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Home My WebLink About20132640.tiffKMG 16-241 Salt Water Disposal Facility Final Drainage Report Prepared for: Kerr-McGee Oil & Gas Onshore L.P. MAY 2013 Prepared by: LOVELAND OFFICE 1635 Foxtrail Drive, Suite 204 Loveland, Colorado 80538 Phone 970-776-4331 SHERIDAN OFFICE 2155 North Main Street Sheridan, Wyoming 82801 Phone 307.674.1X.09 CONSULTING, LLC LOVELAND OFFICE 10)1 lbm.0 Ddn,Soi 304 Lomin&,Cobol& 60336 Moor 07077041)1 SHERIDAN OFFICE 2113 North Mt %ma 51.sa. Wyoming Il2l03 Plan. 3074740303 CONSULTING, LLC May 31, 2013 Clay Kimmi Weld County — Public Works 1111 H Street Greeley, CO 80631 Re: Final Drainage Report for the KMG 16-24i Salt Water Disposal Facility Dear Mr. Kimmi: On behalf of Kerr-McGee Oil & Gas Onshore L.P., we are submitting the Final Drainage Report for the KMG 16-24i Salt Water Disposal Facility. The enclosed report provides information on the site's historic drainage patterns and analyzes the site drainage design for the proposed facility. Sincerely, 609 CONSULTING, LLC Brian J. Venn, P.E. Project Civil Engineer Enclosures LOVELAND OFFICE 1635 Poatro. Ddn, %S 304 Lonemd, Colon.. 60136 Peon. 0704770 413 1 SHERIDAN OFFICE 3153 Norte Mat Sad Sb.ri/.n, Wyoming 62001 Peon. 307474460D CONSULTING, LLC ENGINEER'S CERTIFICATION I hereby certify that this report for the final drainage design of the KMG 16-24i Salt Water Disposal Facility was prepared by me, or under my direct supervision, in accordance with the provisions of the Weld County storm drainage criteria for the owners of the property thereof Zjc,-- Brian J. Vcnn(/ Registered Professional Engineer State of Colorado No. 39864 TABLE OF CONTENTS 1.0 INTRODUCTION 1 2.0 GENERAL LOCATION AND DESCRIPTION 1 2.1 LOCATION 1 2.2 PROPOSED DEVELOPMENT I 3.0 DRAINAGE BASINS AND SUB -BASINS 2 3.1 BASIN CHARACTERISTICS 2 4.0 DRAINAGE FACILITY AND DESIGN 3 4.1 CONCEPT 3 4.2 DESIGN 4 4.3 MAINTENANCE 5 5.0 CONCLUSIONS 6 6.0 REFERENCES 7 LIST OF TABLES TABLE 1: PROPOSED KMG 16-241 SWD FACILITY - HISTORIC RUNOFF SUMMARY 5 TABLE 2: PROPOSED KMG 16-241 SWD FACILITY - DETAINED DEVELOPED RUNOFF SUMMARY 5 LIST OF APPENDICES APPENDIX A VICINITY MAP APPENDIX B REFERENCE DATA APPENDIX C FEMA FIRM (Flood Insurance Rate Map) APPENDIX D HYDROLOGY CALCULATIONS Appendix D-1: Soils Report Appendix D-2: Rainfall Data Appendix D-3: Runoff Calculations APPENDIX E DETENTION POND CALCULATIONS APPENDIX F DRAINAGE PLANS Historic Drainage Plan Final Developed Drainage Plan i 1.0 INTRODUCTION The purpose of this report is to compare pre -development conditions to developed conditions of off -site and on -site drainage basins and propose solutions to mitigate the downstream impact of storm water runoff from the developed area. This includes designing a detention pond for the developed 100 -year, one -hour storm event, and releasing the on -site drainage at a rate equal to or less than the historic 5 -year, one -hour storm event as required by the Weld County Code [H. ]. The proposed detention pond is designed to not adversely affect historic drainage patterns or areas surrounding the proposed site. 2.0 GENERAL LOCATION AND DESCRIPTION 2.1 LOCATION The proposed KMG 16-24i Salt Water Disposal (SWD) Facility is located approximately 4.3 miles northeast of the town of Hudson, Colorado, southwest of the intersection of County Road 49 and County Road 18.5. The described area is located in the Southeast quarter of the Southeast quarter of Section 24, Township 2 North, Range 65 West of the 6`h P.M., Weld County, Colorado. Please refer to Appendix A for the vicinity map. Jim Creek, an ephemeral tributary that empties into Box Elder Creek, enters the property from the center of the south property line and exits to the center of the west property line (as shown in Appendix F). Wetlands have been defined on the property by OtterTail Environmental as areas adjacent to and to the south and west of Jim Creek. 2.2 PROPOSED DEVELOPMENT The proposed SWD facility is located in the northeast corner of 40 acres owned by Kerr-McGee Oil & Gas Onshore L.P. (Kerr-McGee). The land has historically been used for grazing until it was recently purchased by Kerr-McGee. The 40 -acre parcel is now host to a reclaimed well pad with an existing access road, wetlands, a portion of Jim Creek, and a residence. No development will occur in the wetlands area adjacent to Jim Creek. The residence has been uninhabited since May 1, 2013. The existing residence consists of multiple buildings, a concrete slab, corrals, and other personal items. All structures and the concrete slab will be demolished, removed, and properly disposed of prior to construction of the SWD facility. Access to the facility will come 1 from the north off of County Road 18.5, approximately 450 feet west of the intersection of County Road 18.5 and County Road 49. 3.0 DRAINAGE BASINS AND SUB -BASINS 3.1 BASIN CHARACTERISTICS The parcel under review contains an existing ephemeral drainage named Jim Creek. Off -site flows contributing to Jim Creek will not be affected by the addition of the !CMG 16-24i SWD Facility and thus were not considered in the hydrologic computations. A roadside ditch north of County Road 18.5 conveys flows to the west and away from the property. Similarly, a roadside ditch east of County Road 49 conveys flows south until it crosses County Road 49 by means of an existing culvert and finally drains into Jim Creek. The aforementioned areas are both considered to be off -site drainages. The proposed SWD facility is situated near the highest elevation found in the parcel, which is the northeast corner. According to the FEMA Flood Insurance Rate Map (community -panel number 080266 0900 C revised September 28, 1982), the proposed SWD facility falls outside of the floodplain (see appendix C). An applicable Weld County Master Drainage plan for the parcel described or for the surrounding area could not be found. The basin has been subdivided into three basins. The A- I basin is defined as everything south of County Road 18.5, west of County Road 49, and within the property boundary, excluding the proposed development area. The B-1 basin is defined as the area north of the County Road 18.5, west of County Road 49, and within the property boundary. Calculations were completed for the B-1 basin, but were not factored into the design as runoff generated does not contribute to the overall basin. The C-1 basin is defined as the proposed development area. Basin C-1 contains the existing residence, concrete slab, and buildings. Historic coefficients and peak flows for the basins were calculated for the 5-, 10-, and 100 -year events. Detailed calculations can be found in Appendix D-2. 2 Irrigated fields exist to the south of the southwest portion of the parcel and to the east of the northeast portion of the parcel. The fields are irrigated with center pivots. Additional runoff generated from irrigation facilities will not impact the proposed site development The historic drainage pattern for Basin A-1 generally flows southwest to Jim Creek before flowing off -site. The historic drainage pattern for Basin B-1 generally flows west along a roadside ditch before exiting the property. The historic drainage pattern for Basin C-1 generally flows southeast along the existing structures before turning south and eventually into Basin A-1. The rational method was employed to estimate volumes of runoff for the 40 -acre parcel per the Urban Storm Drainage Criteria Manual, Volumes 1, 2 and 3 [2]. The minor storm was based on the 10 -year storm frequency and the major storm was based on the 100 -year storm frequency. The basin was characterized by its current landscape and soil types. According to the Web Soil Survey 2.0, National Cooperate Soil Survey, Weld County, Colorado, Southern Part [3], the basin is comprised mostly of type B soils except where the wetlands are located, which is comprised of type A soils. A detailed soils report can be found in Appendix D-1. The site rainfall depth was found using the Rainfall Depth -Duration -Frequency maps provided by NOAA Atlas 2, Precipitation -Frequency Atlas of the Western United States, Volume III - Colorado [4]. The six -hour and twenty -four-hour rainfall data was entered into the Urban Drainage and Flood Control District's (UDFCD) UD-RainZone v1.01 a and the design storm intensity was interpolated. See Appendix D-2 for additional details. 4.0 DRAINAGE FACILITY AND DESIGN 4.1 CONCEPT This section of the report is prepared in compliance with the Urban Storm Drainage Criteria Manual, Volumes 1, 2 and 3, Weld County Code, and the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals Volumes 1, 2 and 3 [5]. The proposed facility is situated near the northeast corner of the drainage basin under review. Additional runoff will be generated from the proposed KMG 16-24i SWD Facility and accompanying access road. The runoff will be detained in a pond at the south end of the facility which will release the runoff 3 through the proposed outfall structure at a rate that is less than the historic 5 -year runoff. The pond is designed to detain the 100 -year, one -hour developed storm event with a minimum of one foot of freeboard. Flows exceeding the 100 -year storm event will be released over a broad crested weir (6 inches below the top of the detention pond) placed on the south end of the detention pond. The bottom of the pond will drain at a 1% slope towards the outfall structure. 4.2 DESIGN The parcel under review was divided into three sub -basins for post -development analysis. The developed basin designated as A-2 will have increased runoff from the addition of the proposed access road to the SWD facility. The access road placement will add an additional 0.2 cubic feet per second (cfs) during the 100 -year storm event, and the oversized detention pond will more than compensate for this additional flow. The sub -basin designated as B-2 remains unchanged under post -development conditions. The proposed KMG 16-24i SWD Facility will occupy sub - basin C-2. The proposed SWD facility will be constructed in an area where the existing residence, concrete slab, structures, and grassy areas currently exist. The developed area will consist primarily of road base, concrete and areas of natural seeding. The developed condition of Sub -Basin C-2 was calculated by area, weighting the runoff coefficients of each land -cover type based on their percentage of imperviousness (as defined by the Urban Drainage and Flood Control Districts Table RO-3) [2]. Detailed calculations for the basin can be found in Appendix D-3. The proposed facility also includes a self-contained tank area and concrete pad. Storm water that falls on these areas will be collected and either recycled or combined with the industrial water at the SWD facility and directly injected; an impervious value of zero was used for these areas, as it will not contribute to the runoff contained in the detention pond. The additional runoff generated by the proposed site development was calculated in the same manner as the historical runoff. Urban Storm Drainage Criteria Manual, Volumes 1, 2 and 3 requires the detention pond volume to be the detention volume (calculated using the modified FAA method) and 120% of the water quality capture volume (WQCV). The WQCV was calculated using only the on -site runoff as shown in Appendix D-3. The site is designed to have water quality features located in the 4 detention pond as well as water quality orifice plates with water quality perforations. The runoff volumes were calculated using a water quality volume drain time of 40 hours. The detention pond was designed to detain the 100 -year, one -hour developed storm event and WQCV with a minimum of one foot of freeboard. The broad crested weir proposed to act as the emergency spillway was designed to handle flows exceeding this event at a depth of 6 inches. Detailed calculations can be found in Appendix E. Table 1 and Table 2 summarize the historic flow rates vs. the developed flow rates, and demonstrates that the developed flow rates will not be greater than the existing flow rates being added to Jim Creek. Historic and developed runoff calculations are also included in Appendix D-3. TABLE 1: PROPOSED KMG 16-241 SWD FACILITY - HISTORIC RUNOFF SUMMARY Basin Q5 (cfs) Q10 (cfs) Q1oo (cfs) A-1 6.6 15.2 50.0 B-1 0.4 0.8 2.6 C-1 0.6 1.2 3.5 Total 7.6 17.2 56.1 TABLE 2: PROPOSED KMG 16-241 SWD FACILITY - DETAINED DEVELOPED RUNOFF SUMMARY Basin Q5 (cfs) Q10 (cfs) Q1oo (cfs) A-2 6.8 15.4 50.2 B-2 0.4 0.8 2.6 C-2 0.3 0.6 2.3 Total 7.5 16.8 55.1 Developed runoff volumes for basin C-2 are based on allowable release rates as set forth in Urban Storm Drainage Criteria Manual, Volumes 1, 2 and 3 [2] and are included in Appendix E. 4.3 MAINTENANCE The proposed KMG 16-24i SWD Facility has been designed such that maintenance can be completed on all areas of the facility during the life of the project. The detention pond and outlet works should be periodically checked to ensure outlets are clear of debris and sediment build-up. A buffer between the detention pond and the edge of facility has been designed to allow access 5 for maintenance. Maintenance of the recycling and storm water collection systems should be periodically checked by staff. 5.0 CONCLUSIONS In conclusion, the KMG 16-24i SWD Facility is designed to detain on -site flows for the 100 - year, one -hour storm event and release them at a rate less than the historic 5 -year, one -hour storm event. The proposed detention pond has been conservatively designed and will over -detain the on -site flows which will compensate for a slightly increased runoff from the construction of the access road to the KMG 16-24i SWD Facility. These additional flows are not a concern, considering the overall post -development flows leaving the site thru Jim Creek are less than historic flows. Therefore, the proposed KMG 16-24i SWD Facility will not negatively impact the existing flow patterns of the site or adversely affect the areas surrounding the site. 6 6.0 REFERENCES 1. Weld County Code. Weld, County, Colorado, September 6, 2008. 2. Urban Drainage and Flood Control District. Urban Storm Drainage Criteria Manual, Volumes 1, 2 and 3, June 2001. 3. Web Soil Survey 2.0, National Cooperate Soil Survey, Weld County, Colorado, Southern Part. Unites States Department of Agriculture, Natural Resources Conservation Service. http://websoilsurvey.nrcs.usda.gov 4. NOAA Atlas 2, Precipitation -Frequency Atlas of the Western United States, Volume III - Colorado. U.S. Department of Commerce, 1973. 5. Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals Volumes 1, 2 and 3, by Weld County Public Works Department, October, 2006. 7 APPENDIX A - VICINITY MAP 2 a rn 3C-9HZ.mxd, 9/13/2012 12:05: 30 H AV 26 Legend Project Location Residences VICINITY MAP KMG 16-24i SWD LOCATED IN SECTION 24 T2N, R65W, 6TH P.M. WELD COUNTY, COLORADO ICR�18.5 t4.3 miles to Hudson Kerr-McGee Oil & Gas Onshore L.P. 1099 18th Street Denver, Colorado 80202 CR 18 4974 CR 18.5 Jim Creek SCALE:1" = 500ft SCALE: 1" = 2,000ft DRAWN: JFE _ JFE REVISED: CR 20 CONSULTING, LLC 2155 North Main Street Sheridan, Wyoming 82801 Phone 307.674-0609 Fax 307-674-W82 NAD83 CO-Nft DATE: 6 Mav 2013 DATE: 31 Ma 2013 APPENDIX B - REFERENCE DATA DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF 2.0 RATIONAL METHOD For urban catchments that are not complex and are generally 160 acres or less in size, it is acceptable that the design storm runoff be analyzed by the Rational Method. This method was introduced in 1889 and is still being used in most engineering offices in the United States. Even though this method has frequently come under academic criticism for its simplicity, no other practical drainage design method has evolved to such a level of general acceptance by the practicing engineer. The Rational Method properly understood and applied can produce satisfactory results for urban storm sewer and small on -site detention design. 2.1 Rational Formula The Rational Method is based on the Rational Formula: Q=CIA in which: Q = the maximum rate of runoff (cfs) (RO-1) C = a runoff coefficient that is the ratio between the runoff volume from an area and the average rate of rainfall depth over a given duration for that area l = average intensity of rainfall in inches per hour for a duration equal to the time of concentration, tc A = area (acres) Actually, Q has units of inches per hour per acre (in/hr/ac); however, since this rate of in/hr/ac differs from cubic feet per second (cfs) by less than one percent, the more common units of cfs are used. The time of concentration is typically defined as the time required for water to flow from the most remote point of the area to the point being investigated. The time of concentration should be based upon a flow length and path that results in a time of concentration for only a portion of the area if that portion of the catchment produces a higher rate of runoff. The general procedure for Rational Method calculations for a single catchment is as follows: 1. Delineate the catchment boundary. Measure its area. 2. Define the flow path from the upper -most portion of the catchment to the design point. This flow path should be divided into reaches of similar flow type (e.g., overland flow, shallow swale flow, gutter flow, etc.). The length and slope of each reach should be measured. 3. Determine the time of concentration, to for the catchment. 2007-01 RO-3 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF 2.4 Time of Concentration One of the basic assumptions underlying the Rational Method is that runoff is a function of the average rainfall rate during the time required for water to flow from the most remote part of the drainage area under consideration to the design point. However, in practice, the time of concentration can be an empirical value that results in reasonable and acceptable peak flow calculations. The time of concentration relationships recommended in this Manual are based in part on the rainfall -runoff data collected in the Denver metropolitan area and are designed to work with the runoff coefficients also recommended in this Manual. As a result, these recommendations need to be used with a great deal of caution whenever working in areas that may differ significantly from the climate or topography found in the Denver region. For urban areas, the time of concentration, re, consists of an initial time or overland flow time, t;, plus the travel time, t,, in the storm sewer, paved gutter, roadside drainage ditch, or drainage channel. For non - urban areas, the time of concentration consists of an overland flow time, r;, plus the time of travel in a defined form, such as a swale, channel, or drainageway. The travel portion, t,, of the time of concentration can be estimated from the hydraulic properties of the storm sewer, gutter, swale, ditch, or drainageway. Initial time, on the other hand, will vary with surface slope, depression storage, surface cover, antecedent rainfall, and infiltration capacity of the soil, as well as distance of surface flow. The time of concentration is represented by Equation RO-2 for both urban and non -urban areas: tc=t;+1, in which: = time of concentration (minutes) , = initial or overland flow time (minutes) = travel time in the ditch, channel, gutter, storm sewer, etc. (minutes) 2.4.1 Initial Flow Time The initial or overland flow time, t,, may be calculated using equation RO-3: 0.395(1.1- C5 WE S" in which: r; = initial or overland flow time (minutes) C5 = runoff coefficient for 5 -year frequency (from Table RO-5) (RO-2) (RO-3) 2007-01 RO-5 Urban Drainage and Flood Control District RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) L = length of overland flow (500 ft maximum for non -urban land uses, 300 ft maximum for urban land uses) S = average basin slope (ft/ft) Equation RO-3 is adequate for distances up to 500 feet. Note that, in some urban watersheds, the overland flow time may be very small because flows quickly channelize. 2.4.2 Overland Travel Time For catchments with overland and channelized flow, the time of concentration needs to be considered in combination with the overland travel time, r,, which is calculated using the hydraulic properties of the swale, ditch, or channel. For preliminary work, the overland travel time, r,, can be estimated with the help of Figure RO-1 or the following equation (Guo 1999): V = c,,S,os in which: V= velocity (ft/sec) C, = conveyance coefficient (from Table RO-2) S. = watercourse slope (Wit) Table RO-2—Conveyance Coefficient, C. (RO-4) Type of Land Surface Conveyance Coefficient, Cv Heavy meadow 2.5 Tillage/field 5 Short pasture and lawns 7 Nearly bare ground 10 Grassed waterway 15 Paved areas and shallow paved swales 20 The time of concentration, re, is then the sum of the initial flow time, t;, and the travel time, t,, as per Equation RO-2. 2.4.3 First Design Point Time of Concentration in Urban Catchments Using this procedure, the time of concentration at the first design point (i.e., initial flow time, t1) in an urbanized catchment should not exceed the time of concentration calculated using Equation RO-5. t= L +10 180 in which: (RO-5) = maximum time of concentration at the first design point in an urban watershed (minutes) RO-6 2007-01 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF Table RO-3—Recommended Percentage Imperviousness Values Land Use or Surface Characteristics Percentage Imperviousness Business: Commercial areas 95 Neighborhood areas 85 Residential: Single-family * Multi -unit (detached) 60 Multi -unit (attached) 75 Half -acre lot or larger Apartments 80 Industrial: Light areas - 80 Heavy areas 90 Parks, cemeteries 5 Playgrounds 10 Schools 50 Railroad yard areas 15 Undeveloped Areas: Historic flow analysis 2 Greenbelts, agricultural 2 Off -site flow analysis (when land use not defined) 45 Streets: Paved 100 Gravel (packed) 40 Drive and walks 90 Roofs 90 Lawns, sandy soil 0 Lawns, clayey soil 0 * See Figures RO-3 through RO-5 for percentage imperviousness. CA = K4+ (1.31i3 —1.4412 + 1.135i — 0.12) for CA ≥ 0, otherwise CA = 0 (RO-6) CCD = KCD + (0.858P - 0.786i2 + 0.774i + 0.04) CB = (CA + Cc0)/2 (RO-7) 2007-01 Urban Drainage and Flood Control District RO-9 DRAINAGE CRITERIA MANUAL (V. 1) Table RO-5-- Runoff Coefficients, C RUNOFF Percentage Imperviousness Type C and D NRCS Hydrologic Soil Groups 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 0% 0.04 0.15 0.25 0.37 0.44 0.50 5% 0.08 0.18 0.28 0.39 0.46 0.52 10% 0.11 0.21 0.30 0.41 0.47 0.53 15% 0.14 0.24 0.32 0.43 0.49 0.54 20% 0.17 0.26 0.34 0.44 0.50 0.55 25% 0.20 0.28 0.36 0.46 0.51 0.56 30% 0.22 0.30 0.38 0.47 0.52 0.57 35% 0.25 0.33 0.40 0.48 0.53 0.57 40% 0.28 0.35 0.42 0.50 0.54 0.58 45% 0.31 0.37 0.44 0.51 0.55 0.59 50% 0.34 0.40 0.46 0.53 0.57 0.60 55% 0.37 0.43 0.48 0.55 0.58 0.62 60% 0.41 0.46 0.51 0.57 0.60 0.63 65% 0.45 0.49 0.54 0.59 0.62 0.65 70% 0.49 0.53 0.57 0.62 0.65 0.68 75% 0.54 0.58 0.62 0.66 0.68 0.71 80% 0.60 0.63 0.66 0.70 0.72 0.74 85% 0.66 0.68 0.71 0.75 0.77 0.79 90% 0.73 0.75 0.77 0.80 0.82 0.83 95% 0.80 0.82 0.84 0.87 0.88 0.89 100% 0.89 0.90 0.92 0.94 0.95 0.96 TYPE B NRCS HYDROLOGIC SOILS GROUP 0% 0.02 0.08 0.15 0.25 0.30 0.35 5% 0.04 0.10 0.19 0.28 0.33 0.38 10% 0.06 0.14 0.22 0.31 0.36 0.40 15% 0.08 0.17 0.25 0.33 0.38 0.42 20% 0.12 0.20 0.27 0.35 0.40 0.44 25% 0.15 0.22 0.30 0.37 0.41 0.46 30% 0.18 0.25 0.32 0.39 0.43 0.47 35% 0.20 0.27 0.34 0.41 0.44 0.48 40% 0.23 0.30 0.36 0.42 0.46 0.50 45% 0.26 0.32 0.38 0.44 0.48 0.51 50% 0.29 0.35 0.40 0.46 0.49 0.52 55% 0.33 0.38 0.43 0.48 0.51 0.54 60% 0.37 0.41 0.46 0.51 0.54 0.56 65% 0.41 0.45 0.49 0.54 0.57 0.59 70% 0.45 0.49 0.53 0.58 0.60 0.62 75% 0.51 0.54 0.58 0.62 0.64 0.66 80% 0.57 0.59 0.63 0.66 0.68 0.70 85% 0.63 0.66 0.69 0.72 0.73 0.75 90% 0.71 0.73 0.75 0.78 0.80 0.81 95% 0.79 0.81 0.83 0.85 0.87 0.88 100% 0.89 0.90 0.92 0.94 0.95 0.96 2007-01 Urban Drainage and Flood Control District RO-11 Chapter 3 Calculating the WQCV and Volume Reduction 3.0 Calculation of the WQCV The first step in estimating the magnitude of runoff from a site is to estimate the site's total imperviousness. The total imperviousness of a site is the weighted average of individual areas of like imperviousness. For instance, according to Table RO-3 in the Runoff chapter of Volume 1 of this manual, paved streets (and parking lots) have an imperviousness of 100%; drives, walks and roofs have an imperviousness of 90%; and lawn areas have an imperviousness of 0%. The total imperviousness of a site can be determined taking an area -weighted average of all of the impervious and pervious areas. When measures are implemented minimize directly connected impervious area (MDCIA), the imperviousness used to calculate the WQCV is the "effective imperviousness." Sections 4 and 5 of this chapter provide guidance and examples for calculating effective imperviousness and adjusting the WQCV to reflect decreases in effective imperviousness. The WQCV is calculated as a function of imperviousness and BMP drain time using Equation 3-1, and as shown in Figure 3-2: WQCV = a(0.9113 — 1.19/2 + 0.781) Equation 3-1 Where: WQCV = Water Quality Capture Volume (watershed inches) a = Coefficient corresponding to WQCV drain time (Table 3-2) I = Imperviousness (%/100) (see Figures 3-3 through 3-5 [single family land use] and /or the Runoff chapter of Volume 1 [other typical land uses]) Table 3-2. Drain Time Coefficients for WQCV Calculations Drain Time (hrs) Coefficient, a 12 hours 0.8 24 hours 0.9 40 hours 1.0 Figure 3-2, which illustrates the relationship between imperviousness and WQCV for various drain times, is appropriate for use in Colorado's high plains near the foothills. For other portions of Colorado or United States, the WQCV obtained from this figure can be adjusted using the following relationships: WQCV) WQCVother = d6 ( 0.43 Equation 3-2 Where: WQCV = WQCV calculated using Equation 3-1 or Figure 3-2 (watershed inches) WQCVother = WQCV outside of Denver region (watershed inches) d6 = depth of average runoff producing storm from Figure 3-1 (watershed inches) August 2011 Urban Drainage and Flood Control District 3-5 Urban Storm Drainage Criteria Manual Volume 3 Calculating the WQCV and Volume Reduction Chapter 3 Once the WQCV in watershed inches is found from Figure 3-2 or using Equation 3-1 and/or 3-2, the required BMP storage volume in acre-feet can be calculated as follows: QCVI C V = WA 12 Where: V A WQCV 0.500 0.450 0.400 c 0.350 0.300 0.250 co 0.200 0.150 V 0.100 0.050 0.000 • = required storage volume (acre -ft) = tributary catchment area upstream (acres) = Water Quality Capture Volume (watershed inches) Equation 3-3 I I (40 hour drain time II • 1 I• 124 hour drain time WQCV=a(0.91P I I 1.19,2+0.781) I ♦• 12 -hr drain time a =0.8 -hr drain time a=0.9 I a° —24 40 -hr drain time a= 1.0 �•� t4.1 •••� 12 hour drain time I a 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Total Imperviousness Ratio (i = la/100) Figure 3-2. Water Quality Capture Volume (WQCV) Based on BMP Drain Time 3-6 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 3 August 2011 STORAGE DRAINAGE CRITERIA MANUAL (V. 2) the calculated 100 -year volume. Others require that the 100 -year volume be added to the WQCV. All jurisdictions require the WQCV be added to the 5- or 10 -year volume. When clear written local criteria on this matter are absent, the District recommends that no less than 50% of the WQCV be added to the calculated 100 -year volume for 100 -year volumes obtained using empirical equations and the FAA Method. However, unless the local jurisdiction requires adding all or part of the WQCV to the 100 -year volume obtained using the simplified Full Spectrum Detention design; District does not recommend adding any part of the WQCV to the 100 -year volume. When the analysis is done using hydrograph routing methods, each level of controls needs to be accounted for and the resultant 100 -year control volume used in final design. 3.2 Sizing of On -Site Detention Facilities 3.2.1 Maximum Allowable Unit Release Rates for On -Site Facilities The maximum allowable unit release rates in the Denver area per acre of tributary catchment for on -site detention facilities for various design return periods are listed in Table SO -1. These maximum releases rates will apply for all on -site detention facilities unless other rates are recommended in a District - approved master plan. For regional facilities see Section 3.2.5. Allowable unit release rates in Table SO -1 for each a soil group in the tributary catchment shall be area - weighted to composite the allowable unit release rate for the total catchment. Multiply this rate by the total tributary catchment's area to obtain the design release rates in cubic feet per second (cfs). Whenever Natural Resources Conservation Service (NRCS) soil surveys are not available, approximate their equivalent types using results of detailed soil investigations at the site. Table SO -1 —Maximum Unit Flow Release Rates (cfs/acre) from On -Site Detention Facilities Design Return Period (Years) NRCS Hydrologic Soil Group A B C & D 2 0.02 0.03 0.04 5 0.07 0.13 0.17 10 0.13 0.23 0.30 25 0.24 0.41 0.52 50 0.33 0.56 0.68 100 0.50 0.85 1.00 3.2.2 Empirical Equations for the Sizing of On -Site Detention Storage Volumes Urbonas and Glidden (1983), as part of the District's ongoing hydrologic research, conducted studies that evaluated peak storm runoff flows along major drainageways. The following set of empirical equations provided preliminary estimates of on -site detention facility sizing for areas within the District. They are SO -8 12/2011 Urban Drainage and Flood Control District APPENDIX C - FIRM (Flood Insurance Rate Map) a t UI C CC v z d IX V) C ac WSw ea In ' a: O• 0 0 m: J w. z. a. G. a".) 00 n mac' z0 -.a0 W to z" 4 0 0 0 z I C U 1 } 4 r tI i • • 1 V.. 0 N W In - W CO CL. C‘ act W tte W may.• — -... f •_•.Y• 1 i er M I I rA A • • wr•y I w. "I • + ••••,`.1-71 9*' 'J r• i; r t:', _.% . yea • �... c. «. •.ter.. .NN. _..... • • i 5— APPENDIX D - HYDROLOGY CALCULATIONS Appendix Di Soils Report Appendix D-2 Rainfall Data Appendix D-3 Runoff Calculations APPENDIX D-1 - SOIL REPORT Soil Map —Weld County, Colorado, Southern Part HE .9E JO 1. trE .9E . VO L 8 L) S icc 8 a I- r O U, 0 0 8 a O Cn Cn C1 Ci 0 in 0 V M N a E ,9E .VOI. 71 L' X a, (1) N C 0 D 4d a 0 en C)) CO M r O O (N (D N 't t0 a Q) am • V) • VJ O^ (a > O `- d •-• Cd a y if _o O N C O Ct z V7 r _8 s N 0 0c H CO O Z< ZU trE .9E . ho Soil Map —Weld County, Colorado, Southern Part NFORMATION MAP LEGEND Map Scale: 1:3,510 if printed on A size (8.5" x 11") sheet. CO Very Stony Spot Area of Interest (AO') The soil surveys that comprise your AOI were mapped at 1:24,000. Area of Interest (AOI) Warning: Soil Map may not be valid at this scale. c rn C O N N CO 3 14 b_ >p C ��C)p c U O (� N G, C.1 co acs 1)r CO -0 cv C - E cc R) N E 8 4J N 2 a.c co y0L3 N o C Ca 0 C o>1 _c c C a) 0 a) la '0 a) N N L a 4 aa) cv ca > Eo)Em c L O D L 2 c C (0 ~ p c c 0).-a Es) as a C en 8 — w E a uu)) C) 6 0 N 4 Soil Map Units Special Line Features T O Short Steep Slope C) L 6 rdaiHtcl Special Point Features "- 0) a O c as in E fu n a) > $ a) • N ti o 'C 3 C 8 N cvv cn E c) c co E 7 -c a) a) 'a c�j • O as E ti; 1,1cco p (V O O N a) n5i 2 o w co oo '. tLn y Z Z v N V E u) a C Q i p O` N E N O Z a O a a c e N c N M ca z U O E 0 a) a c o 0 3 c o •. � E �' m a) o N Eo ooc a CD to O N >� OC g fl U .2 ca o y cv o c`v v a) Oroc E N ' a) N (III co~J N > N .Z a) = O (aa) E c nis (a v a) a).r o cm o c L --- co aa)) v �' a) C E o'6 7 0 a c t= () , 'Oct < • (9 o C afl (I 7 c a) ▪ Oro c 2 aEi 0aQo.cco) o 7 >. U) C °' Z' a N N act) co a) o a, m co its 7yo N> — a)E(vE a E v)>0 Iw V) v) o f O.E o a o 7 3 a 0 w 3 > 0 O o ca 55 m i"-.5 Political Features 0 Closed Depression • Water Features m O X Streams and Canals Gravelly Spot C 0 ns r 0 ►- U) fd 0 w LL C i CO KS J Interstate Highways Marsh or swamp N C) 0 N Mine or Quarry Major Roads Miscellaneous Water Local Roads Perennial Water Rock Outcrop Severely Eroded Spot d O L C_ C,) a U) `0 C) 0 U) a) 0 a U) 0 a U) C 0 U) o e Isk m o Natural Resources Conservation Service Soil Map —Weld County, Colorado, Southern Part Map Unit Legend Weld County, Colorado, Southern Part (CO618) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 10 Bankard sandy loam, 0 to 3 percent slopes 12.4 30.9% 14 Colby loam, 0 to 1 percent slopes 1.5 3.9% 18 Colby-Adena loans, 3 to 9 percent slopes 8.0 20.1% 25 Haverson loam, 0 to 1 percent slopes 7.8 19.4% 47 Olney fine sandy loam, 1 to 3 percent slopes 2.5 6.3% 74 Vona loamy sand, 5 to 9 percent slopes 7.7 19.3% Totals for Area of Interest 40.0 100.0% Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 4/16/2013 Page 3of3 Map Unit Description: Bankard sandy loam, 0 to 3 percent slopes —Weld County, Colorado, Southern Part Map Unit Description The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions in this report, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. USDA Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 4/16/2013 Page 1 of 3 Map Unit Description: Bankard sandy loam, 0 to 3 percent slopes -Weld County, Colorado, Southern Part Soils that have profiles that are almost alike make up a soil series. All the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of a given series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha -Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha -Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Additional information about the map units described in this report is available in other soil reports, which give properties of the soils and the limitations, capabilities, and potentials for many uses. Also, the narratives that accompany the soil reports define some of the properties included in the map unit descriptions. Weld County, Colorado, Southern Part 10 Bankard sandy loam, 0 to 3 percent slopes Map Unit Setting Elevation: 4,450 to 5,000 feet Mean annual precipitation: 10 to 14 inches Mean annual air temperature: 48 to 52 degrees F Frost -free period: 95 to 160 days Map Unit Composition Bankard and similar soils: 85 percent Minor components: 15 percent �USDA Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 4/16/2013 Page 2 of 3 Map Unit Description: Bankard sandy loam, 0 to 3 percent slopes —Weld County, Colorado, Southern Part Description of Bankard Setting Landform: Low sand ridges, flood plains Down -slope shape: Linear • Across -slope shape: Linear Parent material: Stratified, recent alluvium Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Drainage class: Somewhat excessively drained Capacity of the most limiting layer to transmit water (Ksat): High (2.00 to 6.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum content: '10 percent Available water capacity: Low (about 4.5 inches) Interpretive groups Farmland classification: Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Land capability classification (irrigated): 4w Land capability (nonirrigated): 4w Hydrologic Soil Group: A Ecological site: Sandy Bottomland (R067BY031 CO) Typical profile 0 to 4 inches: Sandy loam 4 to 60 inches: Stratified gravelly sand to loam Minor Components Mollic fluvaquents Percent of map unit: 9 percent Landform: Terraces Blakeland Percent of map unit: 6 percent Data Source Information Soil Survey Area: Weld County, Colorado, Southern Part Survey Area Data: Version 11, Aug 27, 2009 USDA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 4/16/2013 Page 3 of 3 Map Unit Description: Colby loam, 0 to 1 percent slopes —Weld County, Colorado, Southern Part Weld County, Colorado, Southern Part 14 —Colby loam, 0 to 1 percent slopes Map Unit Setting Landscape: Uplands Elevation: 4,850 to 5,050 feet Mean annual precipitation: 12 to 16 inches Mean annual air temperature: 48 to 50 degrees F Frost -free period: 135 to 155 days Map Unit Composition Colby and similar soils: 85 percent Minor components: 15 percent Description of Colby Setting Down -slope shape: Linear Across -slope shape: Linear Parent material: Calcareous eolian deposits Properties and qualities Slope: 0 to 1 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum content: 15 percent Available water capacity: High (about 10.6 inches) Interpretive groups Farmland classification: Prime farmland if irrigated Land capability classification (irrigated): 3e Land capability (nonirrigated): 4c Hydrologic Soil Group: B Ecological site: Loamy Plains (R067BY002CO) Typical profile 0 to 7 inches: Loam 7 to 60 inches: Silt loam Minor Components Wiley Percent of map unit: 6 percent Keith Percent of map unit: 5 percent USDA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 4/16/2013 Page 1 of 2 Map Unit Description: Colby-Adena loans, 3 to 9 percent slopes —Weld County, Colorado, Southern Part Weld County, Colorado, Southern Part 18—Colby-Adena loans, 3 to 9 percent slopes Map Unit Setting Elevation: 4,750 to 4,900 feet Mean annual precipitation: 12 to 16 inches Mean annual air temperature: 48 to 55 degrees F Frost -free period: 120 to 160 days Map Unit Composition Colby and similar soils: 55 percent Adena and similar soils: 30 percent Minor components: 15 percent Description of Colby Setting Landform: Ridges, hills, plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Calcareous eolian deposits Properties and qualities Slope: 5 to 9 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum content: 15 percent Available water capacity: High (about 10.6 inches) Interpretive groups Farmland classification: Not prime farmland Land capability (nonirrigated): 4e Hydrologic Soil Group: B Ecological site: Loamy Slopes (R067BY008CO) Typical profile 0 to 7 inches: Loam 7 to 60 inches: Silt loam Description of Adena Setting Landform: Hills, plains, ridges Down -slope shape: Linear Across -slope shape: Linear Parent material: Calcareous eolian deposits USDA Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 4/16/2013 Page 1 of 2 Map Unit Description: Colby-Adena loarns, 3 to 9 percent slopes —Weld County, Colorado, Southern Part Properties and qualities Slope: 3 to 7 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity 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 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum content: 15 percent Available water capacity: High (about 10.1 inches) Interpretive groups Farmland classification: Not prime farmland Land capability classification (irrigated): 3e Land capability (nonirrigated): 4e Hydrologic Soil Group: C Ecological site: Loamy Plains (R067BY002CO) Typical profile 0 to 6 inches: Loam 6 to 9 inches: Clay loam 9 to 60 inches: Silt loam Minor Components Kim Percent of map unit: 5 percent Keith Percent of map unit: 4 percent Weld Percent of map unit: 3 percent Wiley Percent of map unit: 3 percent Data Source Information Soil Survey Area: Weld County, Colorado, Southern Part Survey Area Data: Version 11, Aug 27, 2009 USDA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 4/16/2013 Page 2 of 2 Map Unit Description: Haverson loam, 0 to 1 percent slopes —Weld County, Colorado, Southern Part Weld County, Colorado, Southern Part 25—Haverson loam, 0 to 1 percent slopes Map Unit Setting Elevation: 4,500 to 4,800 feet Mean annual precipitation: 12 to 17 inches Mean annual air temperature: 46 to 54 degrees F Frost -free period: 125 to 180 days Map Unit Composition Haverson and similar soils: 85 percent Minor components: 15 percent Description of Haverson Setting Landform: Flood plains, stream terraces Down -slope shape: Linear Across -slope shape: Linear Parent material: Stratified, calcareous alluvium Properties and qualities Slope: 0 to 1 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum content: 15 percent Gypsum, maximum content: 1 percent Maximum salinity: Nonsaline to slightly saline (0.0 to 8.0 mmhos/cm) Available water capacity: High (about 9.6 inches) Interpretive groups Farmland classification: Prime farmland if irrigated Land capability classification (irrigated): 3w Hydrologic Soil Group: B Ecological site: Loamy Plains (R067BY002CO) Typical profile 0 to 4 inches: Loam 4 to 60 inches: Stratified loamy sand to loam to clay loam Minor Components Vona Percent of map unit: 8 percent Fluvaquentic haplustolls Percent of map unit: 4 percent Landform: Terraces USDA Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 4/16/2013 Page 1 of 2 Map Unit Description: Olney fine sandy loam, 1 to 3 percent slopes —Weld County, Colorado, Southern Part Weld County, Colorado, Southern Part 47 Olney fine sandy loam, 1 to 3 percent slopes Map Unit Setting Elevation: 4,600 to 5,200 feet Mean annual precipitation: 11 to 15 inches Mean annual air temperature: 46 to 54 degrees F Frost -free period: 125 to 175 days Map Unit Composition Olney and similar soils: 85 percent Minor components: 15 percent Description of Olney Setting Landform: Plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Mixed deposit outwash Properties and qualities Slope: 1 to 3 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum content: 15 percent Maximum salinity: Nonsaline (0.0 to 2.0 mmhos/cm) Available water capacity: Moderate (about 7.0 inches) Interpretive groups Farmland classification: Prime farmland if irrigated and the product of 1 (soil erodibility) x C (climate factor) does not exceed 60 Land capability classification (irrigated): 3e Land capability (nonirrigated): 4c Hydrologic Soil Group: B Ecological site: Sandy Plains (R067BY024CO) Typical profile 0 to 10 inches: Fine sandy loam 10 to 20 inches: Sandy clay loam 20 to 25 inches: Sandy clay loam 25 to 60 inches: Fine sandy loam Minor Components Zigweid Percent of map unit 10 percent UMM Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 4/16/2013 Page 1 of 2 Map Unit Description: Vona loamy sand, 5 to 9 percent slopes —Weld County, Colorado, Southern Part Weld County, Colorado, Southern Part 74 —Vona loamy sand, 5 to 9 percent slopes Map Unit Setting Elevation: 4,600 to 5,200 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 55 degrees F Frost -free period: 130 to 160 days Map Unit Composition Vona and similar soils: 85 percent Minor components: 15 percent Description of Vona Setting Landform: Plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Eolian deposits Properties and qualities Slope: 5 to 9 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): High (1.98 to 6.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum content: 15 percent Maximum salinity: Nonsaline to very slightly saline (0.0 to 4.0 mmhos/ cm) Available water capacity: Moderate (about 6.5 inches) Interpretive groups Farmland classification: Not prime farmland Land capability classification (irrigated): 6e Land capability (nonirrigated): 6e Hydrologic Soil Group: B Ecological site: Sandy Plains (R067BY024CO) Typical profile 0 to 6 inches: Loamy sand 6 to 28 inches: Fine sandy loam 28 to 60 inches: Sandy loam Minor Components Valent Percent of map unit: 10 percent USDA Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 4/16/2013 Page 1 of 2 (D O Q Hydrologic Soil Group —Weld County, Colorado, Southern Part £ ,9£ .fOl hE .9C GPO I. t le c G 0 I.£ .9£ .POI ,510 if printed on A size (B 5" x 11") sheet cu n. O co O C) 0 8 0 CO 0 LC) O Z< ..h£ .9E .VO4 M_ d O O N CO N O) M a a) z TV/ W Zci)^` cn 1 O 1 Q O O O U co C O aw co Z N 8U) D (^n` • O_ LL -z^` W 7N 1/ C (O O ZU Hydrologic Soil Group —Weld County, Colorado, Southern Part z 0 re O 0 Q 2 MAP LEGEND Map Scale: 1:3,510 if printed on A size (8.5" x 11") sheet. Area of Interest (AOI) The soil surveys that comprise your AOI were mapped at 1:24,000. Area of Interest (AOl) Warning: Soil Map may not be valid at this scale. Soil Map Units CO 0 E E m E .c \ @ J \ $ E R k t 2c / co 0 q f E cp- © k .R § § % / 0 2 k O (Sc- n q —a ® //� 0 /©CI z aq 2 a c k« a V 2[ i E 3/ p \ N f / ® � @ O ® < 2 a) §moo /, >, E as"o�% C o z 0 3 C' c E al m o $ d N E o o c ■ 2 E 8 / o Q.g 2 2 2 l lc 2 @ so ® r 2 of $ o /§ & 2 $ m �_CD C c 4 D E a) , \ % o r oA$2 a)# 2 m )« E o» 0c mkm• - </ R Z2 2 en /co 2 2§ >-. r t • $ f 'Sr ._ « T) D 2. 8& e at) / a \a f g > Q o CO G o — m E m E EE • E cn k U / n d w C% S.[ o o 0 0 < k/ m o u e CU 2 \ n ❑ ❑ m ❑ ❑ n Not rated or not available Political Features § 0 D Water Features Streams and Canals tO 2 (t It a -$ E Interstate Highways • et Local Roads Hydrologic Soil Group —Weld County, Colorado, Southern Part Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (ND, BID, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff. None Specified Tie -break Rule: Higher usD4 Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 4/16/2013 Page 4 of 4 APPENDIX D-2 - RAINFALL DATA KMG 16-24i SWD Facility Rainfall Calculations Intensity -Duration -Frequency (IDF) for Zone 1 in the State of Colorado Zone 1: South Platte, Republican. Arkansas, and Cimarron River Basins Elevation at Rainfall Depth -Duration -Frequency Table center of watershed = _ 4,890 Feet Enter the 6 -hour and 24 -hour rainfall depths from NOAA Atlas 2 Volume III in blue columns Return Period Rainfall Depth in Inches at Time Duration 5 -min 10 -min 15 -min 30 -min 1 -hr 2 -hr 3 -hr 6 -hr 24 -hr output output output output output output output Input Input 2-yr 0.29 0.47 0.59 0.68 1.04 1.16 1.25 1.40 1.70 5-yr 0.42 0.66 0.83 0.96 1.47 1.62 1.73 1.90 2.30 10-yr 0.50 0.79 1.00 1.15 1.76 1.91 2.02 2.20 2.60 25-yr 0.60 0.95 1.20 1.39 2.12 2.35 2.52 2.80 3.20 50-yr 0.69 1.11 1.39 1.61 2.46 2.64 2.78 3.00 3.60 100-yr 0.78 1.25 1.57 1.82 2.77 2.99 3.15 3.40 4.00 500-yr _ 0.98 _ 1.56 1.97 2.27 3.46 3.73 3.92 4.23 4.94 Rainfall Intensity -Duration -Frequency Table Return Period Rainfall Intensity in Inches Per Hour at Time Duration 5 -min 10 -min 15 -min 30 -min 1 -hr 2 -hr 3 -hr 6 -hr 24 -hr output output output output output output output output output 2-yr 3.51 2.80 2.35 1.62 1.04 0.64 0.48 0.28 0.10 5-yr 4.98 3.98 3.34 2.31 1.47 0.91 0.68 0.40 0.14 10-yr 5.95 4.75 3.98 2.75 1.76 1.09 0.81 0.48 0.16 25-yr 7.18 5.72 4.80 3.32 2.12 1.31 0.98 0.58 0.20 50-yr 8.33 6.64 5.57 3.85 2.46 1.53 1.13 0.67 0.23 100-yr 9.41 7.51 6.30 4.35 2.77 1.72 1.28 0.76 0.26 500-yr 11.75 9.37 _ 7.87 5.44 3.46 2.15 _ 1.60 _ 0.95 0.32 i a i c, wommersiimmaga E i a a t U • •�L... 3 w fit ! 0 a i I a — —•0 �— ' I- I ISSN — r •. ) N m 1213 ewe, a ...1.• I ft a I L I I last LA, H. 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L '= I 1 — — Ole S O• cc Q --- - a .,... /✓r r. n 12) v -t- 1 7-1 ti. 1 — • 1 O <• J Lie I 1 i I I I i I I I I I z• z J CC CO as ..+ s, a ti al•a - - Co .... - a • Cr) Do SI- 0 4 ter U n. it= ' z ins 04 -J > �z Or V' ♦ I r IMMO APPENDIX D-3 - RUNOFF CALCULATIONS KMG 16-24i SWD Facility Historic Runoff Calculations Time of Concentration _ + U) w F— C • - E co) N ict r) C7 Channelized Flow N (1) F.:' r. m CC) Velocity (ft/min) 56.9 to C; Co r Velocity (ft/sec) LO N O N O N Length (ft) 0 0 CO CO N C .-. "CC N a t O N O o o co-- 00 v r -r - Overland Flow Time T, (Minutes) C'7 W. Ns co a t 0 £l0 N O co ..� O Length (ft) to O CO O Tr LO U N- O O r 0 0 C N r r co Co Site Imperviousness Table 0 0 r 0 0 T- 0 O 0 rt N Concrete Pavement 0 0 Gravel Road Undeveloped CC Pre -Development Basin Characteristics A-1 0 - 0 in .' - N to r 0 co (D n it — N — M N 2 0 0 LC) 0 CO O 0 (D CO 0 N N 0 C') Cr) O coda O CO CO N O L- r CO O oo CD r U o0c)rco co 0 o' 0 o 6o o O 0 NRCS Soil Group aoaomc O O a, a E Cr O r N N Of N Area (Acres) co CO 0 o CD 0 N CO r N O O r r 'Tr N Lo M Land Cover > Lv 0 C a) > (v a Undeveloped [Undeveloped 0 H Pre -Development Basin Characteristics B-1 0 N G O o O O n 1 — - a N — N <2 0 0 LO O CO O O N N O O) N O O 0 CD Cr) 0 N O 0 CO O 0 Lo T- O ,. U 0o'r coO 0 O O O co O C NRCS Soil Group co CD m Impervious O Ict O O rco N O O (sway) eaay 0.43 O O LO V) r O N Land Cover [Gravel Pavement Undeveloped Cu 0 I - Pre -Development Basin Characteristics C-1 3.5 o a Q N r U• C' i (D o . f — 1- CO N i. — c Co N c-; O Or O O O NO N O C'9 O c 0 N O O IS) t` O CO O O (D r O % O o O O co I- O r 0 O 0 r O NRCS Soil Group Co co m to D • _O O E E O O r O O N Cr) r Area (Acres) LO r O t r O t` 01 N (D (D N Land Cover Concrete Roofs Undeveloped 0 0 H Pre -Development Totals n Fy : 0 r La o .. -c N 6- — r d - I Area (Acres) to Ca Q) Developed Runoff Calculations Time of Concentration is + N vcn•co ~ C E N • N. Channelized Flow U, _ a) -5 I— 7 c r co c-- C Velocity (ft/min) O c0 (O U') C Velocity (ft/sec) U) 6 co O Length (ft) O cla O C C1 .t 0 CO co . O C > U) (O U r -a- Overland Flow Time ;5' co CO CO t- C I-- co I - cm_ a.) a.tCOr o r O 5 O O Length (ft) I 465 f 490 C) o O co O -(.7)N N CO CO < 0 Site Imperviousness Table O O r O O r O O O mit O wa- N • Concrete Pavement Gravel Road Recycled Concrete / Gravel Undeveloped O Cf Developed Basin Characteristics A-2 O - N L In o O !t U) r 0 _ CO co ,Th r, _ it 4 q I — CO N In 1- - c 2.3 o 0 co CO O in O CO CO O CO CO O N N O 0.33 _, U O in O co CO O N O) 0 I-- r 0 c0 O 0 (.0 r- O U in O M 0 O 0 O O 0 O T-- 0 O co 0 O NRCS Soil Group m m m m Q U) O O_ o t_ a) Cl. E U7 I� O 't O O r N N N N Area (Acres) (O r O (n CO O O (O O r- (O r N O O r N— 35.24 Land Cover Road Base Gravel a-. C a) > CO a» V a) CL O _ ID C V a) C. _O a) a C CO O F - Developed Basin Characteristics B-2 6 ID N O co a O _t O L v• o f - = co N u-, - Ch N 8 0 OLO 0 O) 0 N 0 N 0 o U co CO O N CO O c0 O O U) r O n o O COO O O O r O O CO O O NRCS Soil Group m m OD 0/0 Impervious O OO r N O O Area (Acres) CO V O CO O O O U) r U) O N Land Cover Gravel Road a C a) aa)) ca a Undeveloped O ►- Developed Basin Characteristics C-2 a Eh c C5 N en a N i 4.4 Z — CO N n - — c) N 0 0 (O O en O Oen 0 M 0 in 0 o O co U) O U) r O 0.75 O r O Q Tr O u 0 in O co O O el O O r O co CO O NRCS Soil Group co m co W ok Impervious 75 O O O in U) Q, Tr Area (Acres) N- r- CO O O O CI O (O N Land Cover Road Base Self Contained Tank Area & Concrete Pad Roofs Grass To 0 I -- Detained Developed Totals o a o 55.1 o y- CO o U O d Area (Acres) U7 O) C) Cr) Undetained Developed Totals cp 59.3 Q N Or...., (7) i H N CA Area (Acres) in rn O) M APPENDIX E - DETENTION POND CALCULATIONS KMG 16-24i SWD Facility WQCV Calculations ok Impervious WQCV (Inches) Contributing Area (Acres) Design Volume (Acre -ft) 49.5 0.20 2.66 0.05 WQCV=x(0.91 "I'-1.19*I`+0.78*I), where a = 1 for 40 hr drain time Design Volume = WQCV/12 * Area * 1.2 Allowable Release Rates Storm Event Release Rate per acre Contributing Area (acres) Allowable Release Rate (cfs) 5 -year 0.13 2.66 0.35 10 -year 0.23 2.66 0.61 100 -year 0.85 2.66 2.26 Broad Crested Weir Q=CBcw*L*H1.s Where CBcw is the broad crested weir coefficient CBcw Lenth (L) (ft) Head (H) (ft) _ Discharge (Q) (cfs) 3.32 2 0.5 2.35 DETENTION VOLUME BY THE MODIFIED FAA METHOD (See USDCM Volume 2 Storage Chapter for description of method) Project: Basin ID: KMG 16-241 SWD C-2 (For catchments less than 160 acres only. For larger catchments, use hydrograph routing method) (NOTE: for catchments larger then 90 acres, CUHP hydrograph and routing ore recorrlrrwnded) Determination of CM!,./Detention Volume Using Modified FAA Method Determination of MAJOR Detention Volume Using Modified FAA Method Dessrin Information (Inaul): I, = A' Type = T - 1c = h = P. r C. = C2= CN r perceN acres A_ B. C, or 0 yeah (2.5. 10, 25, 50, or 100) miasmas cfaiacre riches Design Information (input): I. = A= Type = T : Tc a 9 = P, 3 Cis G== c3'a 49 51 percent acres A, B. C. or 0 years (2 5 10, 25. mutes crsfacre riches 50, w 500 Catchment Dialeage Irnperwousness Catchment Drainage Area Predevoloprnont MRCS Soil Group Return Period for Detention Control Time of Concentralnn of Watershed Allowable Unit Release Rate One -hour Precipitation Design Rainfall IOF Formula i = C,' P,f(C,+T.)ACs Coefficient One Coefficient Two Coefficient Throe 49 51 Catchment Dra,nage Impervousness Catchment Marriage Area Predevelopment NRCS Soil Group Return Period for Detention Control Time of Concentration of Watershed Asowsbb In Rebate Rw One -hour Precipitation Design Rainfall (OF Formula r = C,• P,r(C1+T,)AC, Coefficient Ore Coefficient Two Cceffr-.ent Three 7681 2 661 a B 10 100 32 32 0 23 085 1 76 2 77 28.50 28 50 10 10' 0 789 0.789 Determination of Avesta Outflow from the Basin {Calculated); cfs ofs cubic lest acre -ft 5141.,,rit Determination of Average Outflow from the Basin i1Caltat cls cis cubit tit acts -h Runoff Coe- Mcrent Inflow Peak Runoff Allowable Peak C = Op -in - Oatflow Rate apoul = Mod. FAA Minor Storage Volume a Mod. FAA Minor Storage Volume = : n:615o,rJel Outa'-. • .• Vas* 0 40 Runoff Coefficient C = ieriewPnMRunoff Op -in= A-iowabie Peak Outflow Rate Op-oul = Mod. FAA Major Storage Volume = Mod. FAA Major Storage Volume a 052 281 5.78 061 2.28 5,452 7,595 0.125 0.174 5 Mans 119 5 foe Rainfall Duration minutes r.nn,/ri RalNan Intensity inches /fir (output) inflow Volume cubic feet (output) Adjustment Factor "m- (outputs Average Outflow cfs (output) Outflow Volume cubic feel (outp+A) Storage Volume cubic feet (output) Rainfall Duration minutes japtd) Rainfall Intensity inches / hr (output) Inflow Volume cuDic feet [output) Adjustment Factor "m- (output) Average Outflow cfs (output) Outflow Volume cubic feet (output) Storage Volume cubic feet (oulpun . 590 1,885 100 001 164 1.702 5 9 33 3,875 1 00 2 26 670 3,196 ID 4 71 3 005 1.00 0 61 36/ 2.638 10 7 44 8,176 1 00 e 2 26 1,357 4.819 15 3 95 3,780 1.00 001 551 r 3,229 15 6 24 7368 1.00 2 26 2.035 5.732 20 3 42 4,304 1.00 0 81 734 3.630 20 6 40 8.970 1.00 226 _ 2,714 6,256 25 3.03 4,031 1.00 0.61 910 3,913 25 4.78 9,928 1.00 228 3,392 6.535 30 272 5.217 1.00 0,01 1.102 4,116 30 4 31 10.722 1.00 _ 228 4,071 6,651 35 248 5,547 0.95 0.50 1.222 k 4,324 35 392 11.399 095 215 4.517 6.882 40 228 5.033 0.89 055 1,314 4,519 40 301 11,988 089 202 4,656 7,132 46 012 0,007 0.05 0.82 1,400 4,661 45 335 12,510 0.85 1.925.195 7,314 SO 190 8.315 0.82 0.50 1.498 4.817 50 313 12,978 0.82 184 5,535 7.443 55 1.08 0.521 0.79 0.48 1,689 4,932 55 294 13,402 0.79 1.78 5.074 _7,626 80 116 8.710 0.70 047 1.881 5.029 60 2 77 13,700 0.70 173 6.213 7.577 65 1.00 6.884 0.74 0.46 1.773 5.111 65 202 14.147 0.74 108 6,552 7.595 70 1.56 7.045 0/3 0.44 1,505 5.181 70 240 14,470 0.73 1.64 _8,897 _7,588 75 1.50 7.196 0,71 0.43 1,957 5,240 75 238 14.789 0.71 161 7.231 7.558 80 1.44 7.337 0,70 0.43 2.040 5.209 80 227 15,079 0 70 1-58 7,570 7.509 85 1.38 7.470 0.89 042 2,140 5.330 06 218 15.353 069 1 55 7.909 7.443 00 132 7.596 080 0.41 2.232 5,384 90 209 15,611 0.68 1 53 8.249 7.362 95 1.27 7,715 D87 0.41 2,324 5,392 95 2.01 15,856 0,67 1 Si 8,588 7.268 100 123 7 829 0.80 0.40 2,416 5.413 100 1.94 10,089 0,66 1 49 8.927 7.162 105 1.18 7.937 065 0.40 2,507 5,430 105 1.67 18,311 0.65 147 9.266 7.045 110 1 14 8.040 084 039 2,599 5,441 5,448 110 1.81 18,524 0.64 1 46 9,608 6.918 115 . 1 11 6,139 0.84 0.30 2,691 116 1.75 16,727 16.923 0.64 1 44 _ 9,945 8,782 120 1 07 0.234 ~ 0.63 039 2.783 5,452 120 1.70 083 1 43 10.284 6.839 125 104 8,328 0.63 0.36 _�_ _ 2,875 5.451 125 1.65 17.111 063 142 10623 10,903 0,467 130 101 0414 062 0.38 2,966 5.448 130 1.60 - 17.292 0.62 141 _ 6,329 135 0 99 8.499 0.82 038 -..- 3,058 5.441 135 1.58 4 7.466 J 0.82 1 40 11.302 6.185 140 096 8.581 0.61 0.37 3.150 5.431 140 1,52 17.635 0,81 139 11,641 6.004 145 094 , 8,681 6,738 051 037 3/42 5,410 145 150 1.46 1.44 , 17,799 17.957 18,110 18,259 061 061 138 11,980 17.320 5,6 I8 5,637 150 091 061 037 3,334 5,404 t 37 155 0 89 8,612 0 00 0 37 3.425 5.307 _ 155 1.41 - 0 60 138 17.059 5.451 160 0 87 8.885 - 0 60 0 37 3,517 5.388 160 1,37 0 60 1 35 12.996 5,281 165 0 85 8.955 0 60 0 36 3.609 5.346 16S 1.34 16.404 0 60 1 35 13,337 5,067 170 0 83 9.024 0 59 0 36 3,701 5.323 170 1.31 18,545 16.682 0 59 1 34 13,677 4 868 175 0 81 9,091 9,156 0 59 0 36 3,792 3.684 5.298 175 1:20 0 59 1 33 14,016 4,666 180 0 80 0 59 0 36 5.271 180 1.26 16.816 0 59 1 33 14,355 4,481 185 0 78 9,719 0 59 0 36 3 976 5 243 185 1.23 18.946 0 59 1 37 14,694 4.257 190 0 76 9,28, 0 58 0 36 4 068 5.213 100 1.21 19,073 0 58 1 37 15.033 4,040 195 0 75 9.341 0 58 0 36 4.160 5.182 105 1 19 19,198 0 56 1 31 15.373 15,712 3.825 200 0 74 0.400 0 58 0 35 4 251 5,149 200 1 18 19,319 0 58 1 31 3_607 3,387 205 0 72 9,458 0 58 0 35 4.343 5,115 205 r 1.14 19A38 0 58 1 30 16,051 210 0 71 9,515 0 58 0 35 4.435 5,080 210 1 12 19.554 0 58 1 30 16.390 3,164 7.938 215 0 70 9.570 0 57 0 35 4.527 5,043 215 1 10 19958 0 57 1 30 18,730 220 0 69 0,624 9,677 9.730 0 57 0 35 4,619 5 006 220 1.08 19,779 0 57 1 20 17,069 7.710 225 0 67 0 57 0 35 4,710 4,967 225 1.06 10 888 19,995 0 57 1 20 17.408 .2 .480 230 068 0 57 0 35 4.002 49'27 230 1.05 .� 0 57 1 29 17,747 2248 235 0 65 9.781 0 57 0 35 4.894 4,887 235 - 1 03 20,100 0 57 1 28 128 16.097 18.426 2.014 740 0 64 9,831 9,880 9.928 0 57 0 35 4,968 4,845 240 1 01 20,203 0 57 1,777 245 0 63 0 56 0 35 5,078 1602 245 1 00 20,305 0 56 1.18 16,765 1.539 250 0 62 056 0 34 5,169 4,759 250 0 96 20,404 0 56 127 19.104 1,300 255 0 61 9.976 056 0 34 5.261 5353 4,715 255 0 97 20,502 20,598 20.692 056 1 27 19,444 19,783 20,122 20,461 1,058 815 240 0 60 10,023 056 0 34 4,670 260 _ 0 95 _ 056 1 27 265 0 59 0 59 10.068 10.114 0 56 056 0 34 0 34 5,445 5.537 4,674 4.577 265 270 0 94 0 56 0 56 1 27 1 28 570 323 270 0 93 _ 20,785 20.876 275 0 58 10,158 0 58 0 34 5,828 4.530 275 0 91 _ 056 1.26 20.801 75 280 0 57 10.202 10,245 10.787 056 0 34 5.720 4,482 4,433 4,363 4,333 280 0 90 20,966 0 56 126 21.140 21,479 21.818 22.158 22.497 -174 285 0 56 056 0 55 0 34 5,812 5 904 285 290 0 89 0 88 0 87 21,054 21.142 056 126 .425 .671 290 0 56 0 34 0 55 125 295 0 55 10,329 10,370 0 55 0 34 5.996 295 21,227 055 1 25 -930 - 300 .-- 0 54 0 55 0 34 6.087 4,263 300 - 0 86 21,312 21.395 0 55 1 25 •1.185 305 0 53 10.411 0 55 0 34 6,179 4,232 305 0 85 0 55 115 22.830 .1 441 Mod. FAA Minor Storage Volume (cubic ti.) a 5,452 Mad. FAA Major Storage Volume (cubic ft.) _ Mod. FAA Minor Storage Volume (scre•11.) a 0.1252 Mod FAA Major Storage Volume (acre-ff.) = UDFCD DETENTION VOLUME ESTIMATING WORKBOOK Version 2 03a, Released March 2008 7,595 0.1744 UD-Detention v2 03e, Modified FAA 5(7/2013. 1 17 PI,' DETENTION VOLUME BY THE MODIFIED FAA METHOD (See USDCM Volume 2 Storage Chapter for description of method) Project: Basin ID: I KMG 16-24i SWD C-2 •••••• ••••• • • ••••••• 00UQ0Q0p0000000,00 ••• • • 00000 •• OOOOOOOOOO6O UDFCD DETENTION VOLUME ESTIMATING WORKBOOK Version 2 03a. Released March 2008 UD.Detenbon_v2 03e, Abdmed FAA 5/717013. t 17 PM 5/7/2013, 1:20 PM STAGE -DISCHARGE SIZING OF THE WATER QUALITY CAPTURE VOLUME (WQCV) OUTLET 16-241 SWD N U 5 2 Time to Orain the Pond = O 0 Diameter of holes, D = 8 or Number of holes per row, N = ed er O 0 DODD O 0 O 0 0 0 0000 0000 0000 10000 0 O O O 0 0 0 0 0000 0000 0 G u N N to 0 a E E U M co co O POW < = = z U g t <e22/ 0 1t di 0 d a m (”4132) g s z p3 N V 2.1" co If G 0 > 0 U 5 0.20 watershed inches N N t to Na O NNOOr O O O O • m 41 C C C o • oz., 3 J (N ^ 11 • > 76 CC • U 0 0 r,• 8 8t33 z > N 22 en i 3 3 ooee • ii,tt . 3 i `° • Qtile k;co c c 2 mss. O O t 5B-6 10 2 2 O O 3 F r 5E g R a 3 m ct 0 Calculation of Collection Capacity: w dnii dddddedoddddddddd000ta a s Central Elevations of Rows of Holes in toot Row 1 Row 2 Row 3 Row 4 RowS Row 6 Row? Row 8 Row 9 Row 10 Row 11 Row 12 Row 13 Row 14 Row 15 Row 16 Row 17 Row 18 a i 0 g ct W V o i o L _ 0 000000000000 !� i t ii 0 0 0 8 8 8 0 0 0 _ 0 009 j O 0 O doOdoo O O O O O Z Z ik Z i�i� a w ii iR it t ik R i i R ii M n Ik 1.00 ! 1 33 888Soo��n- O O O O o o O O o0 8 O OO^ o C 0 O C'jf^`v 0 fl' d d fl o f.g4<< O o 4 4 g iek I *NIA R «g$1g<aagZaaaZgZgaaa a t iM ik t t i M i! t �i �Ti ik M i! zZ ii a ik RQ55�� 2525 O o O ogoy�" o00r$ o o 0 o o 0 §§00000000ozz-zzz 0 0 o, 0 0 o o 0 0 0 <<<4< a ft men. <<<<<<C<<<<<<<<<<< 3z27Zkkz ii N R M B it c N 0 N 0 r 0 O N 8 n N N N cn N n N O c^ o; l'J t7 n M 8 'Q N Y 8 O n V 8 N Deter v2 03a, WQCV a rn ri 0 N ui STAGE -DISCHARGE SIZING OF THE WATER QUALITY CAPTURE VOLUME (WQCV) OUTLET KMG 16-241 SWD N U l STAGE -DISCHARGE CURVE FOR THE WQCV OUTLET STRUCTURE • 8 0 0 O 8 u� O (ri ro N N (•AeIe `teal) a6e;S 0 u-) r- 8 0 0 to 0 a 8 O M O O N 0 O N O O 1 O O O O O O O Discharge (cfs) • l RESTRICTOR PLATE SIZING FOR CIRCULAR VERTICAL ORIFICES I Project: Basin ID: KMG 16-24i SWD C-2 X Sizing the Restrictor Plate for Circular Vertical Orifices or Pipes (Input) Water Surface Elevation at Design Depth PipeNertical Orifice Entrance Invert Elevation Required Peak Flow through Orifice at Design Depth PipeNertical Orifice Diameter (inches) Orifice Coefficient Full -flow Capacity (Calculated) Full -flow area Half Central Angle in Radians Full -flow capacity Calculation of Orifice Flow Condition Half Central Angle (0<Theta<3 1416) Flow area Top width of Orifice (inches) Height from Invert of Orifice to Bottom of Plate (feet) Elevation of Bottom of Plate Resultant Peak Flow Through Orifice at Design Depth Width of Equivalent Rectangular Vertical Orifice Centroid Elevation of Equivalent Rectangular Vertical Orifice E0 Elev: WS = Elev: Invert = 0= Dia = Co _ Af = Theta = Qf = Percent of Design Flow = Theta = To= '0= Elev Plate Bottom Edge = Q„= #1 Vertical Orifice #2 Vertical Orifice 4.939.50 4.938.10 0.61 12.0 0.60 0.79 3.14 3.6 587% 0.93 0.11 9.60 020 4,938.30 0.8 Equivalent Width a 0.55 quiv. Centroid El. = 4,938.2 feet feet cfs inches sq ft tad cfs red sq ft Inches feet feet cfs feet feet UD-Detention_v2.03a, Restrictor Plate 5/7/2013, 1:21 PM KMG 16-24i SWD Facility WQCV Required Volume (Acre -ft) Modified FAA Required Volume (Acre -ft) 0.05 0.17 Stage Storage Table Elevation (ft) Area (ft) Volume (fts) Cumulative Volume (ft3) Cumulative Volume (Acre -ft) 4938.1 0.0 4938.3 1350.4 135.0 135.0 0.00 4938.5 1481.0 283.1 418.2 0.01 4938.7 1611.7 309.3 727.5 0.02 4938.9 1742.4 335.4 1062.9 0.02 4939.1 1873.1 361.5 1424.4 0.03 4939.3 2003.8 387.7 1812.1 0.04 4939.5 2134.4 413.8 2225.9 0.05 4939.7 2265.1 440.0 2665.9 0.06 4939.9 2395.8 466.1 3132.0 0.07 4940.1 2570.0 496.6 3628.5 0.08 4940.3 2700.7 527.1 4155.6 0.10 4940.5 2875.0 557.6 4713.2 0.11 4940.7 3049.2 592.4 5305.6 0.12 4940.9 3179.9 622.9 5928.5 0.14 4941.1 3354.1 653.4 6581.9 0.15 4941.3 3528.4 688.2 7270.2 0.17 4941.5 3702.6 723.1 7993.3 0.18 4941.7 3876.8 757.9 8751.2 0.20 4941.9 4094.6 797.1 9548.4 0.22 4942.1 4268.9 836.4 10384.7 0.24 4942.3 4443.1 871.2 11255.9 0.26 4942.5 4660.9 910.4 12166.3 0.28 4942.7 4878.7 954.0 13120.3 0.30 4942.9 5140.1 1001.9 14122.2 0.32 4943.1 5227.2 1036.7_ 15158.9 0.35 < WQCV < 10-yr < 100-yr <----- Broad Crested Weir (Elev. 4942.6') Jll'DNI1lf1SNO, 609011.9*LO( auugd IORZR lulawutM 'uvfN1i4S 1+n1S 1'fV'II"N 551% 371110 NVUIUIHS I (tr9Lt•OL6 aun4d RfSOB upuulu7'Pugaeal 10% •1!RSIlwxnd 5f91 331110 UNV'13A01 OM/11010D 'AIN 1103 a13M Wd H19 'MS92! 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