CIVIL & CONSULTING ENGINEERS * ARCHITECTURE * CONSTRUCTION MANAGEMENT * PROJECT ENGINEERS * PLANNING & PERMIT EXPEDITING

2394 Patterson Rd, Suite 201 Grand Junction, CO 81505 (970) 245-9051 (970) 245-7639 fax www.vortexeng.us

Final Drainage Report For

Iron Wheel Subdivision Fruita, Colorado

Date: February 2, 2017 Prepared by: Vortex Engineering, Inc. 2394 Patterson Road, Suite 201 Grand Junction, CO 81505 970-245-9051 VEI# F10-053 Submitted to: City of Fruita 325 E Aspen Ave,

Fruita, CO 81521 Type of Design: Major Subdivision Owners: Bookcliff Orchards, LLC

Attn: Cody Davis 637 25 Road Grand Junction, CO 81505

Property Address: 1860 Highway 6&50 953, 961 & 973 19 Road 1702 Skiff Avenue

Fruita, CO 81521

Tax Schedule No.: 2697-211-07-003 2697-211-07-004 2697-211-07-005 2697-211-08-005 2697-211-00-011

2697-211-00-012

Drainage Report Page 2 of 13 Iron Wheel Subdivision

“I hereby certify that this Final Drainage Report for the design Iron Wheel Subdivision was prepared by me (or under my direct supervision) in accordance with the provisions of the Stormwater Management Manual for the owners thereof. I understand that City of Fruita does not and will not assume liability for drainage facilities designed by others. _________________________________________________________ James C. Atkinson, P.E. Date As an authorized signing representative of Iron Wheel Subdivision, I hereby certify that the drainage facilities shall be constructed according to the design presented in this report. I understand that City of Fruita does not and will not assume liability for the drainage facilities designed and/or certified by my engineer. I understand that Fruita reviews drainage plans but cannot, on behalf of Iron Wheel Subdivision, guarantee that final drainage design review will absolve Iron Wheel Subdivision and/or their successors and/or assigns of future liability for improper design. I further understand that approval of the Construction Plans does not imply approval of my engineer's drainage design. _____________________________________ ______________ . Date

Drainage Report Page 3 of 13 Iron Wheel Subdivision

Table of Contents 1.0  Introduction ..................................................................................................................... 4 

A.  Background .................................................................................................................. 4 B.  Project Location .......................................................................................................... 4 C.  Property Description ................................................................................................... 4 

2.0   Drainage System Description ........................................................................................ 4 

A.  Existing conditions ......................................................................................................... 4 

3.0  Drainage Analysis and Drainage Criteria ...................................................................... 6 

A.  Regulations ..................................................................................................................... 6 

B.  Development Criteria and Constraints.......................................................................... 6 

C.  Existing conditions Hydrology analysis ....................................................................... 6 

D.  Hydrologic Criteria ......................................................................................................... 6 

E.  Pond Summary Tables ................................................................................................... 7 

F.  Hydraulic Criteria ............................................................................................................ 7 

4.0  Conclusions .................................................................................................................... 8 

A.  General ......................................................................................................................... 8 B.  Compliance with Manual ............................................................................................. 8 

5.0  References ...................................................................................................................... 8 

Appendix A - Vicinty Map 

Appendix B - NRCS Soils Report 

Appendix C - Runoff Calculations 

Appendix D - FIRM Map 

Appendix E - Drainage Maps 

Drainage Report Page 4 of 13 Iron Wheel Subdivision

1.0 Introduction

A. Background

This Final Drainage Report has been prepared by Vortex Engineering, Inc., and is required as part of the Iron Wheel Subdivision submittal. The property being an assemblage of 6 separate land parcels. This Final Drainage report has been created in accordance with the Mesa County/City of Fruita Stormwater Management Manual.

B. Project Location

The Iron Wheel Subdivision is approximately 55.3 acres located in the political boundary of The City of Fruita, Colorado. The site is situated west of 19 Road and north of Highway 6 and 50. There are two main access points proposed for the project; one to the west from 19 Road and the other to the east from an extension of 18 ½ Road from J Road to the project site. A drainage map is provided in Appendix A for reference.

C. Property Description

The site slopes from the northeast to the south and southwest at grades varying between 0.7%. and 1.3%. The site is currently undeveloped. The west 30 acres is covered with native grasses, sparsely located shrubs, and occasional trees. The remaining east portion of the site consists of alfalfa. With the development of the project site, it is planned to draw irrigation water from the Independent Ranch Irrigation Ditch to irrigate the property.

The following are the Natural Resources Conservation Service (NRCS) soils followed by the hydrologic soil group within the Iron Wheel Subdivision: Fruitland Sandy Clay Loam (Rc) – Group B; Turley Clay Loam – Group C; and Massadona silty clay loam (Tr) – Group C.

2.0 Drainage System Description

A. Existing conditions The existing runoff from the project consists of sheets flows, shallow concentrated flows, and shallow ditch flows. There are two discharge points from the site. One discharge point is located in northwest corner of the property discharging basin EX200 into the Palmer Drain, a Grand Valley Drainage District facility, which continues to drain in a westerly direction. The other point of discharge is located approximately mid-way along the southern boundary. These discharge points are identified respectively as Design Point 1 and 2 on the Drainage Map - Existing

Drainage Report Page 5 of 13 Iron Wheel Subdivision

Conditions in the Appendix. The offsite runoff from basin OS-1 enters the EX100 basin at design point 3. From that point the offsite runoff merges with the runoff from EX100; at design point 1 the surface runoff from EX100 and the offsite Basin OS-1 is intercepted by a 12” PVC culvert which conveys the water into a manhole located just on the south side of the Independent Ranch Irrigation Ditch. From there the runoff is carried in a 18” pipe into the Highway 6 and 50 roadway ditch. The runoff is then carried in either ditches or pipes in a southwesterly direction for approximately 1.5 miles; finally discharging into the Colorado River.

B. Master Drainage Plans

This site is in Major Basin 117, which is located between the Major Basins known as Adobe Creek and Little Salt Wash. The site does not drain into either of these basins; instead draining into smaller open drain ditches which empty directly into the Colorado River.

C. Offsite Tributary Areas

Basin OS-1 is the only offsite basin identified in this study. The runoff from this basin will be routed via ditches and storm sewer into the Pond 100 as a by-pass flow.

D. Proposed Drainage System Description

The proposed storm sewer system for this project consists of overland sheet flows, shallow concentrated flows, gutter flows, piped storm sewer and detention ponds. There are two ponds proposed for the site; the ponds are designed to treat and attenuate the Water Quality Capture Volume (WQCV), the 10 year minor storm and the 100 year major storm. Pond 100 discharges into an existing 12”, which then is routed to Colorado River as described above. This pond requires a small sump pump to discharge the water below the invert of the discharge structure of 4523.33 to the invert of the pond of 4518.00. The discharge water from Pond 200 outfalls into the Palmer Drain via gravity, which also outfalls to the Colorado River. The runoff from the offsite Basin OS-1 will be intercepted by a 2’ v-pan and is diverted via storm sewer into the detention Pond 100. The runoff from OS-1 will be treated as a by-pass.

E. Hydrologic Criteria

The hydrologic and hydraulic analysis proposed is to use procedures per the Mesa County Stormwater Management Manual (SWMM) guidelines, dated December 2007. Rational method was applied to estimate flows in this report.

Drainage Report Page 6 of 13 Iron Wheel Subdivision

3.0 Drainage Analysis and Drainage Criteria

A. Regulations

The supporting drainage design and calculations were performed in accordance with the Mesa County/City of Fruita Stormwater Management Manual (SWMM) and the UDFCD “Urban Storm Drainage Criteria Manual, Volume 1”. No variance from SWMM shall be needed for the storm water design as presented in this document.

B. Development Criteria and Constraints

The supporting drainage design and calculations were performed in accordance to the Grand Valley "Stormwater Management Manual" [1] and the UDFCD "Urban Storm Drainage Criteria Manual, Volume 1" [4]. No deviations from these published criteria are requested for this site. The proposed grading on the site is designed to eliminate cross lot drainage and to maintain positive runoff from the site. No cross basin drainage is occurring in the proposed plan.

C. Existing conditions Hydrology analysis

Currently, runoff from the site drains via overland flows and shallow concentrated flows in the south and southwest direction to the discharge points described above.

D. Hydrologic Criteria

The hydrologic and hydraulic analysis proposed is to use procedures per the Mesa County Stormwater Management Manual (SWMM) guidelines, dated December 2007.

Drainage Report Page 7 of 13 Iron Wheel Subdivision

E. Pond Summary Tables

POND 100

VOLUME (CF)

WSEL (FT)

PEAK DISCHARGE FLOW (CFS)

WQCV 25,170 4521.70 40 hrs 10 YEAR 27,192 4522.92 6.0 100 YEAR 85,670 4523.55 25.0

POND 100 VOLUME

(CF) WSEL (FT)

PEAK DISCHARGE FLOW (CFS)

WQCV 25,170 4521.70 40 hrs 10 YEAR 27,192 4522.92 6.0 100 YEAR 85,670 4523.55 25.0

F. Hydraulic Criteria

Storm Drains Storm Drains are designed to have the 2 year HGL below pipes’ crowns.

Street Flow and Inlet Capacities The SWMM criteria were used to check for street flow capacity and inlet capacities.

The Maximum street flow is estimated to be 1.17 cfs for the 2 year flow and 7.65 cfs for the 100 year flow. According to Figure 1105 in the SWMM, the maximum allowable street flow is 2.4 cfs for residential mountable curb for 2 year flows and 10.3 cfs for the 100 year flows at an average grade of 0.5 percent.

According to Figure 1114R in the SWMM, the maximum inlet capacity for a single inlet Type R grate in a on-grade condition for 2 year flow is 1.3 cfs.

In summary, street capacities and inlet capacities exceed the estimated runoff. SWMM Figures 1106 and 1114R will be included in the Appendix in the Final Drainage Report for this project.

Drainage Report Page 8 of 13 Iron Wheel Subdivision

4.0 Conclusions

A. General

This report discusses the information requirements for a Final Drainage Report and Plan as defined by the SWMM, Section 300. The proposed development of the Iron Wheel Subdivision property will effectively convey runoff from the site per the SWMM best recommendations and discharge to Palmer Drain as well as the storm and ditch system that carries the runoff to Colorado River.

The proposed drainage facilities are designed to accept the WQCV and 10 and 100 year runoff and continue the conveyance to the ultimate discharge in the Colorado River. Erosion control BMP's will be implemented during construction in an effort to prevent adverse impacts on downstream properties and drainage facilities. The proposed development will not adversely affect the surrounding properties or existing storm drainage systems.

B. Compliance with Manual

This report discusses the information requirements for a Final Drainage Report and Plan per the Mesa County/City of Fruita Stormwater Management Manual. The proposed drainage facilities are designed to collect and detain the WQCV and 10 and 100 year event runoff rates from the site along with offsite contributory flows and release at/or below the allowed rates. The proposed development will not adversely affect the surrounding properties or existing drainage systems. No variances from the Stormwater Management Manual criteria are requested.

5.0 References

Mesa County/City of Fruita Stormwater Management Manual, adopted March 20, 2008.

“NRCS Soil Survey” web soil survey, generated February 2, 2017.

“Urban Storm Drainage Criteria Manual, Volume 1”, prepared by the Urban Drainage and Flood Control District, effective September 1999.

Federal Emergency Management Agency, Flood Insurance Rate Map, Mesa County, Colorado unincorporated Areas, Map No. 08077C0439F.

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Appendix A Vicinity Map

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Appendix B NRCS Soils Report

Soil Map—Mesa County Area, Colorado

Natural ResourcesConservation Service

Web Soil SurveyNational Cooperative Soil Survey

2/7/2017Page 1 of 3

4335

000

4335

100

4335

200

4335

300

4335

400

4335

500

4335

100

4335

200

4335

300

4335

400

4335

500

4335

600

697800 697900 698000 698100 698200 698300 698400 698500 698600 698700

697900 698000 698100 698200 698300 698400 698500 698600 698700

39° 8' 49'' N10

8° 4

2' 4

0'' W

39° 8' 49'' N

108°

42'

0'' W

39° 8' 29'' N

108°

42'

40'

' W

39° 8' 29'' N

108°

42'

0'' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 12N WGS840 200 400 800 1200

Feet0 50 100 200 300

MetersMap Scale: 1:4,330 if printed on A landscape (11" x 8.5") sheet.

Soil Map may not be valid at this scale.

Map Unit Legend

Mesa County Area, Colorado (CO680)

Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI

BaS Massadona silty clay loam,saline, 0 to 2 percent slopes

3.8 7.0%

Rc Fruitland sandy clay loam, 0 to2 percent slopes

33.9 62.0%

Tr Turley clay loam, 0 to 2percent slopes

17.0 31.0%

Totals for Area of Interest 54.7 100.0%

Soil Map—Mesa County Area, Colorado

Natural ResourcesConservation Service

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2/7/2017Page 3 of 3

Mesa County Area, Colorado

BaS—Massadona silty clay loam, saline, 0 to 2 percentslopes

Map Unit SettingNational map unit symbol: k06pElevation: 4,500 to 4,890 feetMean annual precipitation: 7 to 10 inchesMean annual air temperature: 50 to 54 degrees FFrost-free period: 150 to 190 daysFarmland classification: Not prime farmland

Map Unit CompositionMassadona, saline, and similar soils: 70 percentMinor components: 30 percentEstimates are based on observations, descriptions, and transects of

the mapunit.

Description of Massadona, Saline

SettingLandform: Alluvial fansDown-slope shape: LinearAcross-slope shape: LinearParent material: Alluvium derived from clayey shale

Typical profileA - 0 to 2 inches: silty clay loamBw - 2 to 12 inches: silty clayBky - 12 to 24 inches: silty clayBCky1 - 24 to 48 inches: stratified silty clay loam to fine sandy

loamBCky2 - 48 to 60 inches: stratified silty clay loam to fine sandy

loam

Properties and qualitiesSlope: 0 to 2 percentDepth to restrictive feature: More than 80 inchesNatural drainage class: Well drainedRunoff class: HighCapacity of the most limiting layer to transmit water (Ksat):

Moderately low to moderately high (0.06 to 0.20 in/hr)Depth to water table: More than 80 inchesFrequency of flooding: NoneFrequency of ponding: NoneCalcium carbonate, maximum in profile: 15 percentGypsum, maximum in profile: 2 percentSalinity, maximum in profile: Strongly saline (20.0 to 40.0

mmhos/cm)Available water storage in profile: High (about 10.0 inches)

Map Unit Description: Massadona silty clay loam, saline, 0 to 2 percent slopes---Mesa CountyArea, Colorado

Natural ResourcesConservation Service

Web Soil SurveyNational Cooperative Soil Survey

2/7/2017Page 1 of 2

Interpretive groupsLand capability classification (irrigated): 4sLand capability classification (nonirrigated): 7sHydrologic Soil Group: CHydric soil rating: No

Minor Components

PariettePercent of map unit: 15 percentLandform: Fan remnantsDown-slope shape: LinearAcross-slope shape: LinearHydric soil rating: No

DegaterPercent of map unit: 15 percentLandform: Alluvial fansDown-slope shape: LinearAcross-slope shape: LinearHydric soil rating: No

Data Source Information

Soil Survey Area: Mesa County Area, ColoradoSurvey Area Data: Version 7, Sep 30, 2016

Map Unit Description: Massadona silty clay loam, saline, 0 to 2 percent slopes---Mesa CountyArea, Colorado

Natural ResourcesConservation Service

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2/7/2017Page 2 of 2

Mesa County Area, Colorado

Rc—Fruitland sandy clay loam, 0 to 2 percent slopes

Map Unit SettingNational map unit symbol: k0d0Elevation: 4,600 to 4,800 feetMean annual precipitation: 7 to 10 inchesMean annual air temperature: 50 to 54 degrees FFrost-free period: 150 to 190 daysFarmland classification: Prime farmland if irrigated

Map Unit CompositionFruitland and similar soils: 90 percentMinor components: 10 percentEstimates are based on observations, descriptions, and transects of

the mapunit.

Description of Fruitland

SettingLandform: Alluvial fansDown-slope shape: LinearAcross-slope shape: LinearParent material: Alluvium derived from sandstone and shale

Typical profileA - 0 to 8 inches: sandy clay loamC1 - 8 to 30 inches: stratified sandy loam to gravelly fine sandy

loamC2 - 30 to 60 inches: stratified sandy loam to fine sandy loam

Properties and qualitiesSlope: 0 to 2 percentDepth to restrictive feature: More than 80 inchesNatural drainage class: Well drainedRunoff class: LowCapacity of the most limiting layer to transmit water (Ksat):

Moderately high to high (0.20 to 2.00 in/hr)Depth to water table: More than 80 inchesFrequency of flooding: NoneFrequency of ponding: NoneCalcium carbonate, maximum in profile: 10 percentSalinity, maximum in profile: Nonsaline to very slightly saline (0.0

to 2.0 mmhos/cm)Available water storage in profile: Moderate (about 7.6 inches)

Interpretive groupsLand capability classification (irrigated): 2eLand capability classification (nonirrigated): 7cHydrologic Soil Group: BHydric soil rating: No

Map Unit Description: Fruitland sandy clay loam, 0 to 2 percent slopes---Mesa County Area,Colorado

Natural ResourcesConservation Service

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2/7/2017Page 1 of 2

Minor Components

FruitaPercent of map unit: 5 percentLandform: Alluvial fansDown-slope shape: LinearAcross-slope shape: LinearHydric soil rating: No

FruitvalePercent of map unit: 5 percentLandform: Alluvial fansDown-slope shape: LinearAcross-slope shape: LinearHydric soil rating: No

Data Source Information

Soil Survey Area: Mesa County Area, ColoradoSurvey Area Data: Version 7, Sep 30, 2016

Map Unit Description: Fruitland sandy clay loam, 0 to 2 percent slopes---Mesa County Area,Colorado

Natural ResourcesConservation Service

Web Soil SurveyNational Cooperative Soil Survey

2/7/2017Page 2 of 2

Mesa County Area, Colorado

Tr—Turley clay loam, 0 to 2 percent slopes

Map Unit SettingNational map unit symbol: k0d8Elevation: 4,500 to 4,800 feetMean annual precipitation: 7 to 10 inchesMean annual air temperature: 50 to 54 degrees FFrost-free period: 150 to 190 daysFarmland classification: Prime farmland if irrigated

Map Unit CompositionTurley and similar soils: 90 percentMinor components: 10 percentEstimates are based on observations, descriptions, and transects of

the mapunit.

Description of Turley

SettingLandform: Fan remnantsDown-slope shape: LinearAcross-slope shape: LinearParent material: Alluvium derived from sandstone and shale

Typical profileAp - 0 to 10 inches: clay loamC1 - 10 to 20 inches: fine sandy loamC2 - 20 to 30 inches: clay loamC3 - 30 to 60 inches: stratified loam to silty clay loam

Properties and qualitiesSlope: 0 to 2 percentDepth to restrictive feature: More than 80 inchesNatural drainage class: Well drainedRunoff class: LowCapacity of the most limiting layer to transmit water (Ksat):

Moderately high (0.20 to 0.60 in/hr)Depth to water table: More than 80 inchesFrequency of flooding: NoneFrequency of ponding: NoneCalcium carbonate, maximum in profile: 10 percentGypsum, maximum in profile: 4 percentSalinity, maximum in profile: Nonsaline to very slightly saline (0.0

to 2.0 mmhos/cm)Available water storage in profile: High (about 10.6 inches)

Interpretive groupsLand capability classification (irrigated): 2eLand capability classification (nonirrigated): 7cHydrologic Soil Group: C

Map Unit Description: Turley clay loam, 0 to 2 percent slopes---Mesa County Area, Colorado

Natural ResourcesConservation Service

Web Soil SurveyNational Cooperative Soil Survey

2/7/2017Page 1 of 2

Hydric soil rating: No

Minor Components

FruitlandPercent of map unit: 10 percentLandform: Fan remnantsDown-slope shape: LinearAcross-slope shape: LinearHydric soil rating: No

Data Source Information

Soil Survey Area: Mesa County Area, ColoradoSurvey Area Data: Version 7, Sep 30, 2016

Map Unit Description: Turley clay loam, 0 to 2 percent slopes---Mesa County Area, Colorado

Natural ResourcesConservation Service

Web Soil SurveyNational Cooperative Soil Survey

2/7/2017Page 2 of 2

Drainage Report Page 11 of 13 Iron Wheel Subdivision

Appendix C Runoff Calculations

Iron Wheel Vortex Engineering, Inc.Area Impreviousness February 2, 2018Proposed Conditions

BASIN TOTAL AREA (ft2) BASIN AREA (ac)

PERV.

AREA (ft2)PERV.

AREA (ac)

IMP. AREA

(ft2)IMPREVIOUS AREA (ac)

Impreviousness (%)

P100 2,175,937 49.95 1,033,711 23.73 23.73 26.22 52%

P200 233,131 5.35 91,571 2.10 2.10 3.25 61%

OS-1 504,711 11.59 486,711 11.17 18,000 0.41 4%

Total On-Site Area = 55.30 25.83 29.47

Total Off-Site Area = 11.59 11.17 0.41

Iron Wheel Vortex Engineering, Inc.Pond volume Calculations February 2, 2018Pond 100

Detention Pond Calculations2175937 Stage Change Cumulative Cumulative

Elevation 233131 Volume in Elevation Volume Volume

[ft.] [ft²] [cf] [ft] [cf] [acre-ft]

4517.80 0 0.00 0.0 0.0 0.0004518.00 1024 68.27 0.2 68.3 0.0024519.00 3636 2196.53 1.0 2264.8 0.0524520.00 7151 5295.37 1.0 7560.2 0.1744521.00 10700 8866.11 1.0 16426.3 0.3774522.00 14306 12459.44 1.0 28885.7 0.6634523.00 38406 25384.02 1.0 54269.7 1.2464524.00 77763 56939.49 1.0 111209.2 2.553

WQCV=K(a(0.91*I3-1.19*I2+0.78*I))Where:

K = adjustment to equation for Mesa County = d6/0.43)= 0.65

a = Adjustment for BMP's drain Time (for 40hrs a=1.0)= 1.00I = watershed Imperviousness in decimal = 0.52d6 = Depth of average producing storm d6= 0.28

Watershed area = 49.95

WQCV= 0.139 inReq'd storage WQCV = 25170 cf 4,521.70*

Req'd 10 yr Volume: Where:

K10=(0.95P-1.90)(X10/1000) 0.0125 P = Developed Basin Impreviousness (%)

V10=K10A 0.624 ac-ft X = Mesa Co. adjustment factor X10=0.26, X100=0.42

V10= 27192 cf for impreviousness <50% (SWMM Table 1401)

A = Tributary Area (ac)

V = Volume (ac-ft)

Req'd 100 yr Volume:K100=(1.78P-0.002P2-3.56)(X100/900) 0.0394

V100=K100A 1.967 ac-ft

V100= 85670 cf

WSEL (ft)10 yr Runoff + WQCV = 52361 cf 4,522.92*

100 yr Runoff = 85670 cf 4,523.55*

* Water surface elevation thru linear interpolation

Allowable Pond Discharge:Hydrologic Soil Group C (SWMM Table 1402)

10 yr Discharge Coeficient = 0.12 10 yr = 5.99 cfs100 yr Discharge Coeficient = 0.50 100 yr = 24.98 cfs

Iron Wheel Vortex Engineering, Inc.Pond volume Calculations February 2, 2018Pond 200

Detention Pond CalculationsStage Change Cumulative Cumulative

Elevation Area Volume in Elevation Volume Volume

[ft.] [ft²] [cf] [ft] [cf] [acre-ft]

4524.80 0 0.00 0.0 0.0 0.0004525.00 2550 170.00 0.2 170.0 0.0044526.00 8143 5083.27 1.0 5253.3 0.1214527.00 14600 11215.52 1.0 16468.8 0.378

WQCV=K(a(0.91*I3-1.19*I2+0.78*I))Where:

K = adjustment to equation for Mesa County = d6/0.43)= 0.65

a = Adjustment for BMP's drain Time (for 40hrs a=1.0)= 1.00I = watershed Imperviousness in decimal = 0.61d6 = Depth of average producing storm d6= 0.28

Watershed area = 5.35

WQCV= 0.155 inReq'd storage WQCV = 3018 cf 4,525.80*

Req'd 10 yr Volume: Where:

K10=(0.95P-1.90)(X10/1000) 0.0145 P = Developed Basin Impreviousness (%)

V10=K10A 0.078 ac-ft X = Mesa Co. adjustment factor X10=0.26, X100=0.42

V10= 3387 cf for impreviousness <50% (SWMM Table 1401)

A = Tributary Area (ac)

V = Volume (ac-ft)

Req'd 100 yr Volume:K100=(1.78P-0.002P2-3.56)(X100/900) 0.0453

V100=K100A 0.243 ac-ft

V100= 10569 cf

10 yr Runoff + WQCV = 6406 cf 4,526.23*100 yr Runoff = 10569 cf 4,526.47*

* Water surface elevation thru linear interpolation

Allowable Pond Discharge:Hydrologic Soil Group B (SWMM Table 1402)

10 yr Discharge Coeficient = 0.09 10 yr = 0.48 cfs100 yr Discharge Coeficient = 0.43 100 yr = 2.30 cfs

Iron Wheel Vortex Engineering, Inc.Detention Pond-200 February 2, 2018WQ Orifice Plate

WQCV O ifi Pl t A

K:\IronWheel_F10-053\Drainage\IronWheel-BasinsHGL.xlsx

WQCV Orifice Plate AreaPer UDFCD Volume 2, SO-13a, pg SO-12

Ao= area per row of orifice spaced on 4" centers (in2)

V= design volume (WQCV, ac-ft)

TD= Time to drain the prescribed volume (hrs)

Ao = 88V(0.95/H0.085)

TDS0.09H(2.6S0.8)

Ao = 88V(0.95/H0.085)

TDS0.09H(2.6S0.8)

Ao = 88V(0.95/H0.085)

TDS0.09H(2.6S0.8)

H= Depth of Volume (ft)

S= slope (ft/ft)

V= 0.06929 ac-ft

TD= 40 hrs

H= 1.00

S= 0.02

Ao= 0.2478

# of columns= 1

area per hole in a row (in2)= 0.2478

hole diameter (in)= 0.5617

USE 1/5" DIA. HOLES

#DIV/0!#DIV/0!

K:\IronWheel_F10-053\Drainage\IronWheel-BasinsHGL.xlsx

Iron Wheel Vortex Engineering, Inc.Detention Pond-200 February 2, 2018Outfall

Q10= 0.48 cfs

Allowable Discharge (cfs)= 0.48Weir Coefficient Cw= 3.33

10 yr WS Elevation (ft)= 4526.23Weir Invert Elevation (ft)= 4525.80

Total Head (ft)= 0.43Weir Base Width (ft )= 0.52

6" wide weir

Q100= 2.30 cfs

Allowable Discharge (cfs)= 2.30

100 Year Rectangular Weir

Allowable Discharge (cfs)= 2.30Weir Coefficient Cw= 3.33

100 yr WS Elevation (ft)= 4526.47Weir Invert Elevation (ft)= 4526.23

Total Head (ft)= 0.25Weir Base Width (ft )= 5.62

USE 5.50 ft wide weir

Iron Wheel Vortex Engineering, Inc.Drainage Area C calculations - 2yr and 100yr Events February 2, 2018

BASIN

TOTAL AREA

(ft2)BASIN

AREA (ac)

LOT/PERV.

AREA (ft2)LOT AREA C2

year

LOT AREA C2 100-year

STREET IMP. AREA

(ft2)STREET IMP.

AREA (ac)

STREET AREA C2 year

STREET AREA C100 year

2 yr WEIGHTED C

VALUE

100 yr WEIGHTED C

VALUE

100 153,275 3.52 148,100 0.34 0.34 5,175 0.12 0.89 0.96 0.36 0.36

101 110,492 2.54 93,492 0.34 0.34 17,000 0.39 0.89 0.96 0.42 0.44

102 204,627 4.70 157,127 0.34 0.60 47,500 1.09 0.89 0.96 0.47 0.68

103 514,570 11.81 416,785 0.34 0.60 97,785 2.24 0.89 0.96 0.44 0.67

104 36,108 0.83 18,636 0.34 0.60 17,472 0.40 0.89 0.96 0.61 0.77

105 118,625 2.72 95,375 0.34 0.60 23,250 0.53 0.89 0.96 0.45 0.67

106 140,812 3.23 125,362 0.34 0.60 15,450 0.35 0.89 0.96 0.40 0.64

107 316,851 7.27 242,293 0.34 0.60 74,558 1.71 0.89 0.96 0.47 0.68

108 462,159 10.61 366,919 0.34 0.60 95,240 2.19 0.89 0.96 0.45 0.67

109 57,741 1.33 42,737 0.34 0.60 15,004 0.34 0.89 0.96 0.48 0.69

110 60,674 1.39 45,224 0.34 0.60 15,450 0.35 0.89 0.96 0.48 0.69

200 233,131 5.35 175,541 0.29 0.52 57,590 1.32 0.89 0.96 0.44 0.63

Total On-Site Area = 55.30 44.25 11.05

Iron Wheel Vortex Engineering, Inc.Basin Runoff Calculation February 2, 2018

DRAINAGE

AREA

INLET # Area

(ac)

'C2'

Weighted

'C100'

Weighted

Tc (min) 2-Yr. Storm

Intensity (in/hr)

100-Yr.

Storm

Intensity

(in/hr)

2-Yr. Q (cfs)

Basin Runoff

100-Yr. Q

(cfs) Basin

Runoff

Inlet Type for Minor Storm

100 100 3.52 0.36 0.36 5 1.2 4.68 1.51 5.94101 101 2.54 0.42 0.44 5 1.2 4.68 1.29 5.17102 102 4.70 0.47 0.68 5 1.2 4.68 2.64 15.03103 103 11.81 0.44 0.67 5 1.2 4.68 6.30 36.95104 104 0.83 0.61 0.77 5 1.2 4.68 0.60 3.00105 105 2.72 0.45 0.67 5 1.2 4.68 1.46 8.55106 106 3.23 0.40 0.64 5 1.2 4.68 1.55 9.67107 107 7.27 0.47 0.68 9 1.2 4.68 4.10 23.31108 108 10.61 0.45 0.67 5 1.2 4.68 5.77 33.48109 109 1.33 0.48 0.69 5 1.2 4.68 0.77 4.30110 110 1.39 0.48 0.69 5 1.2 4.68 0.80 4.51200 200 5.35 0.44 0.63 5 1.2 4.68 2.81 15.75

Total on site basins = 55.30 55.3

Autodesk Storm and Sanitary AnalysisAutodesk Storm and Sanitary AnalysisAutodesk Storm and Sanitary Analysis

Autodesk Storm and Sanitary AnalysisAutodesk Storm and Sanitary AnalysisAutodesk Storm and Sanitary Analysis

Autodesk Storm and Sanitary AnalysisAutodesk Storm and Sanitary AnalysisAutodesk Storm and Sanitary Analysis

Autodesk Storm and Sanitary AnalysisAutodesk Storm and Sanitary AnalysisAutodesk Storm and Sanitary Analysis

Autodesk Storm and Sanitary AnalysisAutodesk Storm and Sanitary AnalysisAutodesk Storm and Sanitary Analysis

Drainage Report Page 12 of 13 Iron Wheel Subdivision

Appendix D FEMA FIRM Maps

Drainage Report Page 13 of 13 Iron Wheel Subdivision

Appendix E Drainage Map

LOT 113

LOT 43

LOT 92

LOT 86

LOT 221

LOT 97 LOT 95LOT 96LOT 98

LOT 74

LOT 83 LOT 84 LOT 85 LOT 87LOT 88

LOT 94 LOT 89LOT 91LOT 93 LOT 90

LOT 81

LOT 168

LOT 73

LOT 72

LOT 71

LOT 69

LOT 68

LOT 67

LOT 53

LOT 66

LOT 39

LOT 138

LOT 151LOT 152

LOT 167

LOT 177LOT 178

LOT 187

LOT 100

LOT 186

LOT 169

LOT 173

LOT 153LOT 166

LOT 159

LOT 176

LOT 175

LOT 174

LOT 179

LOT 180

LOT 181

LOT 183

LOT 184

LOT 185

LOT 172

LOT 171

LOT 170

PARK4

LOT 164

LOT 165

LOT 155

LOT 154

LOT 226 LOT 225 LOT 224 LOT 223 LOT 222

LOT 202 LOT 201 LOT 200LOT 205LOT 208 LOT 206LOT 207

LOT 199

LOT 38

LOT 70

LOT 37

LOT 3LOT 4LOT 5LOT 6LOT 7LOT 8LOT 9LOT 10LOT 11LOT 12

PARK2

LOT 112

LOT 230

LOT 2

LOT 62

LOT 49

LOT 56LOT 60

LOT 45

LOT 61

LOT 44

LOT 64

LOT 41

LOT 63

LOT 42

LOT 65

LOT 40

LOT 54

LOT 51

LOT 55

LOT 50

LOT 58

LOT 47

LOT 57

LOT 48

LOT 59

LOT 46

LOT 13

LOT 29

LOT 52

PARK5

LOT 14

LOT 34LOT 31 LOT 32 LOT 33 LOT 36LOT 35LOT 30

LOT 25LOT 23 LOT 24 LOT 27LOT 26 LOT 28

LOT 19

LOT 16

LOT 22

PARK1

LOT 20

LOT 15

LOT 21

LOT 1

PARK7

LOT 209

LOT 210

LOT 211

LOT 212

LOT 213

LOT 214

LOT 215

LOT 216

LOT 217

LOT 218

LOT 219

LOT 190

LOT 239

LOT 234

LOT 237

LOT 236

LOT 238

LOT 235

LOT 231

LOT 233

LOT 232

LOT 103

LOT 150

LOT 149

LOT 148

LOT 139

LOT 147

LOT 182

LOT 160

LOT 163

LOT 162

LOT 161

LOT 156

LOT 157

LOT 158

LOT 127

LOT 128

LOT 129

LOT 130

LOT 124

LOT 123

LOT 122

LOT 121

LOT 101

LOT 102

LOT 104

LOT 146

LOT 145

LOT 144

LOT 143

LOT 142

LOT 141

LOT 140

LOT 131

LOT 132

LOT 133

LOT 134

LOT 135

LOT 136

LOT 137

LOT 120

LOT 119

LOT 118

LOT 117

LOT 116

LOT 115

LOT 114

LOT 105

LOT 106

LOT 107

LOT 108

LOT 109

LOT 110

LOT 111

LOT 204 LOT 203

LOT 195 LOT 197LOT 196LOT 193 LOT 194LOT 192LOT 191LOT 188 LOT 189

LOT 220

LOT 229

LOT 227

PARK6

PARK8

LOT 75

LOT 76LOT 77LOT 78

LOT 79

LOT 80

LOT 82

LOT 17LOT 198

LOT 126LOT 125

LOT 99

TRACT 2315

LOT 18

ELEVATIONPROFILE

* * *B

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SCALE:

DATE:

PROJECT NO:

CAD ID:

ironwheel-drainagemap.dwg

~SHEET~

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Phone: (970) 245-9051

Fax (970) 245-7639

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PROFESSIONAL ENGINEER

COLORADO LICENSE No. 18828

James C.

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POND 100 - OUTLET STRUCTURE DETAIL

POND SUMMARY TABLES

PROJECT BENCHMARK

STANDARD NOTES:

BASIN RUNOFF

LEGEND

19

RO

AD

18 1

/2

RO

AD

INDEPENDENT RANCH IRRIGATION DITCH

PALMER DRAIN (GVDD 50' EASEMENT)

(GRAND VALLEY IRRIGATION DITCH 20' EASEMENT)

POND 200 - OUTLET STRUCTURE DETAIL

POND

200

POND 100