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HomeMy WebLinkAboutSCHOOLSIDE PARK - BDR240009 - SUBMITTAL DOCUMENTS - ROUND 3 - Drainage Related Document FINAL DRAINAGE REPORT FOR SCHOOLSIDE PARK AT 5830 S TIMBERLINE RD FORT COLLINS, CO 80528 PREPARED FOR THE CITY OF FORT COLLINS Fort Collins, CO 80523 OCTOBER 21, 2024 October 21, 2024 Derek Lutz City of Fort Collins Utilities – Stormwater Engineering 700 Wood Street Fort Collins, CO 80521 RE: Schoolside Park –Drainage Report JVA Job No. 240729.CIV Dear Derek: The following Final Drainage Report and attached drainage maps have been prepared for the Schoolside Park redevelopment project. The reports and drainage maps have been produced in accordance with the City of Fort Collins. It is our understanding that the information provided herein meets all requirements of the City of Fort Collins. Please contact us if you have any questions regarding this submission. Sincerely, JVA, Inc. __________________________ Morgan Clements Project Engineer Schoolside Park Drainage Report Page 1 of 8 TABLE OF CONTENTS GENERAL LOCATION AND EXISTING SITE INFORMATION ......................................................... 3 DRAINAGE BASINS AND HISTORIC RUNOFF .......................................................................... 3 HISTORIC DRAINAGE ..................................................................................................... 3 PROPOSED DRAINAGE .................................................................................................. 4 DRAINAGE DESIGN CRITERIA ............................................................................................ 5 HYDROLOGIC METHOD AND DESIGN STORM FREQUENCIES ................................................. 5 HYDRAULIC CRITERIA .................................................................................................... 6 VARIANCES FROM THE CRITERIA......................................................................................... 6 DRAINAGE FACILITY DESIGN ............................................................................................. 7 GENERAL CONCEPT ..................................................................................................... 7 STORMWATER POLLUTION PREVENTION/EROSION CONTROL .................................................. 7 TEMPORARY EROSION CONTROL .................................................................................... 7 PERMANENT EROSION CONTROL .................................................................................... 7 CONCLUSIONS................................................................................................................ 8 REFERENCES ................................................................................................................... 8 Appendix A – Referenced Information 1. Vicinity Map 2. Excerpts From “Drainage and Erosion Control Report for Bacon Elementary School” 3. FEMA FIRM Map 4. NRCS Websoil Survey Appendix B – Hydrologic/Hydraulic Computations 1. Rational Method Calculations 2. Detention Calculations 3. Pipe and Inlet Sizing Calculations 4. LID Calculations 5. Outlet Structure Calculations 6. Rain Garden Calculations 7. Emergency Overflow Calculations Appendix C – Drainage Maps 1. Exhibit 1: Existing Drainage Plan 2. Exhibit 2: Proposed Drainage Plan Schoolside Park Drainage Report Page 2 of 8 ENGINEER’S STATEMENT: “I hereby attest that this report for the final drainage design for Schoolside Park was prepared by me or under my direct supervision, in accordance with the provisions of the City of Fort Collins Stormwater Criteria Manual. I understand that the City of Fort Collins does not and will not assume liability for drainage facilities designed by others.” ______________________________ Cody F Gratny, P.E. Registered Professional Engineer State of Colorado No. 45353 Schoolside Park Drainage Report Page 3 of 8 GENERAL LOCATION AND EXISTING SITE INFORMATION Schoolside Park (site) adjacent to Bacon Elementary School and is located in Section 8, Township 6 North, Range 68 West of the 6th Principal Meridian, in Larimer County, Fort Collins, Colorado. The property address is 5830 S Timberline Road. Refer to Appendix A for the site vicinity map. The site is bordered to the north and east by Mail Creek Ditch, to the west by S Timberline Road, and to the south by Bacon Elementary School. Developed residential areas are to the north, south and east of the site. The property is owned by the City of Fort Collins and is comprised of parcel number 8608253901. The approximate GPS coordinates for the site are 40.504933°N, -105.038809°W. The property is located in the Fossil Creek Basin. The subject property will tie into the existing storm infrastructure at the adjacent Bacon Elementary School property and drainage has been designed referencing the Timberline Site Final Drainage and Erosion Control Report dated May 28, 2002. The site is approximately 5.30 acres of partially developed and partially undeveloped property. A residential building on the northern portion of the site is to be demolished, and along the northeast property line a multi-use trail has been constructed adjacent to the Mail Creek Ditch. The property has an existing percent imperviousness of 9.6%. The existing ground surface slopes to the southeast at grades ranging from 0.5 to 3.0%, with the north portion of the property sloping more sharply to the north at 20 to 30%. From the Geotechnical Investigation dated April 10, 2024 the soil on the site is mainly sandy clay. Groudnwater was measured at a range of 13 to 18 feet below grade. The geotechnical report is attached in Appendix A. The site is located in the Area of Minimal Flood Hazard, Zone X, per FEMA Flood Risk Map number 08069C1000F, effective date 12/19/2006. The site is comprised of hydrologic soil group C/D per NRCS soil survey. The FEMA Flood Map and NRCS Websoil Survey are included in Appendix A. In general, the proposed redevelopment of the site consists of constructing a restroom structure, a shade structure, a parking lot, pedestrian pathways, a multipurpose turf field, playground areas, a basketball court, a detention pond and grass buffers. Grass buffers will be located adjacent to the multipurpose turf field. The site development will increase the overall percent imperviousness by 13.6% to a total of 20.9%. Tthe majority of stormwater runoff is conveyed via surface flow to the detention pond in the southwest corner of the property. The detention pond outlets to the existing storm infrastructure that is part of the Bacon Elementary School site. DRAINAGE BASINS AND HISTORIC RUNOFF HISTORIC DRAINAGE The existing site consists of three historical onsite basins H1, O1, and O2. H1 is the majority of the site and flows to the southwest and onto the Bacon Elementary property. O1 is the north portion that consists of multi-use path that drains north to the Mail Creek Ditch. O2 is the east portion that Schoolside Park Drainage Report Page 4 of 8 consists of multi-use path that drains east to Mail Creek Ditch. See Exhibit 1 Existing Drainage Plan in Appendix A. There are no offsite basins that flow onto the site. There is no existing onsite detention for the site. Table 1: Historic Peak Flow Basin Design Point Area (Acres) 2-yr Runoff (CFS) 100-yr Runoff (CFS) H1 1 3.89 2.75 11.92 O1 2 0.92 1.05 4.31 O2 3 0.49 0.50 2.02 Per the Final Drainage and Erosion Control Report for Bacon Elementary School, future development allowable release rate to the storm system in Bacon Elementary School is 2.00 CFS. This is conveyed to the Bacon Elementary School detention pond on the east side of the site and releases to storm infrastructure within Zephyr Road. PROPOSED DRAINAGE Proposed drainage patterns are to remain generally the same as current, but will utilize landscape areas, inlets and grass buffers to capture the majority of runoff before discharging into the Bacon Elementary storm system and eventually into the public storm system. The site is designed to meet the City’s low impact development (LID) requirements of treating 75% of the sites modified or added impervious area being treated through a rain garden and multiple grass buffers. Detention will be provided onsite and released to the Bacon Elementary School storm system at 2.00 CFS as outlined in the previous Drainage and Erosion Control Report for Bacon Elementary School. The connection to the line is proposed to an inlet further upstream of where the report calls out for the connection. Adequate capacity was confirmed for the affected upstream pipes. See excerpts from “Drainage and Erosion Control Report for Bacon Elementary School” in Appendix A”. The proposed site consists of four onsite basins A1, A2, A3, A4, A5, A6, O1, O2 and O3. Basin A1 contains the majority of the added impervious area, and surface flows to the proposed rain garden, then to the detention pond in the southwest portion of the site. Basin A2 is collected by a swale/grass buffer and conveyed via storm drain to the detention pond. Basin A3 is the majority of the play field in the middle of the property, which surface flows to an area inlet/grass buffer and is conveyed via storm drain to the detention pond. Basin A4 is the detention pond and rain garden area. Basin A5 is collected by a swale/grass buffer and conveyed via storm drain to the detention pond, with the playground area being collected by an underdrain which also connects to the storm drain. Basin A6 is a smaller portion of the play field that surface flows to the detention pond. Basins B1-B4 are basins adjacent to the multi-use path to the north that contain underdrains and drywells to avoid nuisance flooding across the path, which would ultimately spill to the ditch to the north in the event that the drywells overtop. The Basin O1 surface flows to the north to Mail Schoolside Park Drainage Report Page 5 of 8 Creek Ditch, following existing drainage patterns. Basin O2 surface flows to the east to Mail Creek Ditch, also following existing drainage patterns. Basin O3 is a small portion of the proposed drive that surface flows offsite and is picked up by an existing storm inlet in Timberline Rd, which is connected to the storm line for the Bacon Elementary School to the south. There are no offsite basins that contribute to the site. See Figure 2 Proposed Drainage Plan in Appendix A. Table 2: Developed Peak Flow Basin Design Point Area (Acres) 2-yr Runoff (CFS) 100-yr Runoff (CFS) A1 4 0.97 1.43 5.51 A2 5 0.38 0.32 1.39 A3 6 0.51 0.39 1.66 A4 7 0.82 0.66 2.80 A5 8 0.28 0.28 1.15 A6 9 0.12 0.08 0.36 B1 10 0.05 0.05 0.22 B2 11 0.06 0.06 0.25 B3 12 0.10 0.10 0.44 B4 13 0.17 0.13 0.58 O1 14 1.43 1.35 5.66 O2 15 0.40 0.44 1.77 O3 16 0.02 0.03 0.11 DRAINAGE DESIGN CRITERIA HYDROLOGIC METHOD AND DESIGN STORM FREQUENCIES The drainage for the site was designed to meet or exceed the City of Fort Collin’s Standards and Specifications. The design one hour point rainfall used for the 2 year and 100 year storm events are 0.82 inches and 2.86 inches respectively. The Rational Method (Q=CIA) was used to determine the storm runoff (Q) from the areas contributing to the new storm system, with composite runoff coefficients (C) and contributing areas (A) given for design points in sub-basins. The runoff coefficients for various land usages Schoolside Park Drainage Report Page 6 of 8 were obtained from Table 3.2-2, and the Frequency Adjustment Factor, Cf, per Table 3.2-3 were applied from Chapter 5 of the Fort Collins Storm Criteria Manual. Intensities (I) were determined using the Time-Intensity-Frequency equations, and a calculated Time of Concentration (tc). See Appendix B for the runoff coefficient calculations. HYDRAULIC CRITERIA The proposed drainage facility has been designed to comply with the City of Fort Collins Stormwater Criteria Manual, and provides both detention and water quality. The required detention volume has been calculated to be 0.321 acre-feet using the Modified FAA Method, per Fort Collins requirements. The water quality capture volume (WQCV) portion of the detention pond is calculated to be 0.033 acre-feet for a 40-hour drain time, using the Extended Detention Basin (EDB) Design Procedure Form from MHFD. Additionally, as part of the LID requirements, a rain garden has been included upstream of the detention pond. This volume was calculated using the Rain Garden Design Procedure form from MHFD. A summary table of the detention facility volumes are provided below: Table 3: Detention and Water Quality Basin Summary Table Parameter Required Detention Volume (cu-ac) Detention Pond Water Surface Elevation (feet) Rain Garden 0.014 4957.57 WQCV – Detention Pond 0.033 4955.50 100yr – Detention Pond 0.321 4956.60 Pipes and inlets have been designed to convey the 100-year storm event from their respective basins to the detention basin. The overflow weir for the rain garden has been sized to convey the 100-year storm of Basin A1. The emergency overflow weir for the extended detention basin has been sized to convey the 100-year storm for all tributary basins at a low velocity in order to minimize effects of runoff downstream in the event that the overflow weir is used. Complete drainage plans, details, dimensions, etc. are included in the grading and drainage plans in the site’s construction documents. VARIANCES FROM THE CRITERIA No variances are requested for this design. Schoolside Park Drainage Report Page 7 of 8 DRAINAGE FACILITY DESIGN GENERAL CONCEPT The site’s private storm drainage system has been designed to convey the 100-year storm event through inlets and pipes that connect into the proposed detention pond. The site was graded to surface flow or capture runoff into the storm system, and direct it to the proposed detention pond in the southwest portion of the site. The site was graded to minimize the amount of flow being directed to the adjacent roads. The proposed rain garden will treat the flow from Basin A1 before it spills to the detention pond. There are grass buffers in Basins A2, A3, A5 and A6 that also provide water treatment. These two methods treat more than the minimum of 75% of the modified or added impervious area on the site for water quality prior to discharge into the public storm system, satisfying the City of Fort Collins LID requirements. These features facilitate sedimentation and filtration while limiting erosion, providing both treatment and slowed release of the water quality capture volume. The detention pond additionally treats water quality within the outlet structure. The proposed redevelopment of this site will serve to limit water quality and quantity impacts to natural drainageways by decreasing the frequency, rate, duration, and volume of runoff. The site has been designed to minimize directly connected impervious areas by grading the site such that stormwater runoff sheet flows from paved areas through landscaped areas to grass buffers to be treated prior to entering the proposed and existing storm systems. STORMWATER POLLUTION PREVENTION/EROSION CONTROL During construction, temporary erosion and sediment control practices will be used to limit soil erosion and sediment discharge off the site. TEMPORARY EROSION CONTROL A temporary erosion control plan is to be implemented for the site during construction. Temporary erosion control measures include, but are not limited to, slope and swale protection provided using erosion control wattles/sediment control logs, rock socks, etc. All temporary erosion control measures are to be removed after they are deemed unnecessary. A general erosion control plan has been provided in the civil construction documents and attached. PERMANENT EROSION CONTROL Chapter 2 of the MHFD’s Urban Storm Drainage Criteria Manual Volume 3 (USDCM) provides guidelines for the selection of appropriate permanent structural BMPs for a site that is to be developed or redeveloped. The Schoolside Park is best characterized as a “conventional redevelopment” with under 5 acres of impervious area on the project site. The BMP decision tree for such sites is provided in Figure 2-2 of the USDCM. As previously stated, the site and surrounding vicinity is comprised of hydrologic soil group Type C/D soils, per the NRCS soil survey. The water quality for this site is treated in both the design of the rain garden and in the water quality portion of the Extended Detention Basin. Runoff will be treated in the proposed rain garden or in grass buffers before spilling to the detention pond, where the outlet structure detains the Schoolside Park Drainage Report Page 8 of 8 Water Quality Capture Volume (WQCV) and releases it over 40 hours. Downstream, the outlet connects to the existing Bacon Elementary School storm system, where water is detained in the existing Bacon Elementary detention pond, and then released to the public storm system in Zephyr Road. CONCLUSIONS This Drainage Report for the Schoolside Park has been prepared to comply with the stormwater criteria set by the City of Fort Collins. The proposed drainage system presented in this report is designed to convey the 100-year peak stormwater runoff through the site via the proposed storm system. Through calculations, modeling, and review of the proposed storm drain system, there appears to be adequate capacity to convey the proposed flows. It can therefore be concluded that development of the Schoolside Park complies with all of the stormwater jurisdictional criteria and will not adversely affect the existing streets, storm drain system and/or detention/water quality facilities. REFERENCES 1. City of Fort Collins Stormwater Criteria Manual, City of Fort Collins, December 2018. 2. “Final Drainage and Erosion Control Report”, Nolte Associates, Inc, Dated May 28, 2002. 3. “Geotechnical Investigation Bacon Park Improvements”, CTL Thompson Incorporated, Dated April 10, 2024. 4. “Urban Storm Drainage Criteria Manual”, Mile High Flood District, August 2018 version. APPENDIX A – REFERENCED INFORMATION Schoolside Park 5830 S Timberline Road Fort Collins, CO MAP NOT TO SCALE (Image from Google Earth) Subject Property Au1111 7 17- 1 M/ ) I> TL I cn ( ) T Il 0 m O m m M w o m m M m m M M m M m O^ n m 0 0 0 M N N m m W m m 0^ t0 V M N N O 6m V V M th M O m m t0 m m m m m m 1 V m m 10 m m m m m m m m V 09 m 0) 0) m 0) m 0) m ON 0) m 0) rn 0) 0) 0) 0) m 0) 0) S J a v v v v v c= c} v a v v v v c c v v v c E O) m C 0 M m 0 O co SO O O N O O O O O O m MD c V n m m^ N N t0 ( V M V V n V ^ M M M m - 0 c 9^ n V V V V M M— n f W n f m N m m V V V M m y m m m m m m m m m m m m m m m m m V c O> v O) O) m O) O) 0) O) O 0) 1O ) O) m O) m ( m ( m O) 0) 0) O) ( 3) 0 WOn M N ( D O N 0) O V 2 o M ( O M O V 0) m 0 O m co D m m V M M N V M M O m m m m m m m m n m m m m m m m m m m m m m 0) 0) 0) 0) O 0) ( 7) 0) , 0) 0) m 0) 0) O) ( 3) 0) m 0) 0) 0) c v a v v v c r vi a c v v a v v v c v v v E c 0) 0) m C) O M 0 _ • ) O I m O O N n 0 N O m O O m D 0 c= o C n to m^ O N m M M^ M n h C^ M ch t0 V V V V M m m co V N n m N to N V M y O> bt u m m m m m m m 0) m, 0) O) 0) 0) O O) O) 0) 0) m m m c v c a v v v v c v v v v v v v v v v v v v m m M m n N c _ 7 ' O O M N 0N V N n V V d 3 N m V O N 7 m 0 m m N m M V m N m m V M M N N N N N N I^ ^ O n N^ 00 N m V m m F% a= t ^ ^ - ' N N N m f n N m V M m N M Vi n n ( O m N n O N O m m 0 W N O n 1^ ^ O m M 6 ( O M ( O V m M i a U N N M M M M M M N N ^ N N N U M O O N M CO m 00 . m ^ . 0 m M N V m N n^ O 0 O` m V m m m m ' - t' ) m r V M m N M ( D N M m V m m E m m M M n n n ( Di M ( D to M m m m m 0 m m N n m O m m co N i m CO V^ OO m m m 7 N Cl ^ m^ 0 m j0 ^ „ M N 1 O O CO 0) m' m M M O CO m m 00 Co N n ( O m tO m m m V V V( m m m m V V V V V yWa > > V V V m m m m m m m c, m1 m m m m m m m m m m m m m v v o v v v v c vv v a v c v v v v c v v m LL l m m m o co m O n V V N m CO NV n CO 0 ( O m m . - . aC CO t O O m NC D m V V m ( O n m M m 0 0 00 O O O O m O m m 0) m N m m 0) O O O O O m O` O co m m V m V c V l n 00 N V V M m m m O V M n O O O O O O O O M O O M 0 0 0 O O O O O O O O O O OR 0 0 0 0 0 0 0 0 0 0 0 0 C O O O O O C C Oj 6 C C O C O O C ci C O C E` c rn MU ' ) mc l ) M ; rn v v o n a o vo rM uM ( O W CD C Cc 0 0 0 0 0 0 6 6 61 0 O O O O O O O O O O O m i c1 6 m LN U LN U LM U LM U LU LU Lc Lc LU LU L U LU LU LU L— U L. 0L. 0U L. pN CC C C c c C C• U U C C C c c cC C C C fm 0 ul • u V V O O O O O O' m N Go N ML U M N M M( OD m^ N— N NN M M L N m O O m N 0 © Oi m O M N M 0, - m O O N 0 O N N O N O^ M N m m m m V n n m N O N O c v m N N M O O N . - N M N co V 00 ( 0 M f 0) C r V M n m m m M 0 O1 O N n O O O V V N t0 m J N MI N N O! 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Q L R TN r NPDAL :Sn H e JI I ALLOWABLE RELEASE RATE PROPOSED CONNECTION POINT ADEQUATE PIPE CAPACITY CONFIRMED FOR PIPES CONNECTING HIGHLIGHTED INLETS EXERPT FROM "DRAINAGE AND EROSION CONTROL REPORT FOR BACON ELEMENTARY SCHOOL" National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250 Feet Ü SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone A, V, A99 With BFE or DepthZone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mileZone X Future Conditions 1% Annual Chance Flood HazardZone X Area with Reduced Flood Risk due to Levee. See Notes.Zone X Area with Flood Risk due to LeveeZone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood HazardZone D Channel, Culvert, or Storm Sewer Levee, Dike, or Floodwall Cross Sections with 1% Annual Chance 17.5 Water Surface Elevation Coastal Transect Coastal Transect Baseline Profile Baseline Hydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of Study Jurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 6/10/2024 at 4:12 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. Legend OTHER AREAS OF FLOOD HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 8 B 20.2 The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. 1:6,000 105°2'37"W 40°30'29"N 105°2'W 40°30'2"N Basemap Imagery Source: USGS National Map 2023 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 April 23, 2024 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................8 Soil Map................................................................................................................9 Legend................................................................................................................10 Map Unit Legend................................................................................................11 Map Unit Descriptions.........................................................................................11 Larimer County Area, Colorado......................................................................13 74—Nunn clay loam, 1 to 3 percent slopes.................................................13 References............................................................................................................15 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and Custom Soil Resource Report 6 identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 7 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 44 8 3 6 8 0 44 8 3 7 2 0 44 8 3 7 6 0 44 8 3 8 0 0 44 8 3 8 4 0 44 8 3 8 8 0 44 8 3 9 2 0 44 8 3 9 6 0 44 8 3 6 8 0 44 8 3 7 2 0 44 8 3 7 6 0 44 8 3 8 0 0 44 8 3 8 4 0 44 8 3 8 8 0 44 8 3 9 2 0 44 8 3 9 6 0 496590 496630 496670 496710 496750 496790 496830 496870 496910 496950 496990 497030 496590 496630 496670 496710 496750 496790 496830 496870 496910 496950 496990 497030 40° 30' 23'' N 10 5 ° 2 ' 2 4 ' ' W 40° 30' 23'' N 10 5 ° 2 ' 5 ' ' W 40° 30' 13'' N 10 5 ° 2 ' 2 4 ' ' W 40° 30' 13'' N 10 5 ° 2 ' 5 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 100 200 400 600 Feet 0 30 60 120 180 Meters Map Scale: 1:2,060 if printed on A landscape (11" x 8.5") 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 18, Aug 24, 2023 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 2, 2021—Aug 25, 2021 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 74 Nunn clay loam, 1 to 3 percent slopes 7.3 100.0% Totals for Area of Interest 7.3 100.0% 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 74—Nunn clay loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol: 2tlpl Elevation: 3,900 to 5,840 feet Mean annual precipitation: 13 to 17 inches Mean annual air temperature: 50 to 54 degrees F Frost-free period: 135 to 160 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 9 inches: clay loam Bt - 9 to 13 inches: clay loam Btk - 13 to 25 inches: clay loam Bk1 - 25 to 38 inches: clay loam Bk2 - 38 to 80 inches: clay loam Properties and qualities Slope:1 to 3 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 to very slightly saline (0.1 to 2.0 mmhos/cm) Sodium adsorption ratio, maximum:0.5 Available water supply, 0 to 60 inches: High (about 9.9 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 3e 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 Satanta 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 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 15 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 16 APPENDIX B – HYDROLOGIC/HYDRAULIC COMPUTATIONS JVA Incorporated Job Name: CoFC Schoolside Park I% C2 C5 C10 C100 213 Linden Street, S 200 Job Number: 240729.CIV Streets Paved 100% 0.95 0.95 0.95 1.00 Fort Collins, CO 80524 Date: 10/21/24 Concrete Drives/Walks 100% 0.95 0.95 0.95 1.00 Ph: (970) 225 9099 By: MMC Roof 90% 0.95 0.95 0.95 1.00 Gravel 40% 0.50 0.50 0.50 0.63 Landscaping (B soil) 2% 0.20 0.20 0.25 0.31 CoFC Schoolside Park Landscaping (C/D soil) 2% 0.35 0.35 0.35 0.44 Historic Runoff Coefficient & Time of Concentration Calculations Playground 25% 0.35 0.35 0.35 0.44 Location: Fort_Collins Artificial Turf 0% 0.20 0.20 0.20 0.25 Minor Design Storm: 2 Major Design Storm: 100 Soil Type: C/D Basin Design Data I (%) = 100% 100% 90% 40% 25% 0% 2% 2%I (%)tc Comp tc Final Basin Name Design Point Apaved streets (sf) Adrives/co nc (sf) Aroof (sf) Agravel (sf) NOT USED Aart. turf (sf) Alscape (B soil) (sf) Alscape (C/D soil) (sf) ATotal (sf) ATotal (ac) Imp (%)C2 C5 C10 C100 Upper most Length (ft) Slope (%)ti (min) Length (ft) Slope (%)Type of Land Surface K Velocity (fps) tt (min) Time of Conc ti + tt = tc Total Length (ft) tc=(L/180)+ 10 (min.) Min tc H1 1 0 0 3,359 0 0 0 0 165,977 169,335 3.89 3.7% 0.36 0.36 0.36 0.45 200 0.7%21.6 412 0.4%Short Pasture and lawns 7 0.4 16.0 37.7 612 13.4 13.4 O1 2 0 7,485 0 1,822 0 0 0 30,948 40,255 0.92 21.9% 0.47 0.47 0.47 0.55 100 4.1%7.2 159 5.0%Paved areas & shallow paved swales 20 4.5 0.6 7.8 259 11.4 7.8 O2 3 0 5,319 0 2,565 0 0 0 13,330 21,214 0.49 31.2% 0.52 0.52 0.52 0.60 200 3.5%9.9 360 0.1% Grassed waterway 15 0.6 10.7 20.7 560 13.1 13.1 TotalTOTAL SITE 0 12,804 3,359 4,387 0 0 0 210,255 230,804 5.30 9.4% 0.39 0.39 0.39 0.48 Basin Name Design Point Time of Conc (tc) C2 C5 C10 C100 2 5 10 100 ATotal (sf) ATotal (ac) Q2 Q5 Q10 Q100 H1 1 13.4 0.36 0.36 0.36 0.45 1.96 0.00 3.35 6.84 169,335 3.89 2.75 0.00 4.71 11.92 O1 2 7.8 0.47 0.47 0.47 0.55 2.42 0.00 4.14 8.46 40,255 0.92 1.05 0.00 1.79 4.31 O2 3 13.1 0.52 0.52 0.52 0.60 1.97 0.00 3.38 6.90 21,214 0.49 0.50 0.00 0.85 2.02 TOTAL SITE 230,804 5.30 4.30 0.00 7.36 18.25 Initial Overland Time (ti)Travel Time (tt) tt=Length/(Velocity x 60) tc Urbanized Check ON Runoff Coeff's Rainfall Intensities (in/hr) Area Flow Rates (cfs) Runoff Coeff's JVA Civil Rational Calculations 20241021 Historic Page 1 of 1 JVA Incorporated Job Name: CoFC Schoolside Park I% C2 C5 C10 C100 213 Linden Street, S 200 Job Number: 240729.CIV Streets Paved 100% 0.95 0.95 0.95 1.00 Fort Collins, CO 80524 Date: 10/21/24 Concrete Drives/Walks 100% 0.95 0.95 0.95 1.00 Ph: (970) 225 9099 By: MMC Roof 90% 0.95 0.95 0.95 1.00 Gravel 40% 0.50 0.50 0.50 0.63 Landscaping (B soil) 2% 0.20 0.20 0.25 0.31 CoFC Schoolside Park Landscaping (C/D soil) 2% 0.35 0.35 0.35 0.44 Composite Runoff Coefficient Calculations Playground 25% 0.35 0.35 0.35 0.44 Location: Fort_Collins Artificial Turf 0% 0.20 0.20 0.20 0.25 Minor Design Storm: 2 Major Design Storm: 100 Soil Type: C/D Basin Design Data I (%) = 100% 100% 90% 40% 25% 0% 2% 2%I (%) Basin Name Design Point Apaved streets (sf) Adrives/c onc (sf) Aroof (sf) Agravel (sf) NOT USED NOT USED NOT USED Alscape (C/D soil) (sf) ATotal (sf) ATotal (ac) Imp (%)C2 C5 C10 C100 A1 4 0 20,941 0 0 0 0 0 21,306 42,246 0.97 50.6% 0.65 0.65 0.65 0.72 A2 5 0 130 0 1,771 0 0 0 14,824 16,725 0.38 6.8% 0.37 0.37 0.37 0.46 A3 6 0 782 0 0 0 0 0 21,433 22,215 0.51 5.4% 0.37 0.37 0.37 0.46 A4 7 0 3,522 113 0 0 0 0 31,914 35,549 0.82 12.0% 0.41 0.41 0.41 0.50 A5 8 0 2,435 0 405 0 0 0 9,360 12,200 0.28 22.8% 0.47 0.47 0.47 0.56 A6 9 0 0 0 0 0 0 0 5,033 5,033 0.12 2.0% 0.35 0.35 0.35 0.44 B1 10 0 0 0 0 0 0 0 2,173 2,173 0.05 2.0% 0.35 0.35 0.35 0.44 B2 11 0 0 0 0 0 0 0 2,497 2,497 0.06 2.0% 0.35 0.35 0.35 0.44 B3 12 0 418 0 322 0 0 0 3,419 4,159 0.10 14.8% 0.42 0.42 0.42 0.51 B4 13 0 0 0 375 0 0 0 7,001 7,376 0.17 3.9% 0.36 0.36 0.36 0.45 O1 14 0 7,460 0 1,822 0 0 0 53,008 62,290 1.43 14.8% 0.43 0.43 0.43 0.51 O2 15 0 5,319 0 2,565 0 0 0 9,689 17,573 0.40 37.2% 0.55 0.55 0.55 0.64 O3 16 0 628 0 0 0 0 0 201 829 0.02 76.2% 0.80 0.80 0.80 0.86 Detention A Basins 0 27,810 113 2,176 0 0 0 103,870 133,968 3.08 23.0% 0.48 0.48 0.48 0.56 TotalTOTAL SITE 0 41,635 113 7,260 0 0 0 181,858 230,865 5.30 20.9% 0.46 0.46 0.46 0.55 Runoff Coeff's JVA Civil Rational Calculations 20241021 Basin Data Page 1 of 2 JVA Incorporated Job Name: CoFC Schoolside Park 213 Linden Street, S 200 Job Number: 240729.CIV Fort Collins, CO 80524 Date: 10/21/24 Ph: (970) 225 9099 By: MMC CoFC Schoolside Park Time of Concentration Calculations Location: Fort_Collins Minor Design Storm: 2 Major Design Storm: 100 Soil Type: C/D Sub-Basin Data tc Comp tc Final Basin Name Design Point ATotal (ac)C5 Upper most Length (ft) Slope (%)ti (min) Length (ft)Slope (%) Type of Land Surface Cv Velocity (fps) tt (min) Time of Conc ti + tt = tc Total Length (ft) tc=(L/180) +10 (min) Min tc A1 4 0.97 0.65 157 1.7%8.6 107 2.0%Paved areas & shallow paved swales 20 2.8 0.6 9.3 264 11.5 9.3 A2 5 0.38 0.37 38 4.1%5.1 208 1.2% Short Pasture and lawns 7 0.8 4.6 9.7 308 11.7 9.7 A3 6 0.51 0.37 100 1.5%11.6 92 2.4% Short Pasture and lawns 7 1.1 1.4 13.0 392 12.2 12.2 A4 7 0.82 0.41 52 7.3%4.7 245 0.5% Short Pasture and lawns 7 0.5 8.3 13.0 545 13.0 13.0 A5 8 0.28 0.47 138 2.1%10.5 71 1.0%Paved areas & shallow paved swales 20 2.0 0.6 11.1 371 12.1 11.1 A6 9 0.12 0.35 83 1.5%10.9 59 1.9% Short Pasture and lawns 7 1.0 1.0 11.9 359 12.0 11.9 B1 10 0.05 0.35 10 3.4%2.9 75 1.3% Short Pasture and lawns 7 0.8 1.6 4.5 375 12.1 5.0 B2 11 0.06 0.35 10 3.3%2.9 87 1.3% Short Pasture and lawns 7 0.8 1.8 4.7 387 12.2 5.0 B3 12 0.10 0.42 40 4.6%4.7 90 1.3% Short Pasture and lawns 7 0.8 1.9 6.6 390 12.2 6.6 B4 13 0.17 0.36 51 3.6%6.3 142 0.7% Short Pasture and lawns 7 0.6 4.0 10.3 442 12.5 10.3 O1 14 1.43 0.43 100 3.8%7.9 159 0.8% Grassed waterway 15 1.3 2.0 9.9 459 12.6 9.9 O2 15 0.40 0.55 300 1.3%16.1 260 0.5% Grassed waterway 15 1.0 4.2 20.3 560 13.1 13.1 O3 16 0.02 0.80 300 2.3%7.1 260 0.2% Grassed waterway 15 0.7 6.6 13.7 560 13.1 13.1 Initial Overland Time (ti)Travel Time (tt) tt=Length/(Velocity x 60) tc Urbanized Check ON JVA Civil Rational Calculations 20241021 Basin Data Page 2 of 2 JVA Incorporated Job Name: CoFC Schoolside Park 213 Linden Street, S 200 Job Number: 240729.CIV Fort Collins, CO 80524 Date: 10/21/24 Ph: (970) 225 9099 By: MMC CoFC Schoolside Park Developed Storm Runoff Calculations Design Storm : 100 Year Point Hour Rainfall (P1) : 2.86 B a s i n N a m e D e s i g n P o i n t A r e a ( a c ) R u n o f f C o e f f t c ( m i n ) C * A ( a c ) I ( i n / h r ) Q ( c f s ) T o t a l t c (m i n ) Σ C* A ( a c ) I ( i n / h r ) Q ( c f s ) I n l e t T y p e Q i n t e r c e p t e d Q c a r r y o v e r Q b y p a s s P i p e S i z e ( i n ) or e q u i v a l e n t P i p e M a t e r i a l S l o p e ( % ) P i p e F l o w (c f s ) M a x P i p e Ca p a c i t y ( c f s ) L e n g t h ( f t ) V e l o c i t y ( f p s ) t t ( m i n ) To t a l T i m e (m i n ) N o t e s A1 4 0.97 0.72 9.30 0.69 7.94 5.51 9.30 0.69 7.94 5.51 A2 5 0.38 0.46 9.70 0.18 7.81 1.39 9.70 0.18 7.81 1.39 Small Pipe Headwall 1.39 0.00 0.00 10 in PVC 0.8% 1.4 2.6 76 4.6 0.28 9.98 A5 8 0.28 0.56 11.10 0.16 7.39 1.15 11.10 0.16 7.39 1.15 24" Area Drain 1.15 0.00 0.00 11.10 0.33 7.39 2.46 Pipe A 2.46 0.00 0.00 10 in PVC 0.8% 2.5 2.6 60 4.5 0.22 11.32 A3 6 0.51 0.46 12.20 0.23 7.11 1.66 12.20 0.23 7.11 1.66 24" Area Drain 1.66 0.00 0.00 10 in PVC 2.0% 1.7 4.3 29 6.8 0.07 12.27 A4 7 0.82 0.50 13.00 0.40 6.92 2.80 13.00 0.40 6.92 2.80 2.00 Outfall Pipe 2.00 0.00 0.00 12 in PVC 0.3% 2.0 2.7 97 3.5 0.46 0.46 A6 9 0.12 0.44 11.90 0.05 7.19 0.36 11.90 0.05 7.19 0.36 13.00 1.72 6.92 11.87 All A Basins B1 10 0.05 0.44 5.00 0.02 9.95 0.22 5.00 0.02 9.95 0.22 B2 11 0.06 0.44 5.00 0.03 9.95 0.25 5.00 0.03 9.95 0.25 B3 12 0.10 0.51 6.60 0.05 9.00 0.44 6.60 0.05 9.00 0.44 B4 13 0.17 0.45 10.30 0.08 7.63 0.58 10.30 0.08 7.63 0.58 O1 14 1.43 0.51 9.90 0.73 7.75 5.66 9.90 0.73 7.75 5.66 O2 15 0.40 0.64 13.10 0.26 6.90 1.77 13.10 0.26 6.90 1.77 O3 16 0.02 0.86 13.10 0.02 6.90 0.11 13.10 0.02 6.90 0.11 Pipe/Swale Travel TimeDirect Runoff Total Runoff Inlets Pipe JVA Civil Rational Calculations 20241021 Q100 Page 1 of 1 JVA Incorporated Job Name: CoFC Schoolside Park 213 Linden Street, S 200 Job Number: 240729.CIV Fort Collins, CO 80524 Date: 10/21/24 Ph: (970) 225 9099 By: MMC CoFC Schoolside Park Developed Storm Runoff Calculations Design Storm : 2 Year Point Hour Rainfall (P1) : 0.82 B a s i n N a m e D e s i g n P o i n t A r e a ( a c ) R u n o f f C o e f f t c ( m i n ) C * A ( a c ) I ( i n / h r ) Q ( c f s ) T o t a l t c (m i n ) Σ C* A ( a c ) I ( i n / h r ) Q ( c f s ) I n l e t T y p e Q i n t e r c e p t e d Q c a r r y o v e r Q b y p a s s P i p e S i z e ( i n ) or e q u i v a l e n t P i p e M a t e r i a l S l o p e ( % ) P i p e F l o w (c f s ) M a x P i p e Ca p a c i t y ( c f s ) L e n g t h ( f t ) V e l o c i t y ( f p s ) t t ( m i n ) To t a l T i m e (m i n ) N o t e s A1 4 0.97 0.65 9.30 0.63 2.27 1.43 9.30 0.63 2.27 1.43 A2 5 0.38 0.37 9.70 0.14 2.24 0.32 9.70 0.14 2.24 0.32 Small pipe headwall 0.32 0.00 0.00 10 in PVC 0.8% 0.3 2.6 76 3.1 0.42 10.12 A5 8 0.28 0.47 11.10 0.13 2.12 0.28 11.10 0.13 2.12 0.28 24" Area Drain 0.28 0.00 0.00 11.10 0.90 2.12 1.92 Pipe A 1.92 0.00 0.00 10 in PVC 0.8% 1.9 2.6 60 4.9 0.20 11.30 A3 6 0.51 0.37 12.20 0.19 2.04 0.39 12.20 0.19 2.04 0.39 24" Area Drain 0.39 0.00 0.00 10 in PVC 2.0% 0.4 4.3 29 4.5 0.11 12.31 A4 7 0.82 0.41 13.00 0.34 1.98 0.66 13.00 0.34 1.98 0.66 Outfall Pipe A5 8 0.28 0.47 11.10 0.13 2.12 0.28 11.10 0.13 2.12 0.28 A6 9 0.12 0.35 11.90 0.04 2.06 0.08 11.90 0.04 2.06 0.08 13.00 1.60 1.98 3.17 All A Basins B1 10 0.05 0.35 5.00 0.02 2.85 0.05 5.00 0.02 2.85 0.05 B2 11 0.06 0.35 5.00 0.02 2.85 0.06 5.00 0.02 2.85 0.06 B3 12 0.10 0.42 6.60 0.04 2.58 0.10 6.60 0.04 2.58 0.10 B4 13 0.17 0.36 10.30 0.06 2.19 0.13 10.30 0.06 2.19 0.13 O1 14 1.43 0.43 9.90 0.61 2.22 1.35 9.90 0.61 2.22 1.35 O2 15 0.40 0.55 13.10 0.22 1.97 0.44 13.10 0.22 1.97 0.44 O3 16 0.02 0.80 13.10 0.02 1.97 0.03 13.10 0.02 1.97 0.03 Direct Runoff Total Runoff Inlets Pipe Pipe/Swale Travel Time JVA Civil Rational Calculations 20241021 Qminor Page 1 of 1 JVA Incorporated Job Name: CoFC Schoolside Park 213 Linden Street, S 200 Job Number: 240729.CIV Fort Collins, CO 80524 Date: 10/21/24 Ph: (970) 225 9099 By: MMC FLOW CALCULATIONS - GRATE INLET SUMP CONDITION (Reference: Urban Drainage and Flood Control District Drainage Criteria Manual, 2001, V.1, Section 3.3.6) (Note: Spreadsheet assumes orifice condition for fully developed flow.) INLET TYPE:BASIN: Orifice Equation:Q = Cd*Ao*(2gH)^0.5 K = Clogging Coefficent value for multiple inlets Adjust Ao (open area) due to clogging as follows:N Grate 1 1 Effective Area Opening Ae = (1-C) Ao, where: 2 1.5 C = K * Co / N 3 1.75 N = Number of Inlets 4 1.88 Co = Single Inlet Clogging Factor: 5 1.94 Co(grate) = 0.5 (50% clogging) 6 1.97 7 1.98 8 1.99 Number of inlets:N =1 Inlet Dimensions and Effective Open Area: Grate Opening:Ao(g) =1.6 ft^2 Total Ao(g) = 1.60 ft^2 K = 1.00 C = K*Co/N = 0.50 Ae(g) = (1-C)Ao = 0.80 ft^2 Allowable depth:H =6.0 in = 0.5 ft Constants:g = 32.20 ft/s^2 Cd = 0.67 Flow Calculations: Grate Flow:Q = Cd * Ae(g) * (2g*H)^0.5 Qg= 3.04 CFS Total Intercepted Flow with 1 inlet(s) and an allowable depth of 6 inches is 3.0 cfs Required Flow (Q 2 ) = 0.39 cfs Bypass = 0.0 cfs Required Flow (Q 100 ) = 1.66 cfs Bypass = 0.0 cfs A324" Area Drain JVA Civil Rational Calculations 20241021 A3 - 24" Area Drain Page 1 of 1 JVA Incorporated Job Name: CoFC Schoolside Park 213 Linden Street, S 200 Job Number: 240729.CIV Fort Collins, CO 80524 Date: 10/21/24 Ph: (970) 225 9099 By: MMC FLOW CALCULATIONS - GRATE INLET SUMP CONDITION (Reference: Urban Drainage and Flood Control District Drainage Criteria Manual, 2001, V.1, Section 3.3.6) (Note: Spreadsheet assumes orifice condition for fully developed flow.) INLET TYPE:BASIN: Orifice Equation:Q = Cd*Ao*(2gH)^0.5 K = Clogging Coefficent value for multiple inlets Adjust Ao (open area) due to clogging as follows:N Grate 1 1 Effective Area Opening Ae = (1-C) Ao, where: 2 1.5 C = K * Co / N 3 1.75 N = Number of Inlets 4 1.88 Co = Single Inlet Clogging Factor: 5 1.94 Co(grate) = 0.5 (50% clogging) 6 1.97 7 1.98 8 1.99 Number of inlets:N =1 Inlet Dimensions and Effective Open Area: Grate Opening:Ao(g) =1.6 ft^2 Total Ao(g) = 1.60 ft^2 K = 1.00 C = K*Co/N = 0.50 Ae(g) = (1-C)Ao = 0.80 ft^2 Allowable depth:H =2.0 in = 0.1666667 ft Constants:g = 32.20 ft/s^2 Cd = 0.67 Flow Calculations: Grate Flow:Q = Cd * Ae(g) * (2g*H)^0.5 Qg= 1.76 CFS Total Intercepted Flow with 1 inlet(s) and an allowable depth of 2 inches is 1.8 cfs Required Flow (Q 2 ) = 0.28 cfs Bypass = 0.0 cfs Required Flow (Q 100 ) = 1.15 cfs Bypass = 0.0 cfs 24" Area Drain A5 JVA Civil Rational Calculations 20241021 A5 - 24" Area Drain Page 1 of 1 JVA Incorporated Job Name: CoFC Schoolside Park 213 Linden Street, S 200 Job Number: 240729.CIV Fort Collins, CO 80524 Date: 10/21/24 Ph: (970) 225 9099 By: MMC CoFC Schoolside Park LID AREA Calculations per City of Fort Collins The implementation of LID systems requires one of the following two options: OPTION 2 Acre Total Impervious Area = 0.638 Required Impervious Area Treatment Required =0.479 Provided Impervious Area to RG =0.558 75% of added or modified impervious area Impervious area added Sum Basin A1 Impervious area (Rain garden) and Basin A2, A3, A5 and A6 Impervious areas (grass buffers) Notes JVA Civil Rational Calculations 20241021 LID Area Page 1 of 1 Project: Basin ID: Design Information (Input):Design Information (Input): Catchment Drainage Imperviousness Ia =23.00 percent Catchment Drainage Imperviousness Ia =23.00 percent Catchment Drainage Area A = 3.08 acres Catchment Drainage Area A = 3.080 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 = 12 minutes Time of Concentration of Watershed Tc = 12 minutes Allowable Unit Release Rate q = 0.65 cfs/acre Allowable Unit Release Rate q = 0.65 cfs/acre One-hour Precipitation P1 =0.82 inches One-hour Precipitation P1 =2.86 inches Design Rainfall IDF Formula i = C1* P1/(C2+Tc)^C3 Design Rainfall IDF Formula i = C1* P1/(C2+Tc)^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 = 0.19 Runoff Coefficient C = 0.56 Inflow Peak Runoff Qp-in = 1.22 cfs Inflow Peak Runoff Qp-in = 12.49 cfs Allowable Peak Outflow Rate Qp-out =2.00 cfs Allowable Peak Outflow Rate Qp-out =2.00 cfs Mod. FAA Minor Storage Volume = 0 cubic feet Mod. FAA Major Storage Volume = 13,985 cubic feet Mod. FAA Minor Storage Volume = 0.000 acre-ft Mod. FAA Major Storage Volume = 0.321 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) 0 0.00 0.000 0.00 0.00 0.000 0.000 0 0.00 0.000 0.00 0.00 0.000 0.000 5 2.76 0.011 1.00 2.00 0.014 -0.003 5 9.62 0.114 1.00 2.00 0.014 0.101 10 2.20 0.018 1.00 2.00 0.028 -0.010 10 7.67 0.182 1.00 2.00 0.028 0.155 15 1.84 0.022 0.88 1.77 0.037 -0.014 15 6.43 0.229 0.88 1.77 0.037 0.193 20 1.60 0.026 0.79 1.58 0.043 -0.018 20 5.57 0.265 0.79 1.58 0.043 0.221 25 1.41 0.028 0.73 1.46 0.050 -0.022 25 4.93 0.293 0.73 1.46 0.050 0.243 30 1.27 0.031 0.69 1.38 0.057 -0.026 30 4.44 0.316 0.69 1.38 0.057 0.259 35 1.16 0.033 0.66 1.33 0.064 -0.031 35 4.04 0.336 0.66 1.33 0.064 0.272 40 1.07 0.034 0.64 1.29 0.071 -0.037 40 3.72 0.354 0.64 1.29 0.071 0.283 45 0.99 0.036 0.63 1.26 0.078 -0.042 45 3.45 0.369 0.63 1.26 0.078 0.291 50 0.92 0.037 0.62 1.23 0.085 -0.047 50 3.22 0.383 0.62 1.23 0.085 0.298 55 0.87 0.038 0.60 1.21 0.092 -0.053 55 3.03 0.395 0.60 1.21 0.092 0.304 60 0.82 0.040 0.60 1.19 0.098 -0.059 60 2.85 0.407 0.60 1.19 0.098 0.308 65 0.77 0.041 0.59 1.18 0.105 -0.065 65 2.70 0.417 0.59 1.18 0.105 0.312 70 0.74 0.042 0.58 1.16 0.112 -0.071 70 2.57 0.427 0.58 1.16 0.112 0.315 75 0.70 0.042 0.58 1.15 0.119 -0.077 75 2.45 0.436 0.58 1.15 0.119 0.317 80 0.67 0.043 0.57 1.14 0.126 -0.083 80 2.34 0.445 0.57 1.14 0.126 0.319 85 0.64 0.044 0.57 1.14 0.133 -0.089 85 2.24 0.453 0.57 1.14 0.133 0.320 90 0.62 0.045 0.56 1.13 0.140 -0.095 90 2.15 0.461 0.56 1.13 0.140 0.321 95 0.59 0.046 0.56 1.12 0.147 -0.101 95 2.07 0.468 0.56 1.12 0.147 0.321 100 0.57 0.046 0.56 1.12 0.154 -0.107 100 2.00 0.475 0.56 1.12 0.154 0.321 105 0.55 0.047 0.55 1.11 0.160 -0.114 105 1.93 0.481 0.55 1.11 0.160 0.321 110 0.53 0.047 0.55 1.10 0.167 -0.120 110 1.87 0.487 0.55 1.10 0.167 0.320 115 0.52 0.048 0.55 1.10 0.174 -0.126 115 1.81 0.493 0.55 1.10 0.174 0.319 120 0.50 0.049 0.55 1.10 0.181 -0.133 120 1.75 0.499 0.55 1.10 0.181 0.318 125 0.49 0.049 0.55 1.09 0.188 -0.139 125 1.70 0.505 0.55 1.09 0.188 0.317 130 0.47 0.050 0.54 1.09 0.195 -0.145 130 1.65 0.510 0.54 1.09 0.195 0.315 135 0.46 0.050 0.54 1.09 0.202 -0.152 135 1.61 0.515 0.54 1.09 0.202 0.313 140 0.45 0.051 0.54 1.08 0.209 -0.158 140 1.56 0.520 0.54 1.08 0.209 0.312 145 0.44 0.051 0.54 1.08 0.216 -0.164 145 1.52 0.525 0.54 1.08 0.216 0.309 150 0.43 0.052 0.54 1.08 0.222 -0.171 150 1.49 0.530 0.54 1.08 0.222 0.307 155 0.42 0.052 0.54 1.07 0.229 -0.177 155 1.45 0.534 0.54 1.07 0.229 0.305 160 0.41 0.052 0.54 1.07 0.236 -0.184 160 1.42 0.539 0.54 1.07 0.236 0.302 165 0.40 0.053 0.53 1.07 0.243 -0.190 165 1.39 0.543 0.53 1.07 0.243 0.300 170 0.39 0.053 0.53 1.07 0.250 -0.197 170 1.35 0.547 0.53 1.07 0.250 0.297 175 0.38 0.054 0.53 1.07 0.257 -0.203 175 1.33 0.551 0.53 1.07 0.257 0.294 180 0.37 0.054 0.53 1.06 0.264 -0.210 180 1.30 0.555 0.53 1.06 0.264 0.291 185 0.36 0.054 0.53 1.06 0.271 -0.216 185 1.27 0.559 0.53 1.06 0.271 0.288 190 0.36 0.055 0.53 1.06 0.278 -0.223 190 1.25 0.563 0.53 1.06 0.278 0.285 195 0.35 0.055 0.53 1.06 0.284 -0.229 195 1.22 0.566 0.53 1.06 0.284 0.282 200 0.34 0.055 0.53 1.06 0.291 -0.236 200 1.20 0.570 0.53 1.06 0.291 0.279 205 0.34 0.056 0.53 1.06 0.298 -0.242 205 1.18 0.573 0.53 1.06 0.298 0.275 210 0.33 0.056 0.53 1.05 0.305 -0.249 210 1.16 0.577 0.53 1.05 0.305 0.272 215 0.33 0.056 0.53 1.05 0.312 -0.256 215 1.14 0.580 0.53 1.05 0.312 0.268 220 0.32 0.057 0.53 1.05 0.319 -0.262 220 1.12 0.583 0.53 1.05 0.319 0.265 225 0.31 0.057 0.53 1.05 0.326 -0.269 225 1.10 0.587 0.53 1.05 0.326 0.261 230 0.31 0.057 0.53 1.05 0.333 -0.275 230 1.08 0.590 0.53 1.05 0.333 0.257 235 0.30 0.058 0.52 1.05 0.340 -0.282 235 1.06 0.593 0.52 1.05 0.340 0.253 240 0.30 0.058 0.52 1.05 0.346 -0.288 240 1.05 0.596 0.52 1.05 0.346 0.250 245 0.30 0.058 0.52 1.05 0.353 -0.295 245 1.03 0.599 0.52 1.05 0.353 0.246 250 0.29 0.059 0.52 1.05 0.360 -0.302 250 1.01 0.602 0.52 1.05 0.360 0.242 255 0.29 0.059 0.52 1.05 0.367 -0.308 255 1.00 0.605 0.52 1.05 0.367 0.238 260 0.28 0.059 0.52 1.04 0.374 -0.315 260 0.98 0.608 0.52 1.04 0.374 0.234 265 0.28 0.059 0.52 1.04 0.381 -0.321 265 0.97 0.610 0.52 1.04 0.381 0.230 270 0.27 0.060 0.52 1.04 0.388 -0.328 270 0.96 0.613 0.52 1.04 0.388 0.225 275 0.27 0.060 0.52 1.04 0.395 -0.335 275 0.94 0.616 0.52 1.04 0.395 0.221 280 0.27 0.060 0.52 1.04 0.402 -0.341 280 0.93 0.618 0.52 1.04 0.402 0.217 285 0.26 0.060 0.52 1.04 0.408 -0.348 285 0.92 0.621 0.52 1.04 0.408 0.213 290 0.26 0.061 0.52 1.04 0.415 -0.355 290 0.91 0.624 0.52 1.04 0.415 0.208 295 0.26 0.061 0.52 1.04 0.422 -0.361 295 0.89 0.626 0.52 1.04 0.422 0.204 300 0.25 0.061 0.52 1.04 0.429 -0.368 300 0.88 0.629 0.52 1.04 0.429 0.200 Mod. FAA Minor Storage Volume (cubic ft.) = 0 Mod. FAA Major Storage Volume (cubic ft.) = 13,985 Mod. FAA Minor Storage Volume (acre-ft.) = 0.0000 Mod. FAA Major Storage Volume (acre-ft.) = 0.3211 DETENTION VOLUME BY THE MODIFIED FAA METHOD Schoolside Park A Basin 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 Detention v 2.34 - FAA Method, Modified FAA 10/21/2024, 6:24 PM 100-YR STORAGE REQUIREMENT Project: Basin ID: DETENTION VOLUME BY THE MODIFIED FAA METHOD Schoolside Park A Basin 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 50 100 150 200 250 300 350 Vo l u m e ( a c r e - f e e t ) 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 Detention v 2.34 - FAA Method, Modified FAA 10/21/2024, 6:24 PM Project: Basin ID: Design Information (Input): Width of Basin Bottom, W = ft Right Triangle OR… Length of Basin Bottom, L = ft Isosceles Triangle OR… Dam Side-slope (H:V), Zd =ft/ft Rectangle OR… Circle / Ellipse OR… Irregular (Use Overide values in cells G32:G52) MINOR MAJOR Storage Requirement from Sheet 'Modified FAA': 0.32 acre-ft. Stage-Storage Relationship:Storage Requirement from Sheet 'Hydrograph': acre-ft. Storage Requirement from Sheet 'Full-Spectrum': acre-ft. Labels Water Side Basin Basin Surface Surface Volume Surface Volume Target Volumes for WQCV, Minor, Surface Slope Width at Length at Area at Area at Below Area at Below for WQCV, Minor, & Major Storage Elevation (H:V) Stage Stage Stage Stage Stage Stage Stage & Major Storage Stages ft ft/ft ft ft ft2 ft2 User ft3 acres acre-ft Volumes (input) (input)Below El.(output) (output) (output)Overide (output) (output) (output) (for goal seek) 4954.70 (input)13 0.000 0.000 4954.80 0.00 0.00 23 2 0.001 0.000 4955.00 0.00 0.00 376 42 0.009 0.001 WQCV 4955.50 0.00 0.00 5,470 1,503 0.126 0.035 0.033 4956.00 0.00 0.00 12,110 5,898 0.278 0.135 4956.50 0.00 0.00 16,487 13,047 0.378 0.300 100 -Year Vol. 4956.60 0.00 0.00 17,089 14,726 0.392 0.338 0.321 4957.00 0.00 0.00 18,654 21,875 0.428 0.502 4957.50 0.00 0.00 20,532 31,671 0.471 0.727 4958.00 0.00 0.00 24,868 43,021 0.571 0.988 Emergency Spillway Elev.4958.25 0.00 0.00 26,592 49,454 0.610 1.135 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A STAGE-STORAGE SIZING FOR DETENTION BASINS Schoolside Park Check Basin Shape A Basin Detention v 2.34 - FAA Method, Basin 10/21/2024, 8:10 PM Project: Basin ID: STAGE-STORAGE SIZING FOR DETENTION BASINS 4954.00 4954.50 4955.00 4955.50 4956.00 4956.50 4957.00 4957.50 4958.00 4958.50 4959.00 0.00 0.20 0.40 0.60 0.80 1.00 1.20 St a g e ( f t . e l e v . ) Storage (acre-feet) STAGE-STORAGE CURVE FOR THE POND Detention v 2.34 - FAA Method, Basin 10/21/2024, 8:10 PM Sheet 1 of 3 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia =23.0 % B) Tributary Area's Imperviousness Ratio (i = Ia / 100 )i = 0.230 C) Contributing Watershed Area Area = 3.080 ac D) For Watersheds Outside of the Denver Region, Depth of Average d6 = in Runoff Producing Storm E) Design Concept (Select EURV when also designing for flood control)1 F) Design Volume (WQCV) Based on 40-hour Drain Time VDESIGN=0.033 ac-ft (VDESIGN = (1.0 * (0.91 * i3 - 1.19 * i2 + 0.78 * i) / 12 * Area ) G) For Watersheds Outside of the Denver Region, VDESIGN OTHER= ac-ft Water Quality Capture Volume (WQCV) Design Volume (VWQCV OTHER = (d6*(VDESIGN/0.43)) H) User Input of Water Quality Capture Volume (WQCV) Design Volume VDESIGN USER= ac-ft (Only if a different WQCV Design Volume is desired) Design Procedure Form: Extended Detention Basin (EDB) Schoolside Park JVA October 21, 2024 Morgan Clements UD-BMP (Version 3.07, March 2018) Choose One Excess Urban Runoff Volume (EURV) Water Quality Capture Volume (WQCV) UD-BMP_v3 (version 1), EDB 10/21/2024, 6:27 PM TOTAL WQCV REQUIRED Project: Basin ID: WQCV Design Volume (Input): Catchment Imperviousness, Ia =23.0 percent Catchment Area, A = 3.08 acres Diameter of holes, D = 0.481 inches Depth at WQCV outlet above lowest perforation, H = 1.0 feet Number of holes per row, N = 1 Vertical distance between rows, h = 4.00 inches OR Number of rows, NL = 3 Orifice discharge coefficient, Co =0.60 Height of slot, H = inches Slope of Basin Trickle Channel, S = 0.005 ft / ft Width of slot, W = inches Time to Drain the Pond = 40 hours Watershed Design Information (Input):1 Percent Soil Type A = 0 % Percent Soil Type B = 0 % Percent Soil Type C/D = 100 % 3 Row 1 Row 2 Row 3 Row 4 Row 5 Row 6 Row 7 Row 8 Row 9 Row 10 Row 11 Row 12 Row 13 Row 14 Row 15 Row 16 Row 17 Row 18 Row 19 Row 20 Row 21 Row 22 Row 23 Row 23 Σ 4954.70 4955.03 4955.37 Flow 4954.70 0.0000 0.0000 0.0000 0.00 4955.20 0.0043 0.0025 0.0000 0.01 4955.70 0.0061 0.0050 0.0035 0.01 4956.20 0.0074 0.0066 0.0055 0.02 4956.70 0.0086 0.0078 0.0070 0.02 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A Override Area Row 1 Override Area Row 2 Override Area Row 3 Override Area Row 4 Override Area Row 5 Override Area Row 6 Override Area Row 7 Override Area Row 8 Override Area Row 9 Override Area Row 10 Override Area Row 11 Override Area Row 12 Override Area Row 13 Override Area Row 14 Override Area Row 15 Override Area Row 16 Override Area Row 17 Override Area Row 18 Override Area Row 19 Override Area Row 20 Override Area Row 21 Override Area Row 22 Override Area Row 23 Override Area Row 24 Central Elevations of Rows of Holes in feet Collection Capacity for Each Row of Holes in cfs STAGE-DISCHARGE SIZING OF THE WATER QUALITY CAPTURE VOLUME (WQCV) OUTLET Schoolside Park A Basin Detention v 2.34 - FAA Method, WQCV 10/21/2024, 6:30 PM WQCV PLATE DESIGN Worksheet Protected Project: Basin ID: STAGE-DISCHARGE SIZING OF THE WATER QUALITY CAPTURE VOLUME (WQCV) OUTLET Schoolside Park A Basin 4954.00 4954.50 4955.00 4955.50 4956.00 4956.50 4957.00 4957.50 4958.00 4958.50 4959.00 0.00 0.01 0.01 0.02 0.02 0.03 St a g e ( f e e t , e l e v . ) Discharge (cfs) STAGE-DISCHARGE CURVE FOR THE WQCV OUTLET STRUCTURE Detention v 2.34 - FAA Method, WQCV 10/21/2024, 6:30 PM Project: Basin ID: X 1 #1 Vertical #2 Vertical Sizing the Restrictor Plate for Circular Vertical Orifices or Pipes (Input)Orifice Orifice Water Surface Elevation at Design Depth Elev: WS = 5,956.60 feet Pipe/Vertical Orifice Entrance Invert Elevation Elev: Invert = 5,954.63 feet Required Peak Flow through Orifice at Design Depth Q = 2.00 cfs Pipe/Vertical Orifice Diameter (inches) Dia = 12.0 inches Orifice Coefficient Co =0.60 Full-flow Capacity (Calculated) Full-flow area Af = 0.79 sq ft Half Central Angle in Radians Theta = 3.14 rad Full-flow capacity Qf = 4.6 cfs Percent of Design Flow = 229% Calculation of Orifice Flow Condition Half Central Angle (0<Theta<3.1416) Theta = 1.41 rad Flow area Ao =0.31 sq ft Top width of Orifice (inches)To =11.85 inches Height from Invert of Orifice to Bottom of Plate (f eet)Yo =0.42 feet Elevation of Bottom of Plate Elev Plate Bottom Edge = 5,955.05 feet Resultant Peak Flow Through Orifice at Design Depth Qo =2.0 cfs Width of Equivalent Rectangular Vertical Orifice Equivalent Width = 0.74 feet Schoolside Park A Basin RESTRICTOR PLATE SIZING FOR CIRCULAR VERTICAL ORIFICES Detention v 2.34 - FAA Method, Restrictor Plate 10/21/2024, 4:25 PM RESTRICTOR PLATE CLEARANCE Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia =50.6 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.506 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.17 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 44,001 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =610 cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER =cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum)DWQCV =5 in B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft (Use "0" if rain garden has vertical walls) C) Mimimum Flat Surface Area AMin =445 sq ft D) Actual Flat Surface Area AActual =1563 sq ft E) Area at Design Depth (Top Surface Area)ATop =2049 sq ft F) Rain Garden Total Volume VT=753 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media Design Procedure Form: Rain Garden (RG) Morgan Clements JVA October 21, 2024 CoFC Schoolside Park UD-BMP (Version 3.07, March 2018) Choose One 18" Rain Garden Growing Media Other (Explain): UD-BMP_v3 (version 1), RG 10/21/2024, 6:29 PM RAIN GARDEN WQCV REQUIRED Weir Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Monday, Oct 21 2024 Rain Garden Emergency Spillway Trapezoidal Weir Crest = Sharp Bottom Length (ft) = 65.50 Total Depth (ft) = 0.25 Side Slope (z:1) = 4.00 Calculations Weir Coeff. Cw = 3.10 Compute by: Known Q Known Q (cfs) = 5.51 Highlighted Depth (ft) = 0.10 Q (cfs) = 5.510 Area (sqft) = 6.59 Velocity (ft/s) = 0.84 Top Width (ft) = 66.30 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 Depth (ft)Depth (ft)Rain Garden Emergency Spillway -0.50 -0.50 0.00 0.00 0.50 0.50 1.00 1.00 Length (ft)Weir W.S. Weir Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Monday, Oct 21 2024 Detention Basin Emergency Spillway Trapezoidal Weir Crest = Sharp Bottom Length (ft) = 94.00 Total Depth (ft) = 1.00 Side Slope (z:1) = 4.00 Calculations Weir Coeff. Cw = 3.10 Compute by: Known Q Known Q (cfs) = 11.87 Highlighted Depth (ft) = 0.12 Q (cfs) = 11.87 Area (sqft) = 11.34 Velocity (ft/s) = 1.05 Top Width (ft) = 94.96 0 10 20 30 40 50 60 70 80 90 100 110 120 130 Depth (ft)Depth (ft)Detention Basin Emergency Spillway -0.50 -0.50 0.00 0.00 0.50 0.50 1.00 1.00 1.50 1.50 2.00 2.00 Length (ft)Weir W.S. APPENDIX C – DRAINAGE MAPS 15 ' U T I L I T Y E S M T . T O CI T Y O F F O R T C O L L I N S , RE C . N O . 2 0 0 3 0 0 8 3 3 1 9 20' DRAINAGE ESMT. TO CITY OF FORT COLLINS, REC. NO. 20030083318 EMERG. ACCESS ESMT. TO CITY OF FORT COLLINS, REC. NO. 20030083320 EX I S T I N G D R A I N A G E M A P EX1 RE V I S I O N D E S C R I P T I O N D' W N DE S ' D DA T E NO . DESIGNED BY: DRAWN BY: CHECKED BY: JOB #: DATE: © JVA, INC. CI T Y O F F O R T C O L L I N S SC H O O L S I D E P A R K SHEET NO. 240729.CIV JUNE, 2024 CFG MMC/CMS MEC/MMC JVA, Inc.213 Linden Street, Suite 200 www.jvajva.com Fort Collins, CO 80524 970.225.9099 Boulder ● Fort Collins ● Winter Park Glenwood Springs ● Denver PRE L I M I N A R Y NOT F O R CON S T R U C T I O N 15 ' U T I L I T Y E S M T . T O CI T Y O F F O R T C O L L I N S , RE C . N O . 2 0 0 3 0 0 8 3 3 1 9 20' DRAINAGE ESMT. TO CITY OF FORT COLLINS, REC. NO. 20030083318 EMERG. ACCESS ESMT. TO CITY OF FORT COLLINS, REC. NO. 20030083320 PR O P O S E D D R A I N A G E M A P EX2 RE V I S I O N D E S C R I P T I O N D' W N DE S ' D DA T E NO . DESIGNED BY: DRAWN BY: CHECKED BY: JOB #: DATE: © JVA, INC. CI T Y O F F O R T C O L L I N S SC H O O L S I D E P A R K SHEET NO. 240729.CIV JUNE, 2024 CFG MMC/CMS MEC/MMC JVA, Inc.213 Linden Street, Suite 200 www.jvajva.com Fort Collins, CO 80524 970.225.9099 Boulder ● Fort Collins ● Winter Park Glenwood Springs ● Denver PRE L I M I N A R Y NOT F O R CON S T R U C T I O N