little otter creek watershed phase 2 stream geomorphic assessment: appendix j

8/2/2019 Little Otter Creek Watershed Phase 2 Stream Geomorphic Assessment: Appendix J

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Appendix J: Flow Monitoring Little Otter Creek WatershedSeptember 2011 (revised Dec 2011) DRAFT Phase 2 Stream Geomorphic Assessment

APPENDIX J

Flow Monitoring


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TABLE OF CONTENTS

1.0 Introduction.........................................................................................................................32.0 Background ......................................................................................................................... 4

2.1 Location of Flow Monitoring Stations.................................................................................. 42.2 Soil and Land Use Characteristics of Flow-based Subunits ....................................................72.3 Climate.......................................................................................................................... 112.4 Hydrology...................................................................................................................... 11

3.0 Methods ............................................................................................................................ 13

3.1 Flow Measurements........................................................................................................ 133.2 Flow Duration Curve....................................................................................................... 143.3 Water Quality Sampling .................................................................................................. 143.4 Load Estimates .............................................................................................................. 16

3.4.1 Load Duration Curve............................................................................................... 163.4.2 Instantaneous Loads............................................................................................... 163.4.3 Predicted Loads...................................................................................................... 16

4.0 Results .............................................................................................................................. 164.1 Flow Measurements........................................................................................................ 164.2 Water Quality Results ..................................................................................................... 19

4.2.1 Load Duration Curve............................................................................................... 194.2.2 Instantaneous Loads............................................................................................... 194.2.3 Predicted Loads / Seasonal Loads............................................................................ 23

5.0 Discussion & Conclusions .................................................................................................... 246.0 Recommendations for further study ..................................................................................... 297.0 References ....................................................................................................................... 29


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1.0 Introduction

Since 1997, the Addison County River Watch Collaborative (ACRWC) has monitored water quality atseveral stations located within the Little Otter Creek watershed. These efforts have been carried out tounderstand water quality trends at the sub-watershed scale and to complement the longterm waterquality monitoring station maintained by VTDEC Water Quality Division in vicinity of the Route 7 bridge,and periodic fish and macroinvertebrate sampling carried out by the VTDEC Biomonitoring & AquaticStudies Section program.

Recently, ACRWC became interested to evaluate nutrient and sediment loading within the watershed, to

inform identification and prioritization of watershed management strategies.

A pilot test was proposed in the Little Otter Creek watershed to:

Evaluate spatial and seasonal variability in nutrient (phosphorus) and sediment loading at thesubwatershed scale through empirical means;

Estimate the variable sources / transport mechanisms of phosphorus and sediment underdifferent hydrologic regimes and vegetative conditions (leaf-on vs leaf-off); and

Prioritize management strategies for reduced sediment and nutrient loading.


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2.0 Background

The Little Otter Creek watershed is a 72.5-square-mile basin located in Addison County, Vermont, withinthe Champlain Valley physiographic province (Stewart, 1973). Details of the geographic, geologic,geomorphic and land use settings are provided in Section 2 of the geomorphic assessment report (SMRC,2011).

2.1 Location of Flow Monitoring Stations

Four flow monitoring sites were established to evaluate constituent loading at major sub-units of thewatershed (Figure 1). Flow monitoring stations were co-located with established water qualitymonitoring stations (Table 1). Temporary flow-monitoring gages were set up at two of the four stations(LOC14.4, LOC10; see Attachment 1 for location details), and USGS stations were relied upon for flowmonitoring data at the other two locations.

LOC14.4 FS is a temporary gaging station consisting of a staff gage and pressure transducer (onloan from VTDEC MAPP). This station is located just upstream of the North Street culvert crossingin New Haven, approximately 630 feet upstream of the ACRWC water quality station (LOC14.4) at

the Plank Road culvert crossing.

LOC10 FS is a temporary gaging station consisting of a staff gage and pressure transducer (on

loan from VTDEC MAPP). This station is located approximately 500 feet upstream of the MonktonRoad bridge crossing in Ferrisburgh where ACRWC has an established water quality monitoringstation (LOC10).

LOC7.8 FS is located at the Middlebrook Road crossing in Ferrisburgh. No instrumentation wasset up at this site. Rather, flows were estimated (using the ratio of upstream drainage areas) in

relation to the active, USGS Gaging Station #04282650 located approximately 3.9 milesdownstream. A flow gaging station had previously been established and maintained at thisMiddlebrook Road site by USGS for a study conducted from 2000-2005. That previous studydetermined that flows at Middlebrook Road could reliably be estimated by applying a proportionalarea to the flow data collected at downstream USGS Station #04282650 (Medalie, 2007).

LOC4.3 FS is synonymous with the USGS Gaging Station #04282650. Provisional USGS gagingdata were relied on for this study. ACRWC has an established water quality station at this location(LOC4.3).

These four stations complement the long-term monitoring station (VT LTM) maintained by VTDEC at theLittle Chicago Road bridge crossing in Ferrisburgh, approximately 0.64 mile downstream from the USGS

gaging station at Route 7.


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South Mountain RCS J- 6

Table 1. Water Quality Monitoring Stations associated with Flow-based Subunits of the Little Otter Creek Watershed.

Sample Site Flow Gage

Upstream Upstream

Drainage Drainage

Sample Area Geomorphic Location Nearest Flow Gage Area

Site Latitude Longitude (sq miles) Reach (sq miles) Ratio

LOC14.4 44.157109 -73.15892 11.9 M13 Plank Road culvert Temporary Gage LOC14.4 FS 11.9 1.000

630 ft upstream

LOC10 44.193848 -73.192366 35.8 M09 Monkton Road bridge Temporary Gage LOC10 FS 35.7 1.003500 ft upstream

LOC7.8 44.198815 -73.212174 43.6 mid-M05 Middlebrook Road bridge Former USGS Gage #04282636 43.6 1.000

20 ft downstream

Active USGS Gage #04282650 58.4 0.747

3.9 mile downstream

LOC4.3 44.198184 -73.249044 58.4 mid-M02 Route 7 bridge Active USGS Gage #04282650 58.4 * 1.000

50 ft downstream

VT LTM 44.20400 -73.2518 58.6 M02 Little Chicago Rd bridge Active USGS Gage #04282650 58.4 1.003

0.64 mile upstream

*

Sample Site Coordinates

Due to slight differences in watershed delineations, USGS publishes the upstream drainage area for USGS Gage #04282650 as 57.1

square miles (a Relative Percent Difference of 2.3%).


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Figure 2 depicts the location of these stations along a longitudinal profile of the Little Otter Creek.

0

200

400

600

800

0 5 10 15 20 25

Distance Upstream from the Mouth (miles)

Elev

ationabovemeansealevel(feet)

Monkton

New

HavenFerrisburgh

Birkett's Falls

Frasers Falls

Walkers Falls

Bristol

VT Longterm

Monitoring Site

LOC4.3 and

USGS Stn #04282650

Mud Creek tributary

LOC7.8

LOC10

LOC14.4

Figure 2. Longitudinal Profile of Little Otter Creek main stem indicating major bedrock

grade controls (Falls) and location of flow-related water quality sampling sites.

2.2 Soil and Land Use Characteristics of Flow-based Subunits

Sediments of the Little Otter Creek watershed are dominantly of glaciolacustrine origin (Figure 3).

Approximately 83% of the soil types are of low to very low infiltration rate, classified as C and DHydrologic Soil Group (see Table 2). The remainder of the soils are of greater permeability (HydrologicSoil Groups A and B), tend to be associated with surficial deposits of glaciofluvial and alluvial origin, andare concentrated along the eastern side of the watershed and in isolated pockets along the river network.Generally, the percentage of very-low-infiltration soil types (D soils) in the upstream drainage areaincreases with distance downstream in the watershed.


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Figure 3. Generalized map of soil parent material in the Little Otter Creek watershed andflow-based sub-units. (NRCS parent material classification of lacustrine does not differentiate

between lake silts/clays of glacial versus marine origin).

Table 2. Distribution of Hydrologic Soil Groups in Flow-based Sub-Units, Little Otter Creek watershed.

Drainage % of Total

Flow Study Area Watershed A B C D not rated water

Sub-watershed (sq miles) Area % % % % % %

Headwaters to LOC14.4 11.9 16.4% 19.5 23.2 16.2 40.8 0.2 0.1

Headwaters to LOC10 35 8 49 4% 7 0 18 3 12 2 62 3 0 1 0 1

Hydrologic Soil Groups

LEGEND


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Table 3. Geologic and Land Use Characteristics of Flow-based Subunits, Little Otter Creek watershed.

Incremental Sub-watersheds

Drainage % of Total Hydric Wetlands

Flow Study Area Watershed Relief Gradient Soils (VSWI)

Subshed (sq miles) Area (ft) (ft / mile) (%) (%) Forest Agric Urban

Headwaters to LOC14.4 11.9 16.4% 235 32 17.2 9.0 34% 43% 6%LOC14.4 to LOC10 23.9 33.0% 47 10 27.1 10.8 31% 49% 5%

LOC10 to LOC7.8 7.8 10.8% 71 20 17.0 3.2 35% 50% 4%

LOC7.8 to LOC4.3 14.7 20.3% 17 4 28.9 8.8 16% 66% 5%

LOC4.3 to VTLTM 0.3 0.4% 17 26 77.0 9.7 4% 68% 21%

VTLTM to M01 13.9 19.2% 31 8 56.0 13.0 14% 67% 4%

Cumulative Upstream Watershed

Drainage % of Total Hydric Wetlands

Flow Study Area Watershed Relief Gradient Soils (VSWI)

Subshed (sq miles) Area (ft) (ft / mile) (%) (%) Forest Agric Urban

Headwaters to LOC14.4 11.9 16.4% 235 32 17.2 9.0 34% 43% 6%

Headwaters to LOC10 35.8 49.4% 282 24 23.8 10.2 32% 47% 6%

Headwaters to LOC7.8 43.6 60.1% 353 23 22.6 9.0 33% 48% 5%

Headwaters to LOC4.3 58.4 80.6% 370 19 24.2 8.9 28% 52% 5%Headwaters to VTLTM 58.6 80.8% 387 19 24.4 8.9 28% 52% 5%

Headwaters to M01 72.5 100.0% 418 18 30.5 9.7 25% 55% 5%

Topography Major Land Cover/

Topography Major Land Cover/

Land Use

Land Use


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2.3 Climate

Precipitation in calendar year 2010 was somewhat wetter than normal, due in part to greater than normalmonthly rainfall totals in June and October: 40.7 inches of rain were recorded in South Burlington(Airport), 45.8 inches in Rutland, and 58.0 inches in South Lincoln, Vermont (Table J2-1, Attachment 2). Based on recent records maintained by the National Weather Service (1971 2000), average annualprecipitation at weather stations near the Little Otter Creek watershed varies with elevation andgeographic location. Average annual precipitation at the Airport in South Burlington (330 ft elevation) forthis 30-year period was 36.1 inches; an average of 39.1 inches was recorded in Rutland (620 ft elevation)

and 46.7 inches was recorded in South Lincoln, Vermont (at 1,370 ft elevation) (National Climatic DataCenter, 2002).

Snowfall in the winter of 20092010 was somewhat greater than normal as recorded at the Burlington

Airport, and somewhat less than normal as recorded in Rutland, but much less than normal in the higherelevations, as recorded at the South Lincoln, VT weather station (Table J2-1, Attachment 2).

Regional trends indicate an increased frequency of larger floods over the last century. Average annualprecipitation in the Northeastern United States has increased approximately 3.3 inches over the periodfrom the year 1900 to 2000 (UNH Climate Change Research Center, 2005). The frequency and numberof intense precipitation events (defined as more than two inches of rain in a 48-hour period) has alsoincreased, particularly in the last quarter of the 19th century (UNH Climate Change Research Center,2005).

2.4 Hydrology

A USGS streamflow gaging station (#04282650) is located at the Route 7 crossing of Little Otter Creek in

Ferrisburgh, Vermont (Figure 1). The upstream drainage area of this gage is 57.1 square miles (or78.8% of the watershed). During the twenty years of available records for this station, the Mean AnnualFlow (MAF) has ranged from 26.8 cfs (in 2002) to 105.9 cfs (in 2008). The average MAF for that periodof record was 64 cfs. The MAF for water year 2010 (1 October 2009 through 30 September 2010) in theLittle Otter Creek was 66 cfs, indicating water year 2010 was a near-typical year as compared to recenthistory.

Figures J2-3 and J2-4 in Attachment 2 present the cumulative annual flow in the Little Otter Creek forwater years 1991 through 2000 and water years 2001 through 2010, respectively. A majority of the total

annual streamflow in Little Otter Creek occurs from late Winter through late Spring, from ice-out to mid-May in a typical year. This phenomenon is typical for other tributaries in the Lake Champlain basin(Shanley & Denner, 1999), and is due to melting of the snow pack stored in higher elevations, lowevapotranspiration rates prior to leafing of deciduous vegetation, saturated or frozen ground, and

occurrence of spring rains. These conditions are coincident with wide-spread bare (tilled) soils in theagricultural portions of the watershed.


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While up to one half of the total annual flow for the Little Otter Creek occurs between ice out andmid-May (see Attachment 2, Figures J2-3, J2-4), individual storm events (typically in the Spring

or Fall) can account for between 5 and 15 % of the total annual flow. Often the peak storm in agiven water year is coincident with snowmelt in the late Winter or early Spring, but the peakevent can also occur during a Summer thunderstorm, or late Fall.

While the primary driver of hydrology is climate (precipitation and snowmelt), hydrology in the

Little Otter Creek has been influenced by human land use impacts, including ditching oftributaries and wetlands, installation of subsurface drainage tiles, and hydrologically-connectedroad ditch networks. Examples of these modifications were documented in various locations inthe watershed during the Phase 2 geomorphic assessment (SMRC, 2011).

The Addison County region was affected by major flood events of 1913, 1927, 1936, and 1938 (USGS,1990). Local residents recall flood events in 1973 (June 30/ July 1) and 1976 (August) that weredocumented in the Otter Creek basin (VTDEC WQD, 1999). A flash flood occurring on 28 August 2004impacted the headwaters of Little Otter Creek in Bristol and New Haven (NCDC, 2011).

USGS (Olson, 2002) has estimated the approximate magnitude of peak flows for the gaging station at

Route 7 (Table 4). From the available record, it is evident that the Little Otter Creek has not experienceda substantial flood event in the previous 20 years (see Figure 5, next page). The maximum peak flow

recorded at the Route 7 gage during this period was 2,210 cfs on 20 January 1996; which corresponds toan approximate 10-year to 25-year flood magnitude, or Q10 to Q25 (Olson, 2002; see Table 4). Note:As of the printing of this report, central and southern Vermont was impacted by flooding resulting from

Tropical Storm Irene on 28 August 2011. Provisional USGS data indicates that flows at the Route 7 gageon Little Otter Creek peaked at 658 cfs on the morning of 30 August 2011, less than a bankfull-flowmagnitude.

Table 4. Estimated flood magnitudes for Little Otter Creek watershed

USGS Stn # 04282650

USGS Description

Little Otter Creek at

Ferrisburg, VT

USGS Period of Record (flow)

1990 - present (real-

time station)

Upstream Dr. Area (sq mi) 57.1

Geomorphic Reach M02Magnitude Data Source Discharge (cfs)

Q1.5 (VTDEC, 2001) 1,340

Q2 1,120

Q5 1,640


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0

500

1,000

1,500

2,000

2,500

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

Water Year

Disch

arge(cfs)

2,210 cfs

1/20/1996

Q2 = 1,120 cfs

Q5 = 1,640 cfs

Q10 = 1,990 cfs

Q25 = 2,440 cfs

Figure 5. Recorded Peak Flows for Little Otter Creek at Ferrisburg, VT gage, USGS Stn #04282650

57.1 square miles, reach M02 (compared to estimated flood peaks after Olson, 2002)

3.0 Methods

3.1 Flow Measurements

LOC14.4 FS and LOC10 FSA stage / discharge rating curve was developed for each of these temporary gaging sites based on aregression of the measured discharge to stage relationship based on periodic discharge measurementscollected over a range of flow conditions. Discharge was measured with a vertical-axis current meter bythe area-velocity technique (USGS mid-section method; Rantz, et al, 1982). Stage at these temporarygaging stations was monitored at 15 minute intervals using a YSITM Model 600LS pressure transducer.

Transducers were loaned by VTDEC MAPP and were deployed on 12 June 2010. Transducers wereremoved from the channel on 14 December 2010 to avoid damages due to onset of ice and snow. A staffgage was installed at each site to facilitate manual measurement of stage during sampling events andmaintenance of the pressure transducer. Elevation of the staff gage was surveyed with reference to alocal benchmark (chiseled X in nearby large boulder at each site).


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3.2 Flow Duration Curve

A flow duration curve was developed for the 19 years of record available for the USGS Gage on Route 7(Figure 6; Cleland, 2002; Cleland, 2003). A flow duration curve was not prepared for LOC10 FS sinceflows at this station are calculated based on reference to the USGS gaging station (near LOC4.3) and thecurve would be redundant. Nor were curves developed for temporary stations LOC14.4 FS and LOC10FS, since insufficient records exist for these new stations.

Figure 6. Flow Duration Curve for Little Otter Creek at Ferrisburgh, VT(Water Years: 1991 2009; USGS Stn# 04282650).

3.3 Water Quality SamplingWater quality samples were collected in vicinity of each of the gaging stations at long-establishedmonitoring sites maintained by the ACRWC (see Table 1). Samples were collected in accordance withprocedures outlined in the ACRWC Quality Assurance Project Plan. Samples were analyzed for TotalPhosphorus, Dissolved Phosphorus, Turbidity, and Total Suspended Solids (and select other constituents)

at the LaRosa Laboratory in Waterbury, Vermont.

In calendar year 2010, four(4) sample dates were scheduled for each station, in addition to the 6scheduled ACRWC sample dates (first Wednesday of the month, April through Oct). Sample events arepresented relative to the daily mean flow in Figure 7. These four additional sample dates were focusedon the storm event which occurred 30 September / 1 October 2010 (see Section 2.4, p.10 of the mainPhase 2 geomorphic report)


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0

100

200

300

400

500

600

700

800

900

1000

10/1/2009

10/15/2009

10/29/2009

11/12/2009

11/26/2009

12/10/2009

12/24/2009

1/7/2010

1/21/2010

2/4/2010

2/18/2010

3/4/2010

3/18/2010

4/1/2010

4/15/2010

4/29/2010

5/13/2010

5/27/2010

6/10/2010

6/24/2010

7/8/2010

7/22/2010

8/5/2010

8/19/2010

9/2/2010

9/16/2010

9/30/2010

10/14/2010

10/28/2010

11/11/2010

11/25/2010

12/9/2010

12/23/2010

1/6/2011

1/20/2011

2/3/2011

Date

Me

anDailyDischarge(cfs)

pressure transducers

deployed, LOC14.4, LOC10

Ice

Sampling Events

Figure 7. Daily Mean Flow recorded at Little Otter Creek at Ferrisburg, VT (USGS Stn #04282650)during water quality sampling, water year 2010 and part of water year 2011.


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3.4 Load Estimates

3.4.1 Load Duration CurveA load duration curve was developed for the 19 years of record available for the USGS Gage on Route 7(Cleland, 2002; Cleland, 2003). Water quality data from 1990 through 2009 were downloaded from theVT Longterm Monitoring Program. For each sample date, the corresponding daily mean flow wasobtained from the archives of flow data available from the USGS website. An approximate daily load ofphosphorus was calculated from the instantaneous total phosphorus concentration using the daily meanflow. From the flow duration curve analysis (Section 3.2), a Flow Duration Interval (FDI) correspondingto the daily mean flow was obtained to graph the approximate daily load of total phosphorus versus FDI.(Note: Constituent concentrations can vary considerably during high-flow conditions, depending in part

on whether sampling occurs on the rising limb or receding limb of the hydrograph. Daily loads calculatedusing the daily mean flow data paired with instantaneous concentration data can be inaccurate,particularly during high-flow conditions. However, an archive of instantaneous flows corresponding tothe sample dates / times was not available at the time this load duration analysis was completed. Dailyloading estimates derived in this manner should be considered approximate and have been used only tocommunicate the relative magnitude of loading at high-flow infrequent events versus moderate to low-flow conditions which predominate in the watershed).

3.4.2 Instantaneous Loads

At each monitoring station, instantaneous load estimates were based on constituent concentration datareported by LaRosa Laboratory and the estimated instantaneous discharge for the nearest time interval tothe sampling time at the relevant flow gaging station.

3.4.3 Predicted Loads

To enable coarse estimates of phosphorus loading at each of the four flow monitoring stations for thosetime periods between actual sampling dates, a rating curve was developed for each station based on a

regression of the instantaneous total phosphorus load (g/sec) to instantaneous discharge normalized toupstream drainage area (cfs/sqmi). The rating curve was then used to estimate instantaneous load fordaily mean flow values for each station. An assumption was made that the instantaneous load wasrepresentative of the full days load. Thus, instantaneous load was multiplied by 86,400 to calculate thedaily load. The appropriate daily loads were summed to calculate the Summer and Fall seasonal loads.Due to project schedules and weather conditions, flow (and therefore loading) data are available for allfour stations for the period from 6/13/10 through 11/26/10. Thus, the seasonal summaries of loadingrepresent a somewhat truncated time period.

4.0 Results

4.1 Flow Measurements

Manual discharge measurements and stage/discharge rating curves for the two temporary gaging

stations (LOC14 4FS and LOC10FS) are presented in Attachment 3 Flow records for the four flow


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#04282525 (New Haven River at Brooksville, near Middlebury, VT) and records for the weather stationsin South Burlington, VT (Airport) and in Rutland, VT accessed at WeatherUnderground, more than 4

inches of rain fell locally during this storm (Table 5). Rainfall was fairly widespread moving from west toeast and ceased in the area of Little Otter Creek at approximately 3 PM on 1 October 2010. Prior to thisevent, the Little Otter Creek had been near baseflow conditions.

Table 5. Rainfall recorded during storm on 30 Sept / 1 Oct 2010.

Precipitation Gage

Elevation

(ft amsl)

Distance from centerof Little Otter Creek

watershed

TotalRainfall

(inches)

New Haven River at Brooksville, VT

(USGS Gage # 04282525)1

235 7.8 mi S 4.73

South Lincoln, VT2

1,370 13.6 mi SE 4.63

Burlington, VT (Airport)2

330 20 mi N 2.95

Rutland, VT2

620 40 mi SSE 4.05

1Provisional precipitation data, http://nwis.waterdata.usgs.gov/vt/nwis/uv?site_no=04282525

2NOAA Online Weather Data: http://www.weather.gov/climate/xmacis.php?wfo=btv

Figure 9a presents the hydrograph for this storm event at each of the four gaging stations; while Figure9b depicts the instantaneous discharge normalized to upstream drainage area. The furthest upstream

sub-unit, LOC14.4FS, demonstrates a flashy response to the storm event, with a short time to peak, andquick recession. In contrast, in the remainder of the watershed (as measured at LOC10, LOC7.8 andLOC4.3 flow stations) the flows tend to be well moderated, due to the low overall gradients and extensivewetland areas which provide for flood storage and attenuation (see Table 3).

It is interesting to note the flashiness of flows draining to LOC14.4FS despite a rather large, channel-contiguous wetland complex in upstream reaches along the main stem (Cedar Swamp, geomorphicreaches M14 and M15). The flashy nature of flows at LOC14.4FS may reflect the drainage from atributary draining 1.8 square miles in The Watershed Center. This tributary enters the Little Otter Creek

downstream of the wetland complex and comprises nearly 16% of the total upstream drainage area (11.6sq mi) at its confluence. The flashy nature of flows monitored at LOC14.4FS may also be related to tiledrain usage in fields along the Little Otter Creek upstream of the flow station.


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Sept 30 / Oct 1, 2010 storm event

0

200

400

600

800

1000

1200

1400

268 270 272 274 276 278 280 282

Ordinal Date

InstantaneousDischarge(cfs)

0

0.1

0.2

0.3

0.4

0.5

0.6

PrecipitationMeasuredatNewHavenRiverUSGS

gage(inches)

Precipitation

LOC14.4 (Temp)

LOC10 (Temp)

LOC7.8 (USGS 04282636)

LOC4.3 (USGS 04282650)

Q1.5 = 1,340 cfs (VTDEC, 2006)

Q2 = 1,120 cfs (Olson, 2002)

4.73 inches

Precipitation


5

10

15

20

25

30

InstantaneousDischarg

eNormalizedtoDrainage

Area(c

fs/sqmi)

0.1

0.2

0.3

0.4

0.5

0.6

PrecipitationMeasured

atNew

HavenRiverUSGS

gage

(inches)

Precipitation

LOC14.4 (Temp)

LOC10 (Temp)LOC7.8 (USGS 04282636)

LOC4.3 (USGS 04282650)

LOC7.8 normalized hydrograph is

same as LOC4.3, since flow at

this station was estimated from

flows recorded at the permanent

USGS gage at LOC4.3 (Route 7

crossing), adjusted for drainage

area differences.

4.73 inches

Precipitation

(a)

(b)


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4.2 Water Quality Results

Water quality results are contained on the Project CD.

4.2.1 Load Duration Curve

Figure 10 illustrates the load duration curve for the USGS Gage on Route 7 (Cleland, 2002; Cleland,2003) relying on 1990 through 2009 water quality data collected as part of the VT Longterm MonitoringProgram. During highest flows, the Little Otter Creek delivers up to 1000 kg/day (or 1 metric ton/day) ofphosphorus to Lake Champlain. This value equates to approximately one fifth of the total annual load oftotal phosphorus (5.4 metric tons) estimated for 1991 by VTDEC and NYSDEC in the Lake ChamplainDiagnostic-Feasibility Study Final Report. It is approximately one quarter of the target total annual load

(4.0 metric tons) estimated for Little Otter Creek (Medalie & Smeltzer, 2004).

Figure 10. Load Duration Curve, vicinity of USGS gage on Route 7,relying on Vermont Longterm Monitoring Data.

4.2.2 Instantaneous Loads

Instantaneous loads of Total Phosphorus were calculated for five of the six regularly-scheduledSpring/Summer sampling dates in 2010 (May 5, June 2, July 7, August 4, and September 1). Qualitycontrol issues resulted in rejection of most of the results for the April 7, 2010 sample date (see ACRWC,2011) Since pressure transducers / staff gages were deployed at temporary flow gaging stations


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Instantaneous Total Phosphorus Load by Station

Spring / Summer sample dates, 2010

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

LOC14.4 LOC10 LOC7.8 LOC4.3

InstantaneousLoad(grams/second)

5/5/10 (107 cfs)

6/2/10 (18 cfs)

7/7/10 (12 cfs)

8/4/10 (71 cfs)

9/1/10 (7 cfs)

Figure 11. (Note: flow value on each date represents the daily mean flow at the USGS gage (LOC4.3))

Instantaneous Total Phosphorus Yield by Station

Spring / Summer sample dates, 2010

0.01

0.02

ntaneousYield(g/sec/sqmi)

5/5/10 (107 cfs)

6/2/10 (18 cfs)

7/7/10 (12 cfs)

8/4/10 (71 cfs)

9/1/10 (7 cfs)


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The Sept 30 / Oct 1, 2010 storm event provided an opportunity to evaluate effects of variable flowconditions on Total Phosphorus concentrations and loading at three of the flow monitoring stations:

LOC14.4, LOC10, and LOC7.8. Figure 13 indicates where on the storm hydrograph each of the gagingsites was sampled. Generally, sites were sampled at the same four positions on the storm hydrograph:(1) during baseflow conditions just prior to the rising limb; (2) on the rising limb; (3) near the peak flow;and (4) on the falling limb.


0

100

200

300

400

500

600

700

800

900

1000

271 272 273 274 275 276 277 278 279 280 281

Ordinal Date

InstantaneousDischarge(cfs)

LOC14.4 (Temp)

LOC10 (Temp)

LOC7.8 (USGS 04282636)

LOC4.3 (USGS 04282650)

Sample

VTDEC Sample

Figure 13. Sampling times denoted on the storm hydrograph.

Figure 14 depicts total phosphorus concentrations during the storm event. Concentration data are highlyvariable with flow. For example, LOC10 happened to be sampled at a similar flow on the rising limb ofthe hydrograph, and then on the falling limb. Total phosphorus concentrations were quite different at

these similar flows (Figure 10). In general, TP concentrations are highest at each station on the risinglimb of the hydrograph.

Figure 15 shows instantaneous loads by station. In contrast to the TP concentration data, the highestTP load at each station corresponds with the peak of the storm hydrograph based on results fromLOC10 and LOC7.8 (station LOC14.4 was not sampled near the peak of its hydrograph).


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Total Phosphorus Concentration by Station

Sept 30 / Oct 1, 2010 Storm Event

0

100

200

300

400

500

600

700

800

900

1000

LOC14.4 LOC10 LOC7.8

Concentration(

ug/L)

9/29/10 (OD 272)

10/1/10 (OD 274)

10/2/10 (OD 275)

10/4/10 (OD 277)

RisingLimb

Risin

Limb

Risin

Limb

Baseflow

Baseflow

Baseflow

Baseflow

Fallin

Limb

Fallin

Limb

Falling

Limb

Peak

Peak

Figure 14

Instantaneous Total Phosphorus Load by Station


2

3

4

5

6

7

ntaneousLoad(g

rams/second)

9/29/10 (OD 272)

10/1/10 (OD 274)

10/2/10 (OD 275)

10/4/10 (OD 277)

RisingLimb

Limb

Limb

Peak

Peak


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Instantaneous Total Phosphorus Yield by Station


0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

LOC14.4 LOC10 LOC7.8

InstantaneousYield(g/se

c/sqmi)

9/29/10 (OD 272)

10/1/10 (OD 274)

10/2/10 (OD 275)

10/4/10 (OD 277)

Risin

Limb

Risin

Limb

Risin

Lim

b

Baseflow

Baseflow

Baseflow

Baseflow

Fallin

Lim

b

Fallin

Lim

b

Fallin

Limb

Peak

Peak

Figure 16

4.2.3 Predicted Loads / Seasonal Loads

To derive a coarse estimate of seasonal loading, a concentration / discharge rating curve was developedfor each of the monitoring stations (see Project CD). The following table summarizes loading:

Table 6. Coarse Estimate of Total Phosphorus Loading inSubunits of the Little Otter Creek watershed

Total

Upstream Summer Fall Summer and Fall

Watershed 6/13 - 8/31/10 9/1 - 11/26/10 6/13 - 11/26/10

LOC14.4 220 760 980

LOC10 780 3,100 3,880

LOC7.8 600 4,100 4,700

LOC4.3 550 2,800 3,350

Coarse Estimate of Phosphorus Load (kg)


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LimitationsCoarse loading estimates for each sub-unit of the Little Otter Creek watershed were developed as part of

a demonstration project to evaluate the feasibility of such monitoring efforts, relying on a professional /volunteer partnership (with support from LaRosa Laboratory) to carry out data collection and analysis.Coarse estimates were used to broadly guide planning and outreach in this 72.5-square-mile watershed(i.e., to focus limited resources toward sub-units of the watershed that appear to have greater loading).These data should be considered very approximate, as the concentration / discharge rating curve is

developed on a limited number of sample results for Summer and Fall seasons only in one calendar year,2010. In addition, the discharge values used in this regression for stations LOC14.4FS and LOC10FS arethemselves developed from a stage / discharge rating curve which was based on relatively few manualmeasurements of discharge; the stage discharge rating curve also extended to flow values which weremore than twice the magnitude of the highest measured flows. These data should not be used to guidespecific restoration / conservation projects, develop TMDL target loads, or as supporting evidence forpotential enforcement actions in the watershed.

5.0 Discussion & Conclusions

Flows in the upper end of Little Otter Creek watershed (upstream of LOC14.4 FS) are flashy. Theremainder of the basin responds gradually to storm events. Hydrographs in the mid- to lower-watershedare characterized by broad peaks of low amplitude, consistent with previous findings (e.g., Medalie,2007). This is probably due to the excellent channel/floodplain connection and extensive channel-

contiguous wetlands related to soil parent material, low overall gradients, and intermittent bedrock-controlled valley pinch points (SMRC, 2011).

These 2010 water quality results, as well as a 12-year history of water quality monitoring in thewatershed by ACRWC, indicate that nutrient and sediment loading are widespread in the basin (seeSection 2.8 of the Phase 2 report). Total Phosphorus concentrations have often been above levels whichwould suggest nutrient enrichment at the regularly-monitored sampling sites on the Little Otter mainstem and Mud Creek (monitored 1997-2008, 2010). Long-term monitoring data collected by VTDECWater Quality Division near the Route 7 bridge (0.65 mile downstream of LOC4.3, monitored 1990-2009)

suggest that phosphorus is more dominantly found in the dissolved phase rather than the particulatephase, sorbed to fine sediments (VTDEC WQD and NYSDEC, 2009; ACRWC, 2009).

A better understanding of flow characteristics in the watershed has helped to characterize the nature andtransport mechanisms of nutrient and sediment loading. The majority of phosphorus (and suspendedsediment loads) are delivered during high flow events which generally occur in the Fall and Springmonths. Therefore, management strategies should be focused on land use practices and conditionsassociated with these less-frequent, higher-magnitude flow events. For example:

Runoff from bare soilsFigure 17 (next page) shows the number of days (by month)over 19 years of record that flow in the Little Otter Creekequaled or exceeded the 10% flow duration interval (156 cfs).High flows occurred most often in the months of April andMarch, followed closely by November. Over 80% of these highflows occurred in months (October through May) when cropped


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Figure 17. Occurrence of high-flow events in the Little Otter Creek watershed coincident with months in which crop lands exhibit bare soils andmanure is applied.


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Streambank erosionEroding streambanks have been identified as a contributing nonpoint source of phosphorus in riversand streams of Vermont (VTANR, 2001; DeWolfe et al., 2004) and elsewhere in the nation (Kalma& Ulmer, 2003; Nelson & Booth, 2002). A study in nearby Lewis Creek watershed found thatstreambank erosion accounted for between 22 and 35% of the total phosphorus load of that

watershed (DeWolfe et al., 2004). A recent study in the Missisquoi basin indicates that streambankerosion contributes between 29% and 42% of the total suspended load and approximately 50% ofthe annual Total Phosphorus load (Simon et al, in preparation). Often streambank sediments aremobilized during the falling limb of storm hydrographs and are therefore associated with the lessfrequent, high-flow conditions on the flow duration curve (Figure 19).

While the Phase 2 study of Little Otter Creek indicated that the main stem reaches are fairly stable(with a few notable exceptions), the network of smaller tributaries, field ditches, road ditches, andtile drains feeding into the main stem is contributing fine sediments (and presumably nutrientssorbed to fine particles).

InundationThe floodplain along Little Otter Creek and its tributaries is frequently inundated following high-flowevents (Figure 20). Flooded areas extend well beyond standard buffer widths (10 ft under AAPguidance; 25 feet under LFO/MFO rules) into cropped lands and/or areas where manure / fertilizershave been applied.

Based in part upon the windshield observations of inundation and this flow study, the Phase 2

project steering committee prioritized land areas within the catchments for reaches M11 and M10for outreach regarding wetland restoration (between LOC14.4FS and LOC10FS). The upstreamdrainage area of Little Otter Creek doubles within reach M11 (from 12.3 to 25.5 square miles) andincreases by a third in reach M10 (from 25.5 to 35.4 square miles). Extensive ditch networks and

ditched tributaries drain directly to these reaches. Large areas of the floodplain in reaches M10and M11 as well as along a forth-order tributary to M10, upstream and downstream of the PlankRoad crossing, are frequently inundated following storm events. Crop and hay fields are abundantthroughout these floodplains. Buffer areas are often inundated and water extends well into fieldsthat have been recently tilled or planted. Rill erosion is also observed through the emergent crops,delivering small deltas of fine sands and silt out into these runoff-contributing areas. Inundationpersists for days to weeks, possibly leading to anaerobic (reducing) conditions that may result inincreased fractions of dissolved phosphorus. Water quality monitoring data indicates increasedloading between Station LOC14.4 (reach M12) and Station LOC10 (reach M09) (based on one fall

storm and limited Spring / Summer sampling from 2010). While similar concerns were noted infrequently inundated areas west of Middlebrook Road in Ferrisburgh (reaches M05, M04, and T2.01between LOC7.8FS and LOC4.3FS), some previously farmed fields in these areas have already beenplaced into conservation. Coarse loading data based on very limited monitoring suggests thatphosphorus contributions may be steady or declining between these two downstream stations.

A di J Fl M i i Li l O C k W h d


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Figure 19. Occurrence of high-flow events in the Little Otter Creek watershed associated with streambank erosion especially on the recessionallimb of the storm hydrograph.

A di J Fl M it i Littl Ott C k W t h d


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Figure 20. Occurrence of high-flow events in the Little Otter Creek watershed associated with floodplain inundation, especially in the Springmonths when partially frozen ground can extend the arial extent and duration of inundation. Inundation can be coincident with manureapplications particularly in the late fall months.

Appendix J: Flow Monitoring Little Otter Creek Watershed


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6.0 Recommendations for further study

This flow monitoring pilot study has demonstrated that a better understanding flow characteristics in awatershed at the sub-unit scale can effectively guide watershed planning and management strategies foroverall reductions in sediment and nutrient loading. Additional study would improve the robustness ofloading estimates across multiple years:

Limited manual measurements of discharge did not happen to capture high-flow events, and thusthe rating curves developed for the two temporary gaging sites may be an inaccurate predictor of

flow magnitude in this higher end of the flow range.

Additional water quality and flow monitoring will improve the regressions for both stage /discharge rating curve and the concentration / discharge rating curves.

Additional flow monitoring and sample collection could provide coarse estimates of loading in theSpring season. Additional storm-event sampling was conducted in 2011 during spring storms inApril and May. These data will be subject to QA review along with regularly-scheduled ACRWCspring/ summer sampling events during the Winter of 2011-2012. Pressure transducer data is

available for these storm events at temporary gaging sites, LOC14.4FS and LOC10FS, to calculateconstituent loads. (Transducers were re-deployed on 31 March 2011 following ice out, andpulled from the river just prior to Tropical Storm Irene in late August 2011). Additional fundingwould enable coarse loading calculations to be completed for this Summer season.

Capturing additional years of data will increase the likelihood of capturing the full range of flowsrepresentative of the watershed.

Additional study could be carried out to evaluate instream wetlands (reaches M11, M10, M08,M05, M04) for their role (seasonally, annually) as either a source or sink for phosphorus transport/ transformation.

7.0 References

Cleland, Bruce, 2002. TMDL Development from the Bottom Up Part II: Using Duration Curves toConnect the Pieces. http://www.tmdls.net/tipstools/docs/BottomUp.pdf

Cleland, Bruce, 2003. TMDL Development from the Bottom Up Part III: Duration Curves and Wet-Weather Assessments. http://www.tmdls.com/tipstools/docs/TMDLsCleland.pdf

Hodgkins, Glenn A. and Robert W. Dudley, 2006, Changes in the timing of winter-spring streamflows ineastern North America, 1913-2002, Geophysical Research Letters, v 33, L06402,



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Medalie, L. and E. Smeltzer, 2004, Status and Trends of Phosphorus in Lake Champlain and itsTributaries, 1990-2000. in Lake Champlain: Partnership and Research in the New Millennium, T.

Manley, Ed., Kluwer Academic/Plenum Publishers.

National Climatic Data Center, 2011, Event Narrative for Flash Flood, 1 October 2010, Addison County,Vermont, accessed on 09 February 2011 at: http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwEvent~storms

NOAA Online Weather Data: Daily Almanac accessed athttp://www.weather.gov/climate/xmacis.php?wfo=btv

Olson, Scott A., 2002, Flow-Frequency Characteristics of Vermont Streams. USGS Water-ResourcesInvestigations Report 02-4238.

Rantz, S. E. et al, 1982. Measurement and Computation of Streamflow: Volume 1. Measurement ofStage and Discharge. USGS Water Supply Paper 2175. United States Government Printing Office.

Shanley, James B. and Jon C. Denner, 1999, The Hydrology of the Lake Champlain Basin, in LakeChamplain in Transition: From Research Toward Restoration, Water Science and Application VolumeI, pp 41-66. T. Manley, P. Manley, Ed., Washington DC: American Geophysical Union.

Simon, A., W. Dickerson, and A. Heins, 2004. Suspended-sediment transport rates at the 1.5-yearrecurrence interval for ecoregions of the United States: transport conditions at the bankfull andeffective discharge?. Geomorphology: 58 (243-262).

UNH Climate Change Research Center and Clean Air Cool Planet, 2005, Indicators of Climate Change inthe Northeast, available at: http://www.cleanair-coolplanet.org/information/pdf/indicators.pdf

USEPA, 2007. An Approach for Using Load Duration Curves in the Development of TMDLs. EPA 841-B-07-006. http://www.epa.gov/owow/tmdl/techsupp.html

Vermont Department of Environmental Conservation and New York State Department of EnvironmentalConservation, 1997, A Phosphorus Budget, Model, and Load Reduction Strategy for Lake Champlain:Lake Champlain Diagnostic-Feasibility Study Final Report.



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September 2011 DRAFT Phase 2 Stream Geomorphic Assessment

Attachment 1

Location Map of Temporary Gaging Stations



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pp g


LOC14.4 Temporary Flow Monitoring Gage



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pp g




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LOC10 Temporary Flow Monitoring Gauge


S t b 2011 DRAFT Ph 2 St G hi A t


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Septembe 2011 DRAFT Phase 2 St eam Geomo phic Assessment


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Attachment 2

Climate and Hydrology Data




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Table J2-1. Monthly / Annual Precipitation at climate stations near Little Otter Creek watershed.

Data Time

Source Period Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

Burlington, VT (Airport) 1 1971-2000 2.22 1.67 2.32 2.88 3.32 3.43 3.97 4.01 3.83 3.12 3.06 2.22 36.05

330 ft amsl 2 2009 1.76 1.81 1.90 1.86 5.25 5.25 4.62 2.32 3.67 2.98 2.98 3.02 37.42

20 miles N 2 2010 2.41 2.13 2.85 3.08 1.52 5.87 2.25 3.51 4.17 6.24 3.10 3.60 40.73

South Lincoln, VT 1 1971-2000 2.92 2.10 3.14 4.20 4.31 4.58 4.24 5.22 4.44 4.39 3.98 3.13 46.65

1,370 ft amsl 2 2009 3.05 2.91 2.14 2.55 8.71 5.52 9.07 3.03 2.25 4.52 4.76 3.80 52.31

13.6 miles SE 2 2010 2.88 3.69 4.65 4.17 2.21 7.50 7.18 5.61 3.36 11.56 2.13 3.08 58.02

Rutland, VT 1 1971-2000 2.70 1.97 2.59 2.80 3.52 3.85 4.58 4.18 3.91 3.21 3.08 2.73 39.12620 ft amsl 2 2009 2.29 1.98 2.04 1.96 4.43 3.86 9.30 7.71 2.27 4.76 3.64 3.00 47.24

40 miles SSE 2 2010 2.22 2.83 4.69 3.04 2.87 3.00 5.35 4.14 1.95 9.76 2.28 3.66 45.79

Total precipitation in inches, including liquid equivalent of snow, sleet.

Data Sources:1

National Climatic Data Center, 2002, Climatography of the United States No. 81 - 43 (Vermont), Monthly Station Normals of

Temperature, Precipitation, and Heating and Cooling Degree Days: 1971-2000

2NOAA Online Weather Data, http://www.weather.gov/climate/index.php?wfo=btv

Table J2-2. Monthly / Seasonal Snowfall Totals at climate stations near Little Otter Creek watershed.

Time

Period Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Season

So. Burlington, VT 1971-2000 0 0 0 0.3 7.2 17.1 20.9 15.3 15.4 5.8 0.0 0 81.9

(Airport) 2009-2010 0 0 0 0.0 0.0 17.7 48.4 24.0 0.9 5.5 0.0 0 96.5

2010-2011 0 0 0 0.1 0.3 27.9 26.9

South Lincoln, VT 1981-2000 0 0 0 2.2 13.9 26.9 29.6 22.8 24.5 10.5 0.7 0 131.12009-2010 0 0 0 0.1 1.1 26.0 22.5 33.0 3.2 10.0 1.0 0 96.9

2010-2011 0 0 0 2.2 4.0 37.5 25.5

Rutland, VT 1971-2000 0 0 0 0.3 5.6 13.5 16.7 13.9 12.4 3.6 0.0 0 66.0

2009-2010 0 0 0 0.0 0.0 18.2 15.9 19.9 0.1 2.1 0.0 0 56.2

2010-2011 0 0 0 0.0 0.9 21.3 26.8

Total snowfall in inches. Values for 1971-2000 period reflect averages for the time period. Values for 2009-2010 season are totals.

Source: http://www.weather.gov/climate/xmacis.php?wfo=btv




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Table J2-3. Mean Annual Flows, Little Otter Creek at Ferrisburgh, VT

Little Otter Creek at Ferrisburg, VT

USGS Gaging Station #04282650

Drainage Area (sq mi) 73

Gaged Area (sq mi) 57.1

Mean

Annual

Flow

Water Year (cfs)

1991 72.2

1992 52.9

1993 53.3

1994 47.5

1995 28.7

1996 102.7

1997 62.61998 79.8

1999 41.5

2000 79.6

2001 58.1

2002 26.8

2003 45.9

2004 80.5

2005 40.9

2006 96.82007 68.6

2008 105.9

2009 64.6

2010 66

Min (1991-2010) 2002 27

Max (1991-2010) 2008 106

Mean (1991-2010) 64

Water Year 2010 66

Note: Estimates for water year 2010 (red highlighted values) are calculated from

provisional Daily Mean Flows accessed 13 Feb 2011 online at:




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Table J2-4. Cumulative Annual Flow, Little Otter Creek at Ferrisburgh, VT (USGS Stn# 04282650) Water Years 19912000

(after Medalie, 2007)

Cummulative Flow on Little Otter Creek (million cubic feet)

Water Years 1991 - 2000 (USGS gaging station # 04282650)

0

500

1,000

1,500

2,000

2,500

3,000

3,500

1 31 61 91 121 151 181 211 241 271 301 331 361

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Water Year

1996

1995




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p p


Table J2-5. Cumulative Annual Flow, Little Otter Creek at Ferrisburgh, VT (USGS Stn# 04282650) Water Years 20012010

(after Medalie, 2007)

Cummulative Flow on Little Otter Creek (million cubic feet)

Water Years 2001 - 2010 (USGS gaging station # 04282650)

0

500

1,000

1,500

2,000

2,500

3,000

3,500

1 31 61 91 121 151 181 211 241 271 301 331 361

2001

2002

2003

2004

2005

2006

2007

20082009

2010

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Water Year

2008

2006

2002




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Attachment 3

Discharge Data

Temporary Flow Gaging Stations


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Temporary Gage: LOC10-FS Upstream Drainage Area (sq mi): 35.8

USGS Stn Drainage Area (sq mi): 57.1

USGS Stn 04282650 Est. Flow

Measured Instantaneous Daily Mean Proportional

Date End Time Flow (cfs) Flow (cfs) Flow (cfs) Area

6/4/2010 14:12 14.8 16 15 10.0

6/28/2010 15:05 89.3 194 118 121.6

7/7/2010 9:50 9.1 12 12 7.5

9/1/2010 9:54 5.3 6.3 7.0 3.911/23/2010 13:20 41.9 56 84 35.1

2010 Stage / Discharge Relationship: Temporary Gage: LOC10-FS

Little Otter Creek, Reach M09, Upstream Drainage Area = 35.8 sq mi

y = 35.658x2.1792

R2

= 0.9912

1

10

100

1000

0.1 1.0 10.0

YSI S d St (ft)

Discharge(cfs)


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6/4/2010 14.8 cfs Measured

Little Otter Creek - LOC10 FS

96

98

100

102

104

106

108

-60 -40 -20 0 20 40 60 80

Distance FromLeft Bank (ft)

Elevation



96

98

100

102

104

106

108

-60 -40 -20 0 20 40 60 80


Elevation


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96

98

100

102

104

106

108

-60 -40 -20 0 20 40 60 80


Elevation



96

98

100

102

104

106

108

-60 -40 -20 0 20 40 60 80


Elevation


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10/2/2010 522 cfs Calculated (Mannings Equation at Mon. XS-1)


96

98

100

102

104

106

108

-60 -40 -20 0 20 40 60 80


Elevation

11/23/2010 41.9 cfs Measured


96

98

100

102

104

106

108

-60 -40 -20 0 20 40 60 80


Elevation


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Date ? 678 cfs Calculated (Mannings Equation at Mon. XS-1)

From High Water Marks at Cross Section Monuments, Possibly 12/15/2010, or ice-out on/ about 3/19/2011 (more likely) Staff Gage / Pressure Transducer not deployed on these

dates.


96

98

100

102

104

106

108

-60 -40 -20 0 20 40 60 80


Elevation

Velocity Equation Coefficients 0.9604 0.0312

Stream Name: Little Otter Creek Date: 6/4/2010 Nearest Permanent Gage: USGS Gage #04282650

Cross Section: LOC10-FS Instantaneous Flow: 16 cfs


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Observers: K. Underwood, B. O'Shea Daily Mean Flow: 15 cfs

Weather: sunny, 75 Water T: NM Flow Gage Used: Pygmy Stage: 0.40 ft

Recent Precip: 6/3 (NHR): 0.25 in; 6/1 (NHR): 0.5 in Begin Time: 13:30 End Time: 14:12

Fixed Pt = LPIN Depth (d) >2.5 ft, Obs Depth = 0.2xd and 0.8xd, otherwise, 0.6xd

Angle Distance from Obs Total Adjusted for Discharge, q

Notes Coeff. fixed point (ft) Depth Depth (ft) Rev (#) Time (sec) R (rev/sec) at pt mean angle coeff. Area (ft2) (ft3/sec) Check

1 LEW 5.0

2 1.0 10.0 0.6 1.0 31 60 0.52 0.527 0.527 2.75 1.450 9.8%

3 1.0 10.5 0.6 0.8 39 55 0.71 0.712 0.712 0.4 0.285 1.9%

4 1.0 11.0 0.6 0.85 45 55 0.82 0.817 0.817 0.425 0.347 2.4%

5 1.0 11.5 0.6 0.75 34 55 0.62 0.625 0.625 0.5625 0.352 2.4%

6 1.0 12.5 0.6 0.9 28 55 0.51 0.520 0.520 0.675 0.351 2.4%

7 1.0 13.0 0.6 0.8 67 55 1.22 1.201 1.201 0.4 0.480 3.3%

8 1.0 13.5 0.6 0.8 69 55 1.25 1.236 1.236 0.4 0.494 3.3%

9 1.0 14.0 0.6 0.85 79 55 1.44 1.411 1.411 0.425 0.600 4.1%

10 1.0 14.5 0.6 0.9 77 55 1.40 1.376 1.376 0.45 0.619 4.2%

11 1.0 15.0 0.6 0.85 87 55 1.58 1.550 1.550 0.425 0.659 4.5%

12 1.0 15.5 0.6 0.85 93 55 1.69 1.655 1.655 0.425 0.703 4.8%

13 1.0 16.0 0.6 0.5 32 55 0.58 0.590 0.590 0.25 0.147 1.0%

14 1.0 16.5 0.6 0.4 86 55 1.56 1.533 1.533 0.2 0.307 2.1%

15 1.0 17.0 0.6 0.55 104 55 1.89 1.847 1.847 0.275 0.508 3.4%

16 1.0 17.5 0.6 0.55 119 55 2.16 2.109 2.109 0.275 0.580 3.9%

17 1.0 18.0 0.6 0.7 97 55 1.76 1.725 1.725 0.35 0.604 4.1%

18 1.0 18.5 0.6 0.75 84 55 1.53 1.498 1.498 0.375 0.562 3.8%19 1.0 19.0 0.6 0.7 111 55 2.02 1.969 1.969 0.35 0.689 4.7%

20 1.0 19.5 0.6 0.35 125 55 2.27 2.214 2.214 0.175 0.387 2.6%

21 1.0 20.0 0.6 0.35 80 55 1.45 1.428 1.428 0.175 0.250 1.7%

22 1.0 20.5 0.6 0.55 105 60 1.75 1.712 1.712 0.275 0.471 3.2%

23 1.0 21.0 0.6 0.7 92 55 1.67 1.638 1.638 0.35 0.573 3.9%

24 1.0 21.5 0.6 0.75 44 55 0.80 0.800 0.800 0.375 0.300 2.0%

25 1.0 22.0 0.6 0.5 94 55 1.71 1.673 1.673 0.25 0.418 2.8%

26 1.0 22.5 0.6 0.75 119 55 2.16 2.109 2.109 0.375 0.791 5.4%

27 1.0 23.0 0.6 0.55 72 55 1.31 1.288 1.288 0.275 0.354 2.4%

28 1.0 23.5 0.6 0.45 96 55 1.75 1.708 1.708 0.225 0.384 2.6%

29 1.0 24.0 0.6 0.5 102 55 1.85 1.812 1.812 0.25 0.453 3.1%30 1.0 24.5 0.6 0.7 81 55 1.47 1.446 1.446 0.35 0.506 3.4%

31 1.0 25.0 0.6 0.5 17 55 0.31 0.328 0.328 0.45 0.148 1.0%

32 REW 1.0 26.30 0.6

TOTAL 12.9375 14.773 100.0%

Velocity (fps)

Use 25 to 30 partial sections,

More narrowly spaced close to thalweg.

Velocity (fps) should not be less than 0.2.Check: No partial section should contain >10% of flow.

AA Meter: V = 2.2048*R +0.0178.Pygmy Meter: V = 0.9604*R + 0.0312


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Cross Section: LOC10-FS Instantaneous Flow: 12 cfs

Obser ers K Under ood Dail Mean Flo 12 cfs


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Observers: K. Underwood Daily Mean Flow: 12 cfs

Weather: clear, hazy, hot, humid Water T: 78 F (Air: 83 F) Flow Gage Used: Pygmy Stage: 0.28 ft

Recent Precip: Dry since 7/1 (0.16 in @ BTV, 0.13 in @ NHR) Begin Time: 9:03 End Time: 9:50




1 LEW 6.7

2 shadow of cobbles 1.0 8.0 0.6 0.3 0 55 0.00 0.031 0.031 0.27 0.008 0.1%

3 1.0 8.5 0.6 0.65 1 55 0.02 0.049 0.049 0.325 0.016 0.2%

4 1.0 9.0 0.6 0.65 0 55 0.00 0.031 0.031 0.325 0.010 0.1%

5 1.0 9.5 0.6 0.7 12 55 0.22 0.241 0.241 0.35 0.084 0.9%

6 1.0 10.0 0.6 0.8 13 55 0.24 0.258 0.258 0.4 0.103 1.1%

7 1.0 10.5 0.6 0.8 27 55 0.49 0.503 0.503 0.52 0.261 2.9%

8 1.0 11.3 0.6 0.8 47 60 0.78 0.784 0.784 0.64 0.501 5.5%

9 moved 0.5' u/s of b 1.0 12.1 0.6 0.75 25 55 0.45 0.468 0.468 0.675 0.316 3.5%

10 1.0 13.1 0.6 0.85 55 55 1.00 0.992 0.992 0.7225 0.716 7.9%

11 1.0 13.8 0.6 0.6 66 55 1.20 1.184 1.184 0.33 0.391 4.3%

12 1.0 14.2 0.6 0.55 80 55 1.45 1.428 1.428 0.2475 0.353 3.9%

13 1.0 14.7 0.6 0.65 72 55 1.31 1.288 1.288 0.325 0.419 4.6%

14 1.0 15.2 0.6 0.5 81 55 1.47 1.446 1.446 0.325 0.470 5.2%

15 1.0 16.0 0.6 0.5 35 55 0.64 0.642 0.642 0.45 0.289 3.2%

16 side shadow of bo 1.0 17.0 0.6 0.4 58 55 1.05 1.044 1.044 0.3 0.313 3.5%

17 side shadow of bo 1.0 17.5 0.6 0.35 112 55 2.04 1.987 1.987 0.175 0.348 3.8%

18 1.0 18.0 0.6 0.45 110 55 2.00 1.952 1.952 0.27 0.527 5.8%

19 1.0 18.7 0.6 0.45 50 55 0.91 0.904 0.904 0.3375 0.305 3.4%

20 1.0 19.5 0.6 0.45 92 55 1.67 1.638 1.638 0.3825 0.626 6.9%

21 1.0 20.4 0.6 0.55 53 60 0.88 0.880 0.880 0.4125 0.363 4.0%

22 1.0 21.0 0.6 0.45 66 55 1.20 1.184 1.184 0.36 0.426 4.7%

23 1.0 22.0 0.6 0.55 83 55 1.51 1.481 1.481 0.495 0.733 8.1%

24 1.0 22.8 0.6 0.65 82 55 1.49 1.463 1.463 0.3575 0.523 5.8%

25 1.0 23.1 0.6 0.4 66 55 1.20 1.184 1.184 0.24 0.284 3.1%

26 1.0 24.0 0.6 0.5 71 55 1.29 1.271 1.271 0.375 0.477 5.3%

27 edge of still water 1.0 24.6 0.6 0.4 49 55 0.89 0.887 0.887 0.2 0.177 2.0%

28 1.0 25.0 0.6 0.3 1 55 0.02 0.049 0.049 0.225 0.011 0.1%

29 REW 1.0 26.1 0.6 030 RTOB 1.0 28.5

TOTAL 10.035 9.052 100.0%

Velocity (fps)







Cross Section: LOC10-FS Instantaneous Flow: 6.3 cfs

Observers: K Underwood Daily Mean Flow: 7 0 cfs


50/64

Observers: K. Underwood Daily Mean Flow: 7.0 cfs

Weather: clear, humid, 80s, high 92 F Water T: 73 F Flow Gage Used: Pygmy Stage: 0.18 ft

Recent Precip: None last 6 days; NHR: 2.2 in 8/22,23; BTV: 1.1in 8/21, 22, 23 Begin Time: 9:09 End Time: 9:54




1 LEW 8.0

2 shadow of boulder 1.0 9.5 0.6 0.6 1 50 0.02 0.050 0.050 0.63 0.032 0.6%

3 1.0 10.1 0.6 0.5 1 50 0.02 0.050 0.050 0.25 0.013 0.2%

4 1.0 10.5 0.6 0.75 5 55 0.09 0.119 0.119 0.3375 0.040 0.8%

5 1.0 11.0 0.6 0.65 13 55 0.24 0.258 0.258 0.325 0.084 1.6%

6 1.0 11.5 0.6 0.6 42 55 0.76 0.765 0.765 0.3 0.229 4.4%

7 1.0 12.0 0.6 0.45 46 55 0.84 0.834 0.834 0.3375 0.282 5.3%

8 1.0 13.0 0.6 0.55 16 55 0.29 0.311 0.311 0.44 0.137 2.6%

9 1.0 13.6 0.6 0.65 56 55 1.02 1.009 1.009 0.3575 0.361 6.8%

10 1.0 14.1 0.6 0.5 49 55 0.89 0.887 0.887 0.25 0.222 4.2%

11 1.0 14.6 0.6 0.65 87 65 1.34 1.317 1.317 0.325 0.428 8.1%

12 1.0 15.1 0.6 0.3 77 55 1.40 1.376 1.376 0.135 0.186 3.5%

13 1.0 15.5 0.6 0.25 62 55 1.13 1.114 1.114 0.15 0.167 3.2%

14 shadow of boulder 1.0 16.3 0.6 0.4 38 55 0.69 0.695 0.695 0.4 0.278 5.3%

15 on cobble & in sha 0.7 17.5 0.6 0.2 15 65 0.23 0.253 0.179 0.17 0.030 0.6%

16 1.0 18.0 0.6 0.25 108 65 1.66 1.627 1.627 0.125 0.203 3.9%

17 1.0 18.5 0.6 0.3 87 55 1.58 1.550 1.550 0.15 0.233 4.4%

18 1.0 19.0 0.6 0.35 60 55 1.09 1.079 1.079 0.175 0.189 3.6%19 1.0 19.5 0.6 0.45 69 55 1.25 1.236 1.236 0.225 0.278 5.3%

20 boulder 1.0 20.0 0.6 0.2 63 55 1.15 1.131 1.131 0.14 0.158 3.0%

21 1.0 20.9 0.6 0.4 42 55 0.76 0.765 0.765 0.34 0.260 4.9%

22 1.0 21.7 0.6 0.45 72 55 1.31 1.288 1.288 0.3375 0.435 8.3%

23 1.0 22.4 0.6 0.45 44 55 0.80 0.800 0.800 0.36 0.288 5.5%

24 cobble @ 23.0 1.0 23.3 0.6 0.5 47 55 0.85 0.852 0.852 0.4 0.341 6.5%

25 1.0 24.0 0.6 0.3 53 55 0.96 0.957 0.957 0.195 0.187 3.5%

26 1.0 24.6 0.6 0.3 29 55 0.53 0.538 0.538 0.21 0.113 2.1%

27 0.9 25.4 0.6 0.35 20 60 0.33 0.351 0.330 0.2975 0.098 1.9%

28 REW 1.0 26.3 0.6 0

29 1.030 1.0

TOTAL 7.3625 5.270 100.0%

Velocity (fps)






51/64


52/64

Temporary Gage: LOC14.4-FS Upstream Drainage Area (sq mi): 11.9

USGS Stn Drainage Area (sq mi): 57.1

Est. Flow

Measured Instantaneous Daily Mean Proportional

Date End Time Flow (cfs) Flow (cfs) Flow (cfs) Area

5/14/2010 11:57 11.6 40 41 8.3

6/4/2010 15:34 6.5 17 15 3.5

6/28/2010 12:40 43.1 138 118 28.8

7/7/2010 11:55 3.7 12 12 2.5

9/1/2010 15:49 3.1 7.5 7 1.6

USGS Stn 04282650

2010 Stage / Discharge Relationship: Temporary Gage: LOC14.4-FS

Little Otter Creek, Reach M13, Upstream Drainage Area = 11.9 sq mi

y = 28.921x1.7616

R2

= 0.9939

1

10

100

1000

0.1 1.0 10.0

YSI Sonde Stage (ft)

Disch

arge(cfs)

5/14/2010 11 6 cfs Measured


53/64


Little Otter Creek - LOC14.4 FS

97

98

99

100

101

102

103

104

105

-20 -10 0 10 20 30 40 50 60 70 80


Elevation



97

98

99

100

101

102

103

104

105

-20 -10 0 10 20 30 40 50 60 70 80


Elevation

6/28/2010 43 1 cfs Measured


54/64



97

98

99

100

101

102

103

104

105

-20 -10 0 10 20 30 40 50 60 70 80


Elevation

6/29/2010 4 AM cfs Calculated (Mannings Equation)


97

98

99

100

101

102

103

104

105

-20 -10 0 10 20 30 40 50 60 70 80Distance FromLeft Bank (ft)

Elevation



55/64



97

98

99

100

101

102

103

104

105

-20 -10 0 10 20 30 40 50 60 70 80


Elevation

7/22/2010 Noon 136 cfs Calculated (Mannings Equation, from water surface elevation

at monumented cross section, XS-1)


97

98

99

100

101

102

103

104

105

-20 -10 0 10 20 30 40 50 60 70 80Distance FromLeft Bank (ft)

Elevation



56/64


97

98

99

100

101

102

103

104

105

-20 -10 0 10 20 30 40 50 60 70 80


Elevation

10/1/2010 16:00 398 cfs Calculated (Mannings Equation)


97

98

99

100

101

102

103

104

105

-20 -10 0 10 20 30 40 50 60 70 80


Elevation


57/64

10/16/2010 Noon 201 cfs Calculated (Mannings Equation at Mon. XS-1)


97

98

99

100

101

102

103

104

105

-20 -10 0 10 20 30 40 50 60 70 80


Elevation

3/31/2011 No conclusive recent high water marks observed at the cross section site.



Cross Section: LOC14.4-FS Instantaneous Flow: 40 cfs



58/64

Weather: overcast, breezy, 60s Water T: 54 Flow Gage Used: Pygmy Stage: 0.38 ft

Recent Precip: 0.2in 5/13-5/14; ~1in 5/4-5/8 (NHR gage) Begin Time: 11:05 End Time: 11:57




1 LEW 31.2

2 1.0 33.0 0.6 0.4 60 58 1.03 1.025 1.025 0.46 0.471 4.1%

3 1.0 33.5 0.6 0.4 65 58 1.12 1.108 1.108 0.3 0.332 2.9%

4 1.0 34.5 0.6 0.5 75 50 1.50 1.472 1.472 0.375 0.552 4.8%

5 1.0 35.0 0.6 0.55 55 45 1.22 1.205 1.205 0.275 0.331 2.9%

6 1.0 35.5 0.6 0.55 85 48 1.77 1.732 1.732 0.275 0.476 4.1%

7 1.0 36.0 0.6 0.55 75 48 1.56 1.532 1.532 0.275 0.421 3.6%

8 1.0 36.5 0.6 0.5 90 49 1.84 1.795 1.795 0.25 0.449 3.9%9 1.0 37.0 0.6 0.55 85 50 1.70 1.664 1.664 0.3575 0.595 5.1%

10 1.0 37.8 0.6 0.6 80 53 1.51 1.481 1.481 0.45 0.666 5.7%

11 mid-channel 1.0 38.5 0.6 0.6 60 47 1.28 1.257 1.257 0.36 0.453 3.9%

12 1.0 39.0 0.6 0.7 90 58 1.55 1.521 1.521 0.35 0.533 4.6%

13 1.0 39.5 0.6 0.65 110 55 2.00 1.952 1.952 0.4875 0.952 8.2%

14 1.0 40.5 0.6 0.6 75 44 1.70 1.668 1.668 0.45 0.751 6.5%

15 1.0 41.0 0.6 0.7 70 49 1.43 1.403 1.403 0.35 0.491 4.2%

16 1.0 41.5 0.6 0.75 85 46 1.85 1.806 1.806 0.375 0.677 5.8%

17 1.0 42.0 0.6 0.85 80 51 1.57 1.538 1.538 0.425 0.654 5.6%

18 1.0 42.5 0.6 0.85 100 49 2.04 1.991 1.991 0.3825 0.762 6.6%

19 TW = 0.9 ft total de 1.0 42.9 0.6 0.85 70 43 1.63 1.595 1.595 0.425 0.678 5.8%

20 at 43.0 1.0 43.5 0.6 0.65 65 49 1.33 1.305 1.305 0.3575 0.467 4.0%

21 1.0 44.0 0.6 0.7 40 63 0.63 0.641 0.641 0.35 0.224 1.9%

22 1.0 44.5 0.6 0.7 35 53 0.66 0.665 0.665 0.35 0.233 2.0%

23 1.0 45.0 0.6 0.75 15 50 0.30 0.319 0.319 0.375 0.120 1.0%

24 shadow of rock 1.0 45.5 0.6 0.6 1 40 0.03 0.055 0.055 0.3 0.017 0.1%

25 1.0 46.0 0.6 0.5 15 42 0.36 0.374 0.374 0.25 0.094 0.8%

26 1.0 46.5 0.6 0.35 55 45 1.22 1.205 1.205 0.175 0.211 1.8%

27 1.0 47.0 0.6 0.4 2 40 0.05 0.079 0.079 0.14 0.011 0.1%

28 REW 1.0 47.2 0.6 0 0.000 0.0%

29 1.0

30 1.0

TOTAL 8.92 11.619 100.0%

Velocity (fps)










59/64

Weather: sunny, 75 Water T: NM Flow Gage Used: Pygmy Stage: 0.25 ft

Recent Precip: 6/3 (NHR): 0.25 in; 6/1 (NHR): 0.5 in Begin Time: 14:55 End Time: 15:34




1 LEW 31.8

2 1.0 33.5 0.6 0.25 53 55 0.96 0.957 0.957 0.275 0.263 4.0%

3 1.0 34.0 0.6 0.2 60 55 1.09 1.079 1.079 0.1 0.108 1.7%

4 1.0 34.5 0.6 0.3 42 55 0.76 0.765 0.765 0.15 0.115 1.8%

5 1.0 35.0 0.6 0.35 34 55 0.62 0.625 0.625 0.175 0.109 1.7%

6 1.0 35.5 0.6 0.4 57 55 1.04 1.027 1.027 0.2 0.205 3.2%

7 1.0 36.0 0.6 0.4 81 55 1.47 1.446 1.446 0.2 0.289 4.4%

8 1.0 36.5 0.6 0.3 89 55 1.62 1.585 1.585 0.15 0.238 3.7%9 1.0 37.0 0.6 0.45 53 55 0.96 0.957 0.957 0.225 0.215 3.3%

10 1.0 37.5 0.6 0.45 33 55 0.60 0.607 0.607 0.225 0.137 2.1%

11 1.0 38.0 0.6 0.45 71 55 1.29 1.271 1.271 0.225 0.286 4.4%

12 1.0 38.5 0.6 0.5 62 55 1.13 1.114 1.114 0.25 0.278 4.3%

13 1.0 39.0 0.6 0.6 32 55 0.58 0.590 0.590 0.3 0.177 2.7%

14 1.0 39.5 0.6 0.55 92 55 1.67 1.638 1.638 0.275 0.450 6.9%

15 1.0 40.0 0.6 0.55 43 55 0.78 0.782 0.782 0.275 0.215 3.3%

16 1.0 40.5 0.6 0.5 101 55 1.84 1.795 1.795 0.25 0.449 6.9%

17 1.0 41.0 0.6 0.45 119 55 2.16 2.109 2.109 0.225 0.475 7.3%

18 1.0 41.5 0.6 0.5 115 55 2.09 2.039 2.039 0.25 0.510 7.8%

19 1.0 42.0 0.6 0.65 86 55 1.56 1.533 1.533 0.325 0.498 7.7%

20 1.0 42.5 0.6 0.75 79 55 1.44 1.411 1.411 0.28125 0.397 6.1%

21 1.0 42.8 0.6 0.8 77 55 1.40 1.376 1.376 0.2 0.275 4.2%

22 1.0 43.0 0.6 0.75 67 55 1.22 1.201 1.201 0.28125 0.338 5.2%

23 1.0 43.5 0.6 0.5 35 55 0.64 0.642 0.642 0.25 0.161 2.5%

24 1.0 44.0 0.6 0.55 20 55 0.36 0.380 0.380 0.275 0.105 1.6%

25 1.0 44.5 0.6 0.55 20 55 0.36 0.380 0.380 0.275 0.105 1.6%

26 1.0 45.0 0.6 0.6 9 55 0.16 0.188 0.188 0.45 0.085 1.3%

27 1.0 46.0 0.6 0.5 0 55 0.00 0.031 0.031 0.625 0.020 0.3%

28 REW 1.0 47.5 0.6 0

29 1.0

30 1.0

TOTAL 6.7125 6.501 100.0%

Velocity (fps)








Observers: K. Underwood Daily Mean Flow: 118 cfs

W th 75 W t T Fl G U d P St 0 9* ft


60/64

Weather: sunny, 75 Water T: Flow Gage Used: Pygmy Stage: 0.9* ft

Recent Precip: Begin Time: 11:41 End Time: 12:40




1 LEW 30.7

2 1.0 31.5 0.6 0.55 12 55 0.22 0.241 0.241 0.495 0.119 0.3%

4 1.0 32.5 0.6 0.85 117 60 1.95 1.904 1.904 0.6375 1.214 2.8%

5 1.0 33.0 0.6 0.9 118 55 2.15 2.092 2.092 0.45 0.941 2.2%

6 1.0 33.5 0.6 0.95 125 55 2.27 2.214 2.214 0.475 1.052 2.4%

7 1.0 34.0 0.6 0.95 150 55 2.73 2.650 2.650 0.475 1.259 2.9%

8 1.0 34.5 0.6 1.1 167 55 3.04 2.947 2.947 0.55 1.621 3.8%

9 1.0 35.0 0.6 1.1 138 55 2.51 2.441 2.441 0.55 1.343 3.1%10 1.0 35.5 0.6 1.1 185 60 3.08 2.992 2.992 0.55 1.646 3.8%

11 (rock) 1.0 36.0 0.6 1 155 50 3.10 3.008 3.008 0.5 1.504 3.5%

12 1.0 36.5 0.6 1 134 50 2.68 2.605 2.605 0.5 1.303 3.0%

13 1.0 37.0 0.6 1.1 169 55 3.07 2.982 2.982 0.55 1.640 3.8%

14 1.0 37.5 0.6 1.1 185 55 3.36 3.262 3.262 0.55 1.794 4.2%

15 1.0 38.0 0.6 1.1 143 60 2.38 2.320 2.320 0.55 1.276 3.0%

16 1.0 38.5 0.6 1.1 124 55 2.25 2.196 2.196 0.55 1.208 2.8%

17 1.0 39.0 0.6 1.15 125 60 2.08 2.032 2.032 0.575 1.168 2.7%

18 1.0 39.5 0.6 1.15 123 65 1.89 1.849 1.849 0.575 1.063 2.5%

19 1.0 40.0 0.6 1.1 141 55 2.56 2.493 2.493 0.55 1.371 3.2%

20 1.0 40.5 0.6 1.1 186 55 3.38 3.279 3.279 0.55 1.804 4.2%

21 1.0 41.0 0.6 1.2 188 55 3.42 3.314 3.314 0.6 1.988 4.6%

22 1.0 41.5 0.6 1.3 160 60 2.67 2.592 2.592 0.65 1.685 3.9%

23 1.0 42.0 0.6 1.4 151 60 2.52 2.448 2.448 0.7 1.714 4.0%

24 TW 1.0 42.5 0.6 1.55 152 55 2.76 2.685 2.685 0.775 2.081 4.8%

25 slightly d/s of tape 1.0 43.0 0.6 1.45 149 50

little otter creek watershed phase 2 stream geomorphic assessment: appendix j

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