lley

Riv

er a

t Fet

term

anW

V.4

21.2

19.2

02.3

284.

498

.155

9703

0566

00R

ight

Fk.

Wic

kwire

Run

nea

r Gra

fton

WV

.319

.225

.094

.104

2.31

0.2

3098

0305

7300

Wes

t For

k R

iver

at W

alke

rsvi

lleW

V.0

86.2

38-.1

52.0

723.

197

.205

9903

0575

00Sk

in C

reek

nea

r Bro

wns

ville

WV

.042

.226

-.184

-.160

3.10

7.1

3010

003

0580

00W

est F

ork

R. b

lw S

tone

wal

l Jac

kson

Dam

nr W

esto

nW

V.0

34.2

18-.1

84.1

263.

507

.172

101

0305

8500

Wes

t For

k R

iver

at B

utch

ervi

lleW

V.0

10.2

05-.1

95-.0

603.

781

.183

102

0305

9000

Wes

t For

k R

iver

at C

lark

sbur

gW

V-.0

24.1

91-.2

15-.3

103.

993

.147

103

0305

9500

Elk

Cre

ek a

t Qui

et D

ell

WV

.135

.206

-.071

.029

3.42

3.2

6210

403

0605

00Sa

lem

For

k at

Sal

emW

V-.0

83.1

65-.2

48-.1

902.

908

.301

105

0306

1000

Wes

t For

k R

iver

at E

nter

pris

eW

V-.0

01.1

78-.1

79-.1

304.

243

.179

106

0306

1500

Buf

falo

Cre

ek a

t Bar

rack

ville

WV

.030

.178

-.148

-.060

3.71

4.1

4810

703

0624

00C

obun

Cre

ek a

t Mor

gant

own

WV

.314

.190

.124

.575

2.70

0.2

7210

803

0625

00D

ecke

rs C

reek

at M

orga

ntow

nW

V.3

65.1

87.1

78.3

633.

195

.256

Table 1 29Ta

ble

1.

Iden

tifica

tion

num

bers

, sta

tion

num

bers

, stre

amga

ge-s

tatio

n na

mes

, and

ske

w c

oeffi

cien

ts a

nd s

tatis

tics

for t

he 2

90 U

.S. G

eolo

gica

l Sur

vey

stre

amga

ge s

tatio

ns o

n ru

ral,

unre

gula

ted

stre

ams

in W

est V

irgin

ia a

nd a

djac

ent s

tate

s.—

Cont

inue

d

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

N.,

Nor

th; S

., So

uth;

E.,

East

; W.,

Wes

t; R

., R

ight

; Br.,

B

ranc

h; F

k., F

ork;

Cr.,

Cre

ek; T

rib.,

Trib

utar

y; S

pgs.,

Spr

ings

; Rt.,

Rou

te; b

l, be

low

; nr,

near

; U.S

. ske

w, U

nite

d St

ates

skew

, the

skew

pre

sent

ed in

Bul

letin

-17B

by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2); W

V sk

ew, W

est V

irgin

ia sk

ew d

eter

min

ed b

y A

tkin

s and

oth

ers (

2009

); sh

adin

g in

dica

tes t

he 4

4 st

ream

gage

stat

ions

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stre

amga

ge-s

tatio

n na

me

Stat

eW

V sk

ew,

unitl

ess

U.S

. ske

w,

unitl

ess

Diff

eren

ce

betw

een

WV

and

US

skew

s,

unitl

ess

Wei

ghte

d W

V an

d st

atio

n sk

ews,

un

itles

s

Mea

n of

log 10

-tr

ansf

orm

ed

flood

-fre

quen

cy

disc

harg

es,

in c

ubic

feet

per

se

cond

Stan

dard

de

viat

ion

of lo

g 10-

tran

sfor

med

flo

od-f

requ

ency

di

scha

rges

, in

cub

ic fe

et p

er

seco

nd10

903

0639

50Jo

b R

un n

ear W

ymer

WV

.817

.351

.466

.967

1.83

6.3

1811

003

0650

00D

ry F

ork

at H

endr

icks

WV

.813

.322

.491

.959

4.13

6.2

1111

103

0654

00B

lack

wat

er R

iver

nea

r Dav

isW

V.6

89.3

42.3

47.7

963.

195

.204

112

0306

6000

Bla

ckw

ater

Riv

er a

t Dav

isW

V.6

71.3

37.3

34.7

213.

416

.197

113

0306

7100

Fern

ow W

S-4

near

Hen

dric

ksW

V.6

66.3

16.3

50.3

16.8

46.2

3911

403

0675

00Sh

aver

s For

k at

Che

at B

ridge

WV

.550

.345

.205

.304

3.61

5.1

3811

503

0686

10Ta

ylor

Run

at B

owde

nW

V.7

59.3

34.4

25.4

392.

379

.203

116

0306

8800

Shav

ers F

ork

belo

w B

owde

nW

V.6

82.3

23.3

59.3

554.

043

.172

117

0306

9000

Shav

ers F

ork

at P

arso

nsW

V.7

10.3

11.3

99.8

463.

957

.162

118

0306

9500

Che

at R

iver

nea

r Par

sons

WV

.795

.307

.488

.845

4.42

2.1

8711

903

0698

50Lo

ng R

un n

ear P

arso

nsW

V.5

19.2

80.2

39.5

481.

906

.185

120

0306

9880

Buf

falo

Cre

ek n

ear R

owle

sbur

gW

V.5

01.2

79.2

22.2

103.

032

.206

121

0307

0000

Che

at R

iver

at R

owle

sbur

gW

V.7

47.2

76.4

71.5

964.

541

.189

122

0307

0500

Big

San

dy C

reek

nea

r Roc

kvill

eW

V.4

76.2

30.2

46.7

503.

875

.176

123

0307

1000

Che

at R

iver

nea

r Pis

gah

WV

.617

.219

.398

.280

4.64

4.2

0012

403

0715

00C

heat

Riv

er n

ear M

orga

ntow

nW

V.6

11.1

96.4

15-.0

104.

665

.190

125

0307

2000

Dun

kard

Cre

ek a

t Sha

nnop

inPA

.114

.164

-.050

-.110

3.85

0.1

9912

603

0725

90G

eorg

es C

reek

at S

mith

field

PA.3

94.1

88.2

06.2

902.

826

.197

127

0307

5450

Littl

e You

ghio

ghen

y R

. Trib

. at D

eer P

ark

MD

.555

.316

.239

.099

1.37

0.2

0512

803

0755

00Yo

ughi

oghe

ny R

iver

nea

r Oak

land

MD

.562

.303

.259

.385

3.63

6.2

1012

903

0756

00To

liver

Run

Trib

utar

y ne

ar H

oyes

Run

MD

.548

.294

.254

.579

1.50

1.2

8413

003

0765

05Yo

ughi

oghe

ny R

. Trib

. nea

r Frie

ndsv

ille

MD

.541

.269

.272

.215

1.07

2.1

4313

103

0766

00B

ear C

reek

at F

riend

svill

eM

D.5

60.2

76.2

84.0

573.

192

.205

132

0308

5500

Cha

rtier

s Cre

ek a

t Car

negi

e

PA.1

08.0

57.0

51.1

363.

737

.223

133

0310

8000

Rac

coon

Cre

ek a

t Mof

fatts

Mill

PA.0

55.0

04.0

51.3

563.

568

.220

134

0310

9000

Lisb

on C

reek

at L

isbo

nO

H.0

94-.0

55.1

49.2

842.

592

.237

135

0310

9500

Littl

e B

eave

r Cre

ek n

ear E

ast L

iver

pool

OH

.098

-.022

.120

.160

3.95

8.2

02


ble

1.

Iden

tifica

tion

num

bers

, sta

tion

num

bers

, stre

amga

ge-s

tatio

n na

mes

, and

ske

w c

oeffi

cien

ts a

nd s

tatis

tics

for t

he 2

90 U

.S. G

eolo

gica

l Sur

vey

stre

amga

ge s

tatio

ns o

n ru

ral,

unre

gula

ted

stre

ams

in W

est V

irgin

ia a

nd a

djac

ent s

tate

s.—

Cont

inue

d

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

N.,

Nor

th; S

., So

uth;

E.,

East

; W.,

Wes

t; R

., R

ight

; Br.,

B

ranc

h; F

k., F

ork;

Cr.,

Cre

ek; T

rib.,

Trib

utar

y; S

pgs.,

Spr

ings

; Rt.,

Rou

te; b

l, be

low

; nr,

near

; U.S

. ske

w, U

nite

d St

ates

skew

, the

skew

pre

sent

ed in

Bul

letin

-17B

by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2); W

V sk

ew, W

est V

irgin

ia sk

ew d

eter

min

ed b

y A

tkin

s and

oth

ers (

2009

); sh

adin

g in

dica

tes t

he 4

4 st

ream

gage

stat

ions

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stre

amga

ge-s

tatio

n na

me

Stat

eW

V sk

ew,

unitl

ess

U.S

. ske

w,

unitl

ess

Diff

eren

ce

betw

een

WV

and

US

skew

s,

unitl

ess

Wei

ghte

d W

V an

d st

atio

n sk

ews,

un

itles

s

Mea

n of

log 10

-tr

ansf

orm

ed

flood

-fre

quen

cy

disc

harg

es,

in c

ubic

feet

per

se

cond

Stan

dard

de

viat

ion

of lo

g 10-

tran

sfor

med

flo

od-f

requ

ency

di

scha

rges

, in

cub

ic fe

et p

er

seco

nd13

603

1100

00Ye

llow

Cre

ek n

ear H

amm

onds

ville

OH

.015

-.025

.040

.391

3.49

7.1

9613

703

1109

80C

onso

l Run

at B

loom

ingd

ale

OH

-.015

-.013

-.002

-.040

.808

.331

138

0311

1150

Bru

sh R

un n

ear B

uffa

loPA

.049

.048

.001

-.110

2.72

1.2

9413

903

1114

50B

rans

on R

un a

t Geo

rget

own

OH

-.034

-.012

-.022

.048

1.76

4.2

9314

003

1114

55So

uth

Fork

Sho

rt C

reek

at G

eorg

etow

nO

H-.0

35-.0

12-.0

23.0

052.

352

.242

141

0311

1470

Littl

e Pi

ney

Fork

at P

arle

ttO

H-.0

19-.0

13-.0

06.1

081.

805

.367

142

0311

1500

Shor

t Cre

ek n

ear D

illon

vale

OH

-.029

.011

-.040

-.130

3.44

8.2

1114

303

1115

40Sl

oan

Run

Trib

utar

y ne

ar H

arris

ville

OH

-.040

-.002

-.038

-.060

1.68

6.5

2014

403

1115

48W

heel

ing

Cre

ek b

elow

Bla

ine

OH

-.045

.016

-.061

.008

3.42

6.2

3914

503

1120

00W

heel

ing

Cre

ek a

t Elm

Gro

veW

V.0

05.0

36-.0

31-.0

403.

955

.205

146

0311

3700

Littl

e G

rave

Cre

ek n

ear G

lend

ale

WV

-.036

.042

-.078

-.070

2.69

3.3

3314

703

1140

00C

aptin

a C

reek

at A

rmst

rong

s Mill

sO

H-.0

66.0

23-.0

89.0

003.

785

.216

148

0311

4240

Woo

d R

un n

ear W

oods

field

OH

-.081

.026

-.107

-.130

1.80

5.3

7714

903

1145

00M

iddl

e Is

land

Cre

ek a

t Litt

leW

V-.1

05.0

79-.1

84.0

904.

132

.132

150

0311

4550

Buf

falo

Run

nea

r Frie

ndly

WV

-.109

.071

-.180

-.250

2.30

7.3

0615

103

1146

00Li

ttle

Buf

falo

Run

nea

r Frie

ndly

WV

-.109

.073

-.182

-.190

2.40

1.2

5815

203

1146

50B

uffa

lo R

un n

ear L

ittle

WV

-.110

.076

-.186

-.340

2.90

5.2

8615

303

1152

80Tr

ail R

un n

ear A

ntio

chO

H-.0

99.0

51-.1

50.2

182.

814

.218

154

0311

5400

Littl

e M

uski

ngum

Riv

er a

t Blo

omfie

ldO

H-.0

91.0

41-.1

32.4

813.

890

.230

155

0311

5410

Gra

ham

Run

nea

r Blo

omfie

ldO

H-.0

99.0

42-.1

41-.2

601.

282

.383

156

0311

5500

Littl

e M

uski

ngum

Riv

er a

t Fay

OH

-.093

.042

-.135

-.010

3.88

6.1

9415

703

1155

10M

oss R

un n

ear W

ingo

ttO

H-.0

95.0

39-.1

34.1

962.

359

.253

158

0311

5600

Bar

ns R

un n

ear S

umm

erfie

ldO

H-.0

59-.0

07-.0

52.0

452.

737

.357

159

0311

5710

Buf

falo

Run

Trib

utar

y ne

ar D

exte

r City

OH

-.057

-.002

-.055

.252

1.64

6.0

8616

003

1506

00Tu

pper

Cre

ek a

t Dev

ola

OH

-.057

.020

-.077

.173

2.15

3.2

3916

103

1514

00Li

ttle

Kan

awha

Riv

er n

ear W

ildca

tW

V.1

81.2

47-.0

66.4

503.

708

.243

162

0315

1500

Littl

e K

anaw

ha R

iver

nea

r Bur

nsvi

lleW

V.1

44.2

27-.0

83-.1

703.

712

.135

Table 1 31Ta

ble

1.

Iden

tifica

tion

num

bers

, sta

tion

num

bers

, stre

amga

ge-s

tatio

n na

mes

, and

ske

w c

oeffi

cien

ts a

nd s

tatis

tics

for t

he 2

90 U

.S. G

eolo

gica

l Sur

vey

stre

amga

ge s

tatio

ns o

n ru

ral,

unre

gula

ted

stre

ams

in W

est V

irgin

ia a

nd a

djac

ent s

tate

s.—

Cont

inue

d

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

N.,

Nor

th; S

., So

uth;

E.,

East

; W.,

Wes

t; R

., R

ight

; Br.,

B

ranc

h; F

k., F

ork;

Cr.,

Cre

ek; T

rib.,

Trib

utar

y; S

pgs.,

Spr

ings

; Rt.,

Rou

te; b

l, be

low

; nr,

near

; U.S

. ske

w, U

nite

d St

ates

skew

, the

skew

pre

sent

ed in

Bul

letin

-17B

by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2); W

V sk

ew, W

est V

irgin

ia sk

ew d

eter

min

ed b

y A

tkin

s and

oth

ers (

2009

); sh

adin

g in

dica

tes t

he 4

4 st

ream

gage

stat

ions

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stre

amga

ge-s

tatio

n na

me

Stat

eW

V sk

ew,

unitl

ess

U.S

. ske

w,

unitl

ess

Diff

eren

ce

betw

een

WV

and

US

skew

s,

unitl

ess

Wei

ghte

d W

V an

d st

atio

n sk

ews,

un

itles

s

Mea

n of

log 10

-tr

ansf

orm

ed

flood

-fre

quen

cy

disc

harg

es,

in c

ubic

feet

per

se

cond

Stan

dard

de

viat

ion

of lo

g 10-

tran

sfor

med

flo

od-f

requ

ency

di

scha

rges

, in

cub

ic fe

et p

er

seco

nd16

303

1520

00Li

ttle

Kan

awha

Riv

er a

t Gle

nvill

eW

V.0

14.1

81-.1

67-.0

103.

986

.149

164

0315

2200

Buc

k R

un n

ear L

eopo

ldW

V-.1

28.1

71-.2

99.0

212.

537

.247

165

0315

2500

Lead

ing

Cre

ek n

ear G

lenv

ille

WV

-.130

.173

-.303

-.300

3.78

3.1

9416

603

1530

00St

eer C

reek

nea

r Gra

ntsv

ille

WV

-.063

.166

-.229

-.260

3.83

8.1

8016

703

1535

00Li

ttle

Kan

awha

Riv

er a

t Gra

ntsv

ille

WV

-.075

.147

-.222

-.270

4.30

1.1

1916

803

1540

00W

. Fk.

Litt

le K

anaw

ha R

iver

at R

ocks

dale

WV

-.097

.141

-.238

-.150

3.88

7.1

7516

903

1542

50Ta

nner

Run

at S

penc

erW

V-.1

18.1

27-.2

45-.0

802.

824

.204

170

0315

4500

Ree

dy C

reek

nea

r Ree

dyW

V-.1

18.0

98-.2

16.0

863.

548

.146

171

0315

5000

Littl

e K

anaw

ha R

iver

at P

ales

tine

WV

-.112

.084

-.196

-.210

4.46

6.1

4117

203

1552

00So

uth

Fork

Hug

hes R

iver

at M

acfa

rlan

WV

-.149

.111

-.260

-.290

3.91

1.1

1917

303

1554

50B

ig Is

land

Run

nea

r Eliz

abet

hW

V-.1

38.0

99-.2

37-.2

402.

865

.246

174

0315

5500

Hug

hes R

iver

at C

isco

WV

-.146

.092

-.238

-.130

4.16

0.1

6417

503

1555

25G

oose

Cre

ek n

ear P

etro

leum

WV

-.130

.086

-.216

.084

3.27

4.2

3117

603

1595

40Sh

ade

Riv

er n

ear C

hest

erO

H.0

51.0

11.0

40.5

653.

579

.182

177

0315

9700

Gra

sslic

k R

un n

ear R

iple

yW

V-.0

77.0

86-.1

63.2

702.

191

.239

178

0317

1500

New

Riv

er a

t Egg

lest

onVA

.370

.412

-.042

.674

4.54

3.2

4617

903

1730

00W

alke

r Cre

ek a

t Ban

eVA

.034

.404

-.370

.005

3.83

3.2

2118

003

1755

00W

olf C

reek

nea

r Nar

row

sVA

-.038

.385

-.423

-.420

3.72

2.2

2818

103

1764

00R

ich

Cre

ek n

ear P

eter

stow

nW

V-.0

44.3

81-.4

25-.1

603.

162

.147

182

0317

6500

New

Riv

er a

t Gle

n Ly

nVA

.307

.378

-.071

.584

4.60

8.2

4418

303

1775

00In

dian

Cre

ek a

t Ind

ian

Mill

sW

V-.0

39.3

66-.4

05-.2

903.

593

.084

184

0317

7700

Blu

esto

ne R

iver

at B

luefi

eld

VA-.0

90.3

43-.4

33-.0

702.

851

.146

185

0317

8500

Cam

p C

reek

nea

r Cam

p C

reek

WV

-.153

.335

-.488

-.240

3.15

3.2

6718

603

1790

00B

lues

tone

Riv

er n

ear P

ipes

tem

WV

-.139

.344

-.483

-.460

3.90

1.2

1718

703

1795

00B

lues

tone

Riv

er a

t Lill

yW

V-.1

40.3

45-.4

85-.1

703.

944

.152

188

0318

0000

New

Riv

er a

t Blu

esto

ne D

amW

V.2

05.3

47-.1

42.5

674.

693

.213

189

0318

0350

W. F

k. G

reen

brie

r Riv

er T

rib. a

t Dur

bin

WV

.635

.357

.278

.553

1.74

1.1

91


ble

1.

Iden

tifica

tion

num

bers

, sta

tion

num

bers

, stre

amga

ge-s

tatio

n na

mes

, and

ske

w c

oeffi

cien

ts a

nd s

tatis

tics

for t

he 2

90 U

.S. G

eolo

gica

l Sur

vey

stre

amga

ge s

tatio

ns o

n ru

ral,

unre

gula

ted

stre

ams

in W

est V

irgin

ia a

nd a

djac

ent s

tate

s.—

Cont

inue

d

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

N.,

Nor

th; S

., So

uth;

E.,

East

; W.,

Wes

t; R

., R

ight

; Br.,

B

ranc

h; F

k., F

ork;

Cr.,

Cre

ek; T

rib.,

Trib

utar

y; S

pgs.,

Spr

ings

; Rt.,

Rou

te; b

l, be

low

; nr,

near

; U.S

. ske

w, U

nite

d St

ates

skew

, the

skew

pre

sent

ed in

Bul

letin

-17B

by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2); W

V sk

ew, W

est V

irgin

ia sk

ew d

eter

min

ed b

y A

tkin

s and

oth

ers (

2009

); sh

adin

g in

dica

tes t

he 4

4 st

ream

gage

stat

ions

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stre

amga

ge-s

tatio

n na

me

Stat

eW

V sk

ew,

unitl

ess

U.S

. ske

w,

unitl

ess

Diff

eren

ce

betw

een

WV

and

US

skew

s,

unitl

ess

Wei

ghte

d W

V an

d st

atio

n sk

ews,

un

itles

s

Mea

n of

log 10

-tr

ansf

orm

ed

flood

-fre

quen

cy

disc

harg

es,

in c

ubic

feet

per

se

cond

Stan

dard

de

viat

ion

of lo

g 10-

tran

sfor

med

flo

od-f

requ

ency

di

scha

rges

, in

cub

ic fe

et p

er

seco

nd19

003

1805

00G

reen

brie

r Riv

er a

t Dur

bin

WV

.728

.359

.369

1.06

83.

687

.210

191

0318

0530

Bru

sh R

un n

ear B

arto

wW

V.6

46.3

70.2

76.3

801.

862

.330

192

0318

0680

Coo

per R

un n

ear G

reen

Ban

kW

V.4

88.3

78.1

10.2

591.

992

.266

193

0318

1900

Mac

k B

utte

rbal

l Hol

low

nea

r Hun

ters

ville

WV

.231

.376

-.145

.043

1.01

9.1

5319

403

1820

00K

napp

Cre

ek a

t Mar

linto

nW

V.1

79.3

67-.1

88.7

283.

708

.163

195

0318

2500

Gre

enbr

ier R

iver

at B

ucke

yeW

V.4

39.3

64.0

75.4

604.

273

.181

196

0318

2700

Ant

hony

Cre

ek n

ear A

ntho

nyW

V.0

49.3

81-.3

32.5

243.

980

.165

197

0318

3000

Seco

nd C

reek

nea

r Sec

ond

Cre

ekW

V-.0

10.3

88-.3

98.0

173.

409

.232

198

0318

3500

Gre

enbr

ier R

iver

at A

lder

son

WV

.110

.364

-.254

-.140

4.52

7.1

6919

903

1835

50G

riffit

h C

reek

nea

r Ald

erso

nW

V-.0

29.3

56-.3

85-.2

702.

441

.130

200

0318

3570

Bug

gar L

ick

at P

ence

Spr

ings

WV

-.041

.361

-.402

.119

2.11

8.2

9620

103

1840

00G

reen

brie

r Riv

er a

t Hill

dale

WV

.090

.356

-.266

.127

4.56

8.1

4820

203

1842

00B

ig C

reek

nea

r Bel

lepo

int

WV

-.058

.352

-.410

.077

2.78

2.3

6120

303

1845

00N

ew R

iver

at H

into

nW

V.0

13.3

44-.3

31.2

064.

898

.212

204

0318

5000

Pine

y C

reek

at R

alei

ghW

V-.1

47.3

05-.4

52.0

703.

091

.235

205

0318

5020

Littl

e B

eave

r Cr.

Trib

. nea

r Sha

dy S

prin

gsW

V-.1

21.3

16-.4

37-.3

101.

472

.328

206

0318

5500

New

Riv

er a

t Cap

erto

nW

V-.0

15.2

93-.3

08-.0

904.

957

.189

207

0318

6000

New

Riv

er a

t Fay

ette

WV

-.016

.281

-.297

-.160

4.97

5.2

1020

803

1865

00W

illia

ms R

iver

at D

yer

WV

.289

.301

-.012

.379

3.91

4.1

8820

903

1870

00G

aule

y R

iver

at C

amde

n on

Gau

ley

WV

.295

.289

.006

.254

4.05

7.1

9121

003

1873

00N

orth

Fk.

Cra

nber

ry R

iver

nea

r Hill

sbor

oW

V.2

44.3

34-.0

90.3

432.

911

.233

211

0318

7500

Cra

nber

ry R

iver

nea

r Ric

hwoo

dW

V.2

38.3

07-.0

69.3

113.

695

.189

212

0318

9000

Che

rry

Riv

er a

t Fen

wic

kW

V.1

75.3

10-.1

35.6

563.

944

.204

213

0318

9100

Gau

ley

Riv

er n

ear C

raig

svill

eW

V.2

43.2

95-.0

52.1

134.

415

.195

214

0318

9500

Gau

ley

Riv

er n

ear S

umm

ersv

ille

WV

.234

.279

-.045

.514

4.39

7.1

7221

503

1896

50C

ollis

on C

reek

nea

r Nal

len

WV

.090

.287

-.197

-.110

2.23

4.2

3121

603

1900

00M

eado

w R

iver

at N

alle

nW

V.0

50.2

96-.2

46.0

363.

779

.149

Table 1 33Ta

ble

1.

Iden

tifica

tion

num

bers

, sta

tion

num

bers

, stre

amga

ge-s

tatio

n na

mes

, and

ske

w c

oeffi

cien

ts a

nd s

tatis

tics

for t

he 2

90 U

.S. G

eolo

gica

l Sur

vey

stre

amga

ge s

tatio

ns o

n ru

ral,

unre

gula

ted

stre

ams

in W

est V

irgin

ia a

nd a

djac

ent s

tate

s.—

Cont

inue

d

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

N.,

Nor

th; S

., So

uth;

E.,

East

; W.,

Wes

t; R

., R

ight

; Br.,

B

ranc

h; F

k., F

ork;

Cr.,

Cre

ek; T

rib.,

Trib

utar

y; S

pgs.,

Spr

ings

; Rt.,

Rou

te; b

l, be

low

; nr,

near

; U.S

. ske

w, U

nite

d St

ates

skew

, the

skew

pre

sent

ed in

Bul

letin

-17B

by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2); W

V sk

ew, W

est V

irgin

ia sk

ew d

eter

min

ed b

y A

tkin

s and

oth

ers (

2009

); sh

adin

g in

dica

tes t

he 4

4 st

ream

gage

stat

ions

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stre

amga

ge-s

tatio

n na

me

Stat

eW

V sk

ew,

unitl

ess

U.S

. ske

w,

unitl

ess

Diff

eren

ce

betw

een

WV

and

US

skew

s,

unitl

ess

Wei

ghte

d W

V an

d st

atio

n sk

ews,

un

itles

s

Mea

n of

log 10

-tr

ansf

orm

ed

flood

-fre

quen

cy

disc

harg

es,

in c

ubic

feet

per

se

cond

Stan

dard

de

viat

ion

of lo

g 10-

tran

sfor

med

flo

od-f

requ

ency

di

scha

rges

, in

cub

ic fe

et p

er

seco

nd21

703

1901

00A

nglin

s Cre

ek n

ear N

alle

nW

V.0

93.2

96-.2

03.2

153.

231

.372

218

0319

0400

Mea

dow

Riv

er n

ear M

ount

Loo

kout

WV

.056

.277

-.221

.276

3.95

8.1

8721

903

1905

00M

eado

w C

reek

nea

r Sum

mer

svill

eW

V.0

78.2

73-.1

95-.1

702.

506

.155

220

0319

1400

Laur

el C

reek

nea

r Sum

mer

svill

eW

V.0

64.2

62-.1

98.0

852.

379

.348

221

0319

1500

Pete

rs C

reek

nea

r Loc

kwoo

dW

V.0

78.2

58-.1

80.1

123.

420

.279

222

0319

2000

Gau

ley

Riv

er a

bove

Bel

vaW

V.1

64.2

42-.0

78.3

194.

624

.158

223

0319

2500

Gau

ley

Riv

er a

t Bel

vaW

V.1

59.2

42-.0

83.2

514.

576

.198

224

0319

3000

Kan

awha

Riv

er a

t Kan

awha

Fal

lsW

V-.0

60.2

53-.3

13-.0

705.

089

.178

225

0319

3725

Littl

e Fo

rk a

t Mos

syW

V-.0

80.2

69-.3

49.1

041.

267

.203

226

0319

3830

Gilm

er R

un n

ear M

arlin

ton

WV

.304

.351

-.047

.621

2.39

3.2

7322

703

1947

00El

k R

iver

bel

ow W

ebst

er S

prin

gsW

V.3

82.2

70.1

12.5

004.

082

.179

228

0319

5000

Elk

Riv

er a

t Cen

tralia

WV

.376

.260

.116

.143

4.04

9.1

0122

903

1951

00R

ight

For

k H

olly

Riv

er a

t Gua

rdia

nW

V.2

74.2

68.0

06.4

783.

395

.187

230

0319

5250

Left

Fork

Hol

ly R

iver

nea

r Rep

lete

WV

.276

.265

.011

.388

3.40

3.1

8723

103

1955

00El

k R

iver

at S

utto

nW

V.3

07.2

35.0

72.2

874.

299

.159

232

0319

5600

Gra

nny

Cre

ek a

t Sut

ton

WV

.062

.233

-.171

.199

2.96

1.1

5923

303

1970

00El

k R

iver

at Q

ueen

Sho

als

WV

.176

.191

-.015

.418

4.44

6.1

5423

403

1971

50A

shle

ycam

p R

un n

ear L

eft H

and

WV

-.080

.174

-.254

.029

2.34

7.1

7523

503

1979

00El

k Tw

omile

Cre

ek T

rib. n

ear C

harle

ston

WV

-.077

.179

-.256

.060

1.84

0.2

5123

603

1983

50C

lear

For

k at

Whi

tesv

ille

WV

-.119

.241

-.360

.096

3.33

2.3

9123

703

1984

50D

raw

dy C

reek

nea

r Pey

tona

WV

-.110

.196

-.306

.263

2.57

1.2

7523

803

1985

00B

ig C

oal R

iver

at A

shfo

rdW

V-.1

29.1

84-.3

13.0

884.

021

.232

239

0319

8780

Hun

ters

Bra

nch

near

Mad

ison

WV

-.133

.201

-.334

-.120

2.08

1.2

5624

003

1988

00Lo

w G

ap C

reek

nea

r Mad

ison

WV

-.126

.195

-.321

-.230

1.86

4.4

3624

103

1990

00Li

ttle

Coa

l Riv

er a

t Dan

ville

WV

-.159

.186

-.345

-.070

3.96

5.2

7324

203

1993

00R

ock

Cre

ek n

ear D

anvi

lleW

V-.1

13.1

83-.2

96-.2

602.

622

.305

243

0319

9400

Littl

e C

oal R

iver

at J

ulia

nW

V-.1

50.1

71-.3

21.1

054.

006

.241


ble

1.

Iden

tifica

tion

num

bers

, sta

tion

num

bers

, stre

amga

ge-s

tatio

n na

mes

, and

ske

w c

oeffi

cien

ts a

nd s

tatis

tics

for t

he 2

90 U

.S. G

eolo

gica

l Sur

vey

stre

amga

ge s

tatio

ns o

n ru

ral,

unre

gula

ted

stre

ams

in W

est V

irgin

ia a

nd a

djac

ent s

tate

s.—

Cont

inue

d

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

N.,

Nor

th; S

., So

uth;

E.,

East

; W.,

Wes

t; R

., R

ight

; Br.,

B

ranc

h; F

k., F

ork;

Cr.,

Cre

ek; T

rib.,

Trib

utar

y; S

pgs.,

Spr

ings

; Rt.,

Rou

te; b

l, be

low

; nr,

near

; U.S

. ske

w, U

nite

d St

ates

skew

, the

skew

pre

sent

ed in

Bul

letin

-17B

by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2); W

V sk

ew, W

est V

irgin

ia sk

ew d

eter

min

ed b

y A

tkin

s and

oth

ers (

2009

); sh

adin

g in

dica

tes t

he 4

4 st

ream

gage

stat

ions

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stre

amga

ge-s

tatio

n na

me

Stat

eW

V sk

ew,

unitl

ess

U.S

. ske

w,

unitl

ess

Diff

eren

ce

betw

een

WV

and

US

skew

s,

unitl

ess

Wei

ghte

d W

V an

d st

atio

n sk

ews,

un

itles

s

Mea

n of

log 10

-tr

ansf

orm

ed

flood

-fre

quen

cy

disc

harg

es,

in c

ubic

feet

per

se

cond

Stan

dard

de

viat

ion

of lo

g 10-

tran

sfor

med

flo

od-f

requ

ency

di

scha

rges

, in

cub

ic fe

et p

er

seco

nd24

403

2005

00C

oal R

iver

at T

orna

doW

V-.1

33.1

40-.2

73-.2

904.

300

.174

245

0320

0600

Littl

e Sc

ary

Cre

ek n

ear N

itro

WV

-.058

.118

-.176

.049

1.92

6.2

2824

603

2010

00Po

cata

lico

Riv

er a

t Sis

sonv

ille

WV

-.099

.135

-.234

-.140

3.82

6.1

8924

703

2014

05H

urric

ane

Cre

ek a

t Hur

rican

eW

V-.0

35.0

99-.1

34-.1

803.

317

.183

248

0320

1410

Popl

ar F

ork

at T

eays

WV

-.045

.108

-.153

-.040

2.95

5.1

7924

903

2014

20Lo

ng B

ranc

h ne

ar T

eays

WV

-.040

.103

-.143

-.300

2.40

6.1

5525

003

2014

40Si

xtee

nmile

Cre

ek n

ear P

liny

WV

.007

.058

-.051

.302

2.49

0.2

2925

103

2014

80Th

reem

ile C

reek

Trib

. nea

r Poi

nt P

leas

ant

WV

.047

.019

.028

-.220

2.11

1.3

2325

203

2020

00R

acco

on C

reek

at A

dam

svill

eO

H.2

00-.0

17.2

17.3

083.

790

.191

253

0320

2245

Mar

sh F

ork

at M

aben

WV

-.202

.290

-.492

.171

2.66

7.2

3925

403

2024

00G

uyan

dotte

Riv

er n

ear B

aile

ysvi

lleW

V-.2

01.2

65-.4

66-.0

303.

911

.343

255

0320

2480

Brie

r Cre

ek a

t Fan

rock

WV

-.225

.268

-.493

-.310

2.54

1.3

6525

603

2027

50C

lear

For

k at

Cle

ar F

ork

WV

-.216

.255

-.471

.042

3.63

8.2

0025

703

2030

00G

uyan

dotte

Riv

er a

t Man

WV

-.227

.223

-.450

-.340

4.29

4.2

1725

803

2036

00G

uyan

dotte

Riv

er a

t Log

anW

V-.2

28.2

00-.4

28-.4

004.

380

.252

259

0320

4000

Guy

ando

tte R

iver

at B

ranc

hlan

dW

V-.2

15.1

07-.3

22-.4

804.

345

.201

260

0320

4500

Mud

Riv

er n

ear M

ilton

WV

-.052

.093

-.145

.250

3.80

8.2

2926

103

2059

95Sa

ndus

ky C

reek

nea

r Bur

lingt

onO

H.1

63.0

30.1

33.3

352.

066

.217

262

0320

6450

Four

pole

Cre

ek n

ear H

untin

gton

WV

.091

.055

.036

-.100

2.82

6.3

3726

303

2066

00Ea

st F

ork

Twel

vepo

le C

reek

nea

r Dun

low

WV

-.050

.124

-.174

-.160

3.24

4.1

9526

403

2068

00E.

Fk.

Tw

elve

pole

Cre

ek n

ear E

ast L

ynn

WV

-.017

.088

-.105

.199

3.53

6.1

8326

503

2070

00Tw

elve

pole

Cre

ek a

t Way

neW

V.0

05.0

68-.0

63.0

003.

811

.228

266

0320

7020

Twel

vepo

le C

reek

bel

ow W

ayne

WV

.008

.066

-.058

-.020

3.81

0.2

2426

703

2074

00Pr

ater

Cre

ek a

t Vas

ant

VA-.1

06.2

51-.3

57-.1

902.

922

.448

268

0320

7500

Levi

sa F

ork

near

Gru

ndy

VA-.1

31.2

38-.3

69-.3

903.

955

.277

269

0320

7800

Levi

sa F

ork

at B

ig R

ock

VA-.1

33.2

21-.3

54.0

003.

946

.323

270

0320

7962

Dic

ks F

ork

at P

hylli

sK

Y-.0

69.1

87-.2

56-.1

801.

796

.369

Table 1 35Ta

ble

1.

Iden

tifica

tion

num

bers

, sta

tion

num

bers

, stre

amga

ge-s

tatio

n na

mes

, and

ske

w c

oeffi

cien

ts a

nd s

tatis

tics

for t

he 2

90 U

.S. G

eolo

gica

l Sur

vey

stre

amga

ge s

tatio

ns o

n ru

ral,

unre

gula

ted

stre

ams

in W

est V

irgin

ia a

nd a

djac

ent s

tate

s.—

Cont

inue

d

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

N.,

Nor

th; S

., So

uth;

E.,

East

; W.,

Wes

t; R

., R

ight

; Br.,

B

ranc

h; F

k., F

ork;

Cr.,

Cre

ek; T

rib.,

Trib

utar

y; S

pgs.,

Spr

ings

; Rt.,

Rou

te; b

l, be

low

; nr,

near

; U.S

. ske

w, U

nite

d St

ates

skew

, the

skew

pre

sent

ed in

Bul

letin

-17B

by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2); W

V sk

ew, W

est V

irgin

ia sk

ew d

eter

min

ed b

y A

tkin

s and

oth

ers (

2009

); sh

adin

g in

dica

tes t

he 4

4 st

ream

gage

stat

ions

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stre

amga

ge-s

tatio

n na

me

Stat

eW

V sk

ew,

unitl

ess

U.S

. ske

w,

unitl

ess

Diff

eren

ce

betw

een

WV

and

US

skew

s,

unitl

ess

Wei

ghte

d W

V an

d st

atio

n sk

ews,

un

itles

s

Mea

n of

log 10

-tr

ansf

orm

ed

flood

-fre

quen

cy

disc

harg

es,

in c

ubic

feet

per

se

cond

Stan

dard

de

viat

ion

of lo

g 10-

tran

sfor

med

flo

od-f

requ

ency

di

scha

rges

, in

cub

ic fe

et p

er

seco

nd27

103

2080

00Le

visa

For

k be

low

Fis

htra

p D

amK

Y-.1

31.1

78-.3

09-.1

304.

076

.216

272

0320

8500

Rus

sel F

ork

at H

aysi

VA-.0

58.2

23-.2

81-.2

404.

099

.295

273

0320

8950

Cra

nes N

est R

iver

nea

r Clin

twoo

dVA

.034

.213

-.179

.189

3.40

2.3

0527

403

2090

00Po

nd R

. blw

. Fla

nnag

an D

am n

ear H

aysi

VA.0

27.2

13-.1

86-.1

003.

970

.236

275

0320

9575

Bill

D. B

ranc

h ne

ar K

iteK

Y.1

32.1

31.0

01.4

302.

464

.203

276

0321

0000

John

s Cre

k ne

ar M

eta

KY

-.064

.153

-.217

-.420

3.39

6.2

4727

703

2115

00Jo

hns C

reek

nea

r Van

Lea

rK

Y.0

03.0

85-.0

82-.1

103.

627

.227

278

0321

2000

Pain

t Cre

ek a

t Sta

fford

svill

eK

Y.2

98.0

47.2

51-.1

703.

706

.303

279

0321

2750

Tug

Fork

at W

elch

WV

-.183

.287

-.470

-.060

3.49

0.3

3628

003

2129

80D

ry F

ork

at B

earto

wn

WV

-.154

.269

-.423

-.310

3.71

8.2

5228

103

2130

00Tu

g Fo

rk a

t Litw

arW

V-.1

83.2

55-.4

38-.2

504.

081

.261

282

0321

3500

Pant

her C

reek

nea

r Pan

ther

WV

-.177

.256

-.433

-.150

3.20

5.3

8528

303

2137

00Tu

g Fo

rk a

t Will

iam

son

WV

-.191

.169

-.360

.043

4.24

2.2

6828

403

2140

00Tu

g Fo

rk n

ear K

erm

itW

V-.1

86.1

33-.3

19-.0

504.

380

.281

285

0321

4500

Tug

Fork

at K

erm

itW

V-.1

80.1

27-.3

07-.1

304.

366

.268

286

0321

4900

Tug

Fork

at G

lenh

ayes

WV

-.165

.087

-.252

-.040

4.27

5.2

4128

703

2155

00B

lain

e C

reek

at Y

ates

ville

KY

.268

.039

.229

.116

3.78

4.2

1928

803

2165

00Li

ttle

Sand

y R

iver

at G

rays

onK

Y.3

70-.0

24.3

94.2

704.

007

.178

289

0321

6540

E. F

k. L

ittle

San

dy R

iver

nea

r Fal

lsbu

rgK

Y.2

58.0

24.2

34.2

492.

975

.168

290

0321

6563

Mile

Bra

nch

near

Rus

hK

Y.2

86-.0

06.2

92.0

882.

280

.185


ble

2.

Floo

d-fre

quen

cy s

tatis

tics

and

drai

nage

are

as fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t st

ates

.—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

- -,

no v

alue

; sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eD

rain

age

area

, in

squ

are

mile

s

Wat

er y

ears

bo

undi

ng

syst

emat

ic

peak

s

Num

ber o

f yea

rs o

f re

cord

Ove

rrid

e of

out

lier t

hres

hold

sN

umbe

r of p

eaks

Tren

d an

alys

is

Syst

emat

icH

isto

ric

Hig

h th

resh

old

disc

harg

e, in

cu

bic

feet

per

se

cond

Low

thre

shol

d di

scha

rge,

in

cubi

c fe

et p

er

seco

nd

Hig

h ou

tlier

Low

ou

tlier

Kend

all’s

ta

uSi

gnifi

canc

e

leve

l

101

5950

00M

D73

.119

55–2

006

52--

----

----

-0.1

300.

175

201

5953

00W

V42

.619

55–1

982

2783

----

1--

-.239

.083

301

5955

00M

D22

519

50–2

006

56--

----

1--

.071

.445

401

5960

00M

D28

719

24–1

950

25--

----

----

-.093

.528

501

5965

00M

D49

.119

49–2

006

58--

----

1--

-.056

.537

601

5970

00M

D16

.719

49–1

981

33--

----

1--

-.030

.816

701

5980

00M

D11

519

25–1

950

24--

----

----

-.007

.980

801

5990

00M

D72

.419

31–2

007

77--

----

----

-.081

.301

901

5995

00W

V46

.519

48–1

969

21--

----

----

-.100

.546

1001

6000

00M

D59

819

36–1

950

15--

----

----

-.495

.012

1101

6015

00M

D24

719

30–2

006

77--

----

2--

.107

.169

1201

6030

00M

D87

719

30–1

981

52--

----

1--

-.088

.360

1301

6045

00W

V22

119

39–2

007

69--

----

----

-.231

.005

1401

6055

00W

V17

919

36–2

007

6113

0--

----

--.1

04.2

3715

0160

5700

WV

0.23

1965

–197

713

----

----

--.4

62.0

3316

0160

6000

WV

310

1940

–200

750

130

----

1--

.065

.509

1701

6065

00W

V65

119

24–2

007

8013

0--

--3

--.0

75.3

2518

0160

6800

WV

1.56

1965

–197

713

----

----

--.3

08.1

6119

0160

7500

WV

103

1944

–200

764

130

----

2--

-.187

.030

2001

6075

10W

V1.

0419

99–2

007

9--

----

----

-.143

.711

2101

6080

00W

V27

719

24–2

007

7813

0--

--1

---.0

92.2

3522

0160

8100

WV

0.21

1965

–197

713

----

----

--.5

13.0

1723

0160

8500

WV

1,46

119

00–2

007

8413

0--

--3

--.0

46.5

3624

0160

9000

MD

148

1928

–200

526

----

----

---.0

52.7

2425

0160

9500

MD

5.08

1948

–197

625

----

----

1.0

33.8

3326

0160

9650

WV

28.9

1999

–200

79

----

----

--.0

001.

000

2701

6098

00W

V10

819

67–1

977

11--

----

----

.309

.213

2801

6100

00W

V3,

114

1939

–200

668

----

--1

----

--29

0161

0150

MD

10.4

1965

–198

318

----

----

--.0

46.8

20

Table 2 37Ta

ble

2.

Floo

d-fre

quen

cy s

tatis

tics

and

drai

nage

are

as fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t st

ates

.—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

- -,

no v

alue

; sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eD

rain

age

area

, in

squ

are

mile

s

Wat

er y

ears

bo

undi

ng

syst

emat

ic

peak

s

Num

ber o

f yea

rs o

f re

cord

Ove

rrid

e of

out

lier t

hres

hold

sN

umbe

r of p

eaks

Tren

d an

alys

is

Syst

emat

icH

isto

ric

Hig

h th

resh

old

disc

harg

e, in

cu

bic

feet

per

se

cond

Low

thre

shol

d di

scha

rge,

in

cubi

c fe

et p

er

seco

nd

Hig

h ou

tlier

Low

ou

tlier

Kend

all’s

ta

uSi

gnifi

canc

e

leve

l

3001

6101

55M

D10

219

68–2

006

18--

----

----

-.033

.880

3101

6105

00W

V30

619

36–1

951

1467

36,0

00--

1--

-.143

.511

3201

6115

00W

V67

519

23–2

007

8411

9--

--1

---.0

18.8

0833

0161

2500

MD

16.9

1948

–196

417

----

----

---.0

15.9

6734

0161

3000

MD

4,07

519

29–2

006

75--

----

1--

----

3501

6131

50M

D4.

8019

65–1

986

22--

----

----

-.013

.955

3601

6131

60M

D1.

2019

65–1

976

12--

----

1--

.089

.788

3701

6139

00VA

15.9

1961

–200

646

----

----

1.0

48.6

4338

0161

4000

WV

235

1929

–200

751

----

----

1.0

36.7

1539

0161

5000

VA58

.219

44–2

006

58--

----

----

.194

.032

4001

6160

00VA

17.0

1950

–199

427

----

----

--.3

96.0

0441

0161

6500

WV

273

1948

–200

760

----

----

--.1

70.0

5642

0161

7000

WV

11.3

1949

–200

726

----

----

1--

--43

0161

7800

MD

18.9

1964

–200

743

----

----

----

--44

0161

8000

MD

5,95

019

29–2

004

69--

----

--1

----

4501

6194

75M

D0.

1019

66–1

976

11--

----

----

----

4601

6195

00M

D28

119

28–2

007

80--

----

--1

----

4701

6205

00VA

17.3

1947

–200

660

----

----

----

--48

0162

1000

VA73

.019

43–1

986

3155

----

1--

-.077

.552

4901

6212

00VA

9.73

1949

–197

628

----

----

--.0

63.6

6150

0162

1400

VA5.

4419

49–1

961

1340

----

1--

-.282

.200

5101

6214

50VA

0.67

1966

–197

510

25--

--1

--.1

56.5

9252

0162

2000

VA37

519

27–2

006

7714

6--

--5

---.0

80.3

0553

0162

2100

VA1.

5619

66–1

975

10--

----

----

.511

.049

5401

6223

00VA

0.54

1967

–197

610

----

----

----

--55

0162

2400

VA0.

4619

67–2

000

32--

----

----

----

5601

6320

00VA

210

1926

–200

681

172

----

12--

.085

.262

5701

6323

00VA

7.94

1950

–197

725

----

--1

--.0

51.7

4758

0163

2900

VA93

.619

61–2

006

45--

----

----

.043

.681


ble

2.

Floo

d-fre

quen

cy s

tatis

tics

and

drai

nage

are

as fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t st

ates

.—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

- -,

no v

alue

; sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eD

rain

age

area

, in

squ

are

mile

s

Wat

er y

ears

bo

undi

ng

syst

emat

ic

peak

s

Num

ber o

f yea

rs o

f re

cord

Ove

rrid

e of

out

lier t

hres

hold

sN

umbe

r of p

eaks

Tren

d an

alys

is

Syst

emat

icH

isto

ric

Hig

h th

resh

old

disc

harg

e, in

cu

bic

feet

per

se

cond

Low

thre

shol

d di

scha

rge,

in

cubi

c fe

et p

er

seco

nd

Hig

h ou

tlier

Low

ou

tlier

Kend

all’s

ta

uSi

gnifi

canc

e

leve

l

5901

6329

50VA

0.34

1966

–197

510

----

----

--.5

33.0

3960

0163

2970

VA6.

6019

72–2

006

35--

----

----

-.166

.173

6101

6330

00VA

508

1944

–200

662

172

----

1--

.124

.157

6201

6335

00VA

77.5

1947

–197

630

69--

----

--.0

74.5

8663

0163

3650

VA3.

4319

71–2

006

36--

----

1--

-.178

.130

6401

6340

00VA

770

1926

–200

680

138

----

1--

.053

.488

6501

6345

00VA

102

1938

–200

669

----

----

1.2

11.0

1066

0163

6500

WV

3,04

118

96–2

007

9013

8--

--4

----

--67

0163

7000

MD

8.83

1948

–197

629

----

----

----

--68

0163

7500

MD

66.9

1948

–200

659

----

----

----

--69

0163

8480

VA89

.619

71–2

006

36--

----

----

----

7001

6385

00M

D9,

651

1895

–200

711

3--

----

----

----

7101

6437

00VA

122

1966

–200

634

----

----

---.0

16.9

0672

0164

4000

VA33

219

10–2

006

7911

9--

--2

--.0

96.2

1373

0164

4100

VA2.

0619

66–1

977

12--

----

----

----

7402

0095

00VA

0.68

1966

–197

510

----

----

1--

--75

0201

1400

VA15

719

72–2

006

3491

----

1--

----

7602

0114

60VA

60.9

1975

–200

632

91--

--1

----

--77

0201

1480

VA88

.619

74–1

984

11--

----

----

-.345

.161

7802

0115

00VA

134

1951

–198

434

----

----

--.1

05.3

8979

0201

2500

VA41

019

25–1

979

5575

----

--1

.238

.010

8002

0129

50VA

0.86

1966

–199

526

----

----

---.2

17.2

5981

0201

3000

VA16

219

29–2

006

78--

----

----

.104

.180

8202

0140

00VA

153

1929

–200

668

----

----

1.1

14.1

7283

0305

0000

WV

185

1916

–200

780

----

----

--.1

66.0

3084

0305

0500

WV

271

1945

–200

460

120

----

1--

.112

.209

8503

0506

50W

V0.

4619

64–2

006

22--

----

11

-.104

.516

8603

0510

00W

V40

619

08–2

007

100

120

----

2--

.044

.516

8703

0515

00W

V12

219

16–1

942

2712

0--

----

--.1

57.2

60

Table 2 39Ta

ble

2.

Floo

d-fre

quen

cy s

tatis

tics

and

drai

nage

are

as fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t st

ates

.—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

- -,

no v

alue

; sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eD

rain

age

area

, in

squ

are

mile

s

Wat

er y

ears

bo

undi

ng

syst

emat

ic

peak

s

Num

ber o

f yea

rs o

f re

cord

Ove

rrid

e of

out

lier t

hres

hold

sN

umbe

r of p

eaks

Tren

d an

alys

is

Syst

emat

icH

isto

ric

Hig

h th

resh

old

disc

harg

e, in

cu

bic

feet

per

se

cond

Low

thre

shol

d di

scha

rge,

in

cubi

c fe

et p

er

seco

nd

Hig

h ou

tlier

Low

ou

tlier

Kend

all’s

ta

uSi

gnifi

canc

e

leve

l

8803

0520

00W

V14

819

43–2

007

5612

0--

----

--.1

53.0

9789

0305

2340

WV

2.33

1966

–200

719

----

----

---.1

35.4

4190

0305

2500

WV

14.3

1947

–200

761

----

----

--.1

21.1

6991

0305

3500

WV

277

1908

–200

793

----

----

--.0

00.9

9792

0305

4500

WV

914

1941

–200

767

120

60,0

00--

1--

.151

.072

9303

0550

20W

V0.

6019

66–1

977

12--

----

----

-.091

.730

9403

0550

40W

V3.

1519

64–1

977

14--

----

----

-.121

.584

9503

0562

50W

V96

.819

85–2

007

23--

----

----

.032

.853

9603

0565

00W

V1,

304

1908

–193

831

----

----

---.0

26.8

5297

0305

6600

WV

2.33

1965

–197

713

----

----

--.0

77.7

6098

0305

7300

WV

28.8

1985

–199

915

----

----

--.1

43.4

8899

0305

7500

WV

25.7

1946

–198

540

----

----

---.0

72.5

2110

003

0580

00W

V10

119

47–1

989

4310

2--

--1

---.1

28.2

2910

103

0585

00W

V18

119

16–1

989

74--

----

----

-.123

.124

102

0305

9000

WV

384

1924

–198

360

102

----

----

-.016

.858

103

0305

9500

WV

84.6

1944

–197

027

----

----

---.0

77.5

8810

403

0605

00W

V8.

3219

52–1

969

18--

----

----

.013

.970

105

0306

1000

WV

759

1908

–198

965

----

----

---.0

02.9

8610

603

0615

00W

V11

619

16–2

007

83--

----

----

-.013

.863

107

0306

2400

WV

11.0

1966

–200

237

42--

--1

---.1

88.1

0510

803

0625

00W

V63

.219

47–2

007

36--

----

----

-.159

.178

109

0306

3950

WV

1.08

1965

–197

712

----

--1

--.0

30.9

4511

003

0650

00W

V34

919

41–2

007

6712

0--

--1

--.1

32.1

1711

103

0654

00W

V54

.719

92–2

007

12--

----

----

-.121

.631

112

0306

6000

WV

85.9

1922

–200

786

----

--1

--.1

11.1

3311

303

0671

00W

V0.

1519

52–2

006

55--

----

----

-.070

.455

114

0306

7500

WV

57.6

1922

–200

721

----

----

1.3

29.0

4011

503

0686

10W

V5.

0619

74–1

998

16--

----

----

.117

.558

116

0306

8800

WV

151

1974

–200

718

----

----

--.1

37.4

49


ble

2.

Floo

d-fre

quen

cy s

tatis

tics

and

drai

nage

are

as fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t st

ates

.—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

- -,

no v

alue

; sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eD

rain

age

area

, in

squ

are

mile

s

Wat

er y

ears

bo

undi

ng

syst

emat

ic

peak

s

Num

ber o

f yea

rs o

f re

cord

Ove

rrid

e of

out

lier t

hres

hold

sN

umbe

r of p

eaks

Tren

d an

alys

is

Syst

emat

icH

isto

ric

Hig

h th

resh

old

disc

harg

e, in

cu

bic

feet

per

se

cond

Low

thre

shol

d di

scha

rge,

in

cubi

c fe

et p

er

seco

nd

Hig

h ou

tlier

Low

ou

tlier

Kend

all’s

ta

uSi

gnifi

canc

e

leve

l

117

0306

9000

WV

213

1911

–200

174

----

--1

--.0

52.5

1311

803

0695

00W

V72

219

14–2

007

9416

4--

--4

--.1

60.0

2311

903

0698

50W

V0.

9519

66–1

977

12--

----

1--

-.030

.945

120

0306

9880

WV

12.2

1968

–200

724

----

----

---.3

55.0

1612

103

0700

00W

V93

919

21–1

996

7416

4--

--2

--.1

80.0

2412

203

0705

00W

V20

019

10–2

007

93--

----

1--

-.041

.564

123

0307

1000

WV

1,35

419

03–1

958

4714

2--

----

---.0

04.9

7812

403

0715

00W

V1,

380

1903

–192

616

142

----

----

----

125

0307

2000

PA22

919

41–2

006

66--

----

----

.007

.943

126

0307

2590

PA16

.319

64–1

978

15--

----

----

.067

.767

127

0307

5450

MD

0.57

1965

–197

612

----

----

----

--12

803

0755

00M

D13

419

36–2

006

65--

----

----

----

129

0307

5600

MD

0.53

1965

–198

622

----

--1

----

--13

003

0765

05M

D0.

2219

65–1

976

12--

----

----

----

131

0307

6600

MD

48.9

1965

–200

743

----

----

----

--13

203

0855

00PA

257

1916

–200

684

----

--1

--.0

78.2

9513

303

1080

00PA

178

1916

–200

680

----

--1

---.1

55.0

4213

403

1090

00O

H6.

1919

47–1

981

35--

----

----

-.032

.798

135

0310

9500

OH

496

1916

–200

691

----

----

---.1

41.0

4913

603

1100

00O

H14

719

41–2

006

66--

----

----

-.189

.025

137

0311

0980

OH

0.04

1978

–198

710

----

----

----

--13

803

1111

50PA

10.3

1961

–198

521

----

----

----

--13

903

1114

50O

H1.

3119

78–1

990

11--

----

----

-.200

.474

140

0311

1455

OH

10.9

1978

–199

011

----

----

----

--14

103

1114

70O

H1.

5719

78–1

987

10--

----

----

----

142

0311

1500

OH

123

1942

–200

665

----

----

1--

--14

303

1115

40O

H0.

3419

78–1

987

10--

----

----

----

144

0311

1548

OH

97.7

1983

–200

623

----

----

--.1

46.3

4214

503

1120

00W

V28

119

41–1

974

34--

----

----

-.037

.767

Table 2 41Ta

ble

2.

Floo

d-fre

quen

cy s

tatis

tics

and

drai

nage

are

as fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t st

ates

.—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

- -,

no v

alue

; sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eD

rain

age

area

, in

squ

are

mile

s

Wat

er y

ears

bo

undi

ng

syst

emat

ic

peak

s

Num

ber o

f yea

rs o

f re

cord

Ove

rrid

e of

out

lier t

hres

hold

sN

umbe

r of p

eaks

Tren

d an

alys

is

Syst

emat

icH

isto

ric

Hig

h th

resh

old

disc

harg

e, in

cu

bic

feet

per

se

cond

Low

thre

shol

d di

scha

rge,

in

cubi

c fe

et p

er

seco

nd

Hig

h ou

tlier

Low

ou

tlier

Kend

all’s

ta

uSi

gnifi

canc

e

leve

l

146

0311

3700

WV

4.95

1970

–199

612

----

----

---.1

82.4

5114

703

1140

00O

H13

419

27–2

002

53--

----

----

.009

.933

148

0311

4240

OH

0.53

1978

–198

710

----

----

---.3

33.2

1014

903

1145

00W

V45

819

16–1

997

78--

----

----

.095

.219

150

0311

4550

WV

0.88

1966

–197

712

----

----

--.2

12.3

7315

103

1146

00W

V1.

2219

67–1

977

11--

----

----

-.018

1.00

015

203

1146

50W

V4.

1919

69–2

007

23--

----

--1

.079

.616

153

0311

5280

OH

5.45

1978

–198

710

----

--1

---.0

221.

000

154

0311

5400

OH

210

1959

–200

634

95--

--1

--.0

66.5

9415

503

1154

10O

H0.

1319

78–1

987

10--

----

----

-.071

.902

156

0311

5500

OH

258

1916

–193

520

----

----

--.0

26.8

9715

703

1155

10O

H1.

5219

78–1

987

10--

----

1--

.444

.118

158

0311

5600

OH

3.46

1947

–197

933

----

----

----

--15

903

1157

10O

H0.

1919

78–1

987

10--

----

1--

----

160

0315

0600

OH

0.99

1966

–198

015

----

----

---.2

38.2

3516

103

1514

00W

V11

219

75–2

007

31--

----

----

.024

.865

162

0315

1500

WV

155

1939

–197

335

----

----

--.0

45.7

1216

303

1520

00W

V38

719

29–1

979

51--

----

----

-.045

.649

164

0315

2200

WV

2.91

1970

–200

621

----

----

--.1

24.4

5016

503

1525

00W

V14

419

38–1

951

14--

----

----

.462

.025

166

0315

3000

WV

166

1939

–197

537

----

----

1.0

87.4

5616

703

1535

00W

V91

319

29–1

979

51--

----

----

.067

.490

168

0315

4000

WV

205

1929

–200

066

----

----

---.1

29.1

2716

903

1542

50W

V2.

8219

70–1

998

13--

----

----

.179

.428

170

0315

4500

WV

79.4

1952

–197

827

51--

--4

--.2

17.1

1817

103

1550

00W

V1,

516

1939

–197

941

----

----

1.0

57.6

0517

203

1552

00W

V21

019

38–1

951

14--

----

----

.330

.112

173

0315

5450

WV

3.52

1965

–199

817

----

----

--.2

06.2

6617

403

1555

00W

V45

319

30–1

997

59--

----

----

-.049

.592


ble

2.

Floo

d-fre

quen

cy s

tatis

tics

and

drai

nage

are

as fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t st

ates

.—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

- -,

no v

alue

; sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eD

rain

age

area

, in

squ

are

mile

s

Wat

er y

ears

bo

undi

ng

syst

emat

ic

peak

s

Num

ber o

f yea

rs o

f re

cord

Ove

rrid

e of

out

lier t

hres

hold

sN

umbe

r of p

eaks

Tren

d an

alys

is

Syst

emat

icH

isto

ric

Hig

h th

resh

old

disc

harg

e, in

cu

bic

feet

per

se

cond

Low

thre

shol

d di

scha

rge,

in

cubi

c fe

et p

er

seco

nd

Hig

h ou

tlier

Low

ou

tlier

Kend

all’s

ta

uSi

gnifi

canc

e

leve

l

175

0315

5525

WV

25.3

1998

–200

710

----

----

---.2

89.2

8317

603

1595

40O

H15

619

66–2

006

41--

----

11

-.029

.796

177

0315

9700

WV

0.70

1965

–197

713

----

--1

---.1

41.5

4117

803

1715

00VA

2,96

119

15–1

939

25--

----

1--

----

179

0317

3000

VA29

919

38–2

006

69--

----

----

-.044

.594

180

0317

5500

VA22

319

09–2

006

77--

----

----

-.027

.735

181

0317

6400

WV

50.6

1942

–195

110

----

----

--.1

56.5

8918

203

1765

00VA

3,78

319

15–1

938

24--

----

1--

----

183

0317

7500

WV

189

1942

–195

110

----

----

1.1

78.5

3018

403

1777

00VA

39.7

1966

–198

015

----

----

1.3

33.0

9218

503

1785

00W

V32

.019

47–1

998

2956

5,00

0--

1--

.005

.985

186

0317

9000

WV

395

1951

–200

757

----

----

1.0

70.4

4518

703

1795

00W

V43

819

09–1

948

27--

----

----

.217

.118

188

0318

0000

WV

4,60

219

24–1

948

25--

----

1--

----

189

0318

0350

WV

1.13

1966

–197

712

----

----

--.1

67.4

9219

003

1805

00W

V13

319

44–2

007

6411

2--

--2

--.1

18.1

7119

103

1805

30W

V1.

2819

66–1

977

11--

----

----

.236

.350

192

0318

0680

WV

1.52

1965

–197

713

----

----

--.2

05.3

6019

303

1819

00W

V0.

1019

65–1

977

13--

----

--1

-.167

.459

194

0318

2000

WV

108

1946

–199

819

9021

,000

--1

--.1

35.4

4119

503

1825

00W

V54

019

30–2

007

7811

2--

--1

--.1

38.0

7519

603

1827

00W

V14

419

72–1

982

1190

----

----

-.309

.213

197

0318

3000

WV

80.8

1946

–199

830

----

----

--.1

52.2

4619

803

1835

00W

V1,

364

1896

–200

711

2--

----

----

-.031

.635

199

0318

3550

WV

3.84

1966

–197

712

----

----

1.1

36.5

8220

003

1835

70W

V2.

3119

66–1

977

12--

----

----

.076

.783

201

0318

4000

WV

1,61

919

36–2

007

72--

----

----

.047

.563

202

0318

4200

WV

8.27

1970

–200

717

----

----

1-.1

91.3

0320

303

1845

00W

V6,

256

1937

–194

812

----

--1

----

--

Table 2 43Ta

ble

2.

Floo

d-fre

quen

cy s

tatis

tics

and

drai

nage

are

as fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t st

ates

.—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

- -,

no v

alue

; sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eD

rain

age

area

, in

squ

are

mile

s

Wat

er y

ears

bo

undi

ng

syst

emat

ic

peak

s

Num

ber o

f yea

rs o

f re

cord

Ove

rrid

e of

out

lier t

hres

hold

sN

umbe

r of p

eaks

Tren

d an

alys

is

Syst

emat

icH

isto

ric

Hig

h th

resh

old

disc

harg

e, in

cu

bic

feet

per

se

cond

Low

thre

shol

d di

scha

rge,

in

cubi

c fe

et p

er

seco

nd

Hig

h ou

tlier

Low

ou

tlier

Kend

all’s

ta

uSi

gnifi

canc

e

leve

l

204

0318

5000

WV

52.7

1952

–200

736

----

----

--.0

21.8

7020

503

1850

20W

V0.

6219

66–1

977

12--

----

----

.167

.492

206

0318

5500

WV

6,82

619

29–1

948

20--

----

----

----

207

0318

6000

WV

6,85

018

96–1

948

3563

----

----

----

208

0318

6500

WV

128

1930

–200

778

----

----

--.1

21.1

1720

903

1870

00W

V23

619

09–2

000

7710

642

,000

--1

--.0

56.4

7321

003

1873

00W

V9.

7819

69–1

998

19--

----

----

.275

.108

211

0318

7500

WV

80.4

1945

–200

749

----

----

--.1

58.1

1121

203

1890

00W

V15

019

30–1

982

4369

----

1--

.171

.109

213

0318

9100

WV

529

1965

–200

741

76--

--2

--.0

39.7

2821

403

1895

00W

V68

019

09–1

965

45--

----

1--

.100

.338

215

0318

9650

WV

2.78

1966

–197

712

----

----

--.0

001.

000

216

0319

0000

WV

287

1909

–197

151

----

----

--.0

73.4

5521

703

1901

00W

V23

.519

99–2

007

9--

----

----

-.333

.251

218

0319

0400

WV

365

1967

–200

739

----

----

---.1

01.3

7121

903

1905

00W

V4.

2219

66–1

976

11--

----

----

.291

.241

220

0319

1400

WV

3.88

1966

–199

817

331,

800

--1

--.2

79.1

2722

103

1915

00W

V40

.219

46–2

007

37--

----

----

-.009

.948

222

0319

2000

WV

1,31

719

29–1

964

36--

----

----

-.081

.496

223

0319

2500

WV

1,40

219

09–1

930

14--

----

1--

.341

.098

224

0319

3000

WV

8,37

118

78–1

948

71--

----

----

----

225

0319

3725

WV

0.33

1966

–197

712

----

----

1.2

42.3

0122

603

1938

30W

V1.

8019

69–2

007

18--

----

1--

.490

.005

227

0319

4700

WV

266

1930

–200

776

----

----

--.1

73.0

2722

803

1950

00W

V28

119

35–1

963

29--

----

----

----

229

0319

5100

WV

51.9

1975

–198

710

----

--1

--.0

221.

000

230

0319

5250

WV

46.5

1975

–200

730

----

----

--.1

49.2

5423

103

1955

00W

V54

219

39–1

960

2229

----

----

.056

.735

232

0319

5600

WV

6.39

1966

–200

423

----

----

1.1

46.3

42


ble

2.

Floo

d-fre

quen

cy s

tatis

tics

and

drai

nage

are

as fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t st

ates

.—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

- -,

no v

alue

; sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eD

rain

age

area

, in

squ

are

mile

s

Wat

er y

ears

bo

undi

ng

syst

emat

ic

peak

s

Num

ber o

f yea

rs o

f re

cord

Ove

rrid

e of

out

lier t

hres

hold

sN

umbe

r of p

eaks

Tren

d an

alys

is

Syst

emat

icH

isto

ric

Hig

h th

resh

old

disc

harg

e, in

cu

bic

feet

per

se

cond

Low

thre

shol

d di

scha

rge,

in

cubi

c fe

et p

er

seco

nd

Hig

h ou

tlier

Low

ou

tlier

Kend

all’s

ta

uSi

gnifi

canc

e

leve

l

233

0319

7000

WV

1,14

519

29–1

960

32--

----

1--

-.181

.149

234

0319

7150

WV

2.01

1966

–200

620

----

----

1.1

79.2

8423

503

1979

00W

V0.

4919

64–1

975

12--

----

----

.030

.945

236

0319

8350

WV

62.8

1997

–200

710

----

----

--.0

67.8

5823

703

1984

50W

V7.

7519

65–1

998

18--

----

----

.176

.325

238

0319

8500

WV

391

1909

–200

785

----

----

--.0

19.7

9623

903

1987

80W

V1.

9719

66–1

977

12--

----

----

-.152

.537

240

0319

8800

WV

1.28

1963

–197

714

----

----

---.0

22.9

5624

103

1990

00W

V26

919

31–1

984

54--

----

----

-.020

.835

242

0319

9300

WV

12.2

1979

–200

614

----

----

---.2

09.3

2424

303

1994

00W

V31

819

75–1

984

10--

----

----

.067

.858

244

0320

0500

WV

862

1909

–200

752

----

----

---.0

85.3

7724

503

2006

00W

V0.

8719

66–1

977

12--

----

--1

.258

.271

246

0320

1000

WV

238

1909

–199

954

----

----

---.0

29.7

6024

703

2014

05W

V26

.819

99–2

007

9--

----

----

-.111

.754

248

0320

1410

WV

8.47

1992

–200

716

----

----

1-.1

67.3

9224

903

2014

20W

V2.

0519

65–1

977

13--

----

--1

-.346

.112

250

0320

1440

WV

1.04

1965

–197

713

----

----

---.0

26.9

5125

103

2014

80W

V0.

7019

65–1

977

13--

----

----

-.436

.044

252

0320

2000

OH

585

1916

–200

683

----

----

----

--25

303

2022

45W

V4.

8519

78–2

007

1231

----

1--

-.389

.175

254

0320

2400

WV

306

1969

–200

739

----

----

---.0

69.5

4525

503

2024

80W

V7.

3419

70–2

007

22--

----

----

-.143

.367

256

0320

2750

WV

126

1975

–200

733

----

----

1-.0

61.6

3125

703

2030

00W

V75

819

29–1

979

51--

----

----

.064

.516

258

0320

3600

WV

833

1961

–197

919

----

----

--.0

94.6

0025

903

2040

00W

V1,

224

1916

–197

958

----

----

--.0

65.4

7726

003

2045

00W

V25

619

38–1

980

43--

----

----

.078

.470

261

0320

5995

OH

0.73

1978

–200

615

----

----

--.1

14.5

86

Table 2 45Ta

ble

2.

Floo

d-fre

quen

cy s

tatis

tics

and

drai

nage

are

as fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t st

ates

.—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

- -,

no v

alue

; sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns

rem

oved

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eD

rain

age

area

, in

squ

are

mile

s

Wat

er y

ears

bo

undi

ng

syst

emat

ic

peak

s

Num

ber o

f yea

rs o

f re

cord

Ove

rrid

e of

out

lier t

hres

hold

sN

umbe

r of p

eaks

Tren

d an

alys

is

Syst

emat

icH

isto

ric

Hig

h th

resh

old

disc

harg

e, in

cu

bic

feet

per

se

cond

Low

thre

shol

d di

scha

rge,

in

cubi

c fe

et p

er

seco

nd

Hig

h ou

tlier

Low

ou

tlier

Kend

all’s

ta

uSi

gnifi

canc

e

leve

l

262

0320

6450

WV

4.02

1999

–200

79

----

----

---.1

79.6

1826

303

2066

00W

V38

.519

65–2

007

43--

----

----

.066

.537

264

0320

6800

WV

139

1962

–197

110

59--

--1

---.1

56.5

9226

503

2070

00W

V29

119

16–1

966

3159

----

----

----

266

0320

7020

WV

300

1916

–197

136

59--

----

---.1

08.3

6126

703

2074

00VA

20.0

1951

–197

727

----

----

1-.1

28.3

5926

803

2075

00VA

239

1942

–199

543

----

----

---.1

42.1

8426

903

2078

00VA

297

1968

–200

639

----

----

---.1

00.3

7727

003

2079

62K

Y0.

8219

75–1

984

9--

----

----

.139

.675

271

0320

8000

KY

392

1938

–196

831

----

----

--.0

62.6

3427

203

2085

00VA

286

1927

–200

680

----

----

---.0

51.5

0427

303

2089

50VA

66.5

1964

–200

642

----

--1

---.0

26.8

2027

403

2090

00VA

221

1927

–196

539

----

----

---.1

65.1

4327

503

2095

75K

Y3.

1719

76–1

986

11--

----

1--

-.236

.350

276

0321

0000

KY

56.3

1938

–200

666

----

----

---.0

79.3

5227

703

2115

00K

Y20

619

38–1

949

12--

----

--1

-.030

.945

278

0321

2000

KY

103

1950

–198

132

----

----

---.1

37.2

7727

903

2127

50W

V17

419

86–2

007

22--

----

----

.095

.554

280

0321

2980

WV

209

1986

–200

722

----

----

1.2

12.1

7628

103

2130

00W

V50

419

31–1

986

56--

----

----

.062

.506

282

0321

3500

WV

31.0

1947

–200

746

----

----

--.1

33.1

9528

303

2137

00W

V93

619

68–2

007

40--

----

--1

-.033

.771

284

0321

4000

WV

1,18

819

35–1

985

51--

----

----

----

285

0321

4500

WV

1,28

019

16–2

007

81--

----

----

-.071

.350

286

0321

4900

WV

1,50

719

77–1

995

12--

----

----

-.182

.451

287

0321

5500

KY

217

1916

–198

149

----

----

---.1

68.0

8928

803

2165

00K

Y40

019

37–1

967

30--

----

--1

-.053

.695

289

0321

6540

KY

12.2

1973

–199

119

----

----

1.1

75.3

1029

003

2165

63K

Y0.

9419

76–1

987

12--

----

--1

.045

.891


ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)1

0159

5000

MD

East

Qs

1,70

02,

600

3,28

05,

390

7,13

09,

760

12,1

0014

,700

17,7

0022

,300

Qr

993

1,62

02,

120

3,84

05,

390

7,78

09,

820

12,1

0014

,600

18,2

00Q

w1,

640

2,53

03,

170

5,08

06,

590

8,89

010

,900

13,2

0015

,800

19,8

002

0159

5300

WV

East

Qs

818

1,05

01,

240

1,87

02,

430

3,35

04,

220

5,28

06,

550

8,67

0Q

r63

81,

030

1,36

02,

440

3,42

04,

920

6,20

07,

610

9,15

011

,400

Qw

799

1,05

01,

250

1,99

02,

750

4,08

05,

290

6,65

08,

180

10,5

003

0159

5500

MD

East

Qs

4,44

06,

160

7,58

012

,400

16,8

0024

,100

31,2

0039

,900

50,6

0068

,600

Qr

2,49

04,

100

5,41

09,

850

13,9

0020

,200

25,6

0031

,600

38,2

0048

,200

Qw

4,28

06,

010

7,39

011

,900

15,9

0022

,500

28,4

0035

,200

43,2

0055

,800

401

5960

00M

DEa

stQ

s4,

050

6,27

08,

020

13,6

0018

,500

26,1

0033

,100

41,2

0050

,700

65,8

00Q

r3,

040

5,02

06,

620

12,1

0017

,000

24,8

0031

,500

38,9

0047

,100

59,5

00Q

w3,

900

6,10

07,

790

13,1

0017

,800

25,3

0032

,000

39,5

0048

,000

60,9

005

0159

6500

MD

East

Qs

847

1,20

01,

480

2,35

03,

100

4,26

05,

300

6,53

07,

960

10,2

00Q

r71

71,

160

1,52

02,

750

3,85

05,

550

7,00

08,

590

10,3

0012

,900

Qw

839

1,20

01,

480

2,41

03,

270

4,71

06,

010

7,50

09,

160

11,7

006

0159

7000

MD

East

Qs

250

376

481

840

1,18

01,

740

2,29

02,

970

3,81

05,

230

Qr

297

477

622

1,11

01,

550

2,23

02,

790

3,42

04,

090

5,09

0Q

w25

438

449

489

81,

300

1,97

02,

570

3,24

03,

990

5,14

07

0159

8000

MD

East

Qs

1,79

02,

690

3,42

05,

860

8,05

011

,600

15,0

0019

,000

23,9

0032

,000

Qr

1,44

02,

350

3,09

05,

610

7,89

011

,400

14,4

0017

,800

21,5

0027

,000

Qw

1,74

02,

640

3,37

05,

780

7,97

011

,500

14,6

0018

,100

22,1

0028

,100

801

5990

00M

DEa

stQ

s1,

010

1,49

01,

860

3,00

03,

960

5,44

06,

750

8,27

010

,000

12,7

00Q

r98

51,

600

2,11

03,

810

5,34

07,

720

9,74

012

,000

14,4

0018

,100

Qw

1,01

01,

490

1,87

03,

090

4,22

06,

080

7,79

09,

730

11,9

0015

,200

901

5995

00W

VEa

stQ

s42

576

01,

020

1,85

02,

520

3,53

04,

400

5,36

06,

430

8,02

0Q

r68

61,

110

1,46

02,

630

3,68

05,

300

6,68

08,

200

9,87

012

,300

Qw

455

801

1,08

02,

080

3,03

04,

560

5,88

07,

340

8,92

011

,200

1001

6000

00M

DEa

stQ

s7,

960

12,2

0015

,600

26,6

0036

,100

51,2

0065

,000

81,3

0010

0,00

013

1,00

0Q

r5,

620

9,33

012

,300

22,6

0032

,000

46,8

0059

,600

73,8

0089

,700

114,

000

Qw

7,41

011

,600

14,8

0024

,700

33,6

0048

,000

60,7

0075

,200

91,4

0011

6,00

0

Table 3 47Ta

ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)11

0160

1500

MD

East

Qs

3,31

04,

820

6,07

010

,400

14,4

0021

,100

27,6

0035

,600

45,6

0062

,400

Qr

2,69

04,

430

5,84

010

,600

15,0

0021

,800

27,7

0034

,200

41,4

0052

,300

Qw

3,28

04,

800

6,06

010

,400

14,5

0021

,300

27,6

0035

,000

43,5

0057

,000

1201

6030

00M

DEa

stQ

s10

,500

14,5

0017

,600

27,3

0035

,500

48,2

0059

,700

73,1

0088

,600

113,

000

Qr

7,59

012

,600

16,8

0030

,800

43,7

0063

,900

81,5

0010

1,00

012

3,00

015

6,00

0Q

w10

,300

14,4

0017

,500

27,9

0037

,700

54,4

0069

,800

87,4

0010

7,00

013

8,00

013

0160

4500

WV

East

Qs

1,52

02,

730

3,67

06,

560

8,91

012

,300

15,3

0018

,400

22,0

0027

,100

Qr

2,46

04,

040

5,33

09,

700

13,7

0019

,900

25,2

0031

,100

37,6

0047

,500

Qw

1,56

02,

780

3,75

06,

940

9,84

014

,600

18,9

0023

,700

28,9

0036

,600

1401

6055

00W

VEa

stQ

s1,

840

3,27

04,

520

9,07

013

,500

21,2

0028

,800

38,4

0050

,300

70,6

00Q

r2,

070

3,39

04,

470

8,13

011

,500

16,6

0021

,100

26,0

0031

,400

39,6

00Q

w1,

850

3,28

04,

520

8,92

013

,000

19,3

0025

,000

31,5

0039

,000

50,9

0015

0160

5700

WV

East

Qs

11.2

1619

.831

.942

.358

.773

.691

.111

214

5Q

r8.

913

.717

.630

.742

.158

.972

.787

.510

312

5Q

w10

.815

.619

.431

.542

.258

.873

88.5

105

130

1601

6060

00W

VEa

stQ

s4,

500

6,43

08,

050

13,7

0018

,900

27,9

0036

,700

47,7

0061

,500

84,9

00Q

r3,

240

5,35

07,

060

12,9

0018

,200

26,5

0033

,600

41,5

0050

,300

63,6

00Q

w4,

420

6,37

07,

980

13,5

0018

,700

27,4

0035

,300

44,5

0055

,200

72,2

0017

0160

6500

WV

East

Qs

6,66

010

,200

13,1

0023

,200

32,9

0049

,300

65,3

0085

,300

110,

000

153,

000

Qr

5,95

09,

880

13,1

0024

,000

34,0

0049

,600

63,2

0078

,400

95,2

0012

1,00

0Q

w6,

630

10,2

0013

,100

23,3

0033

,100

49,4

0064

,500

82,2

0010

3,00

013

6,00

018

0160

6800

WV

East

Qs

14.7

27.1

38.7

84.2

133

223

319

446

613

915

Qr

42.6

6786

.615

321

129

837

145

053

465

6Q

w17

.831

.745

.710

717

027

135

644

955

070

119

0160

7500

WV

East

Qs

1,51

02,

440

3,28

06,

550

10,0

0016

,500

23,5

0032

,800

45,2

0068

,200

Qr

1,31

02,

150

2,82

05,

120

7,19

010

,400

13,2

0016

,200

19,5

0024

,500

Qw

1,50

02,

430

3,25

06,

340

9,32

014

,200

18,6

0023

,800

30,0

0040

,400

2001

6075

10W

VEa

stQ

sa 1

3.8

22.9

30.6

57.5

82.7

125

166

216

278

381

Qr

30.6

47.9

61.8

109

150

212

263

318

377

462

Qw

16.6

2736

.977

.911

918

423

929

635

944

9


ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)21

0160

8000

WV

East

Qs

2,71

04,

440

5,94

011

,300

16,6

0025

,800

34,9

0046

,500

61,2

0086

,500

Qr

2,95

04,

870

6,43

011

,700

16,5

0024

,100

30,5

0037

,700

45,7

0057

,700

Qw

2,72

04,

460

5,97

011

,400

16,6

0025

,200

33,1

0042

,400

53,2

0070

,500

2201

6081

00W

VEa

stQ

s30

.840

.346

.361

.371

.383

.993

.410

311

312

6Q

r8.

312

.716

.328

.539

54.5

67.3

80.9

95.4

116

Qw

25.1

3438

.446

.953

.264

.374

.886

.799

.711

823

0160

8500

WV

East

Qs

10,7

0017

,200

22,7

0041

,700

59,7

0090

,400

120,

000

157,

000

203,

000

280,

000

Qr

11,5

0019

,300

25,6

0047

,200

67,1

0098

,500

126,

000

156,

000

191,

000

243,

000

Qw

10,7

0017

,300

22,8

0042

,300

61,1

0092

,800

122,

000

157,

000

197,

000

262,

000

2401

6090

00M

DEa

stQ

s1,

860

3,00

03,

850

6,36

08,

340

11,2

0013

,600

16,2

0019

,100

23,4

00Q

r1,

770

2,90

03,

820

6,93

09,

760

14,1

0017

,900

22,1

0026

,700

33,6

00Q

w1,

850

2,99

03,

850

6,53

08,

940

12,9

0016

,300

20,2

0024

,400

30,7

0025

0160

9500

MD

East

Qs

163

223

267

398

502

658

792

943

1,11

01,

370

Qr

112

178

231

411

570

811

1,01

01,

230

1,47

01,

820

Qw

156

218

262

401

529

737

922

1,13

01,

350

1,68

026

0160

9650

WV

East

Qs

a 381

a 741

1,05

02,

150

3,18

04,

880

6,47

08,

390

10,7

0014

,400

Qr

465

750

981

1,76

02,

470

3,54

04,

460

5,46

06,

560

8,18

0Q

w40

274

41,

030

1,93

02,

670

3,79

04,

730

5,79

06,

950

8,71

027

0160

9800

WV

East

Qs

2,07

03,

080

3,81

05,

980

7,68

010

,200

12,3

0014

,600

17,2

0021

,000

Qr

1,37

02,

230

2,94

05,

320

7,48

010

,800

13,7

0016

,900

20,3

0025

,600

Qw

1,87

02,

850

3,54

05,

640

7,55

010

,700

13,4

0016

,500

19,9

0025

,000

2801

6100

00W

VEa

stQ

s23

,700

34,0

0041

,700

64,6

0083

,100

111,

000

134,

000

161,

000

191,

000

237,

000

2901

6101

50M

DEa

stQ

s16

728

437

566

691

11,

290

1,62

01,

990

2,42

03,

070

Qr

201

322

419

749

1,04

01,

490

1,87

02,

280

2,73

03,

380

Qw

172

289

383

694

974

1,41

01,

790

2,20

02,

650

3,31

030

0161

0155

MD

East

Qs

1,41

02,

620

3,62

07,

010

10,0

0014

,800

19,2

0024

,300

30,2

0039

,500

Qr

1,30

02,

130

2,80

05,

080

7,13

010

,300

13,0

0016

,100

19,4

0024

,300

Qw

1,39

02,

530

3,44

06,

190

8,37

011

,600

14,4

0017

,600

21,2

0026

,700

Table 3 49Ta

ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)31

0161

0500

WV

East

Qs

2,60

05,

190

7,42

015

,100

22,0

0033

,100

43,1

0054

,900

68,6

0090

,000

Qr

3,21

05,

290

6,98

012

,700

18,0

0026

,200

33,2

0041

,100

49,8

0062

,900

Qw

2,72

05,

210

7,31

014

,000

19,5

0027

,900

35,1

0043

,300

52,4

0066

,400

3201

6115

00W

VEa

stQ

s5,

110

9,49

013

,000

24,1

0033

,400

47,3

0059

,300

72,7

0087

,600

110,

000

Qr

6,12

010

,200

13,5

0024

,700

35,0

0051

,200

65,2

0080

,800

98,2

0012

5,00

0Q

w5,

150

9,52

013

,000

24,2

0033

,700

48,5

0061

,500

76,0

0092

,300

117,

000

3301

6125

00M

DEa

stQ

s24

540

352

490

11,

210

1,68

02,

080

2,54

03,

060

3,84

0Q

r30

048

162

81,

130

1,57

02,

250

2,82

03,

450

4,14

05,

150

Qw

253

414

542

979

1,39

02,

040

2,60

03,

210

3,88

04,

860

3401

6130

00M

DEa

stQ

s28

,400

42,3

0053

,100

86,8

0011

5,00

015

9,00

019

9,00

024

4,00

029

7,00

037

9,00

035

0161

3150

MD

East

Qs

126

190

237

377

489

653

793

949

1,12

01,

380

Qr

107

170

221

392

544

773

966

1,18

01,

400

1,73

0Q

w12

418

823

538

151

272

090

11,

100

1,32

01,

630

3601

6131

60M

DEa

stQ

sa 6

8.4

89.9

105

148

180

226

263

304

349

414

Qr

34.4

53.9

69.6

123

169

239

297

359

426

523

Qw

60.2

8296

.113

717

423

528

834

640

950

037

0161

3900

VAEa

stQ

s29

860

485

61,

660

2,32

03,

310

4,13

05,

040

6,04

07,

480

Qr

285

458

597

1,07

01,

490

2,13

02,

680

3,27

03,

920

4,88

0Q

w29

759

383

21,

530

2,05

02,

750

3,34

03,

990

4,71

05,

790

3801

6140

00W

VEa

stQ

s2,

820

4,40

05,

590

9,25

012

,200

16,7

0020

,600

25,0

0029

,900

37,4

00Q

r2,

580

4,25

05,

610

10,2

0014

,400

20,9

0026

,600

32,8

0039

,700

50,1

00Q

w2,

800

4,39

05,

590

9,42

012

,800

18,4

0023

,400

29,0

0035

,300

44,7

0039

0161

5000

VAEa

stQ

s97

31,

780

2,42

04,

480

6,22

08,

860

11,2

0013

,800

16,7

0021

,100

Qr

824

1,34

01,

760

3,17

04,

450

6,41

08,

090

9,93

012

,000

15,0

00Q

w96

41,

750

2,37

04,

240

5,71

07,

830

9,64

011

,700

13,9

0017

,400

4001

6160

00VA

East

Qs

237

411

544

935

1,24

01,

680

2,04

02,

420

2,84

03,

440

Qr

301

484

631

1,13

01,

580

2,26

02,

840

3,47

04,

160

5,17

0Q

w24

341

855

498

51,

370

1,98

02,

500

3,08

03,

710

4,61

0


ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)41

0161

6500

WV

East

Qs

1,87

03,

320

4,48

08,

230

11,4

0016

,300

20,7

0025

,700

31,3

0040

,000

Qr

2,92

04,

810

6,35

011

,600

16,3

0023

,800

30,2

0037

,300

45,1

0057

,000

Qw

1,92

03,

390

4,59

08,

700

12,5

0018

,900

24,6

0031

,100

38,3

0049

,000

4201

6170

00W

VEa

stQ

s83

.313

116

727

836

850

462

175

490

31,

130

4301

6178

00M

DEa

stQ

s37

.973

.310

319

828

040

651

664

178

199

444

0161

8000

MD

East

Qs

36,2

0053

,900

66,9

0010

5,00

013

5,00

018

0,00

021

7,00

025

8,00

030

4,00

037

3,00

045

0161

9475

MD

East

Qs

8.2

15.1

21.3

44.3

67.2

108

148

199

263

373

4601

6195

00M

DEa

stQ

s1,

220

2,00

02,

600

4,51

06,

110

8,57

010

,700

13,2

0016

,100

20,5

0047

0162

0500

VAEa

stQ

s25

749

972

71,

640

2,63

04,

500

6,49

09,

140

12,6

0019

,000

4801

6210

00VA

East

Qs

1,22

01,

770

2,25

03,

980

5,68

08,

680

11,7

0015

,600

20,6

0029

,300

Qr

992

1,62

02,

120

3,83

05,

380

7,77

09,

810

12,1

0014

,500

18,2

00Q

w1,

190

1,75

02,

230

3,94

05,

560

8,18

010

,500

13,2

0016

,200

20,9

0049

0162

1200

VAEa

stQ

s26

642

254

795

61,

320

1,90

02,

430

3,06

03,

800

5,00

0Q

r19

130

539

770

898

61,

410

1,76

02,

150

2,57

03,

190

Qw

257

409

526

884

1,18

01,

620

2,00

02,

430

2,92

03,

650

5001

6214

00VA

East

Qs

293

396

471

691

866

1,12

01,

340

1,59

01,

860

2,28

0Q

r11

818

824

543

560

486

01,

080

1,31

01,

560

1,93

0Q

w24

634

540

756

970

693

21,

130

1,36

01,

610

1,99

051

0162

1450

VAEa

stQ

s22

.232

.641

.169

.896

139

181

231

293

396

Qr

21.3

33.3

42.9

75.3

104

146

181

218

258

316

Qw

2232

.741

.572

.110

014

418

122

126

532

952

0162

2000

VAEa

stQ

s3,

250

5,19

06,

810

12,4

0017

,700

26,6

0035

,200

45,8

0058

,800

80,8

00Q

r3,

790

6,27

08,

290

15,1

0021

,400

31,2

0039

,600

49,0

0059

,400

75,2

00Q

w3,

270

5,23

06,

880

12,7

0018

,400

28,0

0036

,800

47,2

0059

,100

77,9

0053

0162

2100

VAEa

stQ

s26

.944

.658

.510

213

819

424

329

836

245

9Q

r42

.667

86.6

153

211

298

371

450

534

656

Qw

29.8

48.6

64.6

123

178

265

338

416

500

620

5401

6223

00VA

East

Qs

33.7

45.2

53.0

73.8

88.8

109

125

143

161

187

5501

6224

00VA

East

Qs

a27.

842

.854

.793

.312

718

123

128

935

846

9

Table 3 51Ta

ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)56

0163

2000

VAEa

stQ

s3,

420

6,06

08,

090

14,3

0019

,200

26,4

0032

,400

39,0

0046

,200

56,7

00Q

r2,

360

3,87

05,

110

9,30

013

,100

19,0

0024

,100

29,8

0036

,000

45,4

00Q

w3,

370

5,95

07,

910

13,6

0017

,800

23,9

0029

,000

34,8

0041

,200

51,0

0057

0163

2300

VAEa

stQ

s43

.387

.412

929

447

079

61,

140

1,58

02,

160

3,18

0Q

r16

125

833

559

883

11,

180

1,48

01,

810

2,16

02,

680

Qw

50.2

98.2

146

359

594

992

1,34

01,

730

2,16

02,

810

5801

6329

00VA

East

Qs

707

1,47

02,

130

4,38

06,

380

9,53

012

,300

15,6

0019

,200

24,9

00Q

r1,

220

1,98

02,

610

4,72

06,

630

9,59

012

,100

14,9

0018

,000

22,6

00Q

w73

61,

500

2,17

04,

450

6,46

09,

560

12,2

0015

,200

18,5

0023

,400

5901

6329

50VA

East

Qs

1318

.822

.833

.741

.652

.461

7079

.693

.1Q

r12

.219

24.4

42.6

58.5

8210

112

214

417

6Q

w12

.818

.823

.237

.250

.471

.489

.110

812

815

660

0163

2970

VAEa

stQ

s92

.617

925

552

778

61,

220

1,64

02,

140

2,75

03,

760

Qr

139

221

288

512

712

1,01

01,

270

1,55

01,

850

2,29

0Q

w95

.718

225

852

476

11,

120

1,43

01,

770

2,15

02,

730

6101

6330

00VA

East

Qs

4,62

08,

120

10,8

0019

,100

25,8

0035

,600

43,9

0053

,000

63,0

0077

,700

Qr

4,85

08,

050

10,6

0019

,500

27,6

0040

,200

51,2

0063

,400

77,0

0097

,500

Qw

4,63

08,

120

10,8

0019

,200

26,2

0037

,200

46,9

0057

,800

69,9

0087

,900

6201

6335

00VA

East

Qs

a 934

1,56

02,

050

3,65

05,

030

7,19

09,

120

11,4

0014

,000

18,0

00Q

r1,

040

1,70

02,

230

4,03

05,

660

8,17

010

,300

12,7

0015

,300

19,2

00Q

w94

31,

570

2,07

03,

740

5,25

07,

670

9,81

012

,200

14,8

0018

,800

6301

6336

50VA

East

Qs

39.1

77.3

111

233

350

547

736

966

1,24

01,

700

Qr

81.2

129

167

296

410

582

726

882

1,05

01,

300

Qw

41.3

80.2

115

245

367

562

731

917

1,12

01,

440

6401

6340

00VA

East

Qs

4,91

08,

420

11,4

0021

,500

30,9

0046

,600

61,5

0079

,600

102,

000

138,

000

Qr

6,82

011

,400

15,0

0027

,600

39,1

0057

,200

72,9

0090

,400

110,

000

140,

000

Qw

4,98

08,

530

11,6

0022

,200

32,5

0049

,800

65,8

0084

,300

105,

000

139,

000

6501

6345

00VA

East

Qs

1,25

02,

340

3,25

06,

400

9,25

013

,900

18,1

0023

,200

29,1

0038

,600

Qr

1,30

02,

130

2,80

05,

080

7,13

010

,300

13,0

0016

,100

19,4

0024

,300

Qw

1,25

02,

330

3,22

06,

190

8,72

012

,500

15,8

0019

,500

23,7

0030

,200


ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)66

0163

6500

WV

East

Qs

14,0

0024

,500

32,8

0059

,200

81,4

0011

5,00

014

5,00

017

8,00

021

6,00

027

4,00

067

0163

7000

MD

East

Qs

184

375

553

1,26

01,

990

3,32

04,

690

6,45

08,

710

12,7

0068

0163

7500

MD

East

Qs

1,02

01,

830

2,48

04,

580

6,37

09,

130

11,6

0014

,300

17,5

0022

,300

6901

6384

80VA

East

Qs

1,30

02,

690

3,87

07,

780

11,1

0016

,300

20,8

0025

,800

31,4

0039

,800

7001

6385

00M

DEa

stQ

s54

,000

81,8

0010

2,00

016

1,00

020

7,00

027

2,00

032

7,00

038

7,00

045

3,00

054

9,00

071

0164

3700

VAEa

stQ

s1,

340

2,71

03,

890

8,03

011

,800

18,0

0023

,600

30,3

0038

,100

50,5

00Q

r1,

510

2,47

03,

250

5,90

08,

290

12,0

0015

,200

18,7

0022

,600

28,4

00Q

w1,

360

2,69

03,

810

7,43

010

,300

14,6

0018

,200

22,2

0026

,800

33,8

0072

0164

4000

VAEa

stQ

s2,

920

5,26

07,

260

14,3

0020

,900

31,9

0042

,300

55,1

0070

,600

96,0

00Q

r3,

430

5,66

07,

470

13,6

0019

,300

28,1

0035

,600

44,0

0053

,400

67,5

00Q

w2,

940

5,28

07,

270

14,2

0020

,500

30,6

0039

,600

50,0

0061

,900

80,7

0073

0164

4100

VAEa

stQ

s17

629

538

768

092

51,

300

1,63

02,

000

2,42

03,

070

7402

0095

00VA

Cen

tral

Qs

a 24.

429

.132

.039

.344

.250

.455

.059

.764

.571

.075

0201

1400

VAC

entra

lQ

s1,

940

2,90

03,

650

6,03

08,

080

11,3

0014

,200

17,6

0021

,600

28,0

0076

0201

1460

VAC

entra

lQ

s1,

560

2,28

02,

820

4,49

05,

860

7,95

09,

780

11,9

0014

,300

18,0

0077

0201

1480

VAC

entra

lQ

s2,

620

3,66

04,

360

6,17

07,

430

9,08

010

,400

11,7

0013

,000

14,9

00Q

r2,

010

2,88

03,

480

5,15

06,

370

8,03

09,

340

10,7

0012

,200

14,2

00Q

w2,

510

3,54

04,

220

5,95

07,

150

8,77

010

,000

11,4

0012

,700

14,6

0078

0201

1500

VAC

entra

lQ

s3,

240

4,86

05,

940

8,70

010

,600

12,9

0014

,700

16,5

0018

,300

20,7

00Q

r2,

940

4,15

05,

000

7,31

08,

990

11,3

0013

,000

14,9

0016

,900

19,6

00Q

w3,

220

4,82

05,

890

8,58

010

,400

12,7

0014

,500

16,3

0018

,100

20,5

0079

0201

2500

VAC

entra

lQ

s4,

960

8,14

010

,300

16,0

0019

,900

24,8

0028

,500

32,1

0035

,700

40,5

00Q

r8,

160

11,2

0013

,300

18,8

0022

,800

28,0

0032

,200

36,5

0041

,000

47,3

00Q

w5,

030

8,21

010

,400

16,1

0020

,000

25,0

0028

,700

32,4

0036

,100

41,0

0080

0201

2950

VAC

entra

lQ

sa 6

.06

a 20.

637

.711

821

138

656

679

51,

080

1,56

0Q

r29

.147

.160

.810

213

518

222

126

330

837

3Q

w7.

322

.439

.711

619

432

945

761

179

41,

090

8102

0130

00VA

Cen

tral

Qs

2,52

04,

100

5,27

08,

660

11,3

0015

,000

18,0

0021

,300

24,8

0030

,000

Qr

3,49

04,

910

5,90

08,

580

10,5

0013

,100

15,2

0017

,400

19,6

0022

,800

Qw

2,54

04,

120

5,28

08,

660

11,2

0014

,900

17,8

0021

,000

24,5

0029

,400

Table 3 53Ta

ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)82

0201

4000

VAC

entra

lQ

s1,

920

3,13

03,

980

6,29

07,

940

10,1

0011

,800

13,5

0015

,300

17,8

00Q

r3,

310

4,67

05,

610

8,18

010

,000

12,5

0014

,500

16,6

0018

,800

21,8

00Q

w1,

950

3,16

04,

020

6,35

08,

030

10,2

0012

,000

13,7

0015

,500

18,0

0083

0305

0000

WV

Cen

tral

Qs

4,27

05,

760

6,79

09,

560

11,6

0014

,300

16,6

0018

,900

21,4

0025

,000

Qr

3,94

05,

530

6,63

09,

600

11,7

0014

,600

16,9

0019

,300

21,8

0025

,300

Qw

4,26

05,

760

6,79

09,

560

11,6

0014

,400

16,6

0018

,900

21,4

0025

,000

8403

0505

00W

VC

entra

lQ

s5,

090

6,41

07,

300

9,67

011

,400

13,7

0015

,500

17,4

0019

,400

22,3

00Q

r5,

590

7,76

09,

250

13,3

0016

,100

20,0

0023

,000

26,2

0029

,500

34,1

00Q

w5,

100

6,44

07,

350

9,80

011

,600

14,0

0015

,900

17,9

0020

,000

23,0

0085

0305

0650

WV

Cen

tral

Qs

23.3

35.6

46.2

83.6

120

183

245

325

425

598

Qr

16.4

2735

.260

.380

.410

913

316

018

822

8Q

w22

.234

.444

.678

.811

016

120

826

633

645

086

0305

1000

WV

Cen

tral

Qs

6,97

08,

930

10,2

0013

,500

15,8

0018

,700

21,0

0023

,300

25,8

0029

,100

Qr

8,08

011

,100

13,2

0018

,700

22,6

0027

,800

31,9

0036

,200

40,7

0046

,900

Qw

6,99

08,

960

10,2

0013

,600

15,9

0019

,000

21,3

0023

,800

26,3

0029

,700

8703

0515

00W

VC

entra

lQ

s2,

800

4,00

04,

850

7,23

09,

010

11,5

0013

,600

15,8

0018

,100

21,6

00Q

r2,

690

3,82

04,

610

6,75

08,

310

10,4

0012

,100

13,8

0015

,700

18,2

00Q

w2,

790

3,99

04,

840

7,20

08,

950

11,4

0013

,400

15,5

0017

,800

21,2

0088

0305

2000

WV

Cen

tral

Qs

3,69

05,

100

6,06

08,

630

10,5

0013

,000

15,0

0017

,000

19,2

0022

,300

Qr

3,21

04,

540

5,45

07,

950

9,76

012

,200

14,1

0016

,100

18,3

0021

,200

Qw

3,67

05,

080

6,04

08,

600

10,4

0012

,900

14,9

0017

,000

19,2

0022

,200

8903

0523

40W

VC

entra

lQ

s90

.412

815

522

727

935

140

947

153

663

0Q

r72

.311

414

523

831

041

249

558

467

981

6Q

w87

.512

615

422

928

636

643

150

057

468

090

0305

2500

WV

Cen

tral

Qs

412

631

797

1,30

01,

720

2,34

02,

880

3,50

04,

190

5,26

0Q

r38

057

070

81,

100

1,40

01,

810

2,14

02,

490

2,86

03,

390

Qw

411

629

794

1,29

01,

690

2,29

02,

810

3,39

04,

040

5,03

091

0305

3500

WV

Cen

tral

Qs

4,85

06,

500

7,49

09,

770

11,2

0012

,800

13,9

0015

,000

16,1

0017

,400

Qr

5,70

07,

910

9,43

013

,500

16,4

0020

,400

23,4

0026

,700

30,0

0034

,700

Qw

4,87

06,

520

7,52

09,

850

11,3

0013

,000

14,3

0015

,400

16,6

0018

,000


ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)92

0305

4500

WV

Cen

tral

Qs

14,6

0019

,300

22,3

0030

,200

35,7

0043

,000

48,5

0054

,300

60,3

0068

,600

Qr

17,0

0022

,800

26,7

0037

,100

44,3

0054

,000

61,5

0069

,300

77,4

0088

,700

Qw

14,7

0019

,400

22,4

0030

,400

36,0

0043

,400

49,1

0055

,000

61,1

0069

,600

9303

0550

20W

VC

entra

lQ

s31

.151

.566

.811

214

719

723

828

433

340

4Q

r20

.934

.244

.475

.510

013

616

519

723

228

1Q

w28

.447

.461

.399

.912

917

120

624

428

634

694

0305

5040

WV

Cen

tral

Qs

99.4

160

208

359

489

691

871

1,08

01,

320

1,70

0Q

r95

.214

918

930

739

852

763

174

386

31,

030

Qw

98.6

158

205

347

463

635

784

951

1,14

01,

420

9503

0562

50W

VC

entra

lQ

s2,

910

3,99

04,

720

6,72

08,

170

10,1

0011

,700

13,4

0015

,200

17,7

00Q

r2,

180

3,11

03,

760

5,55

06,

860

8,63

010

,000

11,5

0013

,000

15,2

00Q

w2,

840

3,92

04,

640

6,58

07,

980

9,89

011

,400

13,0

0014

,800

17,2

0096

0305

6500

WV

Cen

tral

Qs

20,2

0026

,600

30,9

0042

,200

50,2

0061

,000

69,5

0078

,500

87,9

0010

1,00

0Q

r23

,500

31,3

0036

,500

50,0

0059

,500

72,1

0081

,900

92,0

0010

3,00

011

7,00

0Q

w20

,300

26,8

0031

,100

42,6

0050

,900

62,0

0070

,700

79,8

0089

,400

103,

000

9703

0566

00W

VC

entra

lQ

s10

416

120

231

840

552

662

473

084

21,

000

Qr

7211

414

523

831

041

249

558

467

981

6Q

w97

152

190

296

375

485

576

673

777

927

9803

0573

00W

VW

est

Qs

864

1,28

01,

570

2,34

02,

890

3,63

04,

220

4,83

05,

470

6,37

0Q

r73

91,

180

1,50

02,

400

3,06

03,

950

4,64

05,

360

6,11

07,

140

Qw

837

1,26

01,

560

2,35

02,

940

3,74

04,

380

5,04

05,

730

6,70

099

0305

7500

WV

Wes

tQ

s86

71,

130

1,29

01,

650

1,87

02,

130

2,31

02,

490

2,65

02,

870

Qr

678

1,08

01,

380

2,21

02,

830

3,65

04,

300

4,97

05,

660

6,62

0Q

w84

81,

130

1,30

01,

700

1,98

02,

340

2,60

02,

870

3,14

03,

480

100

0305

8000

WV

Wes

tQ

s1,

950

2,69

03,

190

4,48

05,

370

6,54

07,

450

8,38

09,

340

10,7

00Q

r1,

930

2,99

03,

750

5,85

07,

360

9,36

010

,900

12,5

0014

,100

16,4

00Q

w1,

950

2,71

03,

220

4,58

05,

560

6,89

07,

930

9,00

010

,100

11,6

0010

103

0585

00W

VW

est

Qs

3,52

05,

060

6,07

08,

620

10,3

0012

,500

14,1

0015

,800

17,4

0019

,600

Qr

3,01

04,

610

5,75

08,

850

11,1

0014

,000

16,2

0018

,500

20,9

0024

,100

Qw

3,50

05,

050

6,06

08,

630

10,4

0012

,600

14,3

0016

,000

17,8

0020

,100

Table 3 55Ta

ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)10

203

0590

00W

VW

est

Qs

6,32

08,

630

10,0

0013

,100

15,0

0017

,100

18,6

0020

,000

21,3

0023

,000

Qr

5,34

08,

060

9,95

015

,100

18,7

0023

,500

27,1

0030

,700

34,5

0039

,500

Qw

6,27

08,

610

10,0

0013

,200

15,2

0017

,600

19,3

0021

,000

22,6

0024

,600

103

0305

9500

WV

Wes

tQ

s1,

230

2,04

02,

640

4,40

05,

750

7,65

09,

220

10,9

0012

,700

15,3

00Q

r1,

680

2,62

03,

300

5,16

06,

500

8,29

09,

670

11,1

0012

,500

14,5

00Q

w1,

280

2,09

02,

690

4,49

05,

870

7,79

09,

320

10,9

0012

,700

15,1

0010

403

0605

00W

VW

est

Qs

329

611

827

1,46

01,

930

2,59

03,

110

3,66

04,

240

5,04

0Q

r28

747

060

699

41,

280

1,68

01,

990

2,32

02,

660

3,14

0Q

w32

058

778

91,

340

1,73

02,

240

2,64

03,

060

3,51

04,

130

105

0306

1000

WV

Wes

tQ

s10

,300

14,8

0017

,700

24,8

0029

,500

35,4

0039

,700

43,9

0048

,200

53,8

00Q

r8,

980

13,3

0016

,400

24,5

0030

,100

37,5

0043

,000

48,6

0054

,300

62,0

00Q

w10

,200

14,8

0017

,700

24,8

0029

,600

35,5

0040

,000

44,4

0048

,800

54,7

0010

603

0615

00W

VW

est

Qs

3,34

04,

490

5,20

06,

910

8,00

09,

340

10,3

0011

,300

12,2

0013

,500

Qr

2,14

03,

320

4,15

06,

450

8,10

010

,300

12,0

0013

,700

15,5

0017

,900

Qw

3,28

04,

450

5,17

06,

890

8,01

09,

410

10,5

0011

,500

12,5

0013

,900

107

0306

2400

WV

Wes

tQ

s23

636

647

382

91,

150

1,68

02,

180

2,79

03,

520

4,72

0Q

r35

557

874

31,

210

1,56

02,

040

2,41

02,

800

3,21

03,

780

Qw

246

379

490

866

1,21

01,

750

2,23

02,

790

3,44

04,

460

108

0306

2500

WV

Wes

tQ

s75

71,

180

1,51

02,

540

3,39

04,

700

5,86

07,

180

8,70

011

,000

Qr

1,35

02,

110

2,66

04,

190

5,30

06,

780

7,93

09,

110

10,3

0012

,000

Qw

798

1,23

01,

570

2,67

03,

610

5,01

06,

220

7,55

09,

040

11,3

0010

903

0639

50W

VC

entra

lQ

s29

.946

.161

120

183

303

435

615

861

1,32

0Q

r35

.857

.674

.212

416

422

026

631

636

944

6Q

w31

.148

.163

.512

117

627

036

047

260

984

111

003

0650

00W

VC

entra

lQ

s7,

890

10,5

0012

,700

19,8

0026

,200

36,7

0046

,600

58,6

0073

,100

97,2

00Q

r7,

040

9,71

011

,500

16,4

0019

,900

24,6

0028

,300

32,1

0036

,100

41,6

00Q

w7,

870

10,5

0012

,700

19,7

0025

,900

35,9

0045

,300

56,5

0069

,900

91,9

0011

103

0654

00W

VC

entra

lQ

s90

61,

220

1,47

02,

260

2,93

03,

980

4,94

06,

060

7,39

09,

500

Qr

1,29

01,

880

2,29

03,

430

4,27

05,

410

6,33

07,

280

8,30

09,

720

Qw

959

1,29

01,

570

2,46

03,

210

4,34

05,

320

6,42

07,

670

9,57

0


ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)11

203

0660

00W

VC

entra

lQ

s1,

530

2,06

02,

470

3,73

04,

780

6,38

07,

800

9,45

011

,300

14,3

00Q

r1,

950

2,80

03,

390

5,02

06,

210

7,83

09,

110

10,5

0011

,900

13,9

00Q

w1,

540

2,07

02,

490

3,77

04,

830

6,44

07,

870

9,50

011

,400

14,3

0011

303

0671

00W

VC

entra

lQ

s3.

55.

46.

811

14.4

19.5

23.8

28.7

34.1

42.3

Qr

5.89

1013

.223

.431

.743

.854

65.1

77.2

94.7

Qw

3.63

5.6

7.08

11.8

15.7

21.6

26.7

32.3

38.6

47.9

114

0306

7500

WV

Cen

tral

Qs

2,77

03,

550

4,06

05,

360

6,26

07,

440

8,35

09,

280

10,3

0011

,600

Qr

1,36

01,

960

2,39

03,

580

4,45

05,

650

6,60

07,

590

8,64

010

,100

Qw

2,58

03,

380

3,88

05,

090

5,94

07,

080

7,97

08,

910

9,89

011

,300

115

0306

8610

WV

Cen

tral

Qs

135

191

231

350

443

578

693

821

963

1,18

0Q

r14

722

728

645

859

077

592

51,

090

1,26

01,

500

Qw

137

195

238

369

474

626

754

893

1,05

01,

270

116

0306

8800

WV

Cen

tral

Qs

6,77

09,

140

10,8

0015

,300

18,5

0023

,100

26,7

0030

,600

34,8

0040

,800

Qr

3,27

04,

620

5,55

08,

090

9,92

012

,400

14,4

0016

,400

18,6

0021

,600

Qw

6,29

08,

620

10,2

0014

,000

16,8

0020

,500

23,6

0026

,800

30,3

0035

,400

117

0306

9000

WV

Cen

tral

Qs

5,88

07,

430

8,60

012

,100

14,9

0019

,100

22,8

0026

,900

31,6

0038

,800

Qr

4,48

06,

260

7,50

010

,800

13,2

0016

,400

19,0

0021

,600

24,4

0028

,300

Qw

5,84

07,

400

8,57

012

,000

14,8

0019

,000

22,5

0026

,600

31,1

0038

,000

118

0306

9500

WV

Cen

tral

Qs

16,1

0021

,000

24,9

0036

,800

46,9

0062

,500

76,4

0092

,700

112,

000

141,

000

Qr

13,7

0018

,500

21,8

0030

,400

36,4

0044

,500

50,8

0057

,400

64,2

0073

,700

Qw

16,1

0021

,000

24,9

0036

,700

46,6

0061

,800

75,4

0091

,000

109,

000

138,

000

119

0306

9850

WV

Cen

tral

Qs

48.1

65.1

77.4

113

142

183

218

256

300

365

Qr

31.8

51.4

66.3

111

147

198

240

285

333

403

Qw

43.8

62.2

7511

314

318

822

626

731

338

012

003

0698

80W

VC

entra

lQ

s59

386

51,

060

1,59

01,

990

2,55

03,

000

3,48

04,

000

4,75

0Q

r32

849

561

796

41,

230

1,59

01,

880

2,19

02,

520

2,99

0Q

w55

982

51,

010

1,49

01,

850

2,33

02,

730

3,16

03,

620

4,29

012

103

0700

00W

VC

entra

lQ

s20

,600

27,9

0033

,300

49,3

0062

,000

80,8

0097

,000

115,

000

136,

000

167,

000

Qr

17,4

0023

,400

27,4

0037

,900

45,3

0055

,200

62,8

0070

,800

79,0

0090

,600

Qw

20,5

0027

,800

33,2

0048

,900

61,4

0079

,700

95,3

0011

3,00

013

2,00

016

2,00

0

Table 3 57Ta

ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)12

203

0705

00W

VC

entra

lQ

s4,

670

6,08

07,

140

10,3

0012

,900

16,7

0020

,000

23,8

0028

,100

34,7

00Q

r4,

230

5,92

07,

090

10,3

0012

,500

15,6

0018

,000

20,5

0023

,200

26,9

00Q

w4,

660

6,08

07,

140

10,3

0012

,900

16,7

0019

,900

23,6

0027

,800

34,3

0012

303

0710

00W

VC

entra

lQ

s24

,800

35,5

0043

,100

64,3

0080

,300

103,

000

121,

000

141,

000

162,

000

194,

000

Qr

24,3

0032

,300

37,7

0051

,700

61,4

0074

,400

84,4

0094

,800

106,

000

121,

000

Qw

24,8

0035

,400

43,0

0063

,800

79,3

0010

1,00

011

9,00

013

7,00

015

8,00

018

7,00

012

403

0715

00W

VC

entra

lQ

s26

,400

38,3

0046

,300

66,9

0081

,000

99,4

0011

3,00

012

8,00

014

2,00

016

2,00

012

503

0720

00PA

Wes

tQ

s3,

920

5,86

07,

150

10,4

0012

,700

15,5

0017

,700

19,8

0022

,000

24,9

00Q

r3,

600

5,49

06,

820

10,5

0013

,000

16,4

0019

,000

21,7

0024

,400

28,1

00Q

w3,

900

5,85

07,

140

10,4

0012

,700

15,6

0017

,800

20,0

0022

,300

25,3

0012

603

0725

90PA

Wes

tQ

s38

154

265

697

41,

210

1,55

01,

820

2,12

02,

440

2,90

0Q

r47

977

499

01,

600

2,06

02,

670

3,15

03,

650

4,18

04,

900

Qw

400

575

703

1,10

01,

420

1,89

02,

270

2,67

03,

090

3,68

012

703

0754

50M

DC

entra

lQ

s12

.919

.023

.234

.843

.154

.463

.372

.782

.696

.512

803

0755

00M

DC

entra

lQ

s2,

390

3,43

04,

200

6,42

08,

170

10,7

0012

,900

15,2

0017

,900

21,8

0012

903

0756

00M

DC

entra

lQ

s14

.422

.929

.853

.675

.511

214

719

024

333

013

003

0765

05M

DC

entra

lQ

sa 7

.79

10.1

11.7

15.5

18.1

21.5

24.1

26.8

29.5

33.2

131

0307

6600

MD

Cen

tral

Qs

851

1,26

01,

550

2,31

02,

860

3,59

04,

160

4,76

05,

390

6,26

013

203

0855

00PA

Wes

tQ

s2,

850

4,34

05,

400

8,38

010

,600

13,7

0016

,300

19,0

0021

,900

26,1

00Q

r3,

930

5,98

07,

420

11,3

0014

,100

17,8

0020

,600

23,4

0026

,400

30,3

00Q

w2,

880

4,38

05,

450

8,49

010

,800

14,0

0016

,600

19,3

0022

,300

26,5

0013

303

1080

00PA

Wes

tQ

s1,

980

2,91

03,

590

5,59

07,

180

9,49

011

,500

13,6

0016

,100

19,7

00Q

r2,

970

4,56

05,

680

8,74

010

,900

13,8

0016

,000

18,3

0020

,600

23,8

00Q

w2,

010

2,95

03,

640

5,71

07,

360

9,78

011

,800

14,0

0016

,500

20,1

0013

403

1090

00O

HW

est

Qs

198

303

381

613

798

1,07

01,

300

1,56

01,

840

2,27

0Q

r22

937

848

880

61,

040

1,37

01,

630

1,90

02,

190

2,58

0Q

w20

130

938

963

583

51,

130

1,37

01,

640

1,93

02,

360

135

0310

9500

OH

Wes

tQ

s5,

050

7,35

08,

960

13,3

0016

,600

20,9

0024

,500

28,2

0032

,100

37,7

00Q

r6,

490

9,74

012

,000

18,1

0022

,400

28,0

0032

,200

36,5

0040

,900

46,8

00Q

w5,

090

7,40

09,

020

13,5

0016

,800

21,3

0025

,000

28,8

0032

,800

38,5

00


ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)13

603

1100

00O

HW

est

Qs

1,80

02,

530

3,05

04,

540

5,68

07,

320

8,69

010

,200

11,8

0014

,300

Qr

2,57

03,

950

4,94

07,

630

9,56

012

,100

14,1

0016

,100

18,1

0021

,000

Qw

1,83

02,

570

3,10

04,

670

5,91

07,

690

9,16

010

,800

12,5

0015

,000

137

0311

0980

OH

Wes

tQ

s2.

44.

66.

512

.217

.024

.130

.237

.044

.455

.413

803

1111

50PA

Wes

tQ

s21

939

653

293

21,

240

1,68

02,

030

2,41

02,

810

3,38

013

903

1114

50O

HW

est

Qs

24.5

43.2

57.7

102

138

191

236

286

341

422

Qr

69.9

119

157

268

353

471

567

668

775

926

Qw

3455

.874

.514

220

429

637

245

454

066

314

003

1114

55O

HW

est

Qs

a 110

a 177

225

360

460

597

707

824

947

1,12

014

103

1114

70O

HW

est

Qs

21.8

43.8

62.8

129

190

289

380

487

612

811

142

0311

1500

OH

Wes

tQ

s1,

490

2,29

02,

840

4,24

05,

200

6,43

07,

370

8,31

09,

270

10,6

0014

303

1115

40O

HW

est

Qs

10.4

29.3

49.1

134

223

385

545

744

988

1,39

014

403

1115

48O

HW

est

Qs

1,32

02,

110

2,67

04,

240

5,40

07,

000

8,27

09,

620

11,0

0013

,000

Qr

1,88

02,

920

3,66

05,

710

7,19

09,

150

10,7

0012

,200

13,8

0016

,000

Qw

1,38

02,

180

2,76

04,

430

5,70

07,

460

8,86

010

,300

11,8

0013

,900

145

0311

2000

WV

Wes

tQ

s4,

900

7,36

09,

030

13,4

0016

,500

20,5

0023

,600

26,7

0029

,900

34,4

00Q

r4,

210

6,39

07,

920

12,1

0015

,000

18,9

0021

,900

24,9

0028

,000

32,2

00Q

w4,

840

7,29

08,

950

13,3

0016

,300

20,2

0023

,200

26,3

0029

,500

33,9

0014

603

1137

00W

VW

est

Qs

183

357

497

942

1,31

01,

850

2,31

02,

810

3,37

04,

180

Qr

193

320

415

688

893

1,18

01,

400

1,64

01,

880

2,23

0Q

w18

634

947

885

61,

140

1,52

01,

820

2,15

02,

490

2,99

014

703

1140

00O

HW

est

Qs

3,22

04,

920

6,09

09,

250

11,5

0014

,500

16,9

0019

,300

21,9

0025

,400

Qr

2,39

03,

690

4,61

07,

150

8,96

011

,400

13,2

0015

,100

17,1

0019

,700

Qw

3,16

04,

860

6,01

09,

090

11,3

0014

,100

16,3

0018

,700

21,1

0024

,400

148

0311

4240

OH

Wes

tQ

s20

.744

.665

133

191

280

356

441

535

674

Qr

3561

.181

.114

118

725

330

636

342

350

9Q

w24

.948

.869

.313

619

026

532

739

446

556

814

903

1145

00W

VW

est

Qs

9,21

011

,800

13,5

0017

,500

20,0

0023

,300

25,6

0028

,000

30,4

0033

,500

Qr

6,11

09,

180

11,3

0017

,100

21,2

0026

,500

30,5

0034

,600

38,8

0044

,400

Qw

9,07

011

,700

13,4

0017

,400

20,1

0023

,500

26,0

0028

,500

31,1

0034

,500

Table 3 59Ta

ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)15

003

1145

50W

VW

est

Qs

80.9

154

209

369

489

653

781

914

1,05

01,

240

Qr

51.6

88.9

117

202

267

358

432

511

594

712

Qw

70.7

135

182

303

384

493

579

672

770

909

151

0311

4600

WV

Wes

tQ

s11

619

825

741

753

268

480

192

21,

040

1,21

0Q

r66

113

149

254

335

449

540

637

739

883

Qw

9717

222

435

243

955

765

275

386

01,

010

152

0311

4650

WV

Wes

tQ

s33

862

483

41,

410

1,82

02,

350

2,75

03,

150

3,55

04,

080

Qr

170

283

367

611

795

1,05

01,

250

1,46

01,

690

2,00

0Q

w30

156

475

01,

210

1,49

01,

850

2,13

02,

410

2,71

03,

120

153

0311

5280

OH

Wes

tQ

s34

751

763

998

61,

250

1,62

01,

930

2,26

02,

620

3,15

0Q

r20

834

444

573

695

51,

260

1,50

01,

750

2,01

02,

380

Qw

296

467

583

893

1,12

01,

430

1,69

01,

960

2,26

02,

680

154

0311

5400

OH

Wes

tQ

s4,

070

5,98

07,

440

11,9

0015

,600

21,3

0026

,300

32,0

0038

,500

48,6

00Q

r3,

370

5,15

06,

410

9,83

012

,300

15,5

0017

,900

20,5

0023

,000

26,5

00Q

w4,

000

5,92

07,

370

11,7

0015

,100

20,2

0024

,400

29,2

0034

,500

42,4

0015

503

1154

10O

HW

est

Qs

a 6.0

613

.519

.940

.657

.782

.710

312

615

018

4Q

r12

21.5

29.1

51.9

70.1

96.2

118

141

166

201

Qw

7.81

15.6

22.4

44.8

63.3

89.8

111

135

159

195

156

0311

5500

OH

Wes

tQ

s4,

340

6,35

07,

690

11,2

0013

,600

16,7

0019

,100

21,6

0024

,100

27,5

00Q

r3,

940

6,00

07,

440

11,4

0014

,200

17,8

0020

,600

23,5

0026

,400

30,4

00Q

w4,

280

6,31

07,

660

11,2

0013

,700

17,0

0019

,500

22,1

0024

,800

28,4

0015

703

1155

10O

HW

est

Qs

a 110

175

224

371

488

659

804

965

1,14

01,

410

Qr

7813

317

529

739

152

262

773

885

61,

020

Qw

9816

321

034

244

358

670

382

996

61,

160

158

0311

5600

OH

Wes

tQ

s19

138

154

21,

090

1,57

02,

330

3,02

03,

800

4,70

06,

090

159

0311

5710

OH

Wes

tQ

sa 3

4.5

40.4

43.9

52.2

57.4

63.7

68.3

72.8

77.3

83.3

160

0315

0600

OH

Wes

tQ

s71

111

140

225

291

385

463

549

642

779

Qr

56.5

9712

821

929

038

946

955

364

376

9Q

w67

108

137

223

290

386

466

551

642

774


ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)16

103

1514

00W

VW

est

Qs

2,58

03,

890

4,90

08,

040

10,7

0014

,700

18,3

0022

,400

27,2

0034

,600

Qr

2,08

03,

230

4,05

06,

290

7,91

010

,100

11,7

0013

,400

15,1

0017

,500

Qw

2,53

03,

840

4,83

07,

820

10,2

0013

,700

16,7

0019

,900

23,6

0029

,100

162

0315

1500

WV

Wes

tQ

s3,

440

4,54

05,

190

6,70

07,

620

8,71

09,

480

10,2

0010

,900

11,8

00Q

r2,

670

4,11

05,

130

7,92

09,

930

12,6

0014

,600

16,7

0018

,800

21,7

00Q

w3,

370

4,51

05,

190

6,82

07,

890

9,26

010

,300

11,3

0012

,300

13,6

0016

303

1520

00W

VW

est

Qs

6,23

08,

350

9,69

012

,900

15,0

0017

,600

19,5

0021

,400

23,3

0025

,800

Qr

5,37

08,

100

10,0

0015

,200

18,8

0023

,600

27,2

0030

,900

34,6

0039

,700

Qw

6,18

08,

340

9,70

013

,100

15,3

0018

,200

20,4

0022

,500

24,7

0027

,600

164

0315

2200

WV

Wes

tQ

s16

626

934

455

671

593

71,

120

1,31

01,

510

1,80

0Q

r12

921

628

147

261

681

697

61,

140

1,32

01,

570

Qw

158

261

334

538

688

897

1,06

01,

240

1,43

01,

700

165

0315

2500

WV

Wes

tQ

s3,

380

5,10

06,

200

8,88

010

,600

12,7

0014

,100

15,6

0017

,000

18,7

00Q

r2,

530

3,89

04,

860

7,52

09,

430

11,9

0013

,900

15,9

0017

,900

20,7

00Q

w3,

200

4,90

05,

980

8,57

010

,300

12,4

0014

,000

15,7

0017

,300

19,5

0016

603

1530

00W

VW

est

Qs

4,01

05,

850

7,01

09,

790

11,5

0013

,700

15,2

0016

,600

18,0

0019

,800

Qr

2,81

04,

330

5,39

08,

320

10,4

0013

,200

15,3

0017

,500

19,7

0022

,700

Qw

3,90

05,

740

6,90

09,

640

11,4

0013

,600

15,2

0016

,800

18,4

0020

,400

167

0315

3500

WV

Wes

tQ

s14

,000

18,0

0020

,200

25,3

0028

,200

31,5

0033

,800

35,9

0037

,800

40,3

00Q

r10

,300

15,3

0018

,700

27,9

0034

,300

42,6

0048

,800

55,1

0061

,500

70,1

00Q

w13

,800

17,9

0020

,100

25,4

0028

,600

32,5

0035

,200

37,9

0040

,400

43,6

0016

803

1540

00W

VW

est

Qs

4,58

06,

540

7,79

010

,800

12,8

0015

,300

17,0

0018

,800

20,5

0022

,800

Qr

3,31

05,

060

6,29

09,

660

12,1

0015

,200

17,7

0020

,100

22,7

0026

,100

Qw

4,51

06,

480

7,73

010

,800

12,8

0015

,300

17,1

0018

,900

20,8

0023

,200

169

0315

4250

WV

Wes

tQ

s36

354

767

199

21,

210

1,50

01,

710

1,93

02,

160

2,46

0Q

r12

621

127

546

160

379

995

51,

120

1,29

01,

540

Qw

273

447

554

791

941

1,14

01,

310

1,48

01,

660

1,92

017

003

1545

00W

VW

est

Qs

2,31

03,

050

3,52

04,

680

5,45

06,

420

7,15

07,

880

8,62

09,

620

Qr

1,60

02,

500

3,15

04,

930

6,22

07,

930

9,26

010

,600

12,0

0014

,000

Qw

2,23

03,

010

3,49

04,

710

5,55

06,

670

7,53

08,

400

9,30

010

,500

Table 3 61Ta

ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)17

103

1550

00W

VW

est

Qs

19,2

0025

,700

29,6

0038

,500

43,9

0050

,300

54,8

0059

,000

63,1

0068

,300

Qr

15,2

0022

,300

27,1

0040

,000

48,9

0060

,300

68,9

0077

,500

86,2

0098

,000

Qw

18,9

0025

,500

29,5

0038

,600

44,4

0051

,400

56,5

0061

,400

66,3

0072

,500

172

0315

5200

WV

Wes

tQ

s5,

700

7,33

08,

260

10,3

0011

,500

12,8

0013

,700

14,5

0015

,300

16,2

00Q

r3,

370

5,15

06,

410

9,83

012

,300

15,5

0017

,900

20,5

0023

,000

26,5

00Q

w5,

170

6,96

07,

960

10,2

0011

,700

13,6

0015

,100

16,5

0018

,000

19,9

0017

303

1554

50W

VW

est

Qs

350

585

748

1,18

01,

490

1,88

02,

170

2,47

02,

770

3,17

0Q

r14

924

932

354

070

493

01,

110

1,30

01,

500

1,78

0Q

w29

150

764

998

11,

190

1,46

01,

670

1,89

02,

120

2,45

017

403

1555

00W

VW

est

Qs

8,87

012

,400

14,6

0019

,900

23,3

0027

,500

30,6

0033

,600

36,5

0040

,400

Qr

6,06

09,

110

11,2

0017

,000

21,0

0026

,300

30,3

0034

,300

38,5

0044

,100

Qw

8,71

012

,300

14,5

0019

,700

23,1

0027

,400

30,5

0033

,600

36,8

0040

,900

175

0315

5525

WV

Wes

tQ

s95

51,

480

1,86

02,

930

3,73

04,

830

5,73

06,

680

7,70

09,

150

Qr

670

1,07

01,

370

2,19

02,

790

3,61

04,

250

4,91

05,

600

6,55

0Q

w86

41,

380

1,73

02,

680

3,34

04,

240

4,95

05,

710

6,50

07,

630

176

0315

9540

OH

Wes

tQ

s2,

290

3,08

03,

650

5,31

06,

610

8,51

010

,100

11,9

0013

,900

16,9

00Q

r2,

680

4,13

05,

160

7,96

09,

970

12,6

0014

,700

16,7

0018

,900

21,8

00Q

w2,

320

3,13

03,

720

5,50

06,

930

9,02

010

,800

12,7

0014

,700

17,8

0017

703

1597

00W

VW

est

Qs

7812

015

124

531

942

752

062

373

790

8Q

r43

.375

99.4

172

227

306

370

438

510

612

Qw

65.9

108

137

219

280

367

440

520

606

733

178

0317

1500

VAC

entra

lQ

s17

,800

26,1

0032

,800

54,7

0074

,200

106,

000

135,

000

171,

000

214,

000

284,

000

179

0317

3000

VAC

entra

lQ

s3,

540

5,46

06,

800

10,4

0013

,100

16,6

0019

,400

22,3

0025

,300

29,6

00Q

r6,

110

8,46

010

,100

14,4

0017

,500

21,7

0024

,900

28,3

0031

,900

36,9

00Q

w3,

590

5,51

06,

860

10,6

0013

,200

16,8

0019

,700

22,6

0025

,700

30,0

0018

003

1755

00VA

Cen

tral

Qs

2,64

04,

340

5,47

08,

260

10,1

0012

,200

13,7

0015

,200

16,6

0018

,400

Qr

4,68

06,

520

7,80

011

,200

13,7

0017

,100

19,7

0022

,400

25,3

0029

,300

Qw

2,68

04,

380

5,51

08,

350

10,2

0012

,400

14,0

0015

,500

17,0

0018

,900


ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)18

103

1764

00W

VC

entra

lQ

s93

71,

260

1,46

01,

930

2,22

02,

570

2,82

03,

060

3,30

03,

600

Qr

1,21

01,

750

2,14

03,

210

4,00

05,

080

5,94

06,

840

7,80

09,

140

Qw

982

1,33

01,

560

2,18

02,

620

3,20

03,

630

4,07

04,

510

5,09

018

203

1765

00VA

Cen

tral

Qs

20,7

0030

,600

38,4

0063

,600

85,5

0012

0,00

015

2,00

018

9,00

023

3,00

030

4,00

018

303

1775

00W

VC

entra

lQ

sa 3

,040

3,63

03,

950

4,61

04,

980

5,38

05,

640

5,88

06,

100

6,37

0Q

r4,

020

5,63

06,

750

9,78

012

,000

14,9

0017

,200

19,6

0022

,200

25,7

00Q

w3,

180

3,86

04,

280

5,40

06,

200

7,21

07,

940

8,64

09,

320

10,2

0018

403

1777

00VA

Cen

tral

Qs

461

616

713

942

1,09

01,

270

1,40

01,

520

1,65

01,

810

Qr

965

1,41

01,

730

2,61

03,

270

4,17

04,

880

5,64

06,

430

7,56

0Q

w51

067

979

51,

130

1,37

01,

690

1,94

02,

180

2,42

02,

740

185

0317

8500

WV

Cen

tral

Qs

639

1,12

01,

460

2,40

03,

080

3,97

04,

650

5,34

06,

050

7,01

0Q

r79

31,

170

1,43

02,

180

2,73

03,

500

4,10

04,

740

5,42

06,

380

Qw

650

1,12

01,

460

2,38

03,

030

3,89

04,

560

5,24

05,

940

6,89

018

603

1790

00W

VC

entra

lQ

s4,

120

6,64

08,

270

12,2

0014

,700

17,6

0019

,600

21,5

0023

,300

25,6

00Q

r7,

880

10,8

0012

,900

18,2

0022

,100

27,2

0031

,200

35,4

0039

,800

45,9

00Q

w4,

200

6,72

08,

370

12,4

0015

,000

18,1

0020

,200

22,3

0024

,200

26,7

0018

703

1795

00W

VC

entra

lQ

s5,

590

7,62

08,

870

11,8

0013

,600

15,9

0017

,400

19,0

0020

,400

22,4

00Q

r8,

670

11,9

0014

,100

19,9

0024

,000

29,6

0033

,900

38,5

0043

,200

49,8

00Q

w5,

740

7,80

09,

100

12,3

0014

,400

17,1

0019

,000

20,9

0022

,700

25,1

0018

803

1800

00W

VC

entra

lQ

s27

,300

38,6

0047

,100

73,1

0094

,500

127,

000

156,

000

188,

000

226,

000

284,

000

189

0318

0350

WV

Cen

tral

Qs

32.4

44.3

52.9

78.5

98.8

129

154

183

215

263

Qr

37.3

6077

.212

917

022

827

632

738

346

2Q

w33

.447

57.1

89.9

118

158

193

230

272

333

190

0318

0500

WV

Cen

tral

Qs

2,84

03,

730

4,47

06,

990

9,30

013

,100

16,8

0021

,400

27,0

0036

,400

Qr

2,92

04,

120

4,97

07,

260

8,93

011

,200

13,0

0014

,800

16,8

0019

,500

Qw

2,84

03,

740

4,48

07,

000

9,28

013

,000

16,5

0020

,800

26,0

0034

,700

191

0318

0530

WV

Cen

tral

Qs

28.5

50.5

69.3

135

197

302

402

524

673

920

Qr

41.8

6786

143

188

252

305

362

422

510

Qw

31.2

53.5

72.6

138

194

282

360

449

552

711

Table 3 63Ta

ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)19

203

1806

80W

VC

entra

lQ

s45

.773

.995

.616

321

830

237

545

755

169

3Q

r48

.978

100

166

217

290

350

415

484

583

Qw

46.3

74.6

96.4

164

218

298

366

441

524

648

193

0318

1900

WV

Cen

tral

Qs

6.7

910

.414

16.4

19.4

21.7

23.9

26.2

29.3

Qr

4.07

6.98

9.28

16.6

22.6

31.5

38.9

47.1

55.9

68.8

Qw

5.93

8.52

10.1

14.8

18.3

23.4

27.6

31.9

36.4

42.8

194

0318

2000

WV

Cen

tral

Qs

3,28

04,

200

4,88

06,

860

8,43

010

,700

12,7

0014

,900

17,3

0021

,000

Qr

2,41

03,

430

4,14

06,

090

7,51

09,

440

11,0

0012

,600

14,2

0016

,600

Qw

3,18

04,

130

4,81

06,

760

8,27

010

,500

12,3

0014

,300

16,6

0019

,900

195

0318

2500

WV

Cen

tral

Qs

11,3

0015

,300

18,2

0026

,300

32,6

0041

,400

48,8

0056

,900

65,8

0078

,800

Qr

10,5

0014

,300

16,9

0023

,700

28,6

0035

,100

40,2

0045

,500

51,0

0058

,700

Qw

11,3

0015

,300

18,2

0026

,200

32,4

0041

,100

48,4

0056

,300

64,9

0077

,600

196

0318

2700

WV

Cen

tral

Qs

6,02

07,

910

9,24

013

,000

15,8

0019

,800

23,1

0026

,700

30,7

0036

,500

Qr

3,13

04,

430

5,32

07,

770

9,54

011

,900

13,8

0015

,800

17,9

0020

,800

Qw

5,65

07,

540

8,81

012

,200

14,6

0018

,100

20,9

0024

,000

27,4

0032

,300

197

0318

3000

WV

Cen

tral

Qs

1,29

02,

030

2,56

04,

020

5,09

06,

560

7,72

08,

950

10,2

0012

,100

Qr

1,85

02,

650

3,21

04,

770

5,90

07,

450

8,67

09,

950

11,3

0013

,200

Qw

1,32

02,

060

2,60

04,

080

5,17

06,

670

7,85

09,

090

10,4

0012

,200

198

0318

3500

WV

Cen

tral

Qs

20,3

0028

,600

33,9

0046

,800

55,0

0065

,200

72,6

0079

,900

87,1

0096

,600

Qr

24,5

0032

,500

37,9

0052

,000

61,8

0074

,800

84,9

0095

,400

106,

000

121,

000

Qw

20,4

0028

,600

33,9

0046

,800

55,2

0065

,500

73,0

0080

,400

87,7

0097

,300

199

0318

3550

WV

Cen

tral

Qs

187

246

280

357

402

454

490

523

555

594

Qr

114

178

225

363

469

619

741

871

1,01

01,

210

Qw

169

232

269

358

421

504

568

632

697

784

200

0318

3570

WV

Cen

tral

Qs

55.4

96.9

130

232

317

445

556

680

820

1,03

0Q

r71

.711

314

423

630

840

949

158

067

581

0Q

w58

.599

.713

323

331

443

253

164

075

993

520

103

1840

00W

VC

entra

lQ

s24

,000

31,7

0036

,700

49,2

0057

,500

68,2

0076

,200

84,4

0092

,700

104,

000

Qr

28,6

0037

,900

44,1

0060

,100

71,3

0086

,100

97,5

0010

9,00

012

2,00

013

9,00

0Q

w24

,100

31,8

0036

,800

49,4

0057

,900

68,8

0077

,100

85,4

0093

,900

106,

000


ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)20

203

1842

00W

VC

entra

lQ

s21

042

059

91,

210

1,77

02,

650

3,44

04,

370

5,45

07,

130

Qr

230

351

439

694

888

1,16

01,

380

1,61

01,

850

2,20

0Q

w21

341

157

61,

100

1,52

02,

150

2,69

03,

300

3,99

05,

040

203

0318

4500

WV

Cen

tral

Qs

42,7

0063

,200

77,7

0011

9,00

014

9,00

019

2,00

022

7,00

026

5,00

030

6,00

036

5,00

020

403

1850

00W

VC

entra

lQ

s61

997

21,

230

1,94

02,

480

3,22

03,

830

4,47

05,

160

6,14

0Q

r1,

250

1,81

02,

210

3,32

04,

140

5,25

06,

140

7,07

08,

050

9,44

0Q

w64

61,

000

1,27

02,

030

2,61

03,

410

4,06

04,

750

5,48

06,

520

205

0318

5020

WV

Cen

tral

Qs

1122

.130

.856

.475

.810

212

314

416

719

7Q

r21

.635

.245

.777

.610

314

017

020

323

828

8Q

w12

.924

.333

.561

.884

115

140

166

193

232

206

0318

5500

WV

Cen

tral

Qs

51,7

0075

,400

91,0

0013

1,00

015

7,00

019

1,00

021

6,00

024

2,00

026

8,00

030

2,00

020

703

1860

00W

VC

entra

lQ

s50

,500

77,6

0095

,700

142,

000

174,

000

214,

000

244,

000

274,

000

304,

000

345,

000

208

0318

6500

WV

Cen

tral

Qs

4,81

06,

670

7,98

011

,700

14,5

0018

,400

21,7

0025

,200

29,1

0034

,700

Qr

2,81

03,

990

4,80

07,

030

8,65

010

,800

12,6

0014

,400

16,3

0018

,900

Qw

4,74

06,

600

7,89

011

,500

14,2

0017

,900

21,0

0024

,400

28,0

0033

,400

209

0318

7000

WV

Cen

tral

Qs

6,57

09,

290

11,2

0016

,400

20,2

0025

,500

29,8

0034

,400

39,2

0046

,300

Qr

4,92

06,

860

8,20

011

,800

14,4

0017

,900

20,6

0023

,500

26,4

0030

,600

Qw

6,52

09,

230

11,1

0016

,200

19,9

0025

,100

29,2

0033

,600

38,3

0045

,100

210

0318

7300

WV

Cen

tral

Qs

419

632

790

1,27

01,

650

2,21

02,

700

3,24

03,

850

4,78

0Q

r26

840

750

880

01,

020

1,33

01,

580

1,84

02,

120

2,52

0Q

w39

660

375

11,

170

1,50

01,

970

2,37

02,

810

3,29

04,

020

211

0318

7500

WV

Cen

tral

Qs

2,89

04,

040

4,85

07,

090

8,76

011

,100

13,0

0015

,000

17,2

0020

,400

Qr

1,84

02,

640

3,20

04,

750

5,88

07,

420

8,63

09,

910

11,3

0013

,200

Qw

2,84

03,

980

4,77

06,

930

8,52

010

,700

12,5

0014

,400

16,5

0019

,500

212

0318

9000

WV

Cen

tral

Qs

5,03

06,

920

8,36

012

,800

16,4

0022

,000

26,9

0032

,600

39,1

0049

,300

Qr

3,25

04,

590

5,52

08,

040

9,87

012

,300

14,3

0016

,300

18,5

0021

,500

Qw

4,93

06,

810

8,22

012

,400

15,8

0020

,900

25,4

0030

,400

36,2

0045

,100

213

0318

9100

WV

Cen

tral

Qs

14,7

0021

,300

25,8

0037

,800

46,4

0058

,000

67,1

0076

,600

86,6

0010

1,00

0Q

r10

,300

14,0

0016

,600

23,3

0028

,100

34,5

0039

,500

44,7

0050

,100

57,7

00Q

w14

,500

21,0

0025

,500

37,0

0045

,100

56,0

0064

,500

73,5

0082

,900

96,0

00

Table 3 65Ta

ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)21

403

1895

00W

VC

entra

lQ

s15

,500

20,5

0024

,100

34,3

0042

,100

53,2

0062

,300

72,4

0083

,400

99,6

00Q

r13

,000

17,5

0020

,700

28,9

0034

,700

42,4

0048

,400

54,7

0061

,200

70,3

00Q

w15

,400

20,4

0024

,000

34,0

0041

,600

52,3

0061

,100

70,7

0081

,200

96,6

0021

503

1896

50W

VC

entra

lQ

s86

.213

717

326

933

642

549

456

463

773

6Q

r85

133

169

276

359

475

571

672

781

937

Qw

85.9

136

172

270

343

442

521

603

689

810

216

0319

0000

WV

Cen

tral

Qs

3,88

05,

180

6,00

08,

020

9,35

011

,000

12,3

0013

,500

14,7

0016

,400

Qr

5,89

08,

160

9,73

013

,900

16,9

0021

,000

24,1

0027

,400

30,9

0035

,700

Qw

3,94

05,

250

6,09

08,

230

9,68

011

,500

12,9

0014

,300

15,7

0017

,500

217

0319

0100

WV

Cen

tral

Qs

581

1,15

01,

650

3,46

05,

190

8,10

010

,900

14,3

0018

,300

25,0

00Q

r59

888

61,

090

1,68

02,

110

2,72

03,

200

3,71

04,

240

5,01

0Q

w58

51,

090

1,52

02,

840

3,89

05,

450

6,80

08,

340

10,1

0012

,800

218

0319

0400

WV

Cen

tral

Qs

5,31

07,

430

8,91

013

,000

15,9

0020

,000

23,4

0026

,900

30,7

0036

,100

Qr

7,34

010

,100

12,0

0017

,100

20,7

0025

,500

29,3

0033

,200

37,4

0043

,100

Qw

5,39

07,

520

9,02

013

,200

16,2

0020

,500

23,9

0027

,500

31,3

0036

,800

219

0319

0500

WV

Cen

tral

Qs

202

278

324

434

504

587

646

704

760

833

Qr

124

193

244

393

508

668

799

939

1,09

01,

300

Qw

182

260

307

423

505

615

700

788

878

1,00

022

003

1914

00W

VC

entra

lQ

s86

.316

823

746

967

499

81,

290

1,63

02,

020

2,62

0Q

r11

517

922

736

647

362

474

787

81,

020

1,22

0Q

w90

.216

923

644

762

288

21,

110

1,36

01,

640

2,06

022

103

1915

00W

VC

entra

lQ

s1,

160

1,97

02,

600

4,49

06,

020

8,28

010

,200

12,3

0014

,700

18,2

00Q

r97

71,

430

1,75

02,

640

3,30

04,

210

4,93

05,

690

6,50

07,

630

Qw

1,15

01,

940

2,55

04,

310

5,68

07,

660

9,31

011

,100

13,1

0016

,100

222

0319

2000

WV

Cen

tral

Qs

26,8

0035

,500

41,3

0056

,800

67,8

0082

,700

94,5

0010

7,00

012

0,00

013

8,00

0Q

r23

,700

31,5

0036

,800

50,5

0060

,000

72,7

0082

,600

92,8

0010

3,00

011

8,00

0Q

w26

,700

35,4

0041

,100

56,4

0067

,300

81,9

0093

,400

105,

000

118,

000

136,

000

223

0319

2500

WV

Cen

tral

Qs

21,3

0030

,500

37,0

0054

,900

68,3

0086

,900

102,

000

118,

000

136,

000

161,

000

Qr

25,1

0033

,300

38,9

0053

,200

63,2

0076

,500

86,8

0097

,500

109,

000

124,

000

Qw

21,6

0030

,700

37,2

0054

,700

67,5

0085

,000

98,9

0011

4,00

012

9,00

015

2,00

0


ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)22

403

1930

00W

VC

entra

lQ

s72

,300

103,

000

123,

000

174,

000

207,

000

249,

000

281,

000

312,

000

344,

000

387,

000

225

0319

3725

WV

Cen

tral

Qs

10.2

1518

.327

.333

.842

.649

.556

.864

.575

.2Q

r12

.120

.126

.345

.661

83.5

102

122

144

176

Qw

10.6

1619

.831

.841

.455

.266

.578

.591

.310

922

603

1938

30W

VC

entra

lQ

s11

618

023

240

857

184

01,

100

1,41

01,

800

2,43

0Q

r57

9111

619

125

033

340

247

555

366

6Q

w10

416

421

135

247

165

682

41,

020

1,25

01,

620

227

0319

4700

WV

Cen

tral

Qs

7,32

09,

850

11,7

0016

,800

20,8

0026

,500

31,2

0036

,400

42,1

0050

,600

Qr

5,49

07,

630

9,10

013

,100

15,9

0019

,700

22,7

0025

,800

29,1

0033

,600

Qw

7,27

09,

800

11,6

0016

,700

20,6

0026

,100

30,7

0035

,700

41,2

0049

,400

228

0319

5000

WV

Cen

tral

Qs

8,34

010

,100

11,1

0013

,600

15,2

0017

,000

18,4

0019

,700

21,1

0022

,800

229

0319

5100

WV

Cen

tral

Qs

1,47

02,

010

2,40

03,

520

4,38

05,

630

6,67

07,

820

9,09

011

,000

Qr

1,23

01,

790

2,18

03,

280

4,09

05,

190

6,06

06,

980

7,96

09,

330

Qw

1,42

01,

970

2,36

03,

460

4,30

05,

480

6,46

07,

520

8,66

010

,300

230

0319

5250

WV

Cen

tral

Qs

1,49

02,

060

2,46

03,

590

4,45

05,

670

6,67

07,

750

8,94

010

,700

Qr

1,12

01,

620

1,98

02,

990

3,73

04,

740

5,55

06,

400

7,29

08,

560

Qw

1,46

02,

030

2,43

03,

530

4,36

05,

530

6,49

07,

520

8,65

010

,300

231

0319

5500

WV

Cen

tral

Qs

12,6

0016

,800

19,6

0026

,900

32,1

0039

,000

44,5

0050

,200

56,2

0064

,700

Qr

10,5

0014

,300

16,9

0023

,800

28,7

0035

,200

40,3

0045

,600

51,1

0058

,800

Qw

12,5

0016

,700

19,4

0026

,600

31,7

0038

,500

43,9

0049

,500

55,4

0063

,700

232

0319

5600

WV

Cen

tral

Qs

577

773

902

1,24

01,

470

1,77

02,

010

2,25

02,

500

2,85

0Q

r18

227

935

055

871

693

81,

120

1,31

01,

510

1,80

0Q

w50

770

282

11,

100

1,30

01,

560

1,77

01,

990

2,22

02,

550

233

0319

7000

WV

Wes

tQ

s18

,100

23,5

0027

,200

37,3

0044

,600

54,5

0062

,500

71,0

0080

,000

93,0

00Q

r12

,300

18,1

0022

,100

32,8

0040

,200

49,7

0056

,900

64,2

0071

,500

81,4

00Q

w17

,600

23,1

0026

,900

36,9

0044

,000

53,8

0061

,500

69,7

0078

,300

90,5

0023

403

1971

50W

VW

est

Qs

133

187

222

312

373

452

511

572

634

718

Qr

9716

421

536

347

663

375

989

21,

030

1,23

0Q

w12

518

322

132

239

950

659

168

077

390

0

Table 3 67Ta

ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)23

503

1979

00W

VW

est

Qs

33.1

53.7

68.8

112

146

193

231

273

317

381

Qr

3357

.676

.613

317

724

029

034

440

248

3Q

w33

.154

.770

.711

915

821

426

030

936

243

623

603

1983

50W

VW

est

Qs

683

1,44

02,

120

4,57

06,

880

10,7

0014

,300

18,6

0023

,700

31,9

00Q

r1,

340

2,10

02,

650

4,17

05,

280

6,75

07,

890

9,07

010

,300

11,9

00Q

w80

71,

550

2,22

04,

450

6,28

08,

870

11,0

0013

,300

15,8

0019

,500

237

0319

8450

WV

Wes

tQ

s16

827

736

262

985

21,

190

1,49

01,

840

2,23

02,

830

Qr

272

446

575

945

1,22

01,

600

1,90

02,

210

2,54

03,

000

Qw

184

298

389

687

941

1,32

01,

630

1,98

02,

350

2,90

023

803

1985

00W

VW

est

Qs

5,32

08,

280

10,4

0016

,400

20,9

0027

,100

32,2

0037

,500

43,3

0051

,600

Qr

5,41

08,

160

10,1

0015

,300

19,0

0023

,700

27,4

0031

,100

34,9

0040

,000

Qw

5,32

08,

280

10,4

0016

,300

20,8

0026

,900

31,8

0036

,900

42,4

0050

,300

239

0319

8780

WV

Wes

tQ

s56

.294

.412

219

925

533

139

145

351

760

7Q

r95

.516

221

235

846

962

474

888

01,

020

1,21

0Q

w65

.510

713

924

032

344

253

863

874

288

624

003

1988

00W

VW

est

Qs

19.8

4976

172

258

391

507

637

781

995

Qr

68.7

117

154

263

347

464

558

658

763

912

Qw

27.5

58.9

88.3

195

287

420

530

647

772

951

241

0319

9000

WV

Wes

tQ

s4,

110

7,08

09,

290

15,7

0020

,500

27,3

0032

,700

38,5

0044

,600

53,3

00Q

r4,

070

6,19

07,

670

11,7

0014

,600

18,4

0021

,200

24,2

0027

,200

31,3

00Q

w4,

110

7,04

09,

220

15,4

0019

,900

26,1

0031

,000

36,1

0041

,600

49,2

0024

203

1993

00W

VW

est

Qs

167

317

432

762

1,01

01,

340

1,61

01,

880

2,16

02,

540

Qr

384

625

801

1,30

01,

680

2,19

02,

590

3,01

03,

440

4,05

0Q

w20

235

848

487

41,

190

1,62

01,

960

2,31

02,

680

3,17

024

303

1994

00W

VW

est

Qs

5,01

07,

920

10,0

0016

,100

20,8

0027

,300

32,7

0038

,500

44,8

0053

,800

Qr

4,62

07,

000

8,67

013

,200

16,4

0020

,600

23,8

0027

,100

30,4

0034

,900

Qw

4,92

07,

740

9,74

015

,300

19,2

0024

,500

28,5

0032

,800

37,3

0043

,600

244

0320

0500

WV

Wes

tQ

s11

,800

17,1

0020

,300

28,1

0032

,900

38,6

0042

,600

46,5

0050

,200

55,0

00Q

r9,

890

14,7

0018

,000

26,8

0032

,900

40,9

0046

,900

53,0

0059

,100

67,5

00Q

w11

,700

17,0

0020

,200

28,0

0032

,900

38,8

0043

,100

47,3

0051

,300

56,6

00


ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)24

503

2006

00W

VW

est

Qs

43.1

6784

131

166

214

252

292

335

395

Qr

51.2

88.2

116

200

265

356

429

507

590

706

Qw

45.4

71.6

9115

120

027

133

039

145

654

724

603

2010

00W

VW

est

Qs

3,81

05,

590

6,76

09,

680

11,6

0014

,000

15,9

0017

,600

19,4

0021

,800

Qr

3,71

05,

650

7,02

010

,700

13,4

0016

,900

19,5

0022

,300

25,0

0028

,800

Qw

3,80

05,

590

6,77

09,

740

11,8

0014

,300

16,3

0018

,200

20,2

0022

,800

247

0320

1405

WV

Wes

tQ

s1,

200

1,75

02,

100

2,97

03,

530

4,22

04,

720

5,22

05,

710

6,35

0Q

r70

01,

120

1,42

02,

280

2,91

03,

760

4,42

05,

110

5,82

06,

810

Qw

1,02

01,

570

1,91

02,

720

3,26

03,

990

4,57

05,

160

5,77

06,

610

248

0320

1410

WV

Wes

tQ

s46

363

173

498

01,

140

1,32

01,

460

1,59

01,

720

1,89

0Q

r29

147

661

41,

010

1,30

01,

700

2,02

02,

350

2,70

03,

180

Qw

419

602

712

986

1,18

01,

450

1,66

01,

870

2,09

02,

390

249

0320

1420

WV

Wes

tQ

s15

922

225

934

539

745

850

054

057

862

6Q

r98

166

218

368

482

641

769

903

1,05

01,

240

Qw

140

209

249

352

427

530

612

697

783

899

250

0320

1440

WV

Wes

tQ

s16

024

130

147

661

581

798

91,

180

1,39

01,

700

Qr

5910

113

322

730

040

248

457

266

479

5Q

w12

119

825

037

946

959

570

181

794

41,

130

251

0320

1480

WV

Wes

tQ

s48

.995

.813

324

332

844

754

364

475

089

8Q

r43

.375

99.4

172

227

306

370

438

510

612

Qw

47.2

90.6

124

218

285

377

450

528

611

729

252

0320

2000

OH

Wes

tQ

s3,

570

5,01

06,

030

8,85

011

,000

13,9

0016

,300

18,9

0021

,700

25,7

0025

303

2022

45W

VW

est

Qs

a 232

a 363

458

735

949

1,26

01,

510

1,79

02,

090

2,54

0Q

r19

031

540

967

888

01,

160

1,38

01,

610

1,86

02,

200

Qw

220

352

447

717

923

1,21

01,

450

1,70

01,

970

2,35

025

403

2024

00W

VW

est

Qs

2,96

05,

820

8,18

015

,900

22,3

0032

,200

40,6

0050

,200

60,8

0076

,600

Qr

4,49

06,

810

8,43

012

,800

16,0

0020

,100

23,2

0026

,400

29,6

0034

,000

Qw

3,05

05,

870

8,19

015

,600

21,5

0030

,100

37,1

0044

,800

53,1

0065

,300

Table 3 69Ta

ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)25

503

2024

80W

VW

est

Qs

115

251

363

712

988

1,38

01,

690

2,02

02,

370

2,85

0Q

r26

042

855

390

91,

180

1,54

01,

830

2,13

02,

450

2,89

0Q

w13

226

938

374

51,

030

1,42

01,

740

2,06

02,

400

2,86

025

603

2027

50W

VW

est

Qs

2,41

03,

560

4,34

06,

400

7,87

09,

810

11,3

0012

,900

14,5

0016

,800

Qr

2,28

03,

530

4,41

06,

840

8,59

010

,900

12,7

0014

,500

16,4

0018

,900

Qw

2,40

03,

560

4,35

06,

450

7,96

010

,000

11,6

0013

,200

14,9

0017

,300

257

0320

3000

WV

Wes

tQ

s10

,200

16,3

0020

,200

30,1

0036

,500

44,3

0049

,900

55,3

0060

,600

67,3

00Q

r8,

970

13,3

0016

,400

24,5

0030

,100

37,4

0043

,000

48,6

0054

,300

62,0

00Q

w10

,100

16,2

0020

,000

29,8

0036

,000

43,5

0049

,000

54,4

0059

,700

66,5

0025

803

2036

00W

VW

est

Qs

11,2

0019

,300

24,9

0039

,400

49,0

0060

,900

69,5

0077

,900

86,1

0096

,700

Qr

9,64

014

,300

17,5

0026

,100

32,2

0040

,000

45,8

0051

,800

57,8

0066

,000

Qw

11,0

0018

,700

24,1

0037

,100

45,3

0055

,100

62,3

0069

,400

76,5

0085

,900

259

0320

4000

WV

Wes

tQ

s12

,000

18,7

0023

,000

32,9

0038

,900

45,9

0050

,600

55,1

0059

,200

64,4

00Q

r12

,900

19,0

0023

,200

34,4

0042

,100

52,1

0059

,600

67,1

0074

,800

85,1

00Q

w12

,000

18,7

0023

,000

33,0

0039

,100

46,4

0051

,500

56,3

0060

,900

66,6

0026

003

2045

00W

VW

est

Qs

3,33

05,

040

6,29

09,

940

12,8

0016

,900

20,3

0024

,100

28,2

0034

,300

Qr

3,92

05,

960

7,40

011

,300

14,1

0017

,700

20,5

0023

,400

26,3

0030

,200

Qw

3,37

05,

080

6,34

010

,000

12,9

0017

,000

20,3

0024

,000

27,9

0033

,500

261

0320

5995

OH

Wes

tQ

s62

.691

.811

317

522

429

435

441

949

159

9Q

r44

.777

.410

217

723

431

538

145

052

462

9Q

w57

.488

.611

117

622

730

336

643

450

761

426

203

2064

50W

VW

est

Qs

a 246

484

678

1,29

01,

790

2,53

03,

160

3,85

04,

600

5,70

0Q

r16

527

435

659

377

21,

020

1,22

01,

420

1,64

01,

940

Qw

215

414

567

968

1,23

01,

580

1,87

02,

170

2,50

02,

970

263

0320

6600

WV

Wes

tQ

s98

01,

460

1,77

02,

560

3,09

03,

750

4,23

04,

720

5,20

05,

850

Qr

923

1,46

01,

860

2,95

03,

750

4,82

05,

660

6,52

07,

410

8,65

0Q

w97

51,

460

1,78

02,

600

3,16

03,

900

4,46

05,

020

5,59

06,

350

264

0320

6800

WV

Wes

tQ

s2,

020

2,83

03,

390

4,87

05,

940

7,38

08,

520

9,72

011

,000

12,8

00Q

r2,

460

3,79

04,

740

7,33

09,

200

11,7

0013

,600

15,5

0017

,500

20,2

00Q

w2,

090

2,94

03,

540

5,26

06,

590

8,44

09,

910

11,4

0013

,000

15,2

00


ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)26

503

2070

00W

VW

est

Qs

3,30

05,

160

6,48

010

,100

12,7

0016

,200

19,0

0022

,000

25,0

0029

,300

266

0320

7020

WV

Wes

tQ

s3,

330

5,18

06,

470

9,98

012

,500

15,9

0018

,500

21,3

0024

,200

28,2

00Q

r4,

420

6,71

08,

310

12,7

0015

,700

19,8

0022

,900

26,0

0029

,200

33,6

00Q

w3,

400

5,25

06,

560

10,2

0012

,800

16,4

0019

,200

22,1

0025

,000

29,2

0026

703

2074

00VA

Wes

tQ

s21

955

186

32,

010

3,07

04,

760

6,27

08,

000

9,96

012

,900

Qr

560

901

1,15

01,

850

2,37

03,

070

3,62

04,

190

4,79

05,

610

Qw

247

578

888

1,98

02,

920

4,29

05,

420

6,65

08,

000

9,96

026

803

2075

00VA

Wes

tQ

s3,

890

7,09

09,

390

15,5

0019

,800

25,2

0029

,200

33,1

0037

,000

42,1

00Q

r3,

720

5,67

07,

040

10,8

0013

,400

16,9

0019

,600

22,3

0025

,100

28,9

00Q

w3,

880

7,01

09,

250

15,1

0019

,000

23,9

0027

,500

31,0

0034

,600

39,3

0026

903

2078

00VA

Wes

tQ

s3,

400

6,41

08,

840

16,5

0022

,900

32,5

0040

,700

49,8

0060

,000

75,1

00Q

r4,

390

6,66

08,

250

12,6

0015

,600

19,7

0022

,700

25,8

0029

,000

33,4

00Q

w3,

460

6,42

08,

810

16,2

0022

,000

30,2

0037

,000

44,4

0052

,400

64,0

0027

003

2079

62K

YW

est

Qs

20.8

44.3

64.1

128

182

261

328

402

481

597

Qr

48.9

84.4

112

192

254

341

412

487

567

679

Qw

28.4

53.7

75.8

151

213

302

374

451

532

648

271

0320

8000

KY

Wes

tQ

s6,

260

9,71

012

,100

18,2

0022

,400

27,9

0032

,000

36,2

0040

,500

46,3

00Q

r5,

420

8,18

010

,100

15,3

0019

,000

23,8

0027

,400

31,2

0034

,900

40,1

00Q

w6,

180

9,60

012

,000

17,9

0021

,900

27,1

0031

,100

35,1

0039

,200

44,8

0027

203

2085

00VA

Wes

tQ

s5,

190

9,59

012

,900

22,4

0029

,400

38,9

0046

,300

54,0

0061

,900

72,8

00Q

r4,

260

6,47

08,

030

12,2

0015

,200

19,2

0022

,100

25,2

0028

,300

32,5

00Q

w5,

150

9,49

012

,700

21,8

0028

,300

36,8

0043

,400

50,2

0057

,200

66,8

0027

303

2089

50VA

Wes

tQ

s1,

040

1,83

02,

470

4,52

06,

280

9,01

011

,400

14,2

0017

,400

22,3

00Q

r1,

400

2,20

02,

770

4,35

05,

490

7,02

08,

210

9,43

010

,700

12,4

00Q

w1,

060

1,85

02,

490

4,51

06,

180

8,67

010

,800

13,2

0015

,800

19,8

0027

403

2090

00VA

Wes

tQ

s4,

630

7,44

09,

410

14,8

0018

,600

23,6

0027

,600

31,6

0035

,800

41,6

00Q

r3,

500

5,35

06,

650

10,2

0012

,700

16,0

0018

,600

21,2

0023

,800

27,4

00Q

w4,

530

7,30

09,

220

14,3

0017

,800

22,3

0025

,800

29,4

0033

,100

38,2

00

Table 3 71Ta

ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)27

503

2095

75K

YW

est

Qs

164

232

282

425

538

702

841

995

1,17

01,

420

Qr

137

230

299

501

654

865

1,03

01,

210

1,40

01,

660

Qw

156

232

286

449

582

775

934

1,10

01,

290

1,55

027

603

2100

00K

YW

est

Qs

1,18

02,

020

2,59

04,

050

5,00

06,

180

7,01

07,

820

8,60

09,

600

Qr

1,23

01,

940

2,45

03,

860

4,89

06,

260

7,33

08,

420

9,56

011

,100

Qw

1,18

02,

020

2,58

04,

040

5,00

06,

180

7,05

07,

900

8,73

09,

810

277

0321

1500

KY

Wes

tQ

s2,

150

3,41

04,

270

6,59

08,

210

10,3

0012

,000

13,7

0015

,400

17,7

00Q

r3,

320

5,08

06,

320

9,70

012

,100

15,3

0017

,700

20,2

0022

,700

26,2

00Q

w2,

360

3,64

04,

560

7,22

09,

220

11,9

0014

,000

16,1

0018

,300

21,2

0027

803

2120

00K

YW

est

Qs

2,06

03,

820

5,18

09,

170

12,2

0016

,500

19,9

0023

,500

27,4

0032

,700

Qr

1,96

03,

040

3,81

05,

930

7,46

09,

490

11,1

0012

,700

14,3

0016

,600

Qw

2,05

03,

760

5,06

08,

740

11,4

0014

,900

17,6

0020

,500

23,5

0027

,600

279

0321

2750

WV

Wes

tQ

s1,

140

2,23

03,

110

5,93

08,

270

11,7

0014

,700

18,0

0021

,600

27,0

00Q

r2,

920

4,48

05,

580

8,60

010

,800

13,6

0015

,800

18,0

0020

,300

23,4

00Q

w1,

290

2,39

03,

300

6,26

08,

690

12,2

0015

,000

18,0

0021

,200

25,8

0028

003

2129

80W

VW

est

Qs

2,44

04,

170

5,38

08,

570

10,7

0013

,500

15,6

0017

,600

19,7

0022

,300

Qr

3,36

05,

130

6,38

09,

800

12,2

0015

,400

17,9

0020

,400

23,0

0026

,400

Qw

2,54

04,

250

5,47

08,

730

11,0

0013

,900

16,2

0018

,400

20,6

0023

,500

281

0321

3000

WV

Wes

tQ

s5,

500

9,49

012

,300

20,1

0025

,500

32,7

0038

,100

43,6

0049

,200

56,7

00Q

r6,

570

9,85

012

,100

18,3

0022

,600

28,3

0032

,600

36,9

0041

,300

47,3

00Q

w5,

550

9,50

012

,300

20,0

0025

,300

32,2

0037

,400

42,7

0048

,000

55,3

0028

203

2135

00W

VW

est

Qs

508

1,12

01,

640

3,40

04,

920

7,22

09,

200

11,4

0013

,800

17,4

00Q

r78

21,

250

1,58

02,

530

3,22

04,

150

4,88

05,

640

6,42

07,

490

Qw

525

1,13

01,

640

3,31

04,

680

6,64

08,

260

10,0

0011

,900

14,7

0028

303

2137

00W

VW

est

Qs

7,95

013

,300

17,4

0029

,300

38,6

0051

,900

62,9

0074

,800

87,7

0010

6,00

0Q

r10

,500

15,6

0019

,100

28,4

0034

,900

43,3

0049

,600

56,0

0062

,500

71,2

00Q

w8,

090

13,4

0017

,500

29,2

0038

,200

50,7

0060

,800

71,5

0082

,900

99,3

0028

403

2140

00W

VW

est

Qs

10,4

0018

,200

24,1

0041

,400

54,7

0073

,500

88,8

0010

5,00

012

3,00

014

8,00

0


ble

3.

Floo

d-fre

quen

cy d

isch

arge

s fo

r the

290

U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

on

rura

l, un

regu

late

d st

ream

s in

Wes

t Virg

inia

and

adj

acen

t sta

tes.

—Co

ntin

ued

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

%, p

erce

nt; A

OP,

ann

ual-o

ccur

renc

e pr

obab

ility

; WV,

Wes

t Virg

inia

; MD

, Mar

ylan

d; V

A, V

irgin

ia; O

H, O

hio;

PA

, Pen

nsyl

vani

a; K

Y, K

entu

cky;

Eas

t, Ea

ster

n Pa

nhan

dle

Reg

ion;

Cen

tral,

Cen

tral M

ount

ains

Reg

ion;

Wes

t, W

este

rn P

late

aus R

egio

n. F

lood

-fre

quen

cy d

isch

arge

s are

pre

sent

ed in

the

follo

win

g es

timat

e-ty

pe o

rder

: firs

t lin

e (Q

s), fr

om th

e sy

stem

atic

an

d hi

stor

ical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia sk

ew (A

tkin

s and

oth

ers,

2009

); se

cond

line

(Qr),

from

the

regi

onal

ized

re

gres

sion

equ

atio

n; a

nd th

ird li

ne (Q

w),

from

wei

ghtin

g (1

) the

syst

emat

ic a

nd h

isto

rical

reco

rd u

sing

gui

delin

es e

stab

lishe

d by

the

Inte

rage

ncy

Adv

isor

y C

omm

ittee

on

Wat

er D

ata

(198

2) w

ith th

e W

est V

irgin

ia

skew

(Atk

ins a

nd o

ther

s, 20

09) a

nd (2

) the

regi

onal

ized

regr

essi

on e

quat

ion,

usi

ng th

e nu

mbe

r of y

ears

of p

eak

disc

harg

e an

d eq

uiva

lent

yea

rs o

f rec

ord.

Sha

ding

indi

cate

s the

44

stre

amga

ge st

atio

ns re

mov

ed

from

con

side

ratio

n as

par

t of t

he re

gion

al re

gres

sion

ana

lysi

s]

Iden

tifica

tion

num

ber

Stre

amga

ge

stat

ion

num

ber

Stat

eRe

gion

Estim

ate

type

Floo

d di

scha

rge,

in c

ubic

feet

per

sec

ond

1.1-

year

(9

0% A

OP)

1.5-

year

(6

7% A

OP)

2-ye

ar

(50%

AO

P)5-

year

(2

0% A

OP)

10-y

ear

(10%

AO

P)25

-yea

r (4

% A

OP)

50-y

ear

(2%

AO

P)10

0-ye

ar

(1%

AO

P)20

0-ye

ar

(0.5

% A

OP)

500-

year

(0

.2%

AO

P)28

503

2145

00W

VW

est

Qs

10,5

0018

,000

23,6

0039

,200

50,8

0066

,600

79,2

0092

,200

106,

000

125,

000

Qr

13,4

0019

,700

24,0

0035

,500

43,4

0053

,700

61,4

0069

,200

77,0

0087

,600

Qw

10,6

0018

,000

23,6

0039

,100

50,4

0065

,700

77,7

0090

,100

103,

000

121,

000

286

0321

4900

WV

Wes

tQ

s9,

240

14,9

0018

,900

30,0

0038

,200

49,3

0058

,000

67,2

0076

,900

90,4

00Q

r15

,200

22,2

0027

,000

39,8

0048

,700

60,1

0068

,600

77,2

0085

,900

97,6

00Q

w10

,100

15,7

0019

,900

31,8

0040

,600

52,4

0061

,500

70,8

0080

,200

93,2

0028

703

2155

00K

YW

est

Qs

3,21

04,

860

6,02

09,

260

11,7

0015

,000

17,6

0020

,500

23,5

0027

,800

Qr

3,45

05,

280

6,56

010

,100

12,6

0015

,800

18,4

0020

,900

23,5

0027

,100

Qw

3,22

04,

880

6,04

09,

320

11,7

0015

,100

17,7

0020

,500

23,5

0027

,700

288

0321

6500

KY

Wes

tQ

s6,

090

8,39

09,

970

14,2

0017

,300

21,6

0024

,900

28,5

0032

,300

37,8

00Q

r5,

510

8,30

010

,300

15,5

0019

,300

24,1

0027

,800

31,6

0035

,400

40,6

00Q

w6,

030

8,38

09,

990

14,4

0017

,600

22,0

0025

,500

29,2

0033

,000

38,4

0028

903

2165

40K

YW

est

Qs

582

789

929

1,30

01,

560

1,92

02,

200

2,49

02,

800

3,23

0Q

r38

462

580

11,

300

1,68

02,

190

2,59

03,

010

3,44

04,

050

Qw

540

764

910

1,30

01,

590

2,00

02,

330

2,67

03,

030

3,54

029

003

2165

63K

YW

est

Qs

111

158

190

272

330

406

465

527

590

678

Qr

5493

123

211

280

375

452

534

621

743

Qw

9013

917

125

030

939

145

953

160

771

4a D

isch

arge

was

com

pute

d ou

tsid

e th

e Pe

akFQ

com

pute

r pro

gram

(Fly

nn a

nd o

ther

s, 20

06) u

sing

the

HA

RTIV

subr

outin

e (K

irby,

198

0) a

nd b

y co

mpu

ting

the

antil

og o

f the

dis

char

ge fr

om e

quat

ion

1 (I

nter

-ag

ency

Adv

isor

y C

omm

ittee

on

Wat

er D

ata,

198

2, p

. 9–1

0).

Table 5 73Ta

ble

5.

Des

crip

tion

of th

e 88

pai

rs o

f U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

in W

est V

irgin

ia a

nd a

djac

ent s

tate

s th

at w

ere

eval

uate

d to

qua

ntify

“ne

ar”

for a

pplic

atio

n of

the

drai

nage

-are

a ra

tio m

etho

d in

this

stu

dy.—

Cont

inue

d

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

MD

, Mar

ylan

d; W

V, W

est V

irgin

ia; V

A, V

irgin

ia; P

A, P

enns

ylva

nia;

OH

, Ohi

o; K

Y, K

entu

cky;

N.,

Nor

th; S

., So

uth;

E.,

East

; R.,

Riv

er; B

r., B

ranc

h; F

k.,

Fork

; nr,

near

; blw

, bel

ow]

Pair

nu

mbe

r

Ups

trea

m s

tatio

nD

owns

trea

m s

tatio

n

Iden

ti-fic

atio

n nu

mbe

r

Stre

amga

ge

stat

ion

nu

mbe

rSt

atio

n na

me

Stat

eId

enti-

ficat

ion

num

ber

Stre

amga

ge

stat

ion

nu

mbe

rSt

atio

n na

me

Stat

e

11

0159

5000

Nor

th B

ranc

h Po

tom

ac R

iver

at S

teye

rM

D3

0159

5500

Nor

th B

r. Po

tom

ac R

iver

at K

itzm

iller

MD

21

0159

5000

Nor

th B

ranc

h Po

tom

ac R

iver

at S

teye

rM

D12

0160

3000

N. B

r. Po

tom

ac R

iver

nea

r Cum

berla

ndM

D3

301

5955

00N

orth

Br.

Poto

mac

Riv

er a

t Kitz

mill

erM

D4

0159

6000

Nor

th B

r. Po

tom

ac R

iver

at B

loom

ingt

onM

D4

401

5960

00N

orth

Br.

Poto

mac

Riv

er a

t Blo

omin

gton

MD

1001

6000

00N

orth

Bra

nch

Poto

mac

Riv

er a

t Pin

toM

D5

401

5960

00N

orth

Br.

Poto

mac

Riv

er a

t Blo

omin

gton

MD

1201

6030

00N

. Br.

Poto

mac

Riv

er n

ear C

umbe

rland

MD

610

0160

0000

Nor

th B

ranc

h Po

tom

ac R

iver

at P

into

MD

1201

6030

00N

. Br.

Poto

mac

Riv

er n

ear C

umbe

rland

MD

714

0160

5500

Sout

h B

ranc

h Po

tom

ac R

iver

at F

rank

linW

V17

0160

6500

S. B

r. Po

tom

ac R

iver

nea

r Pet

ersb

urg

WV

814

0160

5500

Sout

h B

ranc

h Po

tom

ac R

iver

at F

rank

linW

V23

0160

8500

S. B

r. Po

tom

ac R

iver

nea

r Spr

ingfi

eld

WV

917

0160

6500

S. B

r. Po

tom

ac R

iver

nea

r Pet

ersb

urg

WV

2301

6085

00S.

Br.

Poto

mac

Riv

er n

ear S

prin

gfiel

dW

V10

1901

6075

00S.

Fk.

S. B

r. Po

tom

ac R

. at B

rand

ywin

eW

V21

0160

8000

S. F

k. S

. Br.

Poto

mac

R. n

ear M

oore

field

WV

1126

0160

9650

Littl

e C

acap

on R

iver

at F

renc

hbur

gW

V27

0160

9800

Littl

e C

acap

on R

iver

nea

r Lev

els

WV

1231

0161

0500

Cac

apon

Riv

er a

t Yel

low

Spr

ing

WV

3201

6115

00C

acap

on R

iver

nea

r Gre

at C

acap

onW

V13

3901

6150

00O

pequ

on C

reek

nea

r Ber

ryvi

lleVA

4101

6165

00O

pequ

on C

reek

nea

r Mar

tinsb

urg

WV

1456

0163

2000

N. F

k. S

hena

ndoa

h R

. at C

oote

s Sto

reVA

6101

6330

00N

. Fk.

She

nand

oah

R. a

t Mou

nt Ja

ckso

nVA

1556

0163

2000

N. F

k. S

hena

ndoa

h R

. at C

oote

s Sto

reVA

6401

6340

00N

. Fk.

She

nand

oah

Riv

er n

ear S

trasb

urg

VA16

6101

6330

00N

. Fk.

She

nand

oah

R. a

t Mou

nt Ja

ckso

nVA

6401

6340

00N

. Fk.

She

nand

oah

Riv

er n

ear S

trasb

urg

VA17

7101

6437

00G

oose

Cre

ek n

ear M

iddl

ebur

gVA

7201

6440

00G

oose

Cre

ek n

ear L

eesb

urg

VA18

7702

0114

80B

ack

Cr.

at R

t. 60

0 ne

ar M

ount

ain

Gro

veVA

7802

0115

00B

ack

Cre

ek n

ear M

ount

ain

Gro

veVA

1983

0305

0000

Tyga

rt Va

lley

Riv

er n

ear D

aile

yW

V84

0305

0500

Tyga

rt Va

lley

Riv

er n

ear E

lkin

sW

V20

8303

0500

00Ty

gart

Valle

y R

iver

nea

r Dai

ley

WV

9603

0565

00Ty

gart

Valle

y R

iver

at F

ette

rman

WV

2184

0305

0500

Tyga

rt Va

lley

Riv

er n

ear E

lkin

sW

V86

0305

1000

Tyga

rt Va

lley

Riv

er a

t Bel

ingt

onW

V22

8603

0510

00Ty

gart

Valle

y R

iver

at B

elin

gton

WV

9203

0545

00Ty

gart

Valle

y R

iver

at P

hilli

piW

V23

8603

0510

00Ty

gart

Valle

y R

iver

at B

elin

gton

WV

9603

0565

00Ty

gart

Valle

y R

iver

at F

ette

rman

WV

2492

0305

4500

Tyga

rt Va

lley

Riv

er a

t Phi

llipi

WV

9603

0565

00Ty

gart

Valle

y R

iver

at F

ette

rman

WV

2587

0305

1500

Mid

dle

Fork

Riv

er a

t Mid

vale

WV

8803

0520

00M

iddl

e Fo

rk R

iver

at A

udra

WV

2693

0305

5020

Bon

ica

Run

on

U.S

. 250

nea

r Phi

llipi

WV

9403

0550

40B

onic

a R

un o

n R

oute

38

near

Phi

llipi

WV

2798

0305

7300

Wes

t For

k R

iver

at W

alke

rsvi

lleW

V10

003

0580

00W

est F

ork

R. b

lw S

tone

wal

l Jac

kson

Dam

nr W

esto

nW

V28

9803

0573

00W

est F

ork

Riv

er a

t Wal

kers

ville

WV

105

0306

1000

Wes

t For

k R

iver

at E

nter

pris

eW

V29

100

0305

8000

Wes

t For

k R

. blw

Sto

new

all J

acks

on D

am n

r Wes

ton

WV

101

0305

8500

Wes

t For

k R

iver

at B

utch

ervi

lleW

V30

101

0305

8500

Wes

t For

k R

iver

at B

utch

ervi

lleW

V10

203

0590

00W

est F

ork

Riv

er a

t Cla

rksb

urg

WV


ble

5.

Des

crip

tion

of th

e 88

pai

rs o

f U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

in W

est V

irgin

ia a

nd a

djac

ent s

tate

s th

at w

ere

eval

uate

d to

qua

ntify

“ne

ar”

for a

pplic

atio

n of

the

drai

nage

-are

a ra

tio m

etho

d in

this

stu

dy.—

Cont

inue

d

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

MD

, Mar

ylan

d; W

V, W

est V

irgin

ia; V

A, V

irgin

ia; P

A, P

enns

ylva

nia;

OH

, Ohi

o; K

Y, K

entu

cky;

N.,

Nor

th; S

., So

uth;

E.,

East

; R.,

Riv

er; B

r., B

ranc

h; F

k.,

Fork

; nr,

near

; blw

, bel

ow]

Pair

nu

mbe

r

Ups

trea

m s

tatio

nD

owns

trea

m s

tatio

n

Iden

ti-fic

atio

n nu

mbe

r

Stre

amga

ge

stat

ion

nu

mbe

rSt

atio

n na

me

Stat

eId

enti-

ficat

ion

num

ber

Stre

amga

ge

stat

ion

nu

mbe

rSt

atio

n na

me

Stat

e

3110

103

0585

00W

est F

ork

Riv

er a

t But

cher

ville

WV

105

0306

1000

Wes

t For

k R

iver

at E

nter

pris

eW

V32

102

0305

9000

Wes

t For

k R

iver

at C

lark

sbur

gW

V10

503

0610

00W

est F

ork

Riv

er a

t Ent

erpr

ise

WV

3311

003

0650

00D

ry F

ork

at H

endr

icks

WV

118

0306

9500

Che

at R

iver

nea

r Par

sons

WV

3411

003

0650

00D

ry F

ork

at H

endr

icks

WV

123

0307

1000

Che

at R

iver

nea

r Pis

gah

WV

3511

803

0695

00C

heat

Riv

er n

ear P

arso

nsW

V12

103

0700

00C

heat

Riv

er a

t Row

lesb

urg

WV

3611

803

0695

00C

heat

Riv

er n

ear P

arso

nsW

V12

303

0710

00C

heat

Riv

er n

ear P

isga

hW

V37

121

0307

0000

Che

at R

iver

at R

owle

sbur

gW

V12

303

0710

00C

heat

Riv

er n

ear P

isga

hW

V38

111

0306

5400

Bla

ckw

ater

Riv

er n

ear D

avis

WV

112

0306

6000

Bla

ckw

ater

Riv

er a

t Dav

isW

V39

114

0306

7500

Shav

ers F

ork

at C

heat

Brid

geW

V11

603

0688

00Sh

aver

s For

k be

low

Bow

den

WV

4011

403

0675

00Sh

aver

s For

k at

Che

at B

ridge

WV

118

0306

9500

Che

at R

iver

nea

r Par

sons

WV

4111

603

0688

00Sh

aver

s For

k be

low

Bow

den

WV

118

0306

9500

Che

at R

iver

nea

r Par

sons

WV

4215

403

1154

00Li

ttle

Mus

king

um R

iver

at B

loom

field

OH

156

0311

5500

Littl

e M

uski

ngum

Riv

er a

t Fay

OH

4316

103

1514

00Li

ttle

Kan

awha

Riv

er n

ear W

ildca

tW

V16

203

1515

00Li

ttle

Kan

awha

Riv

er n

ear B

urns

ville

WV

4416

103

1514

00Li

ttle

Kan

awha

Riv

er n

ear W

ildca

tW

V17

103

1550

00Li

ttle

Kan

awha

Riv

er a

t Pal

estin

eW

V45

162

0315

1500

Littl

e K

anaw

ha R

iver

nea

r Bur

nsvi

lleW

V16

303

1520

00Li

ttle

Kan

awha

Riv

er a

t Gle

nvill

eW

V46

163

0315

2000

Littl

e K

anaw

ha R

iver

at G

lenv

ille

WV

167

0315

3500

Littl

e K

anaw

ha R

iver

at G

rant

svill

eW

V47

163

0315

2000

Littl

e K

anaw

ha R

iver

at G

lenv

ille

WV

171

0315

5000

Littl

e K

anaw

ha R

iver

at P

ales

tine

WV

4816

703

1535

00Li

ttle

Kan

awha

Riv

er a

t Gra

ntsv

ille

WV

171

0315

5000

Littl

e K

anaw

ha R

iver

at P

ales

tine

WV

4917

203

1552

00So

uth

Fork

Hug

hes R

iver

at M

acfa

rlan

WV

174

0315

5500

Hug

hes R

iver

at C

isco

WV

5018

403

1777

00B

lues

tone

Riv

er a

t Blu

efiel

dVA

186

0317

9000

Blu

esto

ne R

iver

nea

r Pip

este

mW

V51

184

0317

7700

Blu

esto

ne R

iver

at B

luefi

eld

VA18

703

1795

00B

lues

tone

Riv

er a

t Lill

yW

V52

186

0317

9000

Blu

esto

ne R

iver

nea

r Pip

este

mW

V18

703

1795

00B

lues

tone

Riv

er a

t Lill

yW

V53

190

0318

0500

Gre

enbr

ier R

iver

at D

urbi

nW

V19

503

1825

00G

reen

brie

r Riv

er a

t Buc

keye

WV

5419

003

1805

00G

reen

brie

r Riv

er a

t Dur

bin

WV

201

0318

4000

Gre

enbr

ier R

iver

at H

illda

leW

V55

195

0318

2500

Gre

enbr

ier R

iver

at B

ucke

yeW

V19

803

1835

00G

reen

brie

r Riv

er a

t Ald

erso

nW

V56

195

0318

2500

Gre

enbr

ier R

iver

at B

ucke

yeW

V20

103

1840

00G

reen

brie

r Riv

er a

t Hill

dale

WV

5719

803

1835

00G

reen

brie

r Riv

er a

t Ald

erso

nW

V20

103

1840

00G

reen

brie

r Riv

er a

t Hill

dale

WV

5820

803

1865

00W

illia

ms R

iver

at D

yer

WV

209

0318

7000

Gau

ley

Riv

er a

t Cam

den

on G

aule

yW

V59

209

0318

7000

Gau

ley

Riv

er a

t Cam

den

on G

aule

yW

V21

303

1891

00G

aule

y R

iver

nea

r Cra

igsv

ille

WV

6020

903

1870

00G

aule

y R

iver

at C

amde

n on

Gau

ley

WV

223

0319

2500

Gau

ley

Riv

er a

t Bel

vaW

V

Table 5 75Ta

ble

5.

Des

crip

tion

of th

e 88

pai

rs o

f U.S

. Geo

logi

cal S

urve

y st

ream

gage

sta

tions

in W

est V

irgin

ia a

nd a

djac

ent s

tate

s th

at w

ere

eval

uate

d to

qua

ntify

“ne

ar”

for a

pplic

atio

n of

the

drai

nage

-are

a ra

tio m

etho

d in

this

stu

dy.—

Cont

inue

d

[Ide

ntifi

catio

n nu

mbe

r ref

ers t

o th

e nu

mbe

r in

figur

e 3;

MD

, Mar

ylan

d; W

V, W

est V

irgin

ia; V

A, V

irgin

ia; P

A, P

enns

ylva

nia;

OH

, Ohi

o; K

Y, K

entu

cky;

N.,

Nor

th; S

., So

uth;

E.,

East

; R.,

Riv

er; B

r., B

ranc

h; F

k.,

Fork

; nr,

near

; blw

, bel

ow]

Pair

nu

mbe

r

Ups

trea

m s

tatio

nD

owns

trea

m s

tatio

n

Iden

ti-fic

atio

n nu

mbe

r

Stre

amga

ge

stat

ion

nu

mbe

rSt

atio

n na

me

Stat

eId

enti-

ficat

ion

num

ber

Stre

amga

ge

stat

ion

nu

mbe

rSt

atio

n na

me

Stat

e

6121

303

1891

00G

aule

y R

iver

nea

r Cra

igsv

ille

WV

214

0318

9500

Gau

ley

Riv

er n

ear S

umm

ersv

ille

WV

6221

403

1895

00G

aule

y R

iver

nea

r Sum

mer

svill

eW

V22

203

1920

00G

aule

y R

iver

abo

ve B

elva

WV

6321

403

1895

00G

aule

y R

iver

nea

r Sum

mer

svill

eW

V22

303

1925

00G

aule

y R

iver

at B

elva

WV

6422

203

1920

00G

aule

y R

iver

abo

ve B

elva

WV

223

0319

2500

Gau

ley

Riv

er a

t Bel

vaW

V65

216

0319

0000

Mea

dow

Riv

er a

t Nal

len

WV

218

0319

0400

Mea

dow

Riv

er n

ear M

ount

Loo

kout

WV

6622

703

1947

00El

k R

iver

bel

ow W

ebst

er S

prin

gsW

V23

103

1955

00El

k R

iver

at S

utto

nW

V67

227

0319

4700

Elk

Riv

er b

elow

Web

ster

Spr

ings

WV

233

0319

7000

Elk

Riv

er a

t Que

en S

hoal

sW

V68

231

0319

5500

Elk

Riv

er a

t Sut

ton

WV

233

0319

7000

Elk

Riv

er a

t Que

en S

hoal

sW

V69

238

0319

8500

Big

Coa

l Riv

er a

t Ash

ford

WV

244

0320

0500

Coa

l Riv

er a

t Tor

nado

WV

7024

103

1990

00Li

ttle

Coa

l Riv

er a

t Dan

ville

WV

243

0319

9400

Littl

e C

oal R

iver

at J

ulia

nW

V71

254

0320

2400

Guy

ando

tte R

iver

nea

r Bai

leys

ville

WV

257

0320

3000

Guy

ando

tte R

iver

at M

anW

V72

254

0320

2400

Guy

ando

tte R

iver

nea

r Bai

leys

ville

WV

259

0320

4000

Guy

ando

tte R

iver

at B

ranc

hlan

dW

V73

257

0320

3000

Guy

ando

tte R

iver

at M

anW

V25

803

2036

00G

uyan

dotte

Riv

er a

t Log

anW

V74

257

0320

3000

Guy

ando

tte R

iver

at M

anW

V25

903

2040

00G

uyan

dotte

Riv

er a

t Bra

nchl

and

WV

7525

803

2036

00G

uyan

dotte

Riv

er a

t Log

anW

V25

903

2040

00G

uyan

dotte

Riv

er a

t Bra

nchl

and

WV

7626

303

2066

00Ea

st F

ork

Twel

vepo

le C

reek

nea

r Dun

low

WV

264

0320

6800

E. F

k. T

wel

vepo

le C

reek

nea

r Eas

t Lyn

nW

V77

263

0320

6600

East

For

k Tw

elve

pole

Cre

ek n

ear D

unlo

wW

V26

603

2070

20Tw

elve

pole

Cre

ek b

elow

Way

neW

V78

264

0320

6800

E. F

k. T

wel

vepo

le C

reek

nea

r Eas

t Lyn

nW

V26

603

2070

20Tw

elve

pole

Cre

ek b

elow

Way

neW

V79

268

0320

7500

Levi

sa F

ork

near

Gru

ndy

VA26

903

2078

00Le

visa

For

k at

Big

Roc

kVA

8026

803

2075

00Le

visa

For

k ne

ar G

rund

yVA

271

0320

8000

Levi

sa F

ork

belo

w F

isht

rap

Dam

KY

8126

903

2078

00Le

visa

For

k at

Big

Roc

kVA

271

0320

8000

Levi

sa F

ork

belo

w F

isht

rap

Dam

KY

8227

603

2100

00Jo

hns C

rek

near

Met

aK

Y27

703

2115

00Jo

hns C

reek

nea

r Van

Lea

rK

Y83

279

0321

2750

Tug

Fork

at W

elch

WV

281

0321

3000

Tug

Fork

at L

itwar

WV

8427

903

2127

50Tu

g Fo

rk a

t Wel

chW

V28

603

2149

00Tu

g Fo

rk a

t Gle

nhay

esW

V85

281

0321

3000

Tug

Fork

at L

itwar

WV

283

0321

3700

Tug

Fork

at W

illia

mso

nW

V86

283

0321

3700

Tug

Fork

at W

illia

mso

nW

V28

503

2145

00Tu

g Fo

rk a

t Ker

mit

WV

8728

303

2137

00Tu

g Fo

rk a

t Will

iam

son

WV

286

0321

4900

Tug

Fork

at G

lenh

ayes

WV

8828

503

2145

00Tu

g Fo

rk a

t Ker

mit

WV

286

0321

4900

Tug

Fork

at G

lenh

ayes

WV


(This page intentionally left blank.)

Appendix 1


Appendix 1. Matrices Used to Compute Individual Standard Errors of Prediction

[PK(n_n), peak discharge for the (n.n)-year recurrence interval; PK(n), peak discharge for the (n)-year recurrence interval; %, percent; AOP, annual-occurrence probability; γ2, standard error of the model squared; numbers are given in scientific notation where 0.32483E-01 is 0.032483]

Eastern Panhandle Region

PK1_1(90%AOP) γ2 = 0.32483E-01 0.36765E-02 -0.13943E-02 -0.13943E-02 0.79153E-03

PK1_5(67%AOP) γ2 = 0.22559E-01 0.26813E-02 -0.98579E-03 -0.98579E-03 0.55605E-03

PK2(50%AOP) γ2 = 0.18489E-01 0.24610E-02 -0.86628E-03 -0.86628E-03 0.48293E-03

PK5(20%AOP) γ2 = 0.11967E-01 0.24958E-02 -0.76020E-03 -0.76020E-03 0.41065E-03

PK10(10%AOP) γ2 = 0.92526E-02 0.27016E-02 -0.75370E-03 -0.75370E-03 0.40192E-03

PK25(4%AOP) γ2 = 0.71876E-02 0.30780E-02 -0.79872E-03 -0.79872E-03 0.42199E-03

PK50(2%AOP) γ2 = 0.64308E-02 0.34417E-02 -0.86987E-03 -0.86987E-03 0.45750E-03

PK100(1%AOP) γ2 = 0.61728E-02 0.38754E-02 -0.96990E-03 -0.96990E-03 0.50843E-03

PK200(0.5%AOP) γ2 = 0.63080E-02 0.43778E-02 -0.10963E-02 -0.10963E-02 0.57352E-03

PK500(0.2%AOP) γ2 = 0.69967E-02 0.51444E-02 -0.13012E-02 -0.13012E-02 0.68008E-03

Central Mountains Region

PK1_1(90%AOP) γ2 = 0.27978E-01 0.26613E-02 -0.98361E-03 -0.98361E-03 0.47958E-03

PK1_5(67%AOP) γ2 = 0.21308E-01 0.20667E-02 -0.75807E-03 -0.75807E-03 0.36705E-03

PK2(50%AOP) γ2 = 0.19922E-01 0.20406E-02 -0.74156E-03 -0.74156E-03 0.35478E-03

PK5(20%AOP) γ2 = 0.20745E-01 0.24841E-02 -0.88266E-03 -0.88266E-03 0.41029E-03

PK10(10%AOP) γ2 = 0.23263E-01 0.29889E-02 -0.10523E-02 -0.10523E-02 0.48398E-03

PK25(4%AOP) γ2 = 0.27815E-01 0.37621E-02 -0.13163E-02 -0.13163E-02 0.60165E-03

PK50(2%AOP) γ2 = 0.31932E-01 0.44057E-02 -0.15382E-02 -0.15382E-02 0.70196E-03

PK100(1%AOP) γ2 = 0.36527E-01 0.50907E-02 -0.17758E-02 -0.17758E-02 0.81032E-03

PK200(0.5%AOP) γ2 = 0.41553E-01 0.58123E-02 -0.20274E-02 -0.20274E-02 0.92586E-03

PK500(0.2%AOP) γ2 = 0.48810E-01 0.68170E-02 -0.23795E-02 -0.23795E-02 0.10887E-02

Western Plateaus Region

PK1_1(90%AOP) γ2 = 0.25715E-01 0.21782E-02 -0.77332E-03 -0.77332E-03 0.38325E-03

PK1_5(67%AOP) γ2 = 0.19963E-01 0.16074E-02 -0.56593E-03 -0.56593E-03 0.28053E-03

PK2(50%AOP) γ2 = 0.17940E-01 0.14888E-02 -0.51918E-03 -0.51918E-03 0.25507E-03

PK5(20%AOP) γ2 = 0.15490E-01 0.15374E-02 -0.52302E-03 -0.52302E-03 0.24868E-03

PK10(10%AOP) γ2 = 0.15120E-01 0.17035E-02 -0.57249E-03 -0.57249E-03 0.26724E-03

PK25(4%AOP) γ2 = 0.15624E-01 0.19906E-02 -0.66264E-03 -0.66264E-03 0.30467E-03

PK50(2%AOP) γ2 = 0.16517E-01 0.22400E-02 -0.74298E-03 -0.74298E-03 0.33935E-03

PK100(1%AOP) γ2 = 0.17743E-01 0.25100E-02 -0.83124E-03 -0.83124E-03 0.37818E-03

PK200(0.5%AOP) γ2 = 0.19246E-01 0.27968E-02 -0.92609E-03 -0.92609E-03 0.42049E-03

PK500(0.2%AOP) γ2 = 0.21600E-01 0.31977E-02 -0.10601E-02 -0.10601E-02 0.48102E-03

For additional information, write to:DirectorU.S. Geological SurveyWest Virginia Water Science Center11 Dunbar StreetCharleston, WV 25301

or visit our Web site at:http://wv.usgs.gov/

Document prepared by the West Trenton Publishing Service Center

Wiiley, J.B. and Atkins, J.T.—

Estimation of Flood-Frequency D

ischarges for Rural, Unregulated Stream

s in West Virginia—


Printed on recycled paper

estimation of flood-frequency discharges for rural ... · estimation of flood-frequency discharges...

Documents