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HomeMy WebLinkAboutKUM & GO #0951 - FDP230009 - DOCUMENT MARKUPS - ROUND 1 - DRAINAGE REPORT PRELIMINARY DRAINAGE REPORT KUM & GO #0 951 FORT COLLINS , CO 949 E PROSPECT RD Prepared for: Kum & Go, L.C. 1459 Grand Avenue Des Moines, IA 50309 Contact: Dan Garneau (515) 226-0128 Prepared by: Olsson 1880 Fall River Drive, Suite 200 Loveland, CO 80538 Contact: Erica Morton, PE (970) 461-7733 September 21st, 2022 Olsson Project No. 020-2883 December 2018 Fort Collins Utilities Redlines Water, Wastewater & Stormwater Thank you for the opportunity to review the se plans. I encourage you to contact me to discuss questions & revisions prior to resubmittal. dmogen@fcgov.com or 970-305-5989 Reviewed by: Date : Dan Mogen 11/01/2022 Kum & Go #951 September 21, 2022 Project No. 020-2883 S-1 ENGINEER’S STATEMENT This report and plan for the drainage design for Kum & Go #0951 was prepared by me (or under my direct supervision) and is correct to the best of my knowledge and belief. Said report has been prepared in accordance with the City of Fort Collins Storm Drainage Criteria. I understand that the City of Fort Collins does not and will not assume liability for drainage facilities designed by others. I accept responsibility for any liability caused by any negligent acts, errors, or omissions on my part in preparing this report. Erica Morton Colorado Licensed Professional Engineer No. 59328 Kum & Go #951 September 21, 2022 Project No. 020-2883 S-2 TABLE OF CONTENTS 1.0 GENERAL LOCATION AND DESCRIPTION ....................................................................... 1 2.0 DRAINAGE BASIN AND SUB-BASINS ................................................................................ 2 3.0 DRAINAGE BASIN CRITERIA ............................................................................................. 8 4.0 DRAINAGE FACILITY DESIGN ........................................................................................... 9 5.0 CONCLUSION ....................................................................................................................14 6.0 REFERENCES ....................................................................................................................15 APPENDICES APPENDIX A HYDROLOGIC CALCULATIONS APPENDIX B HYDRAULIC CALCULATIONS APPENDIX C REFERENCED INFORMATION Kum & Go #951 September 21, 2022 Project No. 020-2883 1 1.0 GENERAL LOCATION AND DESCRIPTION This document is the Preliminary Drainage Report for Kum & Go #0951 (the “SITE”). The purpose of this report is to identify onsite and offsite drainage patterns, storm sewer, inlet locations, and areas tributary to the site with the goal of safely routing developed storm water runoff to adequate outfall facilities. The proposed project is located within at 949 E Prospect Road, being a portion of the northwest quarter of Section 24, Township 7 North, Range 69 west of the 6th P.M., City of Fort Collins, County of Larimer, State of Colorado. The proposed site is bordered on the north by Prospect Road, on the east by Lemay Avenue, and on the west and south by residential houses. Currently the site consists of a convenience store with two fuel pumps, three single story houses, two garages, a storage shed, and a concrete retaining wall. Development of the site will require demolition of the existing structures, as well as the convenience’s store fuel pumps and concrete retaining wall. The proposed area of improvements is 1.46 acres while the proposed Kum & Go property is to be 0.91 acres. The remainder 0.55 acres is to be for improvements to the adjacent right-of-way along Lemay Avenue and Prospect Road. Based on the NRCS soil survey, the entirety of the soil present on the site is classified as Hydrologic Group C. The site generally slopes away from each of the existing structures. There are curb inlets located adjacent to the property along E Prospect Road and S Lemay Avenue. Changes to the site grading are proposed to ensure proper drainage around the proposed building and parking lot. These changes will include installation of curb, gutter, concrete paving, storm sewer infrastructure, and an underground detention facility. Per FEMA Map Panel 08069C0983H, dated May 2nd, 2012, the majority of the site is within Zone X, Area of Minimal Flood Hazard. The southern property line and western curb and gutter of Lemay Avenue are within Zone AE, with small portions crossing into the subject property. The proposed building and canopy will both be within Zone X. The portions of the property that are located within the FEMA-regulatory, Spring Creek floodplain must conform to the safety regulations of Chapter 10 of City Municipal Code. Development in the floodplain must be preceded by an approved floodplain use permit. For this proposed development, a Floodplain Use Permit will need to be obtained prior to the start of the construction for work within the floodplain. Kum & Go #951 September 21, 2022 Project No. 020-2883 2 2.0 DRAINAGE BASIN AND SUB -B ASINS Existing Basin Description: In the existing condition, the site drains towards the adjacent streets and is collected by curb inlets and underground storm sewer pipes that convey stormwater to the south towards Spring Creek. Using the rational method, runoff generated within the SITE’s proposed property line in the existing condition was calculated to be 1.16 cfs and 4.44 cfs for the 2-year and 100-year storm events, respectively. This area, denoted as Basin EX1, can be seen on the Existing Drainage Basin Map, located within Appendix C of this report. The existing drainage patterns for the land surrounding the property will not be impacted. All drainage from surrounding properties that is currently being routed through the SITE has been accounted for within the design of the SITE’s proposed storm sewer system. Proposed Major Basin Description: The proposed area of improvements has been divided into various major drainage basins based off the proposed drainage patterns. Each of these major basins are used for different analyses of the SITE. Descriptions of each are as follows. The PROPERTY major basin represents the total area within the property line for the SITE. This major basin is utilized to provide a direct comparison to existing EX1 basin, as both represent the total SITE area. The PROPERTY major basin is comprised of basin R-1, R- 2, OS.1, OS.3, OS.4, OS.5 and A through H, excluding E.1, F.1, G.1, and H.1. The CAP major basin represents the area that will be conveyed to and captured by the proposed storm sewer system and underground detention facility, which includes the major of the area within the SITE’s property lines, as well as some of surrounding properties that are currently being routed through the SITE. The CAP major basin has been utilized to properly size the underground detention facility, as it represents the total tributary area to the system. The detained runoff will be released from the underground detention facility at a controlled rate into the adjacent existing sewer infrastructure within S Lemay Avenue. The CAP major basin is comprised of basin R-1, R-2, and A through H, including E.1, F.1, G.1, and H.1. The NO CAP major basin is the remainder of the area within the proposed Kum & Go property that will not be conveyed to or captured by the proposed storm sewer system and underground detention facility. Runoff from this major basin will flow offsite undetained Kum & Go #951 September 21, 2022 Project No. 020-2883 3 and contribute additional runoff to the ROW major drainage basin. The NO CAP major basin is comprised of basins OS.1, OS.3, OS.4, and OS.5. Table 1 below highlights the key parameters of each of the major basins. Table 1. Major Ba sin Characteristics Basin Area (acres) Impervious Area (sq ft) Imperviousness (%) EX1 0.91 10,308 32.47 PROPERTY 0.91 30,024 74.14 DETAINED 0.99 29,554 67.25 UNDETAINED 0.09 783 22.37 By comparing the existing EX1 basin the proposed PROPERTY major basin, we can see that the proposed development of the SITE has will add an additional 19,716 square feet of impervious area. Per the NO CAP basin, only 0.09 acres of total area and 783 square feet of impervious area will not be routed to the underground detention facility. Proposed Sub-Basin Description: The previously mentioned major drainage basins have been further divided into numerous drainage basins. The delineation of each of these basins can be found on the Proposed Drainage Basin Map within Appendix C. Additional descriptions for each of the basins are as follows and are categorized based off of whether they are located within (Onsite) or outside (Offsite) the SITE property line. Onsite Basins: Basin R-1 consists of proposed building roof area. Runoff generated in this basin will be captured by roof drains and be conveyed to the underground detention facility via the proposed storm sewer system. Basin R-2 consists of proposed canopy area. Runoff generated in this basin will be captured by roof drains and be conveyed to the underground detention facility via the proposed storm sewer system. Kum & Go #951 September 21, 2022 Project No. 020-2883 4 Basin A consists of the western portion of the pavement area, proposed building sidewalk, and landscape area along the western side of the building. Runoff generated within this basin will flow southwest to a proposed curb inlet (Inlet I2) in the southwest corner of the site. Stormwater collected in this inlet will drain to the proposed underground detention facility. Basin B (comprised of Basin B.1 and B.2 as it is bisected by Basin R-2) consists of the central portion of the pavement area that will drain southeast to a proposed curb inlet (Inlet A) in the southern curb line. Stormwater collected in this inlet will drain to the proposed underground detention facility. Basin C consists of an eastern portion of the pavement area that will drain southeast to a proposed trench drain located in the access drive along the eastern property line. Stormwater collected by the trench drain will drain to the proposed underground detention facility. Basin D consists of proposed landscape area in the northwestern corner of the site, north of the trash enclosure. Runoff generated in this basin will flow overland in a grass swale before being captured by an area inlet (Inlet P2) and conveyed to the proposed storm sewer system and underground detention facility. Basin E consists of the proposed landscape area along the northeastern building corner. Runoff generated in this basin will flow overland in a grass swale before being captured by an area inlet (Inlet S.1) and conveyed to the proposed storm sewer system and underground detention facility. Basin F consists of proposed building sidewalk and landscape area along the eastern side of the building. Runoff generated in this basin will flow overland in a grass swale before being captured by an area inlet (Inlet O4) and conveyed to the proposed storm sewer system and underground detention facility Basin G consists of proposed landscape area in the western portion of the property. Runoff generated in the basin will flow overland in a grass swale before being captured by an area inlet (Inlet K1) and conveyed to the proposed storm sewer system and underground detention facility. Basin H consists of proposed landscape area in the southwestern corner. Runoff generated in the basin will flow overland in a grass swale before being captured by an area inlet (Inlet I3) and conveyed to the proposed storm sewer system and underground detention facility. Kum & Go #951 September 21, 2022 Project No. 020-2883 5 Basin OS.1 consists of the proposed building sidewalk and landscape area along the northwest side of the building. Runoff generated in the basin will flow offsite undetained to a proposed 5’ Type R inlet (Inlet V) located within basin ROW-1. Basin OS.3 consists of the proposed building sidewalk and landscape area along the southern building corner. Runoff generated in the basin will flow offsite undetained to two existing Type 13 combination inlets located within basin ROW-3. Basin OS.4 consists of the proposed bus stop benches and landscape area adjacent to S Lemay Avenue. Runoff generated in the basin will flow offsite undetained to basin ROW- 4 and make its way to three existing Type 13 combination sump inlets located within the S Lemay Avenue curb line, approximately 200’ to the south of the property. Basin OS.5 consists of the of proposed landscape area in the southern portion of the property. This area, located between the proposed back of curb and property line, contains numerous large trees that will not be impacted through the proposed development of the site. As the grading near the base of the trees will not be impact either, the runoff generated within this basin will match existing drainage patterns and flow offsite undetained to the adjacent property to the south. Offsite Basins: Basin E.1 consists of landscape area behind the proposed Prospect Road sidewalk. This area, which is outside of the SITE’s property line, will be conveyed to Basin E via overland flow. Basin F.1 consists of landscape area behind the proposed sidewalk at the E Prospect Road and S Lemay Avenue intersection. This area, which is outside of the SITE’s property line, will be conveyed to Basin F via overland flow. Basin G.1 consists of landscape area of the adjacent properties to northwest of the SITE that are currently routing runoff through the SITE. This area, which is outside of the SITE’s property line, will be conveyed to Basin G via overland flow. Basin H.1 consists of landscape area of the adjacent properties to west of the SITE that are currently routing runoff through the SITE. This area, which is outside of the SITE’s property line, will be conveyed to Basin H via overland flow. Kum & Go #951 September 21, 2022 Project No. 020-2883 6 The ROW basins represent area within the public right-of-way that will impacted by development of the SITE and will not be conveyed to the underground detention facility. Runoff generated within these basins will follow the existing drainage patterns for both E Prospect Road and S Lemay Avenue. The existing storm sewer infrastructure within both roadways has been either improved upon or analyzed for adequacy. A description of each of the basins can be found in the following section. Basin ROW-1 consists of a large portion of the southern half of E Prospect Road reaching approximately half a mile upstream of the SITE. Runoff generated within this basin will be routed via overland flow and curb and gutter to a proposed 5’ Type R inlet (Inlet V) located within the new proposed curb line of E Prospect Road. This proposed inlet is to serve as a replacement of the existing Type 13 combination inlet that is to be demolished along with the curb and gutter along E Prospect Road. Basin ROW-2 consists primarily of the proposed right turn-lane, with the addition of some area within both E Prospect Road and S Lemay Avenue. Runoff generated within this basin will be routed via overland flow and curb and gutter to a proposed 5’ Type R inlet (Inlet W) located within the new proposed curb line of S Lemay Avenue. This proposed inlet is to serve as a replacement of the existing Type 13 combination inlet that is to be demolished with the curb and gutter along S Lemay Avenue. Basin ROW-3 consists of a portion of the western half of S Lemay Avenue and the proposed adjacent sidewalks. Runoff generated within this basin will be routed via overland flow and curb and gutter to two existing Type 13 combination inlets located within the S Lemay Avenue curb line that is to remain in place through proposed development of the SITE. As ROW-3 represent the total tributary area to these existing inlets, capacity calculations have been performed in order verify their adequacy. These capacity calculations can be found within Appendix B. As the inlets have capacity available for their new tributary area, no adverse effects are to be expected. Basin ROW-4 consists of a portion of the SITE access drive that is not within the proposed Kum & Go property line, in addition to a portion of the western half of S Lemay Avenue and the proposed adjacent sidewalks. Runoff generated within this basin will be routed south via overland flow and curb and gutter to three existing Type 13 combination sump inlets located within the S Lemay Avenue curb line, approximately 200’ to the south of the property. The proposed inlets and pipes located within the SITE have been sized to adequately capture and route the 100-year storm event to the underground detention facility. The inlets and pipes located within the adjacent right-of-way have been analyzed and sized for the 10-year storm event, as the existing regional storm sewer infrastructure would be Kum & Go #951 September 21, 2022 Project No. 020-2883 7 surcharge in any larger storm events. Runoff greater than the 10-year storm event will channelize within the roadway, bypass the inlets, and continue downstream within the curb and gutter. Inlet sizing, calculations, and analyses can be found within Appendix B of this report. A summary of each of the basins and their generated runoff can be seen below in Table 2. The full hydrologic equations and calculations can also be seen in Appendix A of this report. Table 2. Proposed Basin Characteristics Basin Area (acres) Q2 (cfs) Q5 (cfs) Q100 (cfs) R-1 0.095 0.26 0.44 0.95 R-2 0.060 0.16 0.28 0.59 A 0.287 0.76 1.29 2.85 B 0.130 0.35 0.60 1.30 C 0.106 0.29 0.49 1.05 D 0.018 0.01 0.02 0.05 E 0.020 0.01 0.02 0.05 E.1 0.003 0.00 0.00 0.01 F 0.019 0.02 0.03 0.07 F.1 0.001 0.00 0.00 0.00 G 0.027 0.02 0.03 0.07 G.1 0.097 0.07 0.12 0.31 H 0.067 0.04 0.07 0.17 H.1 0.065 0.04 0.06 0.16 OS.1 0.019 0.03 0.05 0.12 OS.3 0.008 0.01 0.02 0.06 OS.4 0.019 0.02 0.04 0.10 OS.5 0.040 0.02 0.04 0.10 ROW-1 1.617 2.54 4.34 9.36 ROW-2 0.156 0.42 0.72 1.55 ROW-3 0.054 0.11 0.19 0.50 ROW-4 0.065 0.13 0.22 0.57 Kum & Go #951 September 21, 2022 Project No. 020-2883 8 3.0 DRAINAGE BASIN CRITERIA Development Criteria Reference and Constraints: The design of the proposed drainage system was completed in accordance with the criteria set forth within the City of Fort Collins Stormwater Criteria Manual (FCSCM). Hydrological Criteria: Hydrologic calculations have been prepared in accordance with criteria set forth within the FCSCM. Hydrologic calculations can be found within Appendix A of this report. Hydraulic Criteria: Hydraulic calculations have been prepared in accordance with the criteria set forth within the FCSCM. Hydraulic calculations can be found within Appendix B of this report. Floodplain Regulations Compliance: Portions of the property are located within the FEMA-regulatory, Spring Creek floodplain and must conform to the safety regulations of Chapter 10 of City Municipal Code. Any development in the floodplain must be preceded by an approved floodplain use permit. For this proposed development, a Floodplain Use Permit will need to be obtained prior to the start of the construction for work within the floodplain. Modifications of Criteria: The proposed development of the SITE will not include the detention and treatment of the stormwater generated within the half of the right-of-way adjacent to the property. The proposed inlets within the right-of-way correlate to an approximate 1.75-acre tributary area, which stretches almost half a mile west up E Prospect Road. This tributary area, denoted as Basin ROW-1 is larger than the SITE itself, and it would not prove feasible or practical to route these flows back onsite for detention and treatment. Kum & Go #951 September 21, 2022 Project No. 020-2883 9 4.0 DRAINAGE FACILITY DESI G N General Concept: In the developed condition, the majority of runoff generated on-site is designed to be collected within the underground detention chambers. Runoff will be conveyed via overland flow and curb and gutter to the storm sewer system. Runoff from the building roof and canopy will be collected and conveyed in roof drains, and runoff from the parking and landscape areas will be conveyed to their respective inlets. 100-year flows entering the storm sewer system will be conveyed to the underground detention system before being discharged at a rate no greater than maximum allowable release rate. Spill Containment: In addition to any standard emergency spill response procedures, COFC requires spill control structures for all new and redeveloping gas stations and vehicle maintenance facilities. Any spills will be contained within the proposed pavement area of the SITE (Basins A, B, and C). As these basins flow to various inlets around the perimeter of the SITE, the spill control structure has been placed at the downstream convergence point of the basins, prior to entering the underground detention facility. The spill control structure is a permanent facility and shall have a minimum capacity of 150 gallons and shall be covered for safety while providing ventilation to allow for evaporation between storms. Groundwater Considerations: Per the geotechnical report for the SITE (Report of Geotechnical Exploration, Kum & Go Store #0951, Olsson, dated June 24, 2021), groundwater was encountered at depths ranging from 7.1 feet to 14.0 feet below the existing grade of the SITE. The proposed underground detention system will only reach approximately 3.5 feet below the existing grade. Kum & Go #951 September 21, 2022 Project No. 020-2883 10 Specific Details: Water Quality – Four Step Process: The FCSCM’s Four Step Process for stormwater quality management was analyzed for the SITE and is addressed as follows: Step 1 – Employ Runoff Reduction Practices During the initial planning phase of the SITE, every effort was made to reduce the total amount of pavement coverage. The majority of the SITE is surrounded by landscaping with runoff draining to private storm inlets and to the underground detention facility. The water quality is improved in the grass and landscaping to provide a better treatment than flowing over hardscape and the runoff volume is reduced as the grass and landscaping reduces the SITE imperviousness. This method ultimately reduces the total volume of runoff and water quality impacts. Step 2 – Implement BMPs That Provide a WQCV with Slow Release Water quality and LID implementation will be provided within the Isolator Row of the proposed underground detention facility for the SITE. The Isolator Row has been adequately sized to withstand the Water Quality Capture Volume (WQCV) for the SITE. The runoff volume leaving the Isolator Row through the system’s filter fabric will create a system which utilized a reduced release rate to provide proper water quality and LID treatment, as well as ensure no adverse effects to downstream storm sewer infrastructure. Step 3 – Stabilize Streams The majority of the SITE flows overland into a private storm s ewer system which will convey the runoff to the underground detention facility through storm pipes, trench drains, roof drains, curb inlets, and landscape inlets. Small grass-lined drainage swales will be utilized to convey small portions of the SITE’s runoff to their appropriate inlets. These drainage swales will be lined with blanket or turf reinforcement mats until its side slopes are fully stabilized with vegetation. The adjacent properties drainage patterns will not be altered from their existing condition, and any area that is currently drainage towards the SITE will be accounted for within the design of the proposed storm sewer infrastructure. Kum & Go #951 September 21, 2022 Project No. 020-2883 11 Step 4 – Implement Site Specific and other Source Control BMPs The SITE has been designed to implement various source control best management practices (BMP’s). The site will have a designated Loading and Unloading Zone for all commercial deliveries. The proposed trash enclosure will provide adequate waste management for the SITE. Both of the forementioned areas, as well as the majority of the remaining pavement area, will be directed toward the proposed spill containment vault. Details of the spill containment vault are included in the previous section. Low Impact Design: COFC requires Low Impact Design (LID) for new projects. Per the previously mentioned Four Step Process, every effort was made to limit directly connected impervious areas and to route stormwater through landscape areas before in enters the proposed storm sewer system. FlexStorm inserts are also to be placed within inlets to provide additional water quality prior to entering the underground detention facility. Additionally, the Isolator Row within the underground detention facility will serve as WQCV treatment and LID for the SITE. The Isolator Row has been sized separately and will drain the WQCV in 12 hours, while allowing the 100-year storm runoff to drain at, or below, its maximum allowable release rate. The following sections provide more inform ation on the design and methodology for the proposed underground detention facility. Minimum Required Storage Volume: Water quality and runoff attenuation for the site will be provided in the underground detention facility. The proposed storm sewer infrastructure has been designed in a manner that maximizes the total amount of the SITE’s generated runoff that is to be routed to the underground detention facility. Approximately 90.6% of the total area within the property line of the SITE will be routed to the underground detention facility. This also equates to approximately 97.4% of the total proposed impervious area within the property line of the SITE. An exhibit detailing the area of the SITE that is to be routed to the underground detention facility can be seen within Appendix C. Kum & Go #951 September 21, 2022 Project No. 020-2883 12 The required WQCV volume for LID Isolator Row was calculated by using criteria set forth within the FCSCM (Chapter 7, Section 5.4, Equations 7-1 & 7-2). The required volume for the 100-Year storm event was completed using by utilizing the COFC Modified FAA Method. The calculations for each of the required volumes are located within Appendix B. Sizing calculations for the StormTech system have been completed separately for the chamber that will be required for the WQCV/LID Isolator Row and for the 100-year storm event. LID sizing calculations have been completed using an COFC methodology, while the 100-year sizing has been completed using the COFC Modified FAA Method. Per these calculations, the underground detention facility will require a minimum of 13 SC-740 chambers for the WQCV/LID Isolator Row and an additional 48 SC-740 chambers for the 100-year storm event. These spreadsheet and calculation can be seen within Appendix B of this report. Table 3 below highlights the key parameters of the underground detention facility. Table 3. Underground Detention Parameters Parameter Required Provided WQCV Volume 912 CF 1262 CF 100-Year Volume 3506 CF 4033 CF Total Volume 4418 CF 5295 CF WQCV Drain Time 12 hours 12 hours 100-Year Drain Time 2.39 cfs 2.07 cfs 100-year release rate?Correct, revised. Kum & Go #951 September 21, 2022 Project No. 020-2883 13 Inlet Structure The inlet structure to the underground detention facility has been designed to route the WQCV into the LID Isolator Row StormTech chambers, while allowing any greater volumes to bypass into the additional chambers provided for the 100-year storm event runoff. The inlet structure will be comprised of a 4’ by 4’ concrete junction box with a rectangular concrete weir located within the box. The height of this weir is to be set at the WQCV water surface elevation. Therefore, any storm events that produce a stage less than the WQCV will be directed to the east and into the LID Isolator Row. Any volumes surpassing the WQCV water surface elevation with overflow the weir, and flow north into the additional chambers. A detail of the inlet structure can be seen within Appendix B. Outlet Structure and Spillway: The outlet structure, located at the downstream end of the underground detention facility, has been designed to release the 100-Year storm volume at, or below, the maximum allowable release rate. Per discussions with the COFC, this maximum allowable release rate has been defined as 100-Year flow from the existing impervious area (2.39 cfs) plus the 2-Year flow the existing pervious area (0.39 cfs) minus any proposed undetained offsite flow (0.38 cfs) for a final value of 2.39 cfs. The maximum allowable release rate calculation is provided in more detail within Appendix B. Per orifice rating curve calculation, a 7” orifice will drain the 100-Year volume at a rate of 2.07 cfs, below the maximum allowable release rate. The orifice rating curve calculation can be seen within Appendix B. The outlet structure will be comprised of a 4-foot diameter concrete manhole with a rectangular concrete weir located within the manhole. The weir will contain an orifice plate covering a cutout at the bottom portion of the weir. To release the 100-Year storm event volume at, or below, the allowable release rate, the orifice plate will contain a 7” diameter orifice with its invert located at the base of stone elevation of the underground detention facility. Emergency overflow is provided by the weir within the manhole, as the top of the weir is set at the 100-year water surface elevation. Runoff exiting the outlet structure will enter the proposed storm sewer infrastructure, which flows east and ties into the existing storm sewer infrastructure within S Lemay Avenue directly to the east of the SITE. A detail of the outlet structure can be seen within Appendix B. Kum & Go #951 September 21, 2022 Project No. 020-2883 14 5.0 CONCLUSION This report and the proposed drainage design for the SITE is compliance with the FCSCM, existing drainage patterns, floodplain regulations, and all other applicable state and federal regulations. The majority of the developed runoff generated onsite will be directed to the underground detention facility located beneath the pavement area. This facility will provide runoff attenuation, WQCV treatment, and LID for the SITE. The outlet structure from the facility will release the 100-Year storm volume at a rate less than the maximum allowable release rate. Any runoff generated within the SITE property boundary that is not directed to the underground facility will flow offsite and match the existing regional drainage patterns. The runoff generated within the right-of-way adjacent o the site will be collected by a combination of proposed and existing inlets. This runoff will not be routed to the proposed underground facility and will instead tie directly into the existing storm sewer infrastructure located within S Lemay Avenue. As this infrastructure is surcharged within the 100-year storm event, the inlet and pipes have been sized and verified for adequacy for the 10-year storm event. The proposed development of the SITE will not create any adverse impacts to the adjacent properties. Any areas located outside of the SITE’s property line that were routed onsite in the existing condition have been accounted for with the proposed storm sewer infrastructure (Basins E.1, F.1, G.1, and H.1). In the existing condition, flows generated in the south portion of 1607 S Lemay Avenue would generally be routed to the adjacent property to the south. This area, comprised of the gravel, lawn, and roof area to the south of the primary existing building, will be reduced to Basin OS.5 in the proposed condition. Basin OS.5, which is comprised solely of the lawn and tree area between the proposed back of curb and property line, will present a smaller and more pervious area being routed the adjacent property to the south. Therefore, overall runoff being routed offsite to the property the south has been reduced by the proposed development of the SITE. This seems to be more appropriate in basin descriptions rather than conclusion. Revised. This has been moved to be after the OS.5 description. Kum & Go #951 September 21, 2022 Project No. 020-2883 15 6.0 R EFERENCES Fort Collins Stormwater Criteria Manual, dated December 2018 Report of Geotechnical Exploration, Kum & Go Store #0951, Olsson, dated June 24, 2021 APPENDIX A HYDROLOGIC CALCULATIONS Kum & Go #951Rational Method CalculationsCity of Fort Collins Equations1880 Fall River Drive, Suite 200Loveland, CO 80538Tel. 970-461-7733 Project Name:Kum & Go #0951Project Number :020-2883Client:Kum & GoBasin Name:KG 951Asphalt, ConcreteRooftop GravelLawns, Clayey, <2%CC*Cf(acres) (acres) (acres) (acres) (acres)2, 5, 10 100 (%)EX1 Existing Site N/A 0.127 0.110 0.151 0.526 0.914 0.44 0.55 32.47%Asphalt, ConcreteRooftop GravelLawns, Clayey, <2%CC*Cf(acres) (acres) (acres) (acres) (acres)2, 5, 10 100 (%)R-1 Building CAP - 0.095 - - 0.095 0.95 1.00 90.00%R-2 Canopy CAP - 0.060 - - 0.060 0.95 1.00 90.00%A Curb Inlet I2 CAP 0.277 - - 0.010 0.287 0.92 1.00 96.70%B Curb Inlet A CAP 0.130 - - - 0.130 0.95 1.00 100.00%C Trench Drain CAP 0.106 - - - 0.106 0.95 1.00 100.00%D Area Inlet P2 CAP - - - 0.018 0.018 0.20 0.25 2.00%E Area Inlet S.1 CAP - - - 0.020 0.020 0.20 0.25 2.00%E.1 Offsite to E CAP - - - 0.003 0.003 0.20 0.25 2.00%F Area Inlet O4 CAP 0.003 - - 0.016 0.019 0.31 0.39 16.75%F.1 Offsite to F CAP - - - 0.001 0.001 0.20 0.25 2.00%G Area Inlet K1 CAP - - - 0.027 0.027 0.20 0.25 2.00%G.1 Offsite to G CAP 0.002 0.005 - 0.090 0.097 0.26 0.32 8.72%H Area Inlet I3 CAP 0.000 - - 0.066 0.067 0.20 0.26 2.54%H.1 Offsite to H CAP - - - 0.065 0.065 0.20 0.25 2.00%OS.1 Onsite to ROW 1 NO CAP 0.008 - - 0.011 0.019 0.52 0.65 43.53%OS.3 Onsite to ROW 3 NO CAP 0.004 - - 0.003 0.008 0.63 0.78 57.90%OS.4 Onsite to ROW 4 NO CAP 0.006 - - 0.014 0.019 0.41 0.52 29.91%OS.5 Onsite to South NO CAP - - - 0.040 0.040 0.20 0.25 2.00%ROW 1 Curb Inlet V N/A 1.611 - - 0.007 1.617 0.95 1.00 99.60%ROW 2 Curb Inlet W N/A 0.155 - - 0.001 0.156 0.95 1.00 99.60%ROW 3 Lemay Northern N/A 0.039 - - 0.016 0.054 0.73 0.92 71.68%ROW 4 Lemay Southern N/A 0.043 - - 0.021 0.065 0.70 0.88 67.69%Asphalt, ConcreteRooftop GravelLawns, Clayey, <2%CC*Cf(acres) (acres) (acres) (acres) (acres)2, 5, 10 100 (%)CAP Captured Area N/A 0.518 0.160 - 0.316 0.995 0.71 0.89 67.25%NO CAP Uncaptured Area N/A 0.018 - - 0.068 0.086 0.36 0.44 22.37%PROPERTY Proposed Site N/A 0.535 0.155 - 0.226 0.915 0.77 0.96 74.14%TOTAL AREABasin DescriptionMajor Basin RoutingSurface TypeTOTAL AREAPercent ImperviousRunoff CoefficientsRunoff CoefficientsPercent ImperviousSurface TypeTOTAL AREABasin Name Basin DescriptionMajor Basin RoutingMajor Basin RoutingBasin DescriptionRATIONAL METHOD CALCULATIONS: COMPOSITE RUNOFF COEFFICIENT & PERCENT IMPERVIOUSRunoff CoefficientsPercent ImperviousBasin NameBasin NameEXISTING BASINSDEVELOPED BASINSMASTER BASINSSurface TypeMWB9/21/2022Prepared By: Date: Project Name:Kum & Go #0951Project Number :020-2883Client:Kum & GoBasin Name:KG 951Tc Final TcC C*CfEquation Equation 5-32, 5, 10 100L(ft)S(ft/ft)Ti (min)L(ft)S(ft/ft)V2(ft/s)Tt(min)Tc (min)LengthTc (min)Tc (min)EX1 Existing Site 0.44 0.55 Yes 20.00 0.020 16.58 2500.00 0.015 Paved Areas 20 2.4 17.01 33.59 2520 24.005.00Tc Final TcC C*CfEquation Equation 5-32, 5, 10 100L(ft)S(ft/ft)Ti (min)L(ft)S(ft/ft)V2(ft/s)Tt(min)Tc (min)LengthTc (min)Tc (min)R-1 Building 0.95 1.00 Yes 20.00 0.020 3.04 2500.00 0.015 Tillage/Field 5 0.6 68.04 71.08 2520 24.005.00R-2 Canopy 0.95 1.00 Yes 20.00 0.020 3.04 2500.00 0.015 Tillage/Field 5 0.6 68.04 71.08 2520 24.005.00A Curb Inlet I2 0.92 1.00 Yes 20.00 0.020 3.04 2500.00 0.015 Tillage/Field 5 0.6 68.04 71.08 2520 24.005.00B Curb Inlet A 0.95 1.00 Yes 20.00 0.020 3.04 2500.00 0.015 Tillage/Field 5 0.6 68.04 71.08 2520 24.005.00C Trench Drain 0.95 1.00 Yes 20.00 0.020 3.04 2500.00 0.015 Tillage/Field 5 0.6 68.04 71.08 2520 24.005.00D Area Inlet P2 0.20 0.25 Yes 20.00 0.020 25.85 2500.00 0.015 Tillage/Field 5 0.6 68.04 93.89 2520 24.005.00E Area Inlet S.1 0.20 0.25 Yes 20.00 0.020 25.85 2500.00 0.015 Tillage/Field 5 0.6 68.04 93.89 2520 24.005.00E.1 Offsite to E 0.20 0.25 Yes 20.00 0.020 25.85 2500.00 0.015 Tillage/Field 5 0.6 68.04 93.89 2520 24.005.00F Area Inlet O4 0.31 0.39 Yes 20.00 0.020 21.56 2500.00 0.015 Tillage/Field 5 0.6 68.04 89.60 2520 24.005.00F.1 Offsite to F 0.20 0.25 Yes 20.00 0.020 25.85 2500.00 0.015 Tillage/Field 5 0.6 68.04 93.89 2520 24.005.00G Area Inlet K1 0.20 0.25 Yes 20.00 0.020 25.85 2500.00 0.015 Tillage/Field 5 0.6 68.04 93.89 2520 24.005.00G.1 Offsite to G 0.26 0.32 Yes 20.00 0.020 23.73 2500.00 0.015 Tillage/Field 5 0.6 68.04 91.77 2520 24.005.00H Area Inlet I3 0.20 0.26 Yes 20.00 0.020 25.69 2500.00 0.015 Tillage/Field 5 0.6 68.04 93.73 2520 24.005.00H.1 Offsite to H 0.20 0.25 Yes 20.00 0.020 25.85 2500.00 0.015 Tillage/Field 5 0.6 68.04 93.89 2520 24.005.00OS.1 Onsite to ROW 1 0.52 0.65 Yes 20.00 0.020 13.77 2500.00 0.015 Tillage/Field 5 0.6 68.04 81.81 2520 24.005.00OS.3 Onsite to ROW 3 0.63 0.78 Yes 20.00 0.020 9.59 2500.00 0.015 Tillage/Field 5 0.6 68.04 77.63 2520 24.005.00OS.4 Onsite to ROW 4 0.41 0.52 Yes 20.00 0.020 17.73 2500.00 0.015 Tillage/Field 5 0.6 68.04 85.77 2520 24.005.00OS.5 Onsite to South 0.20 0.25 Yes 20.00 0.020 25.85 2500.00 0.015 Tillage/Field 5 0.6 68.04 93.89 2520 24.005.00ROW 1 Curb Inlet V 0.95 1.00 No 20.00 0.020 3.04 2500.00 0.015 Paved Areas 20 2.4 17.01 20.05 2520 24.0020.05ROW 2 Curb Inlet W 0.95 1.00 Yes 20.00 0.020 3.04 2500.00 0.015 Tillage/Field 5 0.6 68.04 71.08 2520 24.005.00ROW 3 Lemay Northern 0.73 0.92 Yes 20.00 0.020 5.58 2500.00 0.015 Tillage/Field 5 0.6 68.04 73.62 2520 24.005.00ROW 4 Lemay Southern 0.70 0.88 Yes 20.00 0.020 6.74 2500.00 0.015 Tillage/Field 5 0.6 68.04 74.78 2520 24.005.00Tc Final TcC C*CfEquation Equation 5-32, 5, 10 100L(ft)S(ft/ft)Ti (min)L(ft)S(ft/ft)V2(ft/s)Tt(min)Tc (min)LengthTc (min)Tc (min)CAP Captured Area 0.71 0.890 Yes 20.00 0.020 6.40 2500.00 0.015 Paved Areas 20 2.4 17.01 23.41 2520 24.005.00NO CAP Uncaptured Area 0.36 0.445 Yes 20.00 0.020 19.92 2500.00 0.015 Paved Areas 20 2.4 17.01 36.93 2520 24.005.00PROPERTY Proposed Site 0.77 0.956 Yes 20.00 0.020 4.37 2500.00 0.015 Paved Areas 20 2.4 17.01 21.38 2520 24.005.00(1.49/n)*R^(2/3)(1.49/n)*R^(2/3)DEVELOPED BASINSBasin Name Basin DescriptionBasin CharacteristicsSmall, Urban Basin? Overland FlowChannelized FlowTcRATIONAL METHOD CALCULATIONS: COMPOSITE CALCULATED TIME OF CONCENTRATIONDate: 9/21/2022Prepared By: MWBEXISTING BASINSBasin DescriptionBasin NameBasin CharacteristicsSmall, Urban Basin? Equation 5-4 & 5-5Channelized FlowEquation 3.3-2Overland FlowEquation 3.3-5TcEquation 3.3-5Equation 3.3-2Equation 5-4 & 5-5Equation 3.3-5Basin CharacteristicsSmall, Urban Basin? Overland FlowChannelized FlowTcBasin Name Basin DescriptionMASTER BASINSEquation 3.3-2Equation 5-4 & 5-5(1.49/n)*R^(2/3) Project Name:Kum & Go #0951 Project Number :020-2883 Client:Kum & Go Basin Name:KG 951 Area C C*Cf Tc I2 I10 I100 Q2 Q10 Q100 (acres)2, 5, 10 100 (min) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) EX1 Existing Site 0.914 0.44 0.55 5.0 2.85 4.87 9.95 1.16 1.98 5.05 Area C C*Cf Tc I2 I10 I100 Q2 Q10 Q100 (acres)2, 5, 10 100 (min) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) R-1 Building 0.095 0.95 1.00 5.0 2.85 4.87 9.95 0.26 0.44 0.95 R-2 Canopy 0.060 0.95 1.00 5.0 2.85 4.87 9.95 0.16 0.28 0.59 A Curb Inlet I2 0.287 0.92 1.00 5.0 2.85 4.87 9.95 0.76 1.29 2.85 B Curb Inlet A 0.130 0.95 1.00 5.0 2.85 4.87 9.95 0.35 0.60 1.30 C Trench Drain 0.106 0.95 1.00 5.0 2.85 4.87 9.95 0.29 0.49 1.05 D Area Inlet P2 0.018 0.20 0.25 5.0 2.85 4.87 9.95 0.01 0.02 0.05 E Area Inlet S.1 0.020 0.20 0.25 5.0 2.85 4.87 9.95 0.01 0.02 0.05 E.1 Offsite to E 0.003 0.20 0.25 5.0 2.85 4.87 9.95 0.00 0.00 0.01 F Area Inlet O4 0.019 0.31 0.39 5.0 2.85 4.87 9.95 0.02 0.03 0.07 F.1 Offsite to F 0.001 0.20 0.25 5.0 2.85 4.87 9.95 0.00 0.00 0.00 G Area Inlet K1 0.027 0.20 0.25 5.0 2.85 4.87 9.95 0.02 0.03 0.07 G.1 Offsite to G 0.097 0.26 0.32 5.0 2.85 4.87 9.95 0.07 0.12 0.31 H Area Inlet I3 0.067 0.20 0.26 5.0 2.85 4.87 9.95 0.04 0.07 0.17 H.1 Offsite to H 0.065 0.20 0.25 5.0 2.85 4.87 9.95 0.04 0.06 0.16 OS.1 Onsite to ROW 1 0.019 0.52 0.65 5.0 2.85 4.87 9.95 0.03 0.05 0.12 OS.3 Onsite to ROW 3 0.008 0.63 0.78 5.0 2.85 4.87 9.95 0.01 0.02 0.06 OS.4 Onsite to ROW 4 0.019 0.41 0.52 5.0 2.85 4.87 9.95 0.02 0.04 0.10 OS.5 Onsite to South 0.040 0.20 0.25 5.0 2.85 4.87 9.95 0.02 0.04 0.10 ROW 1 Curb Inlet V 1.617 0.95 1.00 20.1 1.66 2.83 5.79 2.54 4.34 9.36 ROW 2 Curb Inlet W 0.156 0.95 1.00 5.0 2.85 4.87 9.95 0.42 0.72 1.55 ROW 3 Lemay Northern 0.054 0.73 0.92 5.0 2.85 4.87 9.95 0.11 0.19 0.50 ROW 4 Lemay Southern 0.065 0.70 0.88 5.0 2.85 4.87 9.95 0.13 0.22 0.57 Area C C*Cf Tc I2 I10 I100 Q2 Q10 Q100 (acres)2, 5, 10 100 (min) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) CAP Captured Area 0.995 0.71 0.89 5.0 2.85 4.87 9.95 2.02 3.45 8.80 NO CAP Uncaptured Area 0.086 0.36 0.44 5.0 2.85 4.87 9.95 0.09 0.15 0.38 PROPERTY Proposed Site 0.915 0.77 0.96 5.0 2.85 4.87 9.95 1.99 3.41 8.71 Basin Characteristics Intensity Runoff Basin Characteristics Intensity Runoff DEVELOPED BASINS Basin Name Basin Description Basin Name Basin Description Basin Characteristics MASTER BASINS Intensity Runoff Basin Name Basin Description EXISTING BASINS RATIONAL METHOD CALCULATIONS: BASIN RUNOFF CALCULATIONS Date: 9/21/2022 Prepared By: MWB APPENDIX B HYDRAULIC CALCULATIONS 1880 Fall River Drive, Suite 200Loveland, CO 80538Tel. 970-461-7733StormTech Systemfor LID & Underground DetentionAllowable Release Rate:The allowable release rate from the StormTech system has been defined as the following: Release Rate = [100-YR flow of existing impervious area] + [2-YR flow of existing pervious area] - [Proposed 100-YR Undetained Flows]100-YR Existing Impervious Area Flowrate: The existing condition within the proposed property line is defined as basin EX-1EX-1 has 0.24 acres of impervious area (paved and building) with a C100 of 1.00For the assumed 5 minute time of concentration, the 100-YR storm has an intensity of 9.95 in/hrQ=CIA = 1.0 * 0.24 * 9.95 = 2.39 cfsProposed 100-YR Undetained Flowrate: The proposed runoff generated within the property lines that will flow offsite undetained is represented by the OS basins (1 - 5)These basins combine for a 100-YR flowrate of 0.38 cfs2-YR Existing Pervious Area Flowrate:The existing condition within the proposed property line is defined as basin EX-1EX-1 has 0.68 acres of pervious area (gravel and landscaping) with a C2 of 0.20For the assumed 5 minute time of concentration, the 2-YR storm has an intensity of 2.85 in/hrQ=CIA = 0.20 * 0.68 * 2.85 = 0.39 cfsAllowable Release Rate = 2.39cfs + 0.39 cfs - 0.38 cfs = 2.39 cfsKum & Go #951Allowable Release Rate Calculation CAP 2.39 30.0 in 7 inches 0.00 in 0.61 7 in 2.07 cfs 1 0.00 0.00 2 1.25 0.10 3 2.50 0.21 4 3.75 0.31 5 5.00 0.42 6 6.25 0.52 7 7.50 0.63 8 8.75 0.73 9 10.00 0.83 10 11.25 0.94 11 12.50 1.04 12 13.75 1.15 13 15.00 1.25 14 16.25 1.35 15 17.50 1.46 16 18.75 1.56 17 20.00 1.67 18 21.25 1.77 19 22.50 1.88 20 23.75 1.98 21 25.00 2.08 22 26.25 2.19 23 27.50 2.29 24 28.75 2.40 25 30.00 2.50 If the outlet from the detention basin is under free outfall, the effective head is measured from the centroid of the orifice to the upstream water surface elevation. If the downstream jet or orifice is submerged, then the effective head is the difference in elevation between the upstream and downstream water surfaces. 0.73 0.00 0.00 1.46 1.40 1.34 1.64 1.58 1.52 For square-edged, uniform orifice entrance conditions, a discharge coefficient of 0.61 should For rough-edged orifice entrance conditions, a discharge coefficient of 0.4 should be used. 1.84 1.79 1.74 1.69 2.07 2.02 1.98 1.93 1.89 PROPOSED ORIFICE RELEASE RATE : PROPOSED ORIFICE DIAMETER :Max. Allowable Release Rate = Orifice Coefficient = ResultsInput Variables Basin = Detention Depth = Orifice Invert Stage = 1.27 1.19 Client:Kum & Go Basin Name:KG 951 Maximum Orifice Diameter = 1.12 Stage (in ) Stage (ft ) Outlet Release Rate (cfs ) 0.00 1.03 0.94 0.84 Project Number :020-2883 Prepared By: MWB ORIFICE RATING CURVE: OUTLET STRUCTURE ORIFICE SIZING FOR 100-YEAR STORM Project Name:Kum & Go #0951 Date: 9/21/2022 0.211 in A = 0.995 acres V = 0.0209 ac-ft 911.90 cu. ft CAP i = a = DRAIN TIME WQCV = 67.25% CITY OF FORT COLLINS (COFC) CALCULATION FOR: WATER QUALITY CAPTURE VOLUME (WQCV) 12 hr 0.80 Date: Prepared By: Basin Name: Client: Project Number : Project Name: KG 951 Kum & Go 020-2883 Kum & Go #0951 MWB 9/21/2022 MAJOR BASIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Total Required WQ Volume [FCSCM Method] (cf ) Flow WQ (cfs ) Chamber Type Chamber Volume (cf ) Chamber + Aggregate Volume (cf ) Chamber Release Rate (cfs ) Minimum No. of Chambers [FCSCM] Total Release Rate (cfs ) Total Required WQ Volume [FAA Method] (cf ) Minimum No. of Chambers [FAA] Minimum No. of Chambers Total Chamber Volume (cf ) Total Installed System Volume (cf ) KG 951 911.90 1.009 SC-740 45.9 74.9 0.024 13 0.307 319.62 7 13 596.70 973.7 SC-740 MC-4500 MC-3500 SC-310 SC-160LP 30.0 60.0 45.0 16.0 12.0 51.0 100.0 77.0 34.0 25.0 0.350 GPM/SF 85.4 48.3 86.0 85.4 85.4 1 CF = 7.481 GAL 30.2 33.5 46.0 20.2 14.8 1 GALLON = 0.134 CF 45.9 106.5 109.9 14.7 6.9 1 GPM = 0.002 CFS 74.9 162.6 175.0 31.0 15.0 0.024 0.026 0.036 0.016 0.012 5 4 2 CONTENTS: 1 FLOOR AREA (SF) INSTALLED LENGTH (IN) WIDTH (IN) HEIGHT (IN) CHAMBER DIMENSIONS FLOW RATE / CHAMBER (CFS) - ROW 3 CHAMBER/AGGREGATE VOLUME (CF) - ROW 2 CHAMBER VOLUME (CF) - ROW 1 1/2 of the 2-year developed flow rate for the basin. *FLOW RATE BASED ON 1/2 OF NOV 07 QMAX IN FIGURE 17 OF UNH TESTING REPORT FLOW RATE* CHAMBER FLOW RATE CONVERSION (GPM/SF TO CFS) STORMTECH CHAMBER DATA 9 14 13 12 11 10 3 Greater number of required chambers through the two metods (Column 8 versus Column 11) Number of chambers required to provide required FAA storage volume stored within the chamber only (no aggregate storage); Rounded up Required WQCV per FAA Method (based on Flow WQ and Total Release Rate) System volume includes total number of chambers, plus surrounding aggregate. This must meet or exceed the FCSCM Method required WQ Volume Volume provided within the chambers only (no aggregate storage). This must meet or exceed the FAA Method required WQ Volume Required WQCV per FCSCM Equation 7-2 Project Name and/or Vault ID Release rate per chamber times the minimum number of chambers required through the FCSCM Method Number of chambers required to provide full WQCV within total installed system, including aggregate; Rounded Up Release rate per chamber, limited by flow through geotextile with accumulated sediment (Selected Chamber Parameter from ROW 3) Voulme includes chamber and void spaces (40%) in surrounding aggregate (Selected Chamber Parameter from ROW 2) Volume within the chamber only, not accounting for void spaces in surrounding aggregate (Selected Chamber Parameter from ROW 1) Chamber Type Selection 8 7 6 COLUMN: CITY OF FORT COLLINS (COFC) SIZING CALCUALTIONS FOR LID SYSTEMS: ISOLATOR ROW CHAMBERS WITHIN ADS STORMTECH SYSTEM Basin Name:KG 951 Project Name: Kum & Go #0951 Project Number : 020-2883 CHAMBER CONFIGURATION PARAMETERS FCSCM Method FAA METHOD RESULTS Basin Name: Client:Kum & Go Prepared By: MWB Date: 9/21/2022 WQ CAP 0.71 5.00 min 0.995 acres Max Release Rate* =0.307 cfs Time (min ) Time (sec ) Intensity (in/hr ) Inflow Flowrate (cfs ) Inflow Volume (ft 3 ) Outflow Volume (ft 3 ) Storage Volume (ft 3 ) Storage Volume (ac-ft ) 0 0 0.000 0.00 0 0 0 0 5 300 1.425 1.01 303 92 211 0.00 10 600 1.105 0.78 469 184 285 0.01 15 900 0.935 0.66 596 276 320 0.01 20 1200 0.805 0.57 684 368 316 0.01 25 1500 0.715 0.51 759 460 299 0.01 30 1800 0.650 0.46 828 552 276 0.01 35 2100 0.585 0.41 869 644 226 0.01 40 2400 0.535 0.38 909 736 173 0.00 45 2700 0.495 0.35 946 828 118 0.00 50 3000 0.460 0.33 977 920 57 0.00 55 3300 0.435 0.31 1016 1012 4 0.00 60 3600 0.410 0.29 1045 1104 -59 0.00 65 3900 0.385 0.27 1063 1196 -133 0.00 70 4200 0.365 0.26 1085 1288 -203 0.00 75 4500 0.345 0.24 1099 1380 -281 -0.01 80 4800 0.330 0.23 1121 1472 -351 -0.01 85 5100 0.315 0.22 1137 1564 -427 -0.01 90 5400 0.305 0.22 1166 1656 -490 -0.01 95 5700 0.290 0.21 1170 1748 -578 -0.01 100 6000 0.280 0.20 1189 1840 -651 -0.01 105 6300 0.270 0.19 1204 1932 -728 -0.02 110 6600 0.260 0.18 1215 2024 -809 -0.02 115 6900 0.255 0.18 1245 2116 -870 -0.02 120 7200 0.245 0.17 1248 2208 -959 -0.02 Input Variables Design Storm Basin = Results ac-ft0.01 ft3319.62 WQ Volume: Detention Required *DETERMINED BY ISOLATOR ROW PARAMETERS Tc = A = C = Kum & Go #0951 CITY OF FORT COLLINS (COFC) MODIFIED FAA METHOD: REQUIRED DETENTION VOLUME Date: 9/21/2022Project Name: Project Number :020-2883 Client: Basin Name:KG 951 Kum & Go Prepared By: MWB 100-Year CAP 0.89 5.00 min 0.995 acres Max Release Rate* =2.07 cfs Time (min ) Time (sec ) Intensity (in/hr ) Inflow Flowrate (cfs ) Inflow Volume (ft 3 ) Outflow Volume (ft 3 ) Storage Volume (ft 3 ) Storage Volume (ac-ft ) 0 0 0.0 0.00 0 0 0 0 5 300 10.0 8.803 2641 621 2020 0.05 10 600 7.7 6.830 4098 1241 2857 0.07 15 900 6.5 5.768 5191 1862 3330 0.08 20 1200 5.6 4.954 5945 2482 3463 0.08 25 1500 5.0 4.406 6609 3103 3506 0.08 30 1800 4.5 3.999 7198 3723 3474 0.08 35 2100 4.1 3.610 7580 4344 3236 0.07 40 2400 3.7 3.309 7941 4965 2976 0.07 45 2700 3.5 3.061 8265 5585 2680 0.06 50 3000 3.2 2.858 8573 6206 2367 0.05 55 3300 3.0 2.681 8846 6826 2020 0.05 60 3600 2.9 2.530 9109 7447 1662 0.04 65 3900 2.7 2.406 9385 8067 1317 0.03 70 4200 2.6 2.291 9624 8688 936 0.02 75 4500 2.5 2.194 9873 9308 565 0.01 80 4800 2.4 2.106 10107 9929 178 0.00 85 5100 2.3 2.026 10332 10550 -217 0.00 90 5400 2.2 1.955 10558 11170 -612 -0.01 95 5700 2.1 1.884 10741 11791 -1050 -0.02 100 6000 2.1 1.822 10935 12411 -1477 -0.03 105 6300 2.0 1.769 11147 13032 -1885 -0.04 110 6600 1.9 1.716 11328 13652 -2325 -0.05 115 6900 1.9 1.672 11537 14273 -2736 -0.06 120 7200 1.8 1.628 11720 14894 -3173 -0.07 100-Year Input Variables Design Storm Tc = Results Required CITY OF FORT COLLINS (COFC) MODIFIED FAA METHOD: REQUIRED DETENTION VOLUME Project Name:Kum & Go #0951 Date: Client:Kum & Go Basin Name:KG 951 9/21/2022 Project Number :020-2883 Prepared By: MWB *DETERMINED BY ORIFICE PARAMETERS Detention Volume: 3505.81 ft3 0.08 ac-ft A = Basin = C*Cf = Stormwater Facility Name: Facility Location & Jurisdiction: User (Input) Watershed Characteristics User Defined User Defined User Defined User Defined Watershed Slope =0.020 ft/ft Stage [ft] Area [ft^2] Stage [ft] Discharge [cfs] Watershed Length-to-Width Ratio =1.00 L:W 0.00 1,032 0.00 0.00 Watershed Area = 1.00 acres 0.50 1,032 0.50 0.92 Watershed Imperviousness = 67.3%percent 0.58 2,002 0.58 1.00 Percentage Hydrologic Soil Group A = 0.0%percent 0.67 1,998 0.67 1.07 Percentage Hydrologic Soil Group B = 0.0%percent 0.75 1,989 0.75 1.13 Percentage Hydrologic Soil Groups C/D = 100.0%percent 0.83 1,978 0.83 1.19 0.92 1,969 0.92 1.25 1.00 1,957 1.00 1.31 1.08 1,944 1.08 1.36 1.17 1,931 1.17 1.41 User Input: Detention Basin Characteristics 1.25 1,915 1.25 1.46 WQCV Design Drain Time = 12.00 hours 1.33 1,900 1.33 1.51 1.42 1,882 1.42 1.56 1.50 1,864 1.50 1.60 1.58 1,847 1.58 1.64 1.67 1,824 1.67 1.69 1.75 1,802 1.75 1.73 1.83 1,779 1.81 1.77 1.92 1,754 1.92 1.81 2.00 1,727 2.00 1.85 2.08 1,702 2.08 1.89 2.17 1,671 2.17 1.92 2.25 1,628 2.25 1.96 2.33 1,588 2.31 2.00 2.42 1,551 2.42 2.03 2.50 1,504 2.50 2.07 2.58 1,450 2.58 2.10 2.67 1,385 2.67 2.13 2.75 1,298 2.75 2.17 2.83 1,156 2.82 2.20 After completing and printing this worksheet to a pdf, go to:2.92 1,104 2.92 2.23 https://maperture.digitaldataservices.com/gvh/?viewer=cswdif,3.00 1,057 3.00 2.26 create a new stormwater facility, and 3.08 1,032 3.08 2.30 attach the pdf of this worksheet to that record.3.50 1,032 3.50 2.45 Routed Hydrograph Results Design Storm Return Period =WQCV 2 Year 5 Year 10 Year 25 Year 50 Year 100 Year Two-Hour Rainfall Depth =0.53 0.98 1.36 1.71 2.31 2.91 3.67 in Calculated Runoff Volume =0.017 0.053 0.083 0.111 0.162 0.210 0.276 acre-ft OPTIONAL Override Runoff Volume =0.02 0.03 0.00 0.06 0.00 0.00 0.08 acre-ft Inflow Hydrograph Volume =0.020 0.030 #N/A 0.059 #N/A #N/A 0.079 acre-ft Time to Drain 97% of Inflow Volume =1.2 1.2 #N/A 1.3 #N/A #N/A 1.3 hours Time to Drain 99% of Inflow Volume =1.7 1.7 #N/A 1.7 #N/A #N/A 1.7 hours Maximum Ponding Depth =0.21 0.32 #N/A 0.61 #N/A #N/A 0.80 ft Maximum Ponded Area =0.024 0.024 #N/A 0.046 #N/A #N/A 0.046 acres Maximum Volume Stored =0.005 0.008 #N/A 0.016 #N/A #N/A 0.025 acre-ft Stormwater Detention and Infiltration Design Data Sheet Kum & Go #0951 949 E PROSPECT ROAD FORT COLLINS, CO Workbook Protected Worksheet Protected SDI_Design_Data_FC_Rainfall, Design Data 10/11/2022, 2:50 PM Doing_Clear_Formatting =Yes CountA=1 0 1 2 3 #N/A #N/A 0 1 2 3 #N/A #N/A Check Data Set 1 Check Data Set 1 Stormwater Detention and Infiltration Design Data Sheet Area Discharge 0 0.5 1 1.5 2 2.5 0.1 1 10FLOW [cfs]TIME [hr] 100YR IN 100YR OUT 50YR IN 50YR OUT 25YR IN 25YR OUT 10YR IN 10YR OUT 5YR IN 5YR OUT 2YR IN 2YR OUT WQCV IN WQCV OUT 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.1 1 10 100PONDING DEPTH [ft]DRAIN TIME [hr] 100YR 50YR 25YR 10YR 5YR 2YR WQCV SDI_Design_Data_FC_Rainfall, Design Data 10/11/2022, 2:50 PM 1 2 3 4 5 6 7 8 9 100-Year Required Volume (cf ) Chamber Type Chamber Volume (cf ) Chamber + Aggregate Volume (cf ) Chamber Release Rate (cfs ) Minimum No. of Chambers Total Chamber Volume (cf ) Total Installed System Volume (cf ) KG 951 3505.8 SC-740 45.9 74.9 0.024 47 2157.30 3520.3 COLUMN: 1 2 3 4 5 6 7 8 9 SC-740 MC-4500 MC-3500 SC-310 30.0 60.0 45.0 16.0 51.0 100.0 77.0 34.0 85.4 48.3 86.0 85.4 30.2 33.5 46.0 20.2 45.9 106.5 109.9 14.7 74.9 162.6 175.0 31.0 0.024 0.026 0.036 0.016 0.350 GPM/SF 1 CF = 7.481 GAL 1 GALLON = 0.134 CF 1 GPM = 0.002 CFS *FLOW RATE BASED ON 1/2 OF NOV 07 QMAX IN FIGURE 17 OF UNH TESTING REPORT FLOW RATE / CHAMBER (CFS) - ROW 3 14.8 6.9 CHAMBER FLOW RATE CONVERSION (GPM/SF TO CFS) FLOW RATE* 15.0 0.012 FLOOR AREA (SF) CHAMBER VOLUME (CF) - ROW 1 CHAMBER/AGGREGATE VOLUME (CF) - ROW 2 CITY OF FORT COLLINS (COFC) SIZING CALCUALTIONS FOR EXTENDED DETENTION SYSTEMS: ADS STORMTECH SYSTEM FOR 100-YR STORM STORAGE VOLUME Chamber Type Selection Required 100-year storm volume per COFC Modified FAA Method Project Name and/or Vault ID CONTENTS: Basin Name: COFC Modified FAA Method RESULTS Project Name: Kum & Go #0951 Date: 9/21/2022 020-2883 MWB 85.4 Volume within the chamber only, not accounting for void spaces in surrounding aggregate (Selected Chamber Parameter from ROW 1) Client:Kum & Go Basin Name:KG 951 CHAMBER CONFIGURATION PARAMETERS INSTALLED LENGTH (IN) System volume includes total number of chambers, plus surrounding aggregate. Volume provided within the chambers only (no aggregate storage). Number of chambers required to provide full 100-year storm event storage volume within total installed system, including aggregate; Rounded Up Release rate per chamber, limited by flow through geotextile with accumulated sediment (Selected Chamber Parameter from ROW 3) CHAMBER DIMENSIONS 12.0 WIDTH (IN) HEIGHT (IN) SC-160LP Project Number : 25.0 Prepared By: Voulme includes chamber and void spaces (40%) in surrounding aggregate (Selected Chamber Parameter from ROW 2) STORMTECH CHAMBER DATA Project: Chamber Model - SC-740 Units -Imperial Number of chambers - 13 Voids in the stone (porosity) - 40 % Base of Stone Elevation - 4944.31 ft Amount of Stone Above Chambers - 6 in Amount of Stone Below Chambers - 6 in Area of system - 645.25 sf Min. Area - Height of System Incremental Single Chamber Incremental Total Chamber Incremental Stone Incremental Ch & St Cumulative Chamber Elevation (inches)(cubic feet)(cubic feet)(cubic feet)(cubic feet)(cubic feet)(feet) 42 0.00 0.00 21.51 21.51 1261.77 4947.81 41 0.00 0.00 21.51 21.51 1240.26 4947.73 40 0.00 0.00 21.51 21.51 1218.75 4947.64 39 0.00 0.00 21.51 21.51 1197.24 4947.56 38 0.00 0.00 21.51 21.51 1175.73 4947.48 37 0.00 0.00 21.51 21.51 1154.22 4947.39 36 0.05 0.71 21.22 21.94 1132.72 4947.31 35 0.16 2.12 20.66 22.78 1110.78 4947.23 34 0.28 3.67 20.04 23.71 1088.00 4947.14 33 0.60 7.85 18.37 26.22 1064.29 4947.06 32 0.80 10.42 17.34 27.76 1038.07 4946.98 31 0.95 12.36 16.56 28.92 1010.31 4946.89 30 1.07 13.97 15.92 29.89 981.39 4946.81 29 1.18 15.35 15.37 30.72 951.50 4946.73 28 1.27 16.45 14.93 31.38 920.78 4946.64 27 1.36 17.62 14.46 32.08 889.40 4946.56 26 1.45 18.90 13.95 32.85 857.32 4946.48 25 1.52 19.82 13.58 33.40 824.47 4946.39 24 1.58 20.57 13.28 33.85 791.07 4946.31 23 1.64 21.35 12.97 34.32 757.22 4946.23 22 1.70 22.09 12.67 34.76 722.90 4946.14 21 1.75 22.79 12.39 35.18 688.14 4946.06 20 1.80 23.44 12.13 35.57 652.96 4945.98 19 1.85 24.11 11.86 35.98 617.39 4945.89 18 1.89 24.61 11.66 36.27 581.41 4945.81 17 1.93 25.14 11.45 36.59 545.14 4945.73 16 1.97 25.67 11.24 36.91 508.54 4945.64 15 2.01 26.13 11.06 37.19 471.63 4945.56 14 2.04 26.58 10.87 37.46 434.44 4945.48 13 2.07 26.97 10.72 37.69 396.98 4945.39 12 2.10 27.36 10.56 37.93 359.29 4945.31 11 2.13 27.71 10.42 38.14 321.37 4945.23 10 2.15 28.00 10.31 38.31 283.23 4945.14 9 2.18 28.30 10.19 38.49 244.92 4945.06 8 2.20 28.58 10.08 38.66 206.43 4944.98 7 2.21 28.70 10.03 38.73 167.78 4944.89 6 0.00 0.00 21.51 21.51 129.05 4944.81 5 0.00 0.00 21.51 21.51 107.54 4944.73 4 0.00 0.00 21.51 21.51 86.03 4944.64 3 0.00 0.00 21.51 21.51 64.53 4944.56 2 0.00 0.00 21.51 21.51 43.02 4944.48 1 0.00 0.00 21.51 21.51 21.51 4944.39 Kum & Go 951 439 sf min. area StormTech SC-740 Cumulative Storage Volumes Project: Chamber Model - SC-740 Units -Imperial Number of chambers - 48 Voids in the stone (porosity) - 40 % Base of Stone Elevation - 4944.31 ft Amount of Stone Above Chambers - 6 in Amount of Stone Below Chambers - 6 in Area of system - 1935.75 sf Min. Area - Height of System Incremental Single Chamber Incremental Total Chamber Incremental Stone Incremental Ch & St Cumulative Chamber Elevation (inches)(cubic feet)(cubic feet)(cubic feet)(cubic feet)(cubic feet)(feet) 42 0.00 0.00 64.53 64.53 4033.43 4947.81 41 0.00 0.00 64.53 64.53 3968.91 4947.73 40 0.00 0.00 64.53 64.53 3904.38 4947.64 39 0.00 0.00 64.53 64.53 3839.86 4947.56 38 0.00 0.00 64.53 64.53 3775.33 4947.48 37 0.00 0.00 64.53 64.53 3710.81 4947.39 36 0.05 2.64 63.47 66.11 3646.28 4947.31 35 0.16 7.82 61.40 69.22 3580.18 4947.23 34 0.28 13.53 59.11 72.64 3510.96 4947.14 33 0.60 28.99 52.93 81.92 3438.31 4947.06 32 0.80 38.48 49.13 87.61 3356.39 4946.98 31 0.95 45.63 46.27 91.90 3268.78 4946.89 30 1.07 51.58 43.89 95.47 3176.88 4946.81 29 1.18 56.66 41.86 98.52 3081.40 4946.73 28 1.27 60.75 40.22 100.98 2982.88 4946.64 27 1.36 65.04 38.51 103.55 2881.91 4946.56 26 1.45 69.80 36.61 106.40 2778.36 4946.48 25 1.52 73.19 35.25 108.44 2671.95 4946.39 24 1.58 75.95 34.14 110.10 2563.52 4946.31 23 1.64 78.83 32.99 111.82 2453.42 4946.23 22 1.70 81.58 31.89 113.47 2341.60 4946.14 21 1.75 84.14 30.87 115.01 2228.13 4946.06 20 1.80 86.54 29.91 116.45 2113.12 4945.98 19 1.85 89.04 28.91 117.95 1996.67 4945.89 18 1.89 90.87 28.18 119.05 1878.72 4945.81 17 1.93 92.83 27.39 120.22 1759.68 4945.73 16 1.97 94.80 26.61 121.40 1639.45 4945.64 15 2.01 96.48 25.93 122.41 1518.05 4945.56 14 2.04 98.16 25.26 123.42 1395.64 4945.48 13 2.07 99.60 24.69 124.28 1272.22 4945.39 12 2.10 101.04 24.11 125.15 1147.93 4945.31 11 2.13 102.33 23.59 125.92 1022.78 4945.23 10 2.15 103.39 23.17 126.56 896.86 4945.14 9 2.18 104.50 22.73 127.22 770.31 4945.06 8 2.20 105.52 22.32 127.84 643.08 4944.98 7 2.21 105.95 22.14 128.10 515.25 4944.89 6 0.00 0.00 64.53 64.53 387.15 4944.81 5 0.00 0.00 64.53 64.53 322.63 4944.73 4 0.00 0.00 64.53 64.53 258.10 4944.64 3 0.00 0.00 64.53 64.53 193.58 4944.56 2 0.00 0.00 64.53 64.53 129.05 4944.48 1 0.00 0.00 64.53 64.53 64.53 4944.39 Kum & Go 951 1623 sf min. area StormTech SC-740 Cumulative Storage Volumes 4944.31 ft 911.90 cf 4946.62 ft 3505.81 cf 4947.13 ft Height of System Incremental Single Incremental Total Incremental Stone Incremental Ch & St Cumulative Chamber Stage (inches) (cubic feet) (cubic feet) (cubic feet) (cubic feet) (cubic feet) (feet) 28 1.27 16.45 14.93 31.38 920.78 2.33 27 1.36 17.62 14.46 32.08 889.40 2.25 Volume of :911.90 cf 2.31 ft Height of System Incremental Single Incremental Total Incremental Stone Incremental Ch & St Cumulative Chamber Stage (inches) (cubic feet) (cubic feet) (cubic feet) (cubic feet) (cubic feet) (feet) 34 0.28 13.53 59.11 72.64 3510.96 2.83 33 0.60 28.99 52.93 81.92 3438.31 2.75 Volume of :3505.81 cf 2.82 ft Project Number :020-2883 Prepared By: MWB WATER SURFACE ELEVATION LEVELS: FOR WQCV AND 100-YR STORM Project Name:Kum & Go #0951 Date: 9/21/2022 WQCV Client:Kum & Go Basin Name:KG 951 Input Variables Results Base Elev. = Req. WQCV Volume = Req. 100-Yr Volume = WQCV WSEL = 100-Yr WSEL = 100-Year Per Stage-Storage for designed system: Per Stage-Storage for designed system: will be met at Stage: will be met at Stage: WQCV will be met between these two stages: 100-Year Volume will be met between these two stages: Inlet Structure DetailKG # 0951E Prospect Rd & S Lemay Ave1880 Fall River Drive, Suite 200Loveland, CO 80538Tel. 970-461-7733PROJECT NO:DRAWN BY:DATE:STORMTECH INLETMANHOLE020-288306/10/2022MWBWEIR CONFIGURATION Outlet Structure DetailKG # 0951E Prospect Rd & S Lemay Ave1880 Fall River Drive, Suite 200Loveland, CO 80538Tel. 970-461-7733PROJECT NO:DRAWN BY:DATE:STORMTECH OUTLETMANHOLE020-288306/10/2022MWBWEIR CONFIGURATION 3130 Verona Avenue • Buford, GA 30518 (866) 888-8479 / (770) 932-2443 • Fax: (770) 932-2490 © Nyloplast Inlet Capacity Charts June 2012 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 1.10 1.20 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 1.10Capacity (cfs)Head (ft) Nyloplast 8" Dome Grate Inlet Capacity Chart Largest Required Capacity: 0.48 cfs (Area Inlet K1) Largest Required Head: 0.23 ft (Area Inlet K1) 3130 Verona Avenue • Buford, GA 30518 (866) 888-8479 / (770) 932-2443 • Fax: (770) 932-2490 © Nyloplast Inlet Capacity Charts June 2012 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 1.10Capacity (cfs)Head (ft) Nyloplast 2' x 3' Curb Inlet High Flow Grate Inlet Capacity Chart High Hood Setting (8.47" Curb Setting) Mid Hood Setting (6.47" Curb Setting) Low Hood Setting (4.47" Curb Setting) 2.85 cfs Curb Inlet I2 1.30 cfs 0.18 ft 0.09 ft Curb Inlet A 1880 Fall River Drive, Suite 200Loveland, CO 80538Tel. 970-461-7733Kum & Go #951Trench Drain SelectionAn ADS DURASLOT with a Variable Slot Riser Height is proposed across the access to the site, along the eastern propertyline, in order to help limit the flow that leaves the site untreated and undetained.Per ADS recommendations, a DURASLOT Trench Drain will withstand a maximum of 0.04 cfs perlinear foot of slot. Per the current storm infrastructure design for the site, the trench drain is to be 42.31 linear feet. The DURASLOT will be utilized to collected the runoff generated within Basin CPer the Rational Method Calculations: Basin C generated 1.05 cfs in the 100-year storm event.TRENCH DRAIN SPECIFICATIONADS's Standard Details for the DURASLOT with Variable Slot Riser Height can see as follows:Therefore:0.04 cfs/lf * 42.31 lf = 1.69 cfsConclusion:The ADS DURASLOT with be able to withstand the flows generated within Basin C. MHFD-Inlet, Version 5.01 (April 2021) Worksheet Protected INLET NAME ROW-1 ROW-2 ROW-3 User-Defined Site Type (Urban or Rural)URBAN URBAN URBAN Inlet Application (Street or Area) STREET STREET STREET Hydraulic Condition On Grade On Grade On Grade Inlet Type CDOT Type R Curb Opening CDOT Type R Curb Opening CDOT/Denver 13 Combination USER-DEFINED INPUT User-Defined Design Flows Minor QKnown (cfs)2.57 0.42 0.12 Major QKnown (cfs)4.39 0.72 0.22 Bypass (Carry-Over) Flow from Upstream Receive Bypass Flow from: No Bypass Flow Received ROW-1 ROW-2 Minor Bypass Flow Received, Qb (cfs)0.0 0.5 0.0 Major Bypass Flow Received, Qb (cfs)0.0 1.6 0.3 Watershed Characteristics Subcatchment Area (acres) Percent Impervious NRCS Soil Type Watershed Profile Overland Slope (ft/ft) Overland Length (ft) Channel Slope (ft/ft) Channel Length (ft) Minor Storm Rainfall Input Design Storm Return Period, Tr (years) One-Hour Precipitation, P1 (inches) Major Storm Rainfall Input Design Storm Return Period, Tr (years) One-Hour Precipitation, P1 (inches) CALCULATED OUTPUT Minor Total Design Peak Flow, Q (cfs) 2.6 0.9 0.1 Major Total Design Peak Flow, Q (cfs) 4.4 2.3 0.5 Minor Flow Bypassed Downstream, Qb (cfs)0.5 0.0 0.0 Major Flow Bypassed Downstream, Qb (cfs)1.6 0.3 0.0 INLET MANAGEMENT PR INLET W (2) EX TYPE 13 COMBO INLETSPR INLET V Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =9.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.0105 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.013 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =46.9 ft Gutter Width W =2.00 ft Street Transverse Slope SX =0.020 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.007 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.020 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =11.87 11.87 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.00 6.00 inches Allow Flow Depth at Street Crown (check box for yes, leave blank for no) MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow =3.1 3.1 cfs Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a')aLOCAL =3.0 3.0 inches Total Number of Units in the Inlet (Grate or Curb Opening)No = 1 1 Length of a Single Unit Inlet (Grate or Curb Opening)Lo =5.00 5.00 ft Width of a Unit Grate (cannot be greater than W, Gutter Width) Wo =N/A N/A ft Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf-G =N/A N/A Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf-C =0.10 0.10 Street Hydraulics: WARNING: Q > ALLOWABLE Q FOR MAJOR STORM MINOR MAJOR Total Inlet Interception Capacity Q = 2.1 2.8 cfs Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =0.5 1.6 cfs Capture Percentage = Qa/Qo =C% = 82 63 % INLET ON A CONTINUOUS GRADE MHFD-Inlet, Version 5.01 (April 2021) CDOT Type R Curb Opening Minor storm max. allowable capacity GOOD - greater than the design flow given on sheet 'Inlet Management' WARNING: MAJOR STORM max. allowable capacity is less than the design flow given on sheet 'Inlet Management' MHFD-Inlet, Version 5.01 (April 2021) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) KG #0951 ROW-1 CDOT Type R Curb Opening 1 PR INLET V Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =15.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.015 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.013 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =32.0 ft Gutter Width W =2.00 ft Street Transverse Slope SX =0.023 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.008 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.020 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =18.4 18.4 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 6.0 inches Allow Flow Depth at Street Crown (check box for yes, leave blank for no) MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow =8.6 8.6 cfs Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a')aLOCAL =3.0 3.0 inches Total Number of Units in the Inlet (Grate or Curb Opening)No = 1 1 Length of a Single Unit Inlet (Grate or Curb Opening)Lo =5.00 5.00 ft Width of a Unit Grate (cannot be greater than W, Gutter Width) Wo =N/A N/A ft Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf-G =N/A N/A Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf-C =0.10 0.10 Street Hydraulics: OK - Q < Allowable Street Capacity'MINOR MAJOR Total Inlet Interception Capacity Q = 0.9 2.0 cfs Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =0.0 0.3 cfs Capture Percentage = Qa/Qo =C% = 100 86 % Minor storm max. allowable capacity GOOD - greater than the design flow given on sheet 'Inlet Management' Major storm max. allowable capacity GOOD - greater than the design flow given on sheet 'Inlet Management' MHFD-Inlet, Version 5.01 (April 2021) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) KG #0951 ROW-2 INLET ON A CONTINUOUS GRADE MHFD-Inlet, Version 5.01 (April 2021) CDOT Type R Curb OpeningCDOT Type R Curb Opening 1 PR INLET W Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =10.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.023 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.013 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =26.5 ft Gutter Width W =2.00 ft Street Transverse Slope SX =0.020 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.006 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.020 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =23.0 23.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 6.0 inches Allow Flow Depth at Street Crown (check box for yes, leave blank for no) MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow =8.5 8.5 cfs Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a')aLOCAL =2.0 2.0 inches Total Number of Units in the Inlet (Grate or Curb Opening)No = 2 2 Length of a Single Unit Inlet (Grate or Curb Opening)Lo =3.00 3.00 ft Width of a Unit Grate (cannot be greater than W, Gutter Width) Wo =1.73 1.73 ft Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf-G =0.50 0.50 Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf-C =0.10 0.10 Street Hydraulics: OK - Q < Allowable Street Capacity'MINOR MAJOR Total Inlet Interception Capacity Q = 0.1 0.6 cfs Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =0.0 0.0 cfs Capture Percentage = Qa/Qo =C% = 100 100 % Minor storm max. allowable capacity GOOD - greater than the design flow given on sheet 'Inlet Management' Major storm max. allowable capacity GOOD - greater than the design flow given on sheet 'Inlet Management' MHFD-Inlet, Version 5.01 (April 2021) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) KG #0951 ROW-3 INLET ON A CONTINUOUS GRADE MHFD-Inlet, Version 5.01 (April 2021) CDOT/Denver 13 CombinationCDOT/Denver 13 Combination 1 (2) EX TYPE 13 COMBINATION INLETS A PPENDIX C REFERENCED INFORMATION VICINITY MAPE PROSPECT RD & S LEMAY AVE1880 Fall River Drive, Suite 200Loveland, CO 80538Tel. 970-461-7733SITE 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 January 24, 2022 15 Custom Soil Resource Report Map—Hydrologic Soil Group 4490610449062044906304490640449065044906604490670449068044906904490700449071044906104490620449063044906404490650449066044906704490680449069044907004490710495010 495020 495030 495040 495050 495060 495070 495080 495090 495010 495020 495030 495040 495050 495060 495070 495080 495090 40° 34' 1'' N 105° 3' 32'' W40° 34' 1'' N105° 3' 28'' W40° 33' 58'' N 105° 3' 32'' W40° 33' 58'' N 105° 3' 28'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 25 50 100 150 Feet 0 5 10 20 30 Meters Map Scale: 1:531 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 Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available 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 16, Sep 2, 2021 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 16 Table—Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 76 Nunn clay loam, wet, 1 to 3 percent slopes C 0.9 78.8% 95 Satanta loam, 1 to 3 percent slopes C 0.3 21.2% Totals for Area of Interest 1.2 100.0% Rating Options—Hydrologic Soil Group Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Custom Soil Resource Report 17 EX1 0.91 0.34 0.43 E. PROSPECT RD LEMAY AVELEGEND A B C D SHEET NUMBER: CPM: SDM: RDM: 09/21/2022#0951 - FORT COLLINS, COKG PROJECT TEAM:949 E PROSPECT1459 Grand Avenue Des Moines, Iowa 50309 P: 515-226-0128 F: 515-223-9873 DATE: TC DG BS CALL 811 SEVENTY-TWO HOURS PRIOR TO DIGGING, GRADING OR EXCAVATING FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES.DOCUMENT REVISION DATE: JULY 2013Know what's below. before you dig.CallR www.olsson.comTEL 303.237.20721525 Raleigh St. Suite 400Denver, CO 80204DATEREVISION DESCRIPTION OF 37 EXISTING DRAINAGE BASIN MAP SHEET 1 E PROSPECT RD S LEMAY AVETT EV EV R-2 0.06 0.95 1.00 B.1 0.07 0.95 1.00 C 0.11 0.95 1.00 B.2 0.06 0.95 1.00 OS.4 0.02 0.41 0.52 D 0.02 0.20 0.25 F 0.02 0.39 0.31 OS.1 0.02 0.52 0.65 A 0.29 0.92 1.00 R-1 0.10 0.95 1.00 E 0.02 0.20 0.25 E.1 0.00 0.25 0.20 F.1 0.00 0.20 0.25 OS.3 0.01 0.63 0.78 G 0.03 0.20 0.25 H 0.07 0.20 0.26 OS.5 0.04 0.20 0.25 ROW 4 0.06 0.70 0.88 ROW 2 0.16 0.95 1.00 G.1 0.10 0.26 0.32 H.1 0.07 0.20 0.25 ROW 3 0.05 0.73 0.92 ROW 1 1.62 0.95 1.00 ROW 1 1.62 0.95 1.00 T ROW 1 1.62 0.95 1.00 LEGEND A B C D SHEET NUMBER: CPM: SDM: RDM: 09/21/2022#0951 - FORT COLLINS, COKG PROJECT TEAM:949 E PROSPECT1459 Grand Avenue Des Moines, Iowa 50309 P: 515-226-0128 F: 515-223-9873 DATE: TC DG BS CALL 811 SEVENTY-TWO HOURS PRIOR TO DIGGING, GRADING OR EXCAVATING FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES.DOCUMENT REVISION DATE: JULY 2013Know what's below. before you dig.CallR www.olsson.comTEL 303.237.20721525 Raleigh St. Suite 400Denver, CO 80204DATEREVISION DESCRIPTION OF 37 PROPOSED DRAINAGE BASIN MAP SHEET 1 E PROSPECT RD S LEMAY AVET E PROSPECT RD S LEMAY AVEPROPOSED IMPERVIOUS AREALEGEND SHEET NUMBER: CPM: SDM: RDM: 09/21/2022#0951 - FORT COLLINS, COKG PROJECT TEAM:949 E PROSPECT1459 Grand Avenue Des Moines, Iowa 50309 P: 515-226-0128 F: 515-223-9873 DATE: TC DG BS CALL 811 SEVENTY-TWO HOURS PRIOR TO DIGGING, GRADING OR EXCAVATING FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES.DOCUMENT REVISION DATE: JULY 2013Know what's below. before you dig.CallR www.olsson.comTEL 303.237.20721525 Raleigh St. Suite 400Denver, CO 80204DATEREVISION DESCRIPTION OF 37 LEGEND EXHIBIT 1: IMPERVIOUS & PERVIOUS AREA EXHIBIT 2: UNDETAINED & DETAINED AREA SHEET 1 KUM & GO #951 FORT COLLINS , CO 949 E PROSPECT RD Fort Collins, Colorado September 2022 Olsson Project No. 020-2883