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PROSPECT SPORTS CLUB - PDP230009 - DOCUMENT MARKUPS - ROUND 2 - DRAINAGE REPORT
PRELIMINARY DRAINAGE REPORT 19 OLD TOWN SQUARE #238 | FORT COLLINS, CO 80524 | 970-530-4044 | www.unitedcivil.com P ROSPECT S PORTS Lot 5 Prospect Park East P.U.D Fort Collins, CO Prepared for: RB+B Architects, Inc. 315 E. Mountain Ave, Suite 100 Fort Collins, CO 80524 Date: May 30 th , 2023 P RELIMINARY D RAINAGE R EPORT P ROSPECT S PORTS F ORT C OLLINS ,CO i U22014_Drainage Report City of Fort Collins Stormwater Utility 700 Wood Street Fort Collins, Colorado 80521 RE: Prospect Sports Fort Collins, Colorado Project Number: U22014 Dear Staff: United Civil Design Group, LLC. is pleased to submit this Preliminary Drainage Report for the Prospect Sports site in Fort Collins, Colorado. In general, this report serves to document the stormwater impacts associated with the proposed improvements related to the existing site. We understand that review by the City of Fort Collins is to assure general compliance with standardized criteria contained in the Fort Collins Stormwater Criteria Manual (FCSCM). This report was prepared in compliance with technical criteria set forth in the Fort Collins Stormwater Criteria Manual. If you should have any questions or comments as you review this report, please feel free to contact us at your convenience. Sincerely, United Civil Design Group Nate Stroud, PE, LSIT Project Manager P RELIMINARY D RAINAGE R EPORT P ROSPECT S PORTS F ORT C OLLINS ,CO 2 U22014_Drainage Report Soil Type – The USDA’s Web Soil Survey shows that the site consists of “Type C” and “Type D” soils. The Web Soil Survey indicates the site is comprised of Aquepts, Loveland Clay Loam (0% to 1% slopes), and Riverwash material. The on-site soils provide moderate infiltration and are suitable for development. Utilities – The following utilities exist adjacent to the site in Prospect Road, Sharp Point Road, or in easement on the west side of the site: potable water, sanitary sewer, natural gas, electric and telecommunications. Drainage Features and Storm Sewer – Storm sewer infrastructure does not currently exist adjacent to the site. There is an existing detention pond for the proposed subdivision that is located to the south of the site within Tract A of the Prospect Park East P.U.D, but this facility is inaccessible to the proposed site due to lack of drainage easements. There is also an existing lake/pond across Sharp Point Drive to the east of the site that will be utilized by the proposed project and improvements and is owned by the same owner that is developing the Prospect Sports facility. C.PROJECT DESCRIPTION The proposed Prospect Sports site improvements are limited to approximately 2.5 acres of disturbance. The proposed site improvements consist of the construction of a new 3-court basketball venue with associated site improvements including proposed drive lanes, parking, utilities, and storm and water quality infrastructure. On-site stormwater is designed to be conveyed to the proposed storm sewer and conveyed to the existing lake/wet pond east of the proposed site and across Sharp Point Drive. D.FLOODPLAINS AND FLOODPLAIN INFORMATION The proposed development is within the Poudre River designated floodplain. According to the FEMA Flood Insurance Rate Map (08069C0984H), the site is zoned in a “High Risk – Floodway” boundary area. The Floodway boundary is provided on the Drainage Plan (see Appendix D) and FEMA FIRMette map is included in Appendix C. A Floodplain Use Permit will be required for all work within the floodplain and all improvements will be required to be in compliance with Chapter 10 of the City Municipal Code. Note that this development is considered a non-residential and non-critical use structure. Note that the existing Poudre River Floodplain is currently being revised by the City of Fort Collins. Currently, it is anticipated that the proposed development will be removed from the 100-year floodplain. To comply with Chapter 10 of the City Code, the finished floor of the proposed building is proposed to be elevated 2.5 feet above the 100-year Poudre River base flood elevation. However, due to the basketball courts sitting 4.5’ lower than the finished floor in the rest of the building, the walls, and doors adjacent to the basketball courts (largely on the south side of the building) sitting at this lower finished floor are proposed to be floodproofed. Floodproofing information shall be submitted at the time of the building permit application and a FEMA Elevation or floodproofing certificate will be completed prior to the certificate of occupancy being issued. The building is proposing to use slab on-grade foundations with all elevations being tied to the NAVD 1988 Datum. A table summarizing elevations of critical items is shown on this sheet. FIGURE 2:FLOODPLAIN MAP FLOODPLAIN AND STRUCTURE ELEVATIONS SUMMARY DESCRIPTION ELEVATION FEMA BFE at Upstream End of Structure 4,901.00 Regulatory Flood Protection / Floodproofing Elevation 4,903.00 Upper Finished Floor Elevation 4,903.50 Lower Finished Floor Elevation 4,899.00 HVAC Elevation *4,919.50 *HVAC equipment to be located on top of lower roof on north end of building. Site P RELIMINARY D RAINAGE R EPORT P ROSPECT S PORTS F ORT C OLLINS ,CO 3 U22014_Drainage Report II.DRAINAGE BASINS AND SUB-BASINS A.MAJOR BASIN DESCRIPTION The proposed development is located within the Cache La Poudre Basin and will adhere to the Cache La Poudre Master Drainage Plan. B.SUB-BASIN DESCRIPTION Historically the site drains off-site to an existing detention pond within Tract A of the Prospect Park East P.U.D. As drainage easements were never recorded south of the site to the pond and the southern property owner has denied any new easements on the property, from communications with City personnel, the proposed site will not be able to drain developed stormwater flows through the existing property to the south and to the pond. In the proposed conditions, stormwater will be collected via storm sewer, inlets, swales, and curb and gutter and conveyed to the east beyond Sharp Point Drive to an existing lake/pond and lot under the same ownership as this site. In its improved condition, on-site runoff is intended to drain to multiple water quality facilities by way of sheet flow, swales, curb and gutter, inlets, and storm sewer. The Prospect Sports site was previously discussed in the “Final Drainage Report and Erosion Control Plan” for the Advanced Energy Buildings 7 and 8 project. This report shows Lot 5, the project area of the subdivision being included in the calculations as part of Basin J10 which is designed with a 100-year C value of 1.00. This basin was designed to drain to the south via overland flow to the existing detention pond within Tract A and ultimately discharge into culverts across Sharp Point to an existing lake/pond east of the site. III.DRAINAGE DESIGN CRITERIA A.REGULATIONS The design criteria for this study are directly from the City of Fort Collins Storm Drainage Design Criteria and Construction Standards Manual and the Urban Storm Drainage Criteria Manual’s (referred to herein as USDCM) Volumes 2, and 3, used for supplement only. B.DIRECTLY CONNECTED IMPERVIOUS AREA (DCIA) The City drainage criteria has also adopted the “Four Step Process” that is recommended in Volume 3 of the USDCM in selecting structural BMPs for the redeveloping urban areas. The following portions of this summary describe each step and how it has been utilized for this project: Step 1 – Employ Runoff Reduction Practices The objective of this step is to reduce runoff peaks and volumes and to employ the technique of “minimizing directly connected impervious areas” (MDCIA). This project accomplishes this by: Routing the roof and pavement flows through water quality treatment/infiltration facilities and vegetated swales to increase time of concentration, promote infiltration and provide water quality. Step 2 – Provide Water Quality Capture Volume (WQCV) The objective of providing WQCV is to reduce the sediment load and other pollutants that exit the site. For this project WQCV is provided within the permeable paver system in the western parking lot. Step 3 – Stabilize Drainageways Although the site is not adjacent to the Cache La Poudre River, it does exist within its floodplain. The project will not be directly connecting or stabilizing this drainageway but will improve the existing drainageway by providing water quality for the proposed site and reducing peak flows via the existing lake/pond prior to draining to the river. P RELIMINARY D RAINAGE R EPORT P ROSPECT S PORTS F ORT C OLLINS ,CO 4 U22014_Drainage Report Step 4 – Consider Need for Site Specific and Source Control BMPs Site specific and source control BMPs are generally considered for large industrial and commercial sites. The redevelopment of the existing site will include multiple site specific and source controls, including: Dedicated maintenance personnel providing landscape maintenance and snow and ice management. Pervious pavers being utilized in the parking area to collect and treat proposed pavement. C.HYDROLOGICAL CRITERIA City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, provided by Table 3.4-1 of the Fort Collins Stormwater Criteria Manual, are utilized for all hydrologic computations related to the site in its existing/historic and proposed conditions. Since this site is relatively small and does not have complex drainage basins, the peak flow rates for design points have been calculated based on the Rational Method as described in the USDCM and the City of Fort Collins Stormwater Criteria Manual (FCSCM) with storm duration set equal to the time of concentration for each sub-basin. This method was used to analyze the developed runoff from the 2-year (minor) and the 100-year (major) storm events. The Rational Method is widely accepted for drainage design involving small drainage areas (less than 160 acres) and short time of concentrations. Runoff coefficients are assumed based on impervious area and are given in the Appendices. D.HYDRAULIC CRITERIA The developed site will convey runoff to the proposed pond or underground treatment facility via swales, concrete channels, and pipes. The City of Fort Collins Stormwater Criteria Manual (FCSCM) and USDCM are referenced for all hydraulic calculations. In addition, the following computer programs are utilized: Storm Sewer Extension for AutoCAD Civil3D Hydraflow Express Extension for AutoCAD Civil3D UD-Inlet by UDFCD Drainage conveyance facility capacities proposed with the development project, including storm sewer, swales, and inlet capacities, are designed in accordance with criteria outlined in the FCSCM and/or the Urban Drainage and Flood Control District’s Urban Storm Drainage Criteria Manual (UDFCD) used for supplement purposes only. E.MODIFICATIONS OF CRITERIA The original subdivision development planned for drainage to be conveyed via overland flow to the drainage facility located south of the site; therefore, no storm sewer currently exists on the site. Additionally, the development team has worked with the property owner south of the site to determine if improvements and/or easements/agreements could be made to allow stormwater to continue being conveyed through this adjacent property and to the existing detention pond within Tract A of the Prospect Park East P.U.D. After discussion with the south property owner and their attorney, the southern property owner has denied any new easements for drainage and stormwater conveyance. These storm sewer difficulties generated by the design of the existing subdivision, the inability to modify the southern property easements/agreements and the resulting site plan configuration culminate into hardships with providing standard water quality and LID treatment techniques that are approved by the City. A Stormwater Variance Request has been submitted to the City requesting that the development, due to the hardships documented, is allowed to meet reduced or modified water quality and LID treatment requirements and allowed to provide treatment techniques that differ from those typically allowed in the Fort Collins Stormwater Criteria Manual. In addition to a more limited LID requirement for this project, providing detention through conveying stormwater to the existing pond within Tract A of the Prospect Park East P.U.D. will not be feasible. In addition to this, the storm outfall was not able to achieve enough depth for underground detention to be a viable option on site and there is not adequate space to provide a formal detention pond onsite. It was noted through discussions with the City that detention would not be required for this project. It was also noted through these discussions that the existing detention pond in Tract A currently overtops Sharp Point during the 100-year event and drains to the same lake/pond that the Prospect Sports site will outfall to. Due to these conditions, the City waived detention requirements for this project. P RELIMINARY D RAINAGE R EPORT P ROSPECT S PORTS F ORT C OLLINS ,CO 5 U22014_Drainage Report IV.DRAINAGE FACILITY DESIGN A.GENERAL CONCEPT Developed runoff is designed to be conveyed in a safe and effective manner via swales, curb and gutter, and storm sewer systems/inlets. Stormwater is designed to be released to an existing lake/pond east of the site and across Sharp Point Drive and ultimately to the Cache La Poudre River. Runoff that drains off-site to the south was minimized with the proposed site and is greatly reduced from existing flows heading to the same area. Runoff from the proposed site is primarily conveyed to pervious pavers and grass swales for water quality treatment and then collected via storm sewer and discharged offsite to the existing pond east of the site. Although most of the site runoff is treated through the pervious pavers or grass swales, due to grading, site, and legal constraints discussed above, the remainder of the site is treated for water quality using alternative measures discussed in water quality section of this report and in the stormwater variance submitted with the project. B.SPECIFIC DETAILS Hydrology As previously stated, hydrology from the developed site is designed to comply with criteria set forth in the City of Fort Collins Stormwater Criteria Manual. Referenced tables, charts, formulas, etc. are included in the appendices. The area, time of concentration, and runoff of each proposed sub-basin is summarized in Appendix A. The following information outlines the basin characteristics and drainage patterns for each basin. Existing Basins The following basins provide proposed drainage delineations for the site in its existing condition. Refer to Appendix A for hydrology computations. Basin EX1 Basin EX1 represents on-site runoff that drains to the existing property to the south and ultimately to the detention pond within Tract A of the Prospect Park East P.U.D. There is a very small portion of this basin that has existing public concrete sidewalk, but the majority of the existing site is undeveloped. Proposed Basins The following basins provide proposed drainage delineations for the site in its improved condition. Refer to Appendix A for hydrology computations and Appendix B for calculations related to Water Quality, Low Impact Development, and other hydraulic features. Basin A Sub-basins A1-A5 (see Drainage Plans attached) include the area of the site being collected by the proposed storm sewer infrastructure and are a majority of the site. These basins consist of roofs, asphalt and concrete paving, and landscaping. Runoff within these basins is conveyed to permeable pavers, grass swales, and a water quality manhole via sheet flow, curb, inlets, and storm sewer. Runoff from these basins is conveyed through the proposed storm sewer to the existing lake/pond across Sharp Point and ultimately released to the Cache La Poudre River. Basin OS1 Basin OS1 represents the portion of the proposed site draining offsite to the south undetained. This basin consists of concrete sidewalk, asphalt pavement, and landscaping. In its improved condition, this basin will continue to function as most of the existing site did with conveying flows offsite to the south property and ultimately to the detention pond within Tract A of the Prospect Park East P.U.D. Detention and Water Quality No formal detention is being provided for the site due to previously discussed site constraints. Although no extended detention is being provided for water quality on the site, water quality is provided and will be achieved largely through the use of permeable pavers (and LID technique) and other treatment techniques that differ from those typically allowed in the P RELIMINARY D RAINAGE R EPORT P ROSPECT S PORTS F ORT C OLLINS ,CO 6 U22014_Drainage Report Fort Collins Stormwater Criteria Manual. These techniques include grass swales, a water quality manhole, and the use of an existing wet pond (the lake/pond east of the site). As shown in the stormwater variance request submitted with this project, the use of these techniques does meet the requirements set forth in the State MS4 permit. Low Impact Development (LID) In December of 2015, Fort Collins City Council adopted the revised Low Impact Development (LID) policy and criteria which requires developments within City limits to meet certain enhanced stormwater treatment requirements in addition to more standard treatment techniques. The proposed development will be required to meet the newly adopted LID criteria which requires the following: -Treat no less than 75% of any newly added impervious area using one or a combination of LID techniques. -Treat no less than 50% of any newly added impervious area using one or a combination of LID techniques when at least 25% of any newly added pavement is provided with permeable pavement. It should be noted that this project is requesting a variance for lower LID standards due to site constraints and hardships. The following measures are implemented with this proposed development: I.Permeable Paver Water Quality Basins A4 and A5, combined for 23,684-sf of proposed composite impervious area, are designed to be routed through permeable pavers located in the perimeter of the proposed parking area. The proposed impervious area treated through permeable pavers includes proposed parking, driveway, roof areas, and landscaping. Approximately 6,616 sf of impervious area in Basin A4 is proposed to drain to 1,865 sf of permeable pavers. For Basin A5 approximately 11,980 sf of impervious area is proposed to drain to 7,867 sf of permeable pavers. The amount of impervious area “running onto” the paver area within both basins is within the maximum 3:1 ratio as described in City of Fort Collins LID criteria. Additionally, considering all the proposed pavement for the project totals 31,346 sf and permeable paver area totals 9,732 sf, the site proposes to treat approximately 31% of the newly added impervious area with permeable pavers. All permeable paver areas will be designed with underdrains which will be conveyed to the proposed storm sewer onsite. II.Water Quality Manhole Basin A2, accounting for 31,916-sf of proposed composite impervious area (entire roof area), is designed to be conveyed to proposed storm sewer system. The manhole at the downstream end of this basin shall be installed with a stormwater management device attached to the inside of the manhole such as a SAFL Baffle, Snout, or Envirohood. This feature is designed to trap pollutants from stormwater runoff in a manhole and promote the water quality of stormwater being discharged. Although this feature is not a traditional LID or water quality treatment technique approved by the City, it has been shown to improve overall water quality and meet TSS removal thresholds per MS4 requirements. III.Grass Swales Basins A1 and A3, accounting for 3,154-sf of proposed composite impervious area, are designed to be conveyed to grass swales and ultimately to the proposed storm sewer system. The grass swales are proposed to serve as water quality features to disconnect impervious areas and remove pollutants prior to being collected by the storm sewer system and discharging offsite. Although grass swales are not a traditional LID and water quality treatment technique approved by the City, it has been shown to improve overall water quality and meet TSS removal thresholds per MS4 requirements. It should be noted that the grass swales in Basin A3 will be conveyed through the water quality manhole and will be treated further through that water quality feature. Provided the LID measures in the permeable pavers, approximately 37.7% of the site is treated in its improved condition. The 50% requirement for LID treatment will not be met for the site and a separate variance for this has been submitted for this project. Although the grass swales and water quality manhole will provide some water quality treatment, these measures P RELIMINARY D RAINAGE R EPORT P ROSPECT S PORTS F ORT C OLLINS ,CO 7 U22014_Drainage Report 100-year Event: Proposed Runoff to South Basin Designation Flowrate (cfs) Basin OS1 1.17 are not formally accepted as LID treatment techniques. Refer to Appendix B for LID calculations and Appendix D for a LID Treatment Map. Below is a summary LID treatment table for reference. 75% On-Site Treatment by LID Requirement New or Modified Impervious Area (Total) 1.42 acre Required Minimum Impervious Area to be Treated 0.71 acre Impervious Area Treated by Permeable Pavers 0.54 acre Total Impervious Area Treated 0.54 acre Percent of Impervious Areas Treated by LID 37.7 % Drainage Summary A basin summary table is included below: Existing/Historic Basins Basin Area %I C2 C10 C100 Q2 Q10 Q100 (acre) (cfs) (cfs) (cfs) EX1 2.65 3.8% 0.26 0.26 0.33 1.48 2.53 6.46 Proposed Basins Basin Area %I C2 C10 C100 Q2 Q10 Q100 (acre) (cfs) (cfs) (cfs) A1 0.10 15% 0.34 0.34 0.42 0.08 0.13 0.36 A2 0.81 90% 0.95 0.95 1.00 2.20 3.77 8.10 A3 0.48 12% 0.32 0.32 0.40 0.34 0.59 1.50 A4 0.46 42% 0.53 0.53 0.67 0.52 0.89 2.38 A5 0.58 60% 0.66 0.66 0.83 0.78 1.34 4.45 Total 2.44 52% 0.63 0.63 0.79 2.95 5.05 15.41 OS1 0.22 43% 0.54 0.54 0.68 0.26 0.44 1.17 It should be noted from the proposed basins table that the overall site 100-year C value is 0.79 which is less than the previously planned 100-year C value of 1.00 for Basin J10 in the Advanced Energy buildings 7 and 8 drainage report. Refer to Appendix D for an Existing Drainage Map that provides a visual representation of the proposed drainage basins. In the existing conditions, the site drains undetained to the south and is conveyed to the existing detention pond in Tract A of the Prospect Park East P.U.D. The improved site is designed to convey the 100-yr storm to the east to an existing pond / lake. The tables below summarize the impacts of the proposed improvements vs. existing conditions to property to the south. 100-year Event: Existing Runoff to South In relation to the property to the south, the majority of the site is designed to outfall to the east via proposed storm sewer due to previously discussed site and easement constraints. The tables above show that the proposed site is significantly reducing the amount of stormwater being conveyed to the south from existing conditions and no negatives impacts to the south are anticipated from the proposed improvements. Ultimately all stormwater runoff from this site and surrounding sites will be conveyed to the Cache La Poudre River Basin Designation Flowrate (cfs) Basin EX1 6.46 P RELIMINARY D RAINAGE R EPORT P ROSPECT S PORTS F ORT C OLLINS ,CO 8 U22014_Drainage Report Standard Operating Procedures (SOPs) In order for physical stormwater Best Management Practices (BMPs) to be effective, proper maintenance is essential. Maintenance includes both routinely scheduled activities, as well as non-routine repairs that may be required after large storms, or as a result of other unforeseen problems. Standard Operating Procedures should clearly identify BMP maintenance responsibility. BMP maintenance is typically the responsibility of the entity owning the BMP. Identifying who is responsible for maintenance of BMPs and ensuring that an adequate budget is allocated for maintenance is critical to the long-term success of BMPs. Maintenance responsibility may be assigned either publicly or privately. For this project, the privately owned BMPs including grass swales, permeable pavers, and a water quality manhole are to be maintained by the property owner. Storm Sewers There are multiple storm sewer networks proposed with the site improvements. Several networks including roof drains, storm drains, and underdrain lines for permeable pavers are proposed ultimately with outfalls to the existing pond east of the site. Proposed storm sewer systems are designed to accommodate the flows from the 100-year storm event. Hydraulic computations of these systems are provided in Appendix B. Inlets There are multiple inlets proposed with site improvements, including Nyloplast drain basins and Type R inlets. Type R Inlets are designed in sump to capture developed runoff. On-site drain basins are designed in a sump condition and are designed to convey runoff produced within smaller interior basins to proposed storm sewer and ultimately to the existing lake/pond east of the site. All inlets on the site are sized to provide adequate capacity and convey the 100-year storm event. Hydraulic computations of these systems are provided in Appendix B. V.EROSION CONTROL A separate Erosion Control Report / Storm Water Management Plan (SWMP) will be prepared for the site in accordance with the Stormwater Discharge Permit for Colorado Department of Public Health and Environment as the site will disturb an area greater than 1-acre. The Erosion Control Report will be completed during the Final Compliance phase of the project and will include more detailed information on the sediment and erosion control items for this project. It is intended that the proposed improvements will comply with Erosion Control Criteria per the FCSCM, and all Erosion Control Materials will be provided with the Final Drainage Report. At a minimum, the following temporary BMP’s will be installed and maintained to control on-site erosion and prevent sediment from traveling off-site during construction: Silt Fence – a woven synthetic fabric that filters runoff. The silt fence is a temporary barrier that is placed at the base of a disturbed area. Vehicle Tracking Control – a stabilized stone pad located at points of ingress and egress on a construction site. The stone pad is designed to reduce the amount of mud transported onto public roads by construction traffic. Riprap – Riprap will be used downstream of all storm sewer outfalls to control erosion of the receiving channels. Inlet Protection – acts as a sediment filter. It is a temporary BMP and requires proper installation and maintenance to ensure their performance. Straw Wattles – wattles act as a sediment filter in swales around inlets. They are a temporary BMP and require proper installation and maintenance to ensure their performance. Slope Protection – Slopes should be terraced using a “tracked” vehicle, run perpendicular to slope to inhibit rill/gulley erosion. The contractor shall store all construction materials and equipment and shall provide maintenance and fueling of equipment in confined areas on-site from which runoff will be contained and filtered. Temporary Best Management Practices (BMP’s) will be inspected by the contractor at a minimum of once every two weeks and after each significant storm event. A PPENDIX B H YDRAULIC C ALCULATIONS WATER QUALITY Prospect Sports, Fort Collins, CO Required Water Quality Capture Volume Basin Area Area Imperviousness Watershed WQCV WQ Treatment (sf)(acres)(%)(inches)(cf)Method A1 4,361 0.100 15%0.07 32 Grass Swale A2 35,462 0.814 90%0.32 1,139 Snout Manhole A3 21,021 0.483 12%0.06 131 Grass Swale A4 20,050 0.460 42%0.15 298 Pavers A3 25,236 0.579 60%0.19 479 Pavers TOTAL 106,130 2.436 52%0.17 1,795 OS1 9,382 0.215 43%0.15 141 None Water quality provided based on 12-hour storage Date: 5/23/2023 C:\United Civil Dropbox\Projects\U22014 - Prospect Park East\Reports\Drainage\Calculations\U22014-Drain Calcs LOW IMPACT DEVELOPMENT SUMMARY Prospect Sports, Fort Collins, CO Basin Proposed Impervious Area LID Treatment Area Treated % of Site Treated (sf)(acres)(sf)(%) A1 633 Grass Swale 0 0.0% A2 31,916 Snout Manhole 0 0.0% A3 2,522 Grass Swale 0 0.0% A4 8,450 Pavers 8,450 13.5% A5 15,234 Pavers 15,234 24.3% OS1 4,030 None 0 0.0% Total New/Modified Site 62,785 23,684 37.7% Low Impact Development (LID) Treated Areas Date: 5/23/2023 C:\United Civil Dropbox\Projects\U22014 - Prospect Park East\Reports\Drainage\Calculations\U22014-Drain Calcs A PPENDIX C R EFERENCED M ATERIALS 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, Colorado Prospect Sports Natural Resources Conservation Service May 10, 2023 Larimer County Area, Colorado 6—Aquepts, ponded Map Unit Setting National map unit symbol: jpx4 Elevation: 4,500 to 6,700 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 39 to 50 degrees F Frost-free period: 80 to 140 days Farmland classification: Not prime farmland Map Unit Composition Aquepts, ponded, and similar soils:90 percent Minor components:10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Aquepts, Ponded Setting Landform:Draws, channels, drainageways Landform position (three-dimensional):Base slope, tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Variable alluvium Typical profile H1 - 0 to 60 inches: variable Properties and qualities Slope:0 to 3 percent Depth to restrictive feature:More than 80 inches Drainage class:Very poorly drained Runoff class: Negligible Capacity of the most limiting layer to transmit water (Ksat):Moderately high to very high (0.60 to 99.90 in/hr) Depth to water table:About 0 to 18 inches Frequency of flooding:NoneFrequent Frequency of ponding:None Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 8w Hydrologic Soil Group: A/D Hydric soil rating: Yes Minor Components Nunn Percent of map unit:10 percent Ecological site:R067BY002CO - Loamy Plains Hydric soil rating: No Custom Soil Resource Report 13 64—Loveland clay loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: jpx9 Elevation: 4,800 to 5,500 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 50 degrees F Frost-free period: 135 to 150 days Farmland classification: Prime farmland if irrigated Map Unit Composition Loveland and similar soils:90 percent Minor components:10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Loveland Setting Landform:Flood plains, stream terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Alluvium Typical profile H1 - 0 to 15 inches: clay loam H2 - 15 to 32 inches: loam H3 - 32 to 60 inches: very gravelly sand Properties and qualities Slope:0 to 1 percent Depth to restrictive feature:More than 80 inches Drainage class:Poorly drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20 to 0.60 in/hr) Depth to water table:About 18 to 36 inches Frequency of flooding:OccasionalNone Frequency of ponding:None Calcium carbonate, maximum content:15 percent Maximum salinity:Very slightly saline to slightly saline (2.0 to 4.0 mmhos/cm) Available water supply, 0 to 60 inches: Moderate (about 7.5 inches) Interpretive groups Land capability classification (irrigated): 3w Land capability classification (nonirrigated): 3w Hydrologic Soil Group: C Ecological site: R067BY036CO - Overflow Hydric soil rating: No Custom Soil Resource Report 14 Minor Components Aquolls Percent of map unit:5 percent Landform:Swales Hydric soil rating: Yes Poudre Percent of map unit:5 percent Ecological site:R067BY036CO - Overflow Hydric soil rating: No 92—Riverwash Map Unit Composition Riverwash:100 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Riverwash Interpretive groups Land capability classification (irrigated): 8 Land capability classification (nonirrigated): 8 Hydric soil rating: No Custom Soil Resource Report 15 A PPENDIX D D RAINAGE E XHIBITS E. PROSPECT R O A D SHARP POINT DR.EXISTING BUILDING LOT 6 PROSPECT PARK EAST P.U.D. LOT 4 PROSPECT PARK EAST P.U.D. TRACT "A" PROSPECT PARK EAST P.U.D. PROPOSED BUILDING FFE = 4903.50 (NORTH) FFE = 4899.00 (GYM / SOUTH) LOT 5 PROSPECT PARK EAST P.U.D. GRASS SWALE GRASS SWALE GRASS SWALE GRASS SWALE EXISTING LAKE/POND STORM SEWER STORM SEWER PAVER SYSTEM DRAIN PERMEABLE PAVERS (TYP.) STORM SEWER 2' CURB CUT PAVER SYSTEM DRAIN PAVER SYSTEM DRAIN AREA INLET AREA INLET AREA INLET CULVERT AREA INLET FLARED END SECTION CURB INLET POUDRE RIVER 100-YR FLOODPLAIN POUDRE RIVER 100-YR FLOODPLAIN POUDRE RIVER 500-YR FLOODPLAIN FLOODPLAIN CR O S S S E C T I O N " B I " 100-YEAR FLOOD E L E V A T I O N - 4900 (NAVD 88) FLOODPLAIN CROSS SECTION 100-YEAR FLOOD ELEVATION - 4904 (NAVD 88) FLOODPLAIN CROSS SEC T I O N 100-YEAR FLOOD ELEVATI O N - 4901 (NAVD 88) LIMITS OF DISTURBANCE LIMITS OF DISTURBANCE ROOF DRAIN (TYP.) DP A5 DP A4 DP A3 DP OS1 DP A1 OS1 0.22 A5 0.58 A4 0.46 A2 0.81 A3 0.48 A1 0.10 STRUCTURAL RETAINING WALL (SEE STRUCTURAL PLANS) 0 30'60' SCALE: 1" = 30' 15'NORTH 5/31/202310:42:34 AMC:\UNITED CIVIL DROPBOX\PROJECTS\U22014 - PROSPECT PARK EAST\CADD\CP\C5.00 - DRAINAGE PLAN.DWGC5.00 - DRAINAGE PLAN--------PROPOSED MAJOR CONTOUR PROPOSED MINOR CONTOUR LEGEND EXISTING MAJOR CONTOUR EXISTING MINOR CONTOUR EXISTING PROPERTY BOUNDARY RIGHT OF WAY XX.X X BASIN DESIGNATION BASIN AREA (ACRE) PROPOSED BASIN PROPOSED BASIN LINE 1.THE TOP OF FOUNDATION ELEVATIONS SHOWN ARE THE MINIMUM ELEVATIONS REQUIRED FOR PROTECTION FROM THE 100-YEAR STORM. MINIMUM FINISHED FLOOR ELEVATIONS ABOVE THE 100-YEAR WATER SURFACE IN STREETS, CHANNELS, DITCHES, SWALES, OR OTHER DRAINAGE FACILITIES, AS ILLUSTRATED BY A MASTER GRADING PLAN ARE TO BE SHOWN. NOTES 1.PORTIONS OF THIS PROJECT ARE LOCATED WITHIN A FEMA-REGULATORY 100-YEAR FLOODPLAIN FOR THE CACHE LA POUDRE RIVER AND IS SUBJECT TO THE REQUIREMENTS OF CHAPTER 10 OF THE CITY CODE. 2.THE FIRST FLOOR OF THE PROPOSED COMMERCIAL BUILDING IS BEING ELEVATED A MINIMUM OF 24-INCHES ABOVE THE BASE FLOOD ELEVATION OR FLOOD PROOFED. REFER TO ARCHITECTURAL PLANS FOR FLOOD PROOFING DETAILS AND SPECIFICATIONS. ALL FLOOD PROOFING MEASURES SHALL ADHERE TO SECTION 10-38 OF CITY CODE AND THE REQUIREMENTS SET FORTH WITHIN THE CITY'S "FLOODPROOFING GUIDELINES". A FLOOD PROOFING CERTIFICATE WILL BE REQUIRED PRIOR TO THE ISSUANCE OF A CERTIFICATE OF OCCUPANCY. 3.THE DEVELOPER SHALL OBTAIN A FLOODPLAIN USE PERMIT FROM THE CITY OF FORT COLLINS AND PAY ALL APPLICABLE FLOODPLAIN USE PERMIT FEES PRIOR TO COMMENCING ANY CONSTRUCTION ACTIVITY (DEMOLITION, EARTHWORK, BUILDING OF STRUCTURES, PARKING LOTS, UTILITIES, LANDSCAPED AREAS, ETC.) WITHIN THE POUDRE RIVER 100-YEAR FLOODPLAIN LIMITS. 4.ALL SPOT ELEVATIONS AND BASE FLOOD ELEVATIONS AS SHOWN ON THIS DRAWING ARE PER VERTICAL CONTROL DATUM NAVD 88. 5.NO STORAGE OF MATERIAL OR EQUIPMENT MAY OCCUR AT ANY TIME IN THE FLOODPLAIN BEFORE, DURING OR AFTER CONSTRUCTION. 6.ANY ITEMS LOCATED IN THE FLOODPLAIN THAT CAN FLOAT (E.G. PICNIC TABLE, BIKE RACKS, ETC.) MUST BE ANCHORED. FLOODPLAIN NOTES DESIGN / CONCENTRATION POINT FLOW DIRECTION DP 1 A A 1 2 3 4 5 1 2 3 4 5 PROJECT INFORMATIONSHEET INFORMATIONPROJECT PHASEARCHITECTSEALISSUE DATE: PROJECT #:CONSULTANTB C D A B C D T - 970.484.0117 F - 970.484.0264 315 East Mountain Ave Suite 100 Fort Collins, CO 80524-2913 © 2015 www.rbbarchitects.com ARCHITECTS REVISIONS: 2204PROSPECT SPORTSCLUBMAX WEST INC.PROJECTDEVELOPMENTPLAN05/31/20231600 EAST PROSPECT ROADFORT COLLINS, CO 80525DESCRIPTION DATE CIVIL ENGINEERING & CONSULTING UNITED CIVIL Design Group 19 OLD TOWN SQUARE #238 FORT COLLINS, CO 80524 (970) 530-4044 www.unitedcivil.com PROJ. MGR:DRAWING NAME:PATH:DESIGNER:DATE:TIME:C5.00 DRAINAGE PLAN NOTE: 1.THE TYPICAL FOUNDATION DETAIL IS SHOWN FOR REFERENCE ONLY AND IS NOT A CONSTRUCTION DETAIL. ADDITIONAL WATERPROOFING MEMBRANE AND DRAINAGE MATERIAL WILL BE REQUIRED BUT NOT SHOWN ON THIS DETAIL. CONTRACTOR SHALL REFER TO APPROVED ARCHITECTURAL AND STRUCTURAL DRAWINGS FOR ALL FOUNDATION AND BUILDING DETAILS. 2.LOCATION OF HVAC EQUIPMENT IS TO BE LOCATED ON THE ROOF OF THE BUILDING. 3.FLOODPROOFING DETAILS WILL BE PROVIDED DURING BUILDING PERMIT REVIEW. CONCRETE SIDEWALK SOUTH WALL TYPICAL FOUNDATION DETAIL NTS CONCRETE SPREAD FOOTING PER STRUCTURAL DRAWINGS LOWER FFE=4899.00 (NAVD-88)FINISHED GRADE VARIES 100-YEAR BFE=4901.00 (NAVD-88) FLOOD PROOFING ELEV.=4903.00 (MIN.) (NAVD-88) PRE-CAST CONCRETE WALL 12" BITUTHENE (WATERPROOFING MEMBRANE) STRIP BITUTHENE (WATERPROOFING MEMBRANE)