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HomeMy WebLinkAboutSIT AND STAY DOG BAR - PDP210016 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORT 1880 Fall River Drive / Suite 200 / Loveland, CO 80538 O 970.461.7733 / olsson.com September 21, 2021 City of Fort Collins Stormwater Engineering 281 North College Avenue Fort Collins, CO 80522 RE: 1524 N College Ave Dog Day-Care & Bar, PDR210009, Round Number Wes Lamarque: This memo is being submitted as a summary of the stormwater drainage design for the Dog Daycare & Bar located at 1524 N College Ave. The purpose of this memo is to verify the design of the project meets the analysis and intent of the Dry Creek Master Drainage Plan and the “Final Drainage Report for COUNTRY CLUB CORNERS 6th FILING” (Master Report) dated February 4, 2000 by Futura Engineering. A portion of the Master Report are included with this memo. Site Description The site is located at 1524 North College Avenue, Lot 3 of Country Club Corners Six Filing. The project site is approximately 94,269 square feet or 2.16 acres and is currently vacant. The property is bordered by a multi-tenant commercial building to the north, Firehouse car wash and a vacant parcel to the west, and the Health District Family Clinic to the south. The primary access to the proposed development will be from the existing private drive which intersects with College Avenue between Burger King and First National Bank. Secondary points of access would extend from Bristlecone Drive to the south and Willox Ln to the north. Existing ground cover on site consists mostly of short pastured/lawn and native grasses. The proposed improvements for this site include a building with parking and landscaping, potable water and wastewater service connections, and grading and drainage improvements. Generally, the site slopes from southwest to northeast with average slopes of 2% to 4%. Soils within the property classify as Hydrologic Soil Group C according to the Custom Soil Resource Report included with this memo. The property is in Flood Zone X according to FEMA. Drainage Design The conceptual drainage design for the site has been completed in accordance with the City of Fort Collins Stormwater Criteria Manual. Runoff from the building roof will be collected and conveyed in roof drains, and runoff from the parking and landscape areas which can be captured will be conveyed to rain gardens and an underground detention area via storm sewer pipes before being discharged at a rate no greater than the historic 2-year runoff rate of 0.2 cfs/acre. 1880 Fall River Drive / Suite 200 / Loveland, CO 80538 O 970.461.7733 / olsson.com Detention for will be provided by underground Stormtech stormwater tanks located under the southern parking lot and near the northeast corner of the building. A rain garden within the northern landscape area north of the proposed building will provide treatment per LID requirements. Runoff generated on-site will be routed to the detention pond via storm sewer, and runoff from the northern portion of the site will routed into inlets and routed via storm sewer to the rain garden first. In the Dry Creek Basin the two-year historic release rate is 0.2 cfs/acre, therefore the Stormtech underground storage tanks will provide the required 24,518 cf of stormwater runoff, this volume was found using the modified FAA model. The rain gardens were approximately sized using the Colorado Urban Drainage and Flood Control District Stormwater Best Management Practice Design Workbook Rain Garden spreadsheet. The LID bmps will treat 75% of the new impervious areas one site, approximately 5,108 sf of area will be provided within Basin B-1, and approximately 9,183 sf will be provided for a rain garden within basin B-2. Storm Sewer System Design A private storm sewer system is proposed for the site to safely convey stormwater away from the building to the detention pond. Per the Drainage Plan basin B-2 runoff will be captured vis storm sewer and routed to a Stormtech stormwater underground tank system. The runoff generated within basin B-1 will be captured via landscape inlets and roof drains and will be routed via storm sewer to outfall at the proposed rain garden. Water Quality Water quality treatment has been provided in the NECCO pond. Attachments: 1. Vicinity Map 2. Custom Soil Resource Report 3. Impervious Area Calculations 4. Drainage Plan If you have any questions or need additional information, please contact us. Sincerely, Sarah Anderson, EI Ryan Banning, PE Assistant Engineer Technical Leader 1880 Fall River Drive / Suite 200 / Loveland, CO 80538 O 970.461.7733 / olsson.com REPORT CERTIFICATION I hereby certify that this report for the final drainage design of Commercial Lot 1 was prepared by me, or under my direct supervision, in accordance with the provisions of the City of Loveland Storm Drainage Criteria for the owners thereof. Ryan Banning, P.E. State of Colorado No. 44329 © 2021 Microsoft Corporation © 2021 Maxar ©CNES (2021) Distribution Airbus DS © 2021 TomTom PROJECT LOCATION VICINITY MAP SCALE: 1"=500' United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Larimer County Area, ColoradoNatural Resources Conservation Service September 21, 2021 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 8 9 Custom Soil Resource Report Soil Map 4495170449519044952104495230449525044952704495290449531044951704495190449521044952304495250449527044952904495310493700 493720 493740 493760 493780 493800 493700 493720 493740 493760 493780 493800 40° 36' 31'' N 105° 4' 28'' W40° 36' 31'' N105° 4' 23'' W40° 36' 26'' N 105° 4' 28'' W40° 36' 26'' N 105° 4' 23'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 35 70 140 210 Feet 0 10 20 40 60 Meters Map Scale: 1:779 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 15, Jun 9, 2020 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 11, 2018—Aug 12, 2018 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 10 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 73 Nunn clay loam, 0 to 1 percent slopes 2.3 100.0% Totals for Area of Interest 2.3 100.0% Map Unit Descriptions 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, 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. Custom Soil Resource Report 11 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. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one 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. Custom Soil Resource Report 12 Larimer County Area, Colorado 73—Nunn clay loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: 2tlng Elevation: 4,100 to 5,700 feet Mean annual precipitation: 14 to 15 inches Mean annual air temperature: 48 to 52 degrees F Frost-free period: 135 to 152 days Farmland classification: Prime farmland if irrigated Map Unit Composition Nunn and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Nunn Setting Landform:Terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Pleistocene aged alluvium and/or eolian deposits Typical profile Ap - 0 to 6 inches: clay loam Bt1 - 6 to 10 inches: clay loam Bt2 - 10 to 26 inches: clay loam Btk - 26 to 31 inches: clay loam Bk1 - 31 to 47 inches: loam Bk2 - 47 to 80 inches: loam Properties and qualities Slope:0 to 1 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: Medium Capacity 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 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:7 percent Maximum salinity:Nonsaline (0.1 to 1.0 mmhos/cm) Sodium adsorption ratio, maximum:0.5 Available water supply, 0 to 60 inches: High (about 9.1 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: C Ecological site: R067BY042CO - Clayey Plains Hydric soil rating: No Custom Soil Resource Report 13 Minor Components Heldt Percent of map unit:10 percent Landform:Terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Ecological site:R067BY042CO - Clayey Plains Hydric soil rating: No Wages Percent of map unit:5 percent Landform:Terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Ecological site:R067BY002CO - Loamy Plains Hydric soil rating: No Custom Soil Resource Report 14 COMPOSITE PERCENT IMPERVIOUSNESSB-1 NORTH SIDE 0.09 0.03 - 0.20 0.31 0.45 0.56 37.6%B-2 HELD BY TANKS 0.78 0.46 - 0.70 1.94 0.66 0.83 62.4%0 0- - - - - #DIV/0! #DIV/0!TOTAL 2.25 0.63 0.79 59.0%EX-1 Existing Site Conditions 0.280 - - 2.26 2.54 0.24 0.30 12.8%0 0 - - - - - #DIV/0! #DIV/0!TOTAL 2.54 0.24 0.30 12.8%B-1 NORTH SIDE 3741 1320 0 8497 1355837.6%B-2 HELD BY TANKS 33877 20247 0 30285 8440862.4%EX-1 Existing Site Conditions 12,202 0 0 98,521 110,72212.8%LID onlyCOMPOSITE PERCENT IMPERVIOUSNESSA North Area 0.09 0.03 - 0.20 0.31 0.45 1.00 37.6%B South Area 0.78 0.46 - 0.70 1.94 0.66 2.00 62.4%TOTAL 2.25 0.63 1.86 59.0%75% of Imp area = 73,475 SF1.69 acEX-1 Ex Paving Area 0.022 - - 0.32 0.34 0.20 0.25 8.4%TOTAL 0.34 0.20 0.25 8.4%DIFF (SF)A North Area 3,741 1,320 0 8,497 13,55837.6%B South Area 33,877 20,247 0 30,285 84,40862.4%75% of imp area A 3741 132010169510875%-(ROOF+Paveing)33877 2024763306918375%-(ROOF+Paveing)Total Area(SF)Percent ImperviousnessBasin NameBasin DescriptionPaved 100% (SF)Building 90% (SF)Gravel 40% (SF)Landscape 2% (SF)Landscape 2% (acres)Total Area(ac)C2 C100 Percent ImperviousnessTotal Area(ac)C2 C100 Percent ImperviousnessBasin NameBasin DescriptionPaved 100% (acres)Building 90% (acres)Gravel 40% (acres)Basin NameBasin DescriptionPaved 100% (acres)Building 90% (acres)Gravel 40% (acres)Landscape 2% (acres)Percent ImperviousnessBasin NameBasin DescriptionPaved 100% (SF)Building 90% (SF)Gravel 40% (SF)Landscape 2% (SF)Total Area(SF)Percent ImperviousnessBasin NameBasin DescriptionPaved 100% (SF)Building 90% (SF)Gravel / Pavers 40% (SF)Landscape 2% (SF)Total Area(SF)Basin NameBasin DescriptionTotal Area(ac)Total Area(ac)Percent ImperviousnessPaved 100% (acres)Building 90% (acres)Landscape 2% (acres)Gravel 40% (acres)C100C2Percent ImperviousnessC2 C100Basin NameBasin DescriptionPaved 100% (acres)Building 90% (acres)Gravel 40% (acres)Landscape 2% (acres) Project: Basin ID: Design Information (Input):Design Information (Input): Catchment Drainage Imperviousness Ia = 62.40 percent Catchment Drainage Imperviousness Ia = 62.40 percent Catchment Drainage Area A = 1.940 acres Catchment Drainage Area A = 1.940 acres Predevelopment NRCS Soil Group Type = C A, B, C, or D Predevelopment NRCS Soil Group Type = C A, B, C, or D Return Period for Detention Control T = 2 years (2, 5, 10, 25, 50, or 100) Return Period for Detention Control T = 100 years (2, 5, 10, 25, 50, or 100) Time of Concentration of Watershed Tc = 9 minutes Time of Concentration of Watershed Tc = 9 minutes Allowable Unit Release Rate q = 0.200 cfs/acre Allowable Unit Release Rate q = 0.200 cfs/acre One-hour Precipitation P1 = 0.82 inches One-hour Precipitation P1 = 3.67 inches Design Rainfall IDF Formula i = C1* P1/(C2+T c)^C3 Design Rainfall IDF Formula i = C1* P1/(C2+T c)^C3 Coefficient One C1 = 28.50 Coefficient One C1 = 28.50 Coefficient Two C2 = 10 Coefficient Two C2 = 10 Coefficient Three C3 = 0.789 Coefficient Three C3 = 0.789 Determination of Average Outflow from the Basin (Calculated):Determination of Average Outflow from the Basin (Calculated): Runoff Coefficient C = 0.54 Runoff Coefficient C = 0.71 Inflow Peak Runoff Qp-in = 2.39 cfs Inflow Peak Runoff Qp-in = 14.04 cfs Allowable Peak Outflow Rate Qp-out =0.39 cfs Allowable Peak Outflow Rate Qp-out =0.39 cfs Mod. FAA Minor Storage Volume = 2,340 cubic feet Mod. FAA Major Storage Volume = 24,518 cubic feet Mod. FAA Minor Storage Volume = 0.054 acre-ft Mod. FAA Major Storage Volume = 0.563 acre-ft 5 <- Enter Rainfall Duration Incremental Increase Value Here (e.g. 5 for 5-Minutes) Rainfall Rainfall Inflow Adjustment Average Outflow Storage Rainfall Rainfall Inflow Adjustment Average Outflow Storage Duration Intensity Volume Factor Outflow Volume Volume Duration Intensity Volume Factor Outflow Volume Volume minutes inches / hr acre-feet "m" cfs acre-feet acre-feet minutes inches / hr acre-feet "m" cfs acre-feet acre-feet (input)(output) (output) (output) (output) (output) (output) (input) (output) (output) (output) (output) (output) (output) 5 2.76 0.020 1.00 0.39 0.003 0.017 5 12.35 0.117 1.00 0.39 0.003 0.114 10 2.20 0.032 0.96 0.37 0.005 0.027 10 9.84 0.187 0.96 0.37 0.005 0.182 15 1.84 0.040 0.80 0.31 0.006 0.033 15 8.25 0.235 0.80 0.31 0.006 0.228 20 1.60 0.046 0.73 0.28 0.008 0.038 20 7.15 0.271 0.73 0.28 0.008 0.263 25 1.41 0.051 0.68 0.26 0.009 0.042 25 6.33 0.300 0.68 0.26 0.009 0.291 30 1.27 0.055 0.65 0.25 0.010 0.045 30 5.69 0.324 0.65 0.25 0.010 0.314 35 1.16 0.059 0.63 0.24 0.012 0.047 35 5.19 0.345 0.63 0.24 0.012 0.333 40 1.07 0.062 0.61 0.24 0.013 0.048 40 4.78 0.362 0.61 0.24 0.013 0.349 45 0.99 0.064 0.60 0.23 0.014 0.050 45 4.43 0.378 0.60 0.23 0.014 0.364 50 0.92 0.067 0.59 0.23 0.016 0.051 50 4.14 0.392 0.59 0.23 0.016 0.377 55 0.87 0.069 0.58 0.23 0.017 0.052 55 3.88 0.405 0.58 0.23 0.017 0.388 60 0.82 0.071 0.58 0.22 0.018 0.052 60 3.66 0.417 0.58 0.22 0.018 0.398 65 0.77 0.073 0.57 0.22 0.020 0.053 65 3.47 0.428 0.57 0.22 0.020 0.408 70 0.74 0.074 0.57 0.22 0.021 0.053 70 3.30 0.438 0.57 0.22 0.021 0.417 75 0.70 0.076 0.56 0.22 0.022 0.053 75 3.14 0.447 0.56 0.22 0.022 0.425 80 0.67 0.077 0.56 0.22 0.024 0.054 80 3.00 0.456 0.56 0.22 0.024 0.432 85 0.64 0.079 0.55 0.21 0.025 0.054 85 2.88 0.464 0.55 0.21 0.025 0.439 90 0.62 0.080 0.55 0.21 0.026 0.054 90 2.76 0.472 0.55 0.21 0.026 0.445 95 0.59 0.081 0.55 0.21 0.028 0.054 95 2.66 0.479 0.55 0.21 0.028 0.452 100 0.57 0.083 0.55 0.21 0.029 0.053 100 2.56 0.486 0.55 0.21 0.029 0.457 105 0.55 0.084 0.54 0.21 0.030 0.053 105 2.48 0.493 0.54 0.21 0.030 0.463 110 0.53 0.085 0.54 0.21 0.032 0.053 110 2.39 0.500 0.54 0.21 0.032 0.468 115 0.52 0.086 0.54 0.21 0.033 0.053 115 2.32 0.506 0.54 0.21 0.033 0.473 120 0.50 0.087 0.54 0.21 0.035 0.052 120 2.25 0.512 0.54 0.21 0.035 0.477 125 0.49 0.088 0.54 0.21 0.036 0.052 125 2.18 0.517 0.54 0.21 0.036 0.481 130 0.47 0.089 0.54 0.21 0.037 0.052 130 2.12 0.523 0.54 0.21 0.037 0.486 135 0.46 0.090 0.53 0.21 0.039 0.051 135 2.06 0.528 0.53 0.21 0.039 0.490 140 0.45 0.091 0.53 0.21 0.040 0.051 140 2.01 0.533 0.53 0.21 0.040 0.493 145 0.44 0.091 0.53 0.21 0.041 0.050 145 1.96 0.538 0.53 0.21 0.041 0.497 150 0.43 0.092 0.53 0.21 0.043 0.050 150 1.91 0.543 0.53 0.21 0.043 0.500 155 0.42 0.093 0.53 0.21 0.044 0.049 155 1.86 0.547 0.53 0.21 0.044 0.504 160 0.41 0.094 0.53 0.21 0.045 0.049 160 1.82 0.552 0.53 0.21 0.045 0.507 165 0.40 0.095 0.53 0.20 0.047 0.048 165 1.78 0.556 0.53 0.20 0.047 0.510 170 0.39 0.095 0.53 0.20 0.048 0.047 170 1.74 0.561 0.53 0.20 0.048 0.513 175 0.38 0.096 0.53 0.20 0.049 0.047 175 1.70 0.565 0.53 0.20 0.049 0.516 180 0.37 0.097 0.53 0.20 0.051 0.046 180 1.67 0.569 0.53 0.20 0.051 0.518 185 0.36 0.097 0.52 0.20 0.052 0.045 185 1.63 0.573 0.52 0.20 0.052 0.521 190 0.36 0.098 0.52 0.20 0.053 0.045 190 1.60 0.577 0.52 0.20 0.053 0.523 195 0.35 0.099 0.52 0.20 0.055 0.044 195 1.57 0.580 0.52 0.20 0.055 0.526 200 0.34 0.099 0.52 0.20 0.056 0.043 200 1.54 0.584 0.52 0.20 0.056 0.528 205 0.34 0.100 0.52 0.20 0.057 0.043 205 1.51 0.588 0.52 0.20 0.057 0.530 210 0.33 0.100 0.52 0.20 0.059 0.042 210 1.48 0.591 0.52 0.20 0.059 0.533 215 0.33 0.101 0.52 0.20 0.060 0.041 215 1.46 0.595 0.52 0.20 0.060 0.535 220 0.32 0.102 0.52 0.20 0.061 0.040 220 1.43 0.598 0.52 0.20 0.061 0.537 225 0.31 0.102 0.52 0.20 0.063 0.040 225 1.41 0.601 0.52 0.20 0.063 0.539 230 0.31 0.103 0.52 0.20 0.064 0.039 230 1.39 0.604 0.52 0.20 0.064 0.541 235 0.30 0.103 0.52 0.20 0.065 0.038 235 1.36 0.608 0.52 0.20 0.065 0.542 240 0.30 0.104 0.52 0.20 0.067 0.037 240 1.34 0.611 0.52 0.20 0.067 0.544 245 0.30 0.104 0.52 0.20 0.068 0.036 245 1.32 0.614 0.52 0.20 0.068 0.546 250 0.29 0.105 0.52 0.20 0.069 0.036 250 1.30 0.617 0.52 0.20 0.069 0.548 255 0.29 0.105 0.52 0.20 0.071 0.035 255 1.28 0.620 0.52 0.20 0.071 0.549 260 0.28 0.106 0.52 0.20 0.072 0.034 260 1.26 0.623 0.52 0.20 0.072 0.551 265 0.28 0.106 0.52 0.20 0.073 0.033 265 1.24 0.626 0.52 0.20 0.073 0.552 270 0.27 0.107 0.52 0.20 0.075 0.032 270 1.23 0.628 0.52 0.20 0.075 0.554 275 0.27 0.107 0.52 0.20 0.076 0.031 275 1.21 0.631 0.52 0.20 0.076 0.555 280 0.27 0.108 0.52 0.20 0.077 0.030 280 1.19 0.634 0.52 0.20 0.077 0.557 285 0.26 0.108 0.52 0.20 0.079 0.030 285 1.18 0.636 0.52 0.20 0.079 0.558 290 0.26 0.109 0.52 0.20 0.080 0.029 290 1.16 0.639 0.52 0.20 0.080 0.559 295 0.26 0.109 0.52 0.20 0.081 0.028 295 1.15 0.642 0.52 0.20 0.081 0.560 300 0.25 0.109 0.52 0.20 0.083 0.027 300 1.13 0.644 0.52 0.20 0.083 0.562 305 0.25 0.110 0.51 0.20 0.084 0.026 305 1.12 0.647 0.51 0.20 0.084 0.563 Mod. FAA Minor Storage Volume (cubic ft.) = 2,340 Mod. FAA Major Storage Volume (cubic ft.) = 24,518 Mod. FAA Minor Storage Volume (acre-ft.) = 0.0537 Mod. FAA Major Storage Volume (acre-ft.) = 0.5629 DETENTION VOLUME BY THE MODIFIED FAA METHOD Sit and Stay Dog Bar B-2 Determination of MAJOR Detention Volume Using Modified FAA Method (For catchments less than 160 acres only. For larger catchments, use hydrograph routing method) (NOTE: for catchments larger than 90 acres, CUHP hydrograph and routing are recommended) UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released November 2013 Determination of MINOR Detention Volume Using Modified FAA Method 021-04575_Detention v 2.34 - FAA Method.xls, Modified FAA 9/21/2021, 8:34 PM Project: Basin ID: DETENTION VOLUME BY THE MODIFIED FAA METHOD Sit and Stay Dog Bar B-2 UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released November 2013 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 50 100 150 200 250 300 350Volume (acre-feet)Duration (Minutes) Inflow and Outflow Volumes vs. Rainfall Duration Minor Storm Inflow Volume Minor Storm Outflow Volume Minor Storm Storage Volume Major Storm Inflow Volume Major Storm Outflow Volume Major Storm Storage Volume 021-04575_Detention v 2.34 - FAA Method.xls, Modified FAA 9/21/2021, 8:34 PM REVISIONSNO.REV.DATEREVISIONS DESCRIPTIONproject no.: approved by: checked by: drawn by: drawing no.: QA/QC by: date: OLSSON ASSUMES NO RESPONSIBILITY FOR EXISTING UTILITY LOCATIONS (HORIZONTAL OR VERTICAL). THE EXISTING UTILITIES SHOWN ON THIS DRAWING HAVE BEEN PLOTTED FROM THE BEST AVAILABLE INFORMATION. IT IS HOWEVER THE RESPONSIBILITY OF THE CONTRACTOR TO FIELD VERIFY THE LOCATION OF ALL UTILITIES PRIOR TO THE COMMENCEMENT OF ANY CONSTRUCTION ACTIVITIES. NOTE THIS DOCUMENT HAS BEEN RELEASED BY OLSSON ASSOCIATES ONLY FOR REVIEW BY REGULATORY AGENCIES AND OTHER PROFESSIONALS, AND IS SUBJECT TO CHANGE. THIS DOCUMENT IS NOT TO BE USED FOR CONSTRUCTION.www.olsson.comTEL 970.461.7733Suite 200Loveland, CO 805381880 Fall River Drive, UTILITY PLANS FORLOT 3, COUNTRY CLUB CORNERS 6TH FILINGFORT COLLINS, CO2021021-04575 CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. CALL UTILITY NOTIFICATION CENTER OF COLORADO Know what'sbelow. before you dig.Call R 09.21.2021 10SIT AND STAY DOG BARofDRAINAGE PLANSA SA RB RB C_DRN01_02104575.dwg 10 of 10