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Home My WebLink AboutTHE SAVOY - PDP210019 - SUBMITTAL DOCUMENTS - ROUND 3 - DRAINAGE REPORT PRELIMINARY DRAINAGE REPORT THE SAVOY FORT COLLINS, COLORADO SEPTEMBER 14, 2022 NORTHERNENGINEERING.COM 970.221.4158 FORT COLLINS GREELEY This Drainage Report is consciously provided as a PDF. Please consider the environment before printing this document in its entirety. When a hard copy is necessary, we recommend double-sided printing. NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY (514-003) FORT COLLINS | GREELEY COVER LETTER September 14, 2022 City of Fort Collins Stormwater Utility 700 Wood Street Fort Collins, CO 80526 RE: PRELIMINARY DRAINAGE REPORT FOR THE SAVOY (514-003) Dear Staff: Northern Engineering is pleased to submit this Preliminary Drainage Report for your review. This report accompanies the Preliminary Development Review submittal for The Savoy. This report has been prepared in accordance with the Fort Collins Stormwater Criteria Manual (FCSCM) and serves to document the stormwater impacts associated with the proposed The Savoy multi-family project. We understand review by the City of Fort Collins is to assure general compliance with standardized criteria contained in the FCSCM. If you should have any questions as you review this report, please feel free to contact us. Sincerely, NORTHERN ENGINEERING SERVICES, INC. BLAINE MATHISEN, PE Project Engineer NORTHERNENGINEERING.COM | 970.221.4158 FINAL DRAINAGE REPORT: PROJECT NAME FORT COLLINS | GREELEY TABLE OF CONTENTS TABLE OF CONTENTS GENERAL LOCATION AND DESCRIPTION .......................................................... 1 DRAIN BASINS AND SUB-BASINS ..................................................................... 3 DRAINAGE DESIGN CRITERIA .......................................................................... 4 DRAINAGE FACILITY DESIGN ........................................................................... 7 CONCLUSIONS .............................................................................................. 9 REFERENCES .............................................................................................. 11 TABLES AND FIGURES FIGURE 1 - VICINITY MAP ..................................................................................................1 FIGURE 2 - AERIAL PHOTO ................................................................................................2 FIGURE 3 - FIRMETTE MAP 08069C0994F .........................................................................3 TABLE 1 - LID SUMMARY TABLE .......................................................................................9 APPENDICES APPENDIX A – HYDROLOGIC COMPUTATIONS APPENDIX B – HYDRAULIC CALCULATIONS – FOR FUTURE USE APPENDIX C –WATER QUALITY/LID COMPUTATIONS APPENDIX D – EROSION CONTROL REPORT APPENDIX E – EXCERPTS FROM PREVIOUS REPORTS AND USDA SOILS REPORT MAP POCKET DR1 – DRAINAGE EXHIBIT NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY 1 | 11 GENERAL LOCATION AND DESCRIPTION A. LOCATION Vicinity Map The Savoy project site is located in the northeast quarter of Section 4, Township 6 North, Range 68 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer, State of Colorado. The project site (refer to Figure 1) is bordered to the west, east, and south by other multi-family complexes and to the north by a vacant lot. There are no major drainageways located adjacent to the project site. B. DESCRIPTION OF PROPERTY The Savoy project is comprised of ±8.34 acres plus some additional right-of-way dedications. The site is currently vacant with native grasses. The existing on-site runoff generally drains from the north-to-south across flat grades (e.g., <2.00%) into either Brookfield Drive or Precision Drive. Once runoff has entered the right-of- way, it is routed to a 15' Type R inlet at the northwest corner of the Brookfield Drive and Precision Drive intersection. From there, the drainage is routed to Detention Pond A – Brookfield via a series of RCP pipes. The Savoy is proposing to alter this existing drainage pattern to align with the master planning put forth with the Banner Medical Center and Brookfield projects. The site will be split, with roughly 5.94 acres routed north to the ODP Pond, associated with Banner Medical Center. The remaining runoff (3.30 acres) will be routed to Detention Pond A – Brookfield. Additional information regarding these changes will be Figure 1 - Vicinity map NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY 2 | 11 provided in the following sections. In addition, excerpts from both drainage reports have been provided in Appendix F for further clarification. According to the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Soil Survey website: http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx), the site consists entirely of Nunn clay loam (Hydrologic Soil Group C). According to “Geological and Preliminary Geotechnical Investigation – The Savoy” dated November 17, 2021 by CTL Thompson shows that groundwater at this location is roughly 20’ deep. There is no major drainageway within or adjacent to the project site. However, Fossil Creek Reservoir Inlet Ditch runs adjacent to the ODP Pond and Detention Pond A – Brookfield. The proposed development will consist of eight multi-family buildings containing a total of 240 units. Other proposed improvements include a clubhouse, new concrete drive aisles, new sidewalks, and new landscaping. The proposed land use is multi-family dwellings. This use is permitted in the Harmony Corridor District (H-C). Figure 2 - Aerial Photo NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY 3 | 11 C. FLOODPLAIN The subject property is not located in a FEMA regulatory floodplain. In particular, the project site is not located within a FEMA-designated 100-year floodplain per Map Number 08069CO994F (Effective date: December 19, 2006). Additionally, the project site is not located in a City of Fort Collins regulated floodplain. DRAIN BASINS AND SUB-BASINS A. MAJOR BASIN DESCRIPTION The Savoy Project is located within the City of Fort Collins McClelland's major drainage basin. Specifically, the project site is situated in the eastern third of this major drainage basin. This basin is located in southeast Fort Collins and has a drainage area of approximately 3.4 square miles and includes drainage originating near the College and Harmony intersection and draining through the Oakridge, Willow Springs, Stetson Creek, and Harvest Park developments. The McClelland's major drainage basin generally drains from northwest to southeast. Runoff from the major drainage basin drains to the Fossil Creek Reservoir. Figure 3 - FIRMette Map 08069C0994F NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY 4 | 11 B. SUB-BASIN DESCRIPTION There are two separate outfalls for the project. However, both outfalls are routed to the Fossil Creek Reservoir Inlet Ditch. The existing subject site can be defined with one (1) major sub-basins that encompasses the entire project site and the adjacent ROW. The existing site runoff generally drains from northwest to southeast and into either Precision Drive or Brookfield Drive. An existing 15' Type R inlet is routing all the runoff to Detention Pond A – Brookfield via a series of RCP pipes. The project site does not receive runoff from contiguous off-site properties. DRAINAGE DESIGN CRITERIA A. ORIGINAL PROVISIONS AND PREVIOUS STUDIES There are no optional provisions outside of the FCSCM proposed with The Savoy. The Savoy project site has been included in several drainage studies for this area. The "East Harmony Portion of McClelland's Creek Master Drainage Plan Update" (ICON Engineering, Inc., August 1999), "Final Drainage Report for Brookfield" (TST, Inc. Consulting Engineers, December 2001), "Final Drainage and Erosion Control Report Banner Health Medical Campus" (Northern Engineering, September 2013), "Final Drainage and Erosion Control Report for Presidio Apartments" (Northern Engineering, December 2009), and "Final Drainage Report for Milestone Apartments" (Northern Engineering, May 2014). All these reports were reviewed before the preparation of this report. It is noted, City Stormwater previously agreed the off-site ODP Pond and Detention Pond A – Brookfield were to provide all water quality and detention requirements for The Savoy project site. Per "Final Drainage Report and Erosion Control Report Banner Health Medical Campus," the ODP Pond is responsible for detaining 5.90 acres of The Savoy project site. Basin O-2 from the Banner Health Medical Campus Master Drainage Exhibit depicts this. During the design of the ODP Pond, Basin O-2 was assumed to be 85% impervious. Per "Final Drainage Report for Brookfield," Detention Pond A – Brookfield was designed to detain and treat 9.93 acres, with an assumed impervious of 85%, of The Savoy project site. Basins D9 and D5 from the "Final Drainage Report for Brookfield" are the basins associated with The Savoy project site. The "Final Drainage and Erosion Control Report Banner Health Medical Campus" and "Final Drainage Report for Brookfield" contradict one another regarding which pond is responsible for detaining and treating The Savoy site. Banner Health Medical Campus specifies the ODP Pond, north of the project site, is responsible for detaining and treating 5.90 acres of The Savoy project site. However, Brookfield specifies Detention Pond A – Brookfield is responsible for detaining and treating 9.93 acres of the project site and adjacent rights-of- way. Because "Final Drainage and Erosion Control Report Banner Health Medical Campus" was published after "Final Drainage Report for Brookfield," The Savoy will be relying on the ODP Pond to detain 5.94 acres of the project site, while the remaining portion of the site is routed towards Detention Pond A – Brookfield for detention and traditional water quality. After reviewing all the reports mentioned above, it became clear that The Savoy would be responsible for providing on-site Low Impact Development (LID) methods to treat stormwater quality to bring the site into compliance with FCSCM. LID will be provided via NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY 5 | 11 Stormtech isolator chambers and a rain garden. Additional information on LID sizing will be provided below. Please refer to Appendix F for excerpts from previous drainage studies. Complete copies can be provided at request. B. STORMWATER MANAGEMENT STRATEGY The overall stormwater management strategy employed with The Savoy utilizes the "Four Step Process" to minimize adverse impacts of urbanization on receiving waters. The following is a description of how the proposed development has incorporated each step. Step 1 – Employ Runoff Reduction Practices. Several techniques have been utilized with the proposed development to facilitate the reduction of runoff peaks, volumes, and pollutant loads as the site is developed from the current use of implementing multiple Low Impact Development (LID) strategies, including: · Providing vegetated open areas throughout the site to reduce the overall impervious area and to minimize directly connected impervious areas. · Routing runoff through the drain rock within the Stormtech system and rain garden to increase concentration-time and promote infiltration. Step 2 – Implement BMPs that Provide a Water Quality Capture Volume (WQCV) with Slow Release. The efforts taken in Step 1 will help to minimize excess runoff from frequently occurring storm events; however, urban development of this intensity will still have stormwater runoff leaving the site. Water quality treatment will occur in the Stomtech Isolator chambers on the north side of the site and a rain garden on the site's south side. Step 3 – Stabilize Drainageways. As stated in Section I. B. 5. above, there is no major drainageway adjacent to the subject site. While this step may not seem applicable to The Savoy, the proposed project indirectly helps achieve stabilized drainageways, nonetheless. Once again, site selection has a positive effect on stream stabilization. Developing an infill site with existing stormwater infrastructure, combined with LID and MDCIA strategies, reduces the likelihood of bed and bank erosion. Furthermore, this project will pay one-time stormwater development fees and ongoing monthly stormwater utility fees, both of which help achieve Citywide drainageway stability. Step 4 – Implement Site Specific and Other Source Control BMPs. This step typically applies to industrial and commercial developments. However, localized trash enclosures with gates will reduce the potential impacts of garbage making its way downstream. C. DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS The subject property is part of an Overall Development Plan (ODP) drainage study or similar "development/project" drainage master plan. Refer to Section III. A. and Appendix F for a list of all previous drainage studies that include The Savoy project site. The site plan is constrained on all four sides by public streets. It is bound by Cinequefoil Lane to the west, Le Fever Drive to the north, Brookfield Drive to the east, and Precision Drive to the south. NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY 6 | 11 D. HYDROLOGICAL CRITERIA The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as depicted in Figure 3.4-1 of the FCSCM, serves as the source for all hydrologic computations associated with The Savoy development. Tabulated data contained in Table 3.4-1 has been utilized for Rational Method runoff calculations. The Rational Method has been employed to compute stormwater runoff utilizing coefficients contained in Tables RO-11 and RO-12 of the FCSCM. The Rational Formula-based Federal Aviation Administration (FAA) procedure has not been utilized for detention storage calculations since detention is provided off-site at the ODP Pond or Detention Pond A – Brookfield. Three separate design storms have been utilized to address distinct drainage scenarios. The first event analyzed is the "Minor" or "Initial" Storm, with a 2-year recurrence interval. The second event considered is the "Major Storm," which has a 100-year recurrence interval. The final event analyzed was the 10-year recurrence interval for comparative analysis only. E. HYDRAULIC CRITERIA The drainage facilities proposed with The Savoy project are designed in accordance with criteria outlined in the FCSCM and/or the Mile High Flood District's (UDFCD) Urban Storm Drainage Criteria Manual. As stated in Section I. C. 1. above, the subject property is not located within a FEMA or a City of Fort Collins designated floodplain. F. FLOODPLAIN REGULATIONS COMPLIANCE As stated in Section I. C. 1. above, the subject property is not located within a FEMA or a City of Fort Collins designated floodplain. G. MODIFICATIONS OF CRITERIA No formal modifications are requested at this time. However, as previously stated, The Savoy will not provide detention on-site. Two regional detention ponds will provide detention and extended water quality for a portion of the runoff. H. CONFORMANCE WITH WATER QUALITY TREATMENT CRITERIA City Code requires 100% of runoff from a project site to receive water quality treatment. This project proposes to provide water quality treatment by using an underground infiltration gallery (aka – underground chambers) located at the north end of the project and a rain garden at the south end of the site. Stormtech isolator chambers are considered a LID treatment method. Due to the physical constraints associated with an infill project of this nature and the prohibition of providing water quality facilities within the public right-of-way, some areas around the perimeter of the project cannot be captured and adequately routed to either the rain garden or the Stormtech chambers. However, these areas have been accounted for within the ODP Pond and Detention Pond A – Brookfield to receive water quality. Additionally, when the ODP Pond was installed, it did meet the current LID requirements set forth by the FCSCM at the time of approvals. The ODP Pond has a sand filter along the entire length of the bottom. However, the ODP Pond is also used for detention, and thus that is why it no longer meets current LID standards. NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY 7 | 11 I. CONFORMANCE WITH LOW IMPACT DEVELOPMENT (LID) The project site will conform with the requirement to treat a minimum of 75% of the site using a LID technique. Please see Appendix C for LID design information, table, and exhibit(s). As shown in the LID table provided in the appendix, 75.00% of the proposed site, including adjacent right-of-way, will receive LID Treatment, which meets the minimum required. J. SIZING OF LID FACILITIES The Stormtech isolator chambers were sized by determining the required water quality capture volume (WQCV) for Major Basin A. A 12-hour drain time was used in this calculation. Once the WQCV was identified, the minimum number of vaults needed to achieve this volume was calculated. The required WQCV for Major Basin A is 5,469 cf. The number of MC-4500 chambers required is 38, which provides 5,528 cf of WQCV. Each isolator row will have an inspection port and a Nyloplast basin at the end for easy maintenance and cleanout. The rain garden was sized by determining the required water quality capture volume for Major Basin B. The Mile High Flood District's criteria and online tools yielded a required WQCV of 1,746 cf. However, per FCSCM the WQCV needs to be multiplied by 1.2. Therefore, the required WQCV is 2,096 cf. The Savoy proposes installing a rain garden with a total WQCV of 2,516 cf. A volume calculation utilizing the WQ flow rate into the chamber and the calculated release rate through the fabric was completed. The number of chambers has been increased as needed to confirm the resulting volume is provided within the empty volume of the underground chambers. This is intended to ensure the chambers do not become overwhelmed in the water quality storm event before "discharging" flows into the surrounding aggregates. For additional clarification, please refer to Appendix C. DRAINAGE FACILITY DESIGN A. GENERAL CONCEPT The main objective of The Savoy drainage design is to bring the project site into compliance with existing drainage studies the site is associated with. No notable off-site runoff passes directly through the project site. A list of tables and figures used within this report can be found in the Table of Contents at the front of this document. The tables and figures are located within the sections to which the content best applies. Drainage for the project site has been analyzed using four (4) Major Drainage Basins, designated as Basins A, B, ODP, and BF. Basins A, B, and ODP all have associated sub-basins. The drainage patterns anticipated for the basins are further described below. Major Basin A Major Basin A has twelve (12) sub-basins (A1-A12) associated with the north side of The Savoy site. Major Basin A has a total area of 4.78 acres and an impervious value of 80%. All runoff generated within Major Basin A is routed via a combination of overland flow, storm line conveyance, and curb and gutter routing to the Stormtech system. Major Basin A will receive LID treatment within the Stormtech system. Once treated or any event greater than the WQ event, the runoff will be routed via HDPE pipes to the ODP Pond for detention. NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY 8 | 11 Major Basin B Major Basin B has six (6) sub-basins (B1-B6) and is associated with the south side of The Savoy site. Major Basin B has a total area of 2.15 acres and an impervious value of 71%. All runoff generated within Major Basin B is routed via a combination of overland flow, storm line conveyance, and curb and gutter routing to the rain garden at the southeast corner of the site. An overflow inlet will be set at the WQCV water surface elevation (WSEL) to allow storm events larger than the WQ event to bypass the rain garden without draining across public sidewalks. All runoff from Major Basin B will be routed to the existing 15' Type R Inlet at the northwest corner of the Brookfield Drive and Precision Drive intersection. This existing inlet has been acting as the "interim" outfall location for the entire Savoy property. Once runoff has been routed to the existing Type R inlet, it is conveyed to Detention Pond A – Brookfield via a series of RCP pipes gradually upsized as it moves downstream. Major Basin ODP Major Basin ODP has three (3) sub-basins (ODP1-ODP3) and is associated with the area along the north side of the property that cannot be captured and treated for LID on The Savoy project site but is being routed to the ODP Pond. Sub-Basin ODP1 is associated with the north side of Le Fever Drive and, therefore, it is not counted toward any of The Savoy's LID requirements or detention requirements. Sub-Basin ODP2 is on the south side of the Le Fever Drive, and, therefore, The Savoy would be responsible for detaining and treating this basin if it had not been included in the ODP Pond calculations. Sub-Basin ODP3 is associated with a small portion of the east side of Cinequefoil Lane. Existing drainage patterns for Sub- Basin ODP3 are being maintained with The Savoy Development. Water quality and detention for Sub-Basin ODP3 are being provided in the ODP Pond. As previously stated in Section III. A., per "Final Drainage Report and Erosion Control Report Banner Health Medical Campus", the ODP Pond is responsible for detaining and treating 5.90 acres of The Savoy project site. Basin O-2 from the Banner Health Medical Campus Master Drainage Exhibit depicts this. During the design of the ODP Pond, Basin O-2 was assumed to be 85% impervious. The Savoy proposes utilizing the ODP Pond for 5.93 acres with an impervious value of 76%. The 5.93 ac (4.78+0.90+0.25=5.93) acres come from Major Basin A (4.78 ac) plus Sub-Basin ODP2 (0.90 ac) and Sub-Basin ODP3 (0.25 ac). The discrepancy between 5.93 acres and 5.90 is negligible, however, The Savoy is 9% under the assumed impervious value from the “Final Drainage Report and Erosion Control Report Banner Health Medical Campus” will offset the 0.03-acre difference. Sub-Basin ODP1 was not included in this calculation because it is on the north side of Le Fever Drive and thus not associated with Basin O-2, but rather Basin O-3 per "Final Drainage Report and Erosion Control Report Banner Health Medical Campus." Therefore, The Savoy is meeting the requirements set forth by "Final Drainage Report and Erosion Control Report Banner Health Medical Campus." Major Basin BF1 Major Basin BF1 has no sub-basins and is associated with the area along the east, west, and south sides of The Savoy property that cannot be brought into the project site for LID treatment. Major Basin BF1 has an area of 1.16 acres and an impervious value of 54%. Major Basin BF1 will maintain existing runoff patterns, with all runoff being routed to the existing 15' Type R Inlet at the northwest corner of the Brookfield Drive and Precision Drive NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY 9 | 11 intersection. Runoff generated in Major Basin BF1 will be detained and treated within Detention Pond A – Brookfield. As previously stated in Section III. A., per "Final Drainage Report for Brookfield," Detention Pond A – Brookfield was designed to detain and treat 9.93 acres, with an assumed impervious of 85% of The Savoy project site. Basins D9 and D5 from the "Final Drainage Report for Brookfield" are the basins associated with The Savoy project site. However, The Savoy project is proposing to route 3.31 acres, with an impervious value of 65%, to Detention Pond A – Brookfield. The remaining portion of the site will be routed to the ODP Pond. A full-size copy of the Drainage Exhibit can be found in the Map Pocket at the end of this report. In addition, excerpts from earlier drainage reports referenced in this Section can be found in Appendix E. B. SPECIFIC DETAILS Since detention is not required with this site, the existing impervious area has not been considered in determining allowable release from the property. Instead, the site was designed to send roughly 5.90 acres to the ODP Pond while the rest of the runoff would be routed to Detention Pond A – Brookfield. The Savoy was able to successfully route 5.93 acres to the ODP Pond. LID treatment will be provided for Major Basin A and Major Basin B. Major Basin ODP will be treated in the ODP Pond, and Major Basin BF1 will be treated in Detention Pond A – Brookfield. LID SUMMARY TABLE Area treated by Stormtech LID Pond (ac) 4.78 Area treated by Rain Garden (ac) 2.15 Total LID (ac) 6.93 *Total Drainage Area (ac) 9.24 % Treated by LID 75.00% % Treated by ODP Pond and Detention Pond A - Brookfield 25.00% *Includes Major Basin A, Major Basin B, Basin BF1, Sub-Basin ODP2, and Sub-Basin ODP3. Excludes Sub-Basin ODP1. CONCLUSIONS A. COMPLIANCE WITH STANDARDS The design elements comply without the need for variances and meet all LID requirements. The drainage design proposed for The Savoy complies with the City of Fort Collins Master Drainage Plan, "Final Drainage Report and Erosion Control Report Banner Health Medical Table 1 - LID Summary Table NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY 10 | 11 Campus," and "Final Drainage Report for Brookfield." Excerpts from referenced reports can be found in Appendix F. There are no FEMA regulatory floodplains associated with The Savoy development. The drainage plan and stormwater management measures proposed with The Savoy project are compliant with all applicable State and Federal regulations governing stormwater discharge. B. DRAINAGE CONCEPT The drainage design proposed with this project will effectively limit potential damage associated with its stormwater runoff. The Savoy project will provide on-site LID treatment for runoff but will not be detaining any flows. Detention is provided either in the ODP Pond or Detention Pond A- Brookfield. The Savoy development will not impact the Master Drainage Plan recommendations for the McClelland Major Drainage Basin. NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY 11 | 11 REFERENCES 1. City of Fort Collins Landscape Design Guidelines for Stormwater and Detention Facilities, November 5, 2009, BHA Design, Inc. with City of Fort Collins Utility Services. 2. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, adopted by Ordinance No. 159, 2018, and referenced in Section 26-500 of the City of Fort Collins Municipal Code. 3. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation Service, United States Department of Agriculture. 4. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control District, Wright-McLaughlin Engineers, Denver, Colorado, Revised April 2008. 5. Final Drainage Report for Milestone Apartments, Northern Engineering, Fort Collins, Colorado, May 2014. 6. Final Drainage and Erosion Control Report Banner Health Medical Campus, Northern Engineering, Fort Collins, Colorado, September 2013. 7. Final Drainage and Erosion Control Report for Presidio Apartments, Northern Engineering, Fort Collins, Colorado, December 2009. 8. Final Drainage Report for Brookfield, TST, Inc. Consulting Engineers, Fort Collins, Colorado, December 2001. 9. East Harmony Portion of McClelland's Creek Master Drainage Plan Update Final Report, ICON Engineering, Inc., Englewood, Colorado, August 1999. 10. Geological and Preliminary Geotechnical Investigation, CTL Thompson, Fort Collins, Colorado, November 2021 NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINAY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY APPENDIX APPENDIX A HYDROLOGIC COMPUTATIONS CHARACTER OF SURFACE1: Percentage Impervious 2-yr Runoff Coefficient 10-yr Runoff Coefficient 100-yr Runoff Coefficient Developed Asphalt .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………100%0.95 0.95 1.00 Concrete .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………100%0.95 0.95 1.00 Rooftop .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………90%0.95 0.95 1.00 Gravel .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………40%0.50 0.50 0.63 Pavers .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………40%0.50 0.50 0.63 Landscape or Pervious Surface Playgrounds .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………25%0.35 0.35 0.44 Lawns Clayey Soil .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………2%0.25 0.25 0.31 Lawns Sandy Soil .…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..……………………………………………….…………………………..………………………………………………2%0.15 0.15 0.19 Notes: Basin ID Basin Area (ac) Area of Asphalt (ac) Area of Concrete (ac) Area of Rooftop (ac) Area of Gravel (ac) Area of Pavers (ac) Area of Playgrounds (ac) Area of Lawns (ac) Composite % Imperv. 2-year Composite Runoff Coefficient 10-year Composite Runoff Coefficient 100-year Composite Runoff Coefficient A1 0.17 0.00 0.00 0.13 0.00 0.00 0.00 0.03 73% 0.81 0.81 0.86 A2 0.46 0.00 0.37 0.03 0.00 0.00 0.00 0.06 87% 0.86 0.86 0.91 A3 0.64 0.00 0.51 0.03 0.00 0.00 0.00 0.11 83% 0.83 0.83 0.88 A4 0.17 0.00 0.00 0.13 0.00 0.00 0.00 0.03 72% 0.81 0.81 0.86 A5 0.27 0.00 0.01 0.20 0.00 0.00 0.00 0.06 72% 0.80 0.80 0.86 A6 0.19 0.00 0.01 0.10 0.00 0.00 0.00 0.08 56% 0.67 0.67 0.73 A7 0.36 0.00 0.33 0.00 0.00 0.00 0.00 0.03 92% 0.89 0.89 0.94 A8 0.52 0.00 0.47 0.00 0.00 0.00 0.00 0.05 91% 0.88 0.88 0.93 A9 0.63 0.00 0.21 0.18 0.00 0.00 0.00 0.23 61% 0.69 0.69 0.74 A10 0.51 0.00 0.45 0.00 0.00 0.00 0.00 0.06 89% 0.87 0.87 0.92 A11 0.60 0.00 0.46 0.00 0.00 0.00 0.00 0.14 77% 0.79 0.79 0.84 A12 0.24 0.00 0.00 0.20 0.00 0.00 0.00 0.04 77% 0.85 0.85 0.90 ODP1 0.45 0.27 0.00 0.00 0.00 0.00 0.00 0.18 60% 0.67 0.67 0.72 ODP2 0.90 0.27 0.09 0.26 0.00 0.00 0.00 0.28 67% 0.73 0.73 0.79 ODP3 0.25 0.04 0.06 0.04 0.00 0.00 0.00 0.11 57% 0.66 0.66 0.71 B1 0.25 0.00 0.01 0.13 0.00 0.00 0.00 0.11 52% 0.64 0.64 0.70 B2 0.51 0.00 0.48 0.00 0.00 0.00 0.00 0.04 93% 0.90 0.90 0.95 B3 0.58 0.00 0.48 0.00 0.00 0.00 0.00 0.10 82% 0.82 0.82 0.88 B4 0.25 0.00 0.00 0.20 0.00 0.00 0.00 0.04 75% 0.83 0.83 0.88 B5 0.39 0.00 0.01 0.26 0.00 0.00 0.00 0.11 65% 0.75 0.75 0.80 B6 0.17 0.00 0.01 0.00 0.00 0.00 0.00 0.17 7% 0.29 0.29 0.35 BF1 1.16 0.00 0.44 0.19 0.00 0.00 0.00 0.53 54% 0.63 0.63 0.69 MAJOR BASIN A, ODP2, and ODP3 5.93 0.31 3.01 1.32 0.00 0.00 0.00 1.30 76% 0.80 0.80 0.85 MAJOR BASIN A 4.78 0.00 2.92 1.01 0.00 0.00 0.00 0.85 80% 0.83 0.83 0.88 MAJOR BASIN B & BF1 3.31 0.00 1.43 0.79 0.00 0.00 0.00 1.10 65% 0.72 0.72 0.77 MAJOR BASIN B 2.15 0.00 0.98 0.60 0.00 0.00 0.00 0.57 71% 0.76 0.76 0.82 DEVELOPED BASIN % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS 2) Runoff Coefficients are taken from the Fort Collins Stormwater Criteria Manual, Chapter 3. Table 3.2-1 and 3.2-2 1) Percentage impervious taken from the Fort Collins Stormwater Criteria Manual, Chapter 5, Table 4.1-2 and Table 4.1-3 Combined Basins Overland Flow, Time of Concentration: Channelized Flow, Time of Concentration: Total Time of Concentration : T c is the lesser of the values of Tc calculated using T c = T i + T t C2 C100 Length, L (ft) Slope, S (%) Ti2 Ti100 Length, L (ft) Slope, S (%) Roughness Coefficient Assumed Hydraulic Radius Velocity, V (ft/s) Tt (min)Tc (Eq. 3.3-5) Tc2 = Ti +Tt Tc100 = Ti +Tt Tc2 Tc100 a1 A1 0.81 0.86 25 4.00%1.7 1.4 0 N/A N/A N/A N/A N/A 10.1 1.7 1.4 5.0 5.0 a2 A2 0.86 0.91 50 2.00%2.5 2.0 205 0.60%0.013 0.15 2.52 1.4 11.4 3.9 3.4 5.0 5.0 a3 A3 0.83 0.88 50 2.00%2.8 2.3 210 0.60%0.013 0.15 2.50 1.4 11.4 4.2 3.7 5.0 5.0 a4 A4 0.81 0.86 25 4.00%1.7 1.4 0 N/A N/A N/A N/A N/A 10.1 1.7 1.4 5.0 5.0 a5 A5 0.80 0.86 25 4.00%1.8 1.4 25 5.00%0.030 0.40 6.03 0.1 10.3 1.8 1.5 5.0 5.0 a6 A6 0.67 0.73 25 4.00%2.5 2.2 25 5.00%0.030 0.40 6.03 0.1 10.3 2.6 2.2 5.0 5.0 a7 A7 0.89 0.94 50 2.00%2.2 1.7 140 1.57%0.013 0.15 4.06 0.6 11.1 2.8 2.3 5.0 5.0 a8 A8 0.88 0.93 50 2.00%2.3 1.8 140 2.00%0.013 0.15 4.58 0.5 11.1 2.8 2.3 5.0 5.0 a9 A9 0.69 0.74 50 2.00%4.3 3.8 0 N/A N/A N/A N/A N/A 10.3 4.3 3.8 5.0 5.0 a10 A10 0.87 0.92 35 2.00%2.0 1.6 145 1.59%0.013 0.15 4.08 0.6 11.0 2.6 2.2 5.0 5.0 a11 A11 0.79 0.84 35 2.00%2.7 2.3 145 0.60%0.013 0.15 2.51 1.0 11.0 3.7 3.2 5.0 5.0 a12 A12 0.85 0.90 25 4.00%1.5 1.2 0 N/A N/A N/A N/A N/A 10.1 1.5 1.2 5.0 5.0 odp1 ODP1 0.67 0.72 13 5.77%1.6 1.4 467 0.50%0.016 0.19 2.18 3.6 12.7 5.2 5.0 5.2 5.0 odp2 ODP2 0.73 0.79 15 0.67%3.1 2.6 467 0.50%0.016 0.19 2.18 3.6 12.7 6.6 6.1 6.6 6.1 odp3 ODP3 0.66 0.71 50 4.00%3.7 3.2 134 0.75%0.016 0.19 2.66 0.8 11.0 4.5 4.1 5.0 5.0 b1 B1 0.64 0.70 25 4.00%2.7 2.4 0 N/A N/A N/A N/A N/A 10.1 2.7 2.4 5.0 5.0 b2 B2 0.90 0.95 35 2.00%1.8 1.3 289 1.09%0.013 0.15 3.38 1.4 11.8 3.2 2.7 5.0 5.0 b3 B3 0.82 0.88 35 2.00%2.5 1.9 200 2.00%0.013 0.15 4.58 0.7 11.3 3.2 2.7 5.0 5.0 b4 B4 0.83 0.88 25 4.00%1.6 1.3 0 N/A N/A N/A N/A N/A 10.1 1.6 1.3 5.0 5.0 b5 B5 0.75 0.80 25 4.00%2.1 1.8 25 6.00%0.030 0.40 6.60 0.1 10.3 2.1 1.8 5.0 5.0 b6 B6 0.29 0.35 50 12.00%4.7 4.3 0 N/A N/A N/A N/A N/A 10.3 4.7 4.3 5.0 5.0 bf1 BF1 0.63 0.69 25 0.67%5.0 4.4 935 0.63%0.013 0.15 2.57 6.1 15.3 11.1 10.4 11.1 10.4 ODP Pond MAJOR BASIN A, ODP2, and ODP3 0.80 0.85 35 2.00% 2.6 2.2 385 0.60% 1.30% 15.00% 0.25 25.7 12.3 28.3 27.9 12.3 12.3 STORMTECH MAJOR BASIN A 0.83 0.88 35 2.00% 2.4 1.9 385 0.60%1.30% 15.00% 0.25 25.7 12.3 28.0 27.6 12.3 12.3 BROOKFIELD POND MAJOR BASIN B & BF1 0.72 0.77 25 0.68% 4.0 3.5 935 0.02% 1.30% 15.00% 0.04 347.1 15.3 351.1 350.6 15.3 15.3 RAIN GARDEN MAJOR BASIN B 0.76 0.82 25 0.68% 3.6 3.0 935 0.02% 1.30% 15.00% 0.04 347.1 15.3 350.7 350.1 15.3 15.3 Combined Basins DEVELOPED DIRECT TIME OF CONCENTRATION Channelized Flow Design Point Basin Overland Flow Time of Concentration Frequency Adjustment Factor: (Equation 3.3-2 FCSCM) (Equation 5-5 FCSCM) (Equation 5-4 FCSCM) (Equation 3.3-5 FCSCM) Table 3.2-3 FCSCM Therefore Tc2=Tc10 Rational Method Equation: Rainfall Intensity: a1 A1 0.17 5.0 5.0 0.81 0.86 2.85 4.87 9.95 0.39 0.67 1.46 a2 A2 0.46 5.0 5.0 0.86 0.91 2.85 2.85 9.95 1.13 1.13 4.19 a3 A3 0.64 5.0 5.0 0.83 0.88 2.85 2.85 9.95 1.52 1.52 5.62 a4 A4 0.17 5.0 5.0 0.81 0.86 2.85 2.85 9.95 0.39 0.39 1.46 a5 A5 0.27 5.0 5.0 0.80 0.86 2.85 2.85 9.95 0.62 0.62 2.34 a6 A6 0.19 5.0 5.0 0.67 0.73 2.85 2.85 9.95 0.37 0.37 1.40 a7 A7 0.36 5.0 5.0 0.89 0.94 2.85 2.85 9.95 0.91 0.91 3.36 a8 A8 0.52 5.0 5.0 0.88 0.93 2.85 2.85 9.95 1.32 1.32 4.86 a9 A9 0.63 5.0 5.0 0.69 0.74 2.85 2.85 9.95 1.24 1.24 4.64 a10 A10 0.51 5.0 5.0 0.87 0.92 2.85 2.85 9.95 1.27 1.27 4.68 a11 A11 0.60 5.0 5.0 0.79 0.84 2.85 2.85 9.95 1.36 1.36 5.04 a12 A12 0.24 5.0 5.0 0.85 0.90 2.85 2.85 9.95 0.59 0.59 2.17 odp1 ODP1 0.45 5.0 5.0 0.67 0.72 2.85 2.85 9.95 0.87 0.87 3.25 odp2 ODP2 0.90 6.1 6.1 0.73 0.79 2.67 2.67 9.31 1.75 1.75 6.61 odp3 ODP3 0.25 5.0 5.0 0.66 0.71 2.85 2.85 9.95 0.47 0.47 1.78 b1 B1 0.25 5.0 5.0 0.64 0.70 2.85 2.85 9.95 0.45 0.45 1.71 b2 B2 0.51 5.0 5.0 0.90 0.95 2.85 2.85 9.95 1.31 1.31 4.83 b3 B3 0.58 5.0 5.0 0.82 0.88 2.85 2.85 9.95 1.36 1.36 5.09 b4 B4 0.25 5.0 5.0 0.83 0.88 2.85 2.85 9.95 0.59 0.59 2.17 b5 B5 0.39 5.0 5.0 0.75 0.80 2.85 2.85 9.95 0.83 0.83 3.10 b6 B6 0.17 5.0 5.0 0.29 0.35 2.85 2.85 9.95 0.14 0.14 0.61 bf1 BF1 1.16 10.4 10.4 0.63 0.69 2.21 2.21 7.72 1.62 1.62 6.18 ODP Pond MAJOR BASIN A, ODP2, and ODP3 5.93 12.3 12.3 0.80 0.85 2.05 2.05 7.16 9.73 10.34 36.11 STORMTECH MAJOR BASIN A 4.78 12.3 12.3 0.83 0.88 2.05 2.05 7.16 8.14 8.63 30.13 BROOKFIELD POND MAJOR BASIN B & BF1 3.31 15.3 15.3 0.72 0.77 1.87 1.87 6.52 4.46 4.77 16.62 RAIN GARDEN MAJOR BASIN B 2.15 15.3 15.3 0.76 0.82 1.87 1.87 6.52 3.06 3.30 11.50 Combined Basins Tc100 (min) Intensity, i2 (in/hr) Intensity, i100 (in/hr) DEVELOPED RUNOFF COMPUTATIONS Design Point Basin(s)Area, A (acres) Tc2 (min) Flow, Q2 (cfs) Flow, Q100 (cfs) C2 C100 IDF Table for Rational Method - Table 3.4-1 FCSCM Intensity, i10 (in/hr) Flow, Q10 (cfs) ()()()AiCCQf= BASIN TOTAL AREA (acres) Tc2 (min) Tc100 (min) C2 C100 Q2 (cfs) Q100 (cfs) A1 0.17 5.0 5.0 0.81 0.86 0.39 1.46 A2 0.46 5.0 5.0 0.86 0.91 1.13 4.19 A3 0.64 5.0 5.0 0.83 0.88 1.52 5.62 A4 0.17 5.0 5.0 0.81 0.86 0.39 1.46 A5 0.27 5.0 5.0 0.80 0.86 0.62 2.34 A6 0.19 5.0 5.0 0.67 0.73 0.37 1.40 A7 0.36 5.0 5.0 0.89 0.94 0.91 3.36 A8 0.52 5.0 5.0 0.88 0.93 1.32 4.86 A9 0.63 5.0 5.0 0.69 0.74 1.24 4.64 A10 0.51 5.0 5.0 0.87 0.92 1.27 4.68 A11 0.60 5.0 5.0 0.79 0.84 1.36 5.04 A12 0.24 5.0 5.0 0.85 0.90 0.59 2.17 ODP1 0.45 5.0 5.0 0.67 0.72 0.87 3.25 ODP2 0.90 6.1 6.1 0.73 0.79 1.75 6.61 ODP3 0.25 5.0 5.0 0.66 0.71 0.47 1.78 B1 0.25 5.0 5.0 0.64 0.70 0.45 1.71 B2 0.51 5.0 5.0 0.90 0.95 1.31 4.83 B3 0.58 5.0 5.0 0.82 0.88 1.36 5.09 B4 0.25 5.0 5.0 0.83 0.88 0.59 2.17 B5 0.39 5.0 5.0 0.75 0.80 0.83 3.10 B6 0.17 5.0 5.0 0.29 0.35 0.14 0.61 BF1 1.16 10.4 10.4 0.63 0.69 1.62 6.18 MAJOR BASIN A, ODP2, and ODP3 5.93 12.3 12.3 0.80 0.85 9.73 36.11 MAJOR BASIN A 4.78 12.3 12.3 0.83 0.88 8.14 30.13 MAJOR BASIN B & BF1 3.31 15.3 15.3 0.72 0.77 4.46 16.62 MAJOR BASIN B 2.15 15.3 15.3 0.76 0.82 3.06 11.50 Rational Flow Summary | Developed Basin Flow Rates Combined Basins 9/9/20229:29 AM P:\514-003\Drainage\Hydrology\514-003_Proposed Rational Calcs (FCSCM).xlsx\Summary Tables NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY APPENDIX APPENDIX B HYDRAULIC CALCULATIONS – FOR FUTURE USE NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY APPENDIX APPENDIX C WATER QUALITY/LID COMPUTATIONS Project Title Date: Project Number Calcs By: City Basins 0.8 WQCV = Watershed inches of Runoff (inches)80% a = Runoff Volume Reduction (constant) i = Total imperviousness Ratio (i = Iwq/100)0.263 in A =4.78 ac V = 0.1255 ac-ft V = Water Quality Design Volume (ac-ft) WQCV = Water Quality Capture Volume (inches) A = Watershed Area (acres) 5469 cu. ft. Drain Time a = i = WQCV = Figure EDB-2 - Water Quality Capture Volume (WQCV), 80th Percentile Runoff Event The Savoy September 9, 2022 514-003 B. Mathisen Fort Collins Stormtech LID Pond 0.231 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 00.10.20.30.40.50.60.70.80.91WQCV (watershed inches)Total Imperviousness Ratio (i = Iwq/100) Water Quality Capture Volume 6 hr 12 hr 24 hr 40 hr ()iii78.019.10.91aWQCV 23 +-= ()iii78.019.10.91aWQCV 23 +-= 12 hr 1.20 WQCV 12 ∗ Pond No : Stormtech Pond WQ 0.83 5.00 min 3989 ft3 4.78 acres 0.09 ac-ft Max Release Rate =0.96 cfs Time (min) Ft Collins WQ Intensity (in/hr) Inflow Volume (ft3) Outflow Adjustmen t Factor Qav (cfs) Outflow Volume (ft3) Storage Volume (ft3) 5 1.425 1696 1.00 0.96 287 1409 10 1.105 2630 1.00 0.96 574 2056 15 0.935 3339 0.67 0.64 574 2764 20 0.805 3833 0.63 0.60 718 3114 25 0.715 4255 0.60 0.57 862 3393 30 0.650 4642 0.58 0.56 1005 3637 35 0.585 4874 0.57 0.55 1149 3725 40 0.535 5094 0.56 0.54 1292 3802 45 0.495 5302 0.56 0.53 1436 3866 50 0.460 5475 0.55 0.53 1580 3895 55 0.435 5695 0.55 0.52 1723 3972 60 0.410 5856 0.54 0.52 1867 3989 65 0.385 5957 0.54 0.52 2011 3947 70 0.365 6082 0.54 0.51 2154 3928 75 0.345 6159 0.53 0.51 2298 3862 80 0.330 6284 0.53 0.51 2441 3843 85 0.315 6374 0.53 0.51 2585 3789 90 0.305 6534 0.53 0.51 2729 3806 95 0.290 6558 0.53 0.50 2872 3686 100 0.280 6665 0.53 0.50 3016 3649 105 0.270 6749 0.52 0.50 3159 3589 110 0.260 6808 0.52 0.50 3303 3505 115 0.255 6981 0.52 0.50 3447 3534 120 0.245 6998 0.52 0.50 3590 3408 *Note: Using the method described in FCSCM Chapter 6 Section 2.3 A = Tc = Project Location : Design Point C = Design Storm DETENTION POND CALCULATION; MODIFIED FAA METHOD w/ Ft Collins IDF Input Variables Results Required Detention Volume Fort Collins, Colorado 514-003 The Savoy Project Number : Project Name : Stormtech LID Pond Page 2 of 5 514-003 LID Chamber Summary.xlsx Vault IDTotal RequiredWQ Volume(cf)Flow,WQ(cfs)ChamberTypeChamber Release Ratea(cfs)ChamberVolumeb(cf)Installed Camber w/ Aggregatec(cf)Mimimum No. of ChambersdTotal Release Ratee(cfs)Required Storage Volume by FAA Method(cf)Mimimum No. of ChambersfStorage Provided within the Chambersg(cf)Total Installed System Volumeh(cf)Stormtech LID Pond 5469 4.07 MC-4500 0.028 106.50 162.60 34 0.96 3989384047 5528a. Release rate per chamber, limited by flow through geotextile with accumulated sediment.b. Volume within chamber only, not accounting for void spaces in surrounding aggregate.c. Volume includes chamber and void spaces (40%) in surrounding aggregate, per chamber unit.d. Number of chambers required to provide full WQCV within total installed system, including aggregate.e. Release rate per chamber times number of chambers.f. Number of chambers required to provide required FAA storage volume stored within the chamber only (no aggregate storage).g. Volume provided in chambers only (no aggregate storage). This number must meet or exceed the required FAA storage volume.h. System volume includes total number of chambers, plus surrounding aggregate. This number must meet or exceed the required WQCV.Chamber Configuration SummaryP:\514-003\Drainage\LID\514-003 LID Chamber Summary.xlsx Chamber Dimensions SC-160 SC-310 SC-740 MC-3500 MC-4500 Width (in)34.0 34.0 51.0 77.0 100.0 Length (in)85.4 85.4 85.4 90.0 52.0 Height (in)16.0 16.0 30.0 45.0 60.0 Floor Area (sf)20.2 20.2 30.2 48.1 36.1 Chamber Volume (cf)6.9 14.7 45.9 109.9 106.5 Chamber/Aggregate Volume (cf)29.3 29.3 74.9 175.0 162.6 Flow Rate* 0.35 gpm/sf 1 cf =7.48052 gal 1 gallon =0.133681 cf 1 GPM = 0.002228 cfs *Flow rate based on 1/2 of Nov 07 QMAX in Figure 17 of UNH Testing Report SC-160 SC-310 SC-740 MC-3500 MC-4500 Flow Rate/chamber (cfs) 0.015724 0.015724 0.023586 0.037528 0.028159 end caps have a volume of 108.7 cu. ft. StormTech Chamber Data Chamber Flow Rate Chamber Flow Rate Conversion (gpm/sf to cfs) end caps have a volume of 45.1 cu. ft. P:\514-003\Drainage\LID\514-003 LID Chamber Summary.xlsx Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia =71.0 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.710 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.22 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 93,654 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 =0.43 in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER =cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =2,096 cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum)DWQCV =12 in B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft (Use "0" if rain garden has vertical walls) C) Mimimum Flat Surface Area AMin =1330 sq ft D) Actual Flat Surface Area AActual =2119 sq ft E) Area at Design Depth (Top Surface Area)ATop =2913 sq ft F) Rain Garden Total Volume VT=2,516 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media 4. Underdrain System A) Are underdrains provided?1 B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y =2.5 ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 =2,096 cu ft iii) Orifice Diameter, 3/8" Minimum DO =1 in Design Procedure Form: Rain Garden (RG) Blaine Mathisen Northern Engineering September 9, 2022 The Savoy Fort Collins, CO UD-BMP (Version 3.07, March 2018) Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO Major Basin B - Raingarden.xlsm, RG 9/9/2022, 9:21 AM Sheet 2 of 2 Designer: Company: Date: Project: Location: 5. Impermeable Geomembrane Liner and Geotextile Separator Fabric A) Is an impermeable liner provided due to proximity of structures or groundwater contamination? 6. Inlet / Outlet Control A) Inlet Control 7. Vegetation 8. Irrigation A) Will the rain garden be irrigated? Notes: Design Procedure Form: Rain Garden (RG) Blaine Mathisen Northern Engineering September 9, 2022 The Savoy Fort Collins, CO Choose One Choose One Choose One Sheet Flow- No Energy Dissipation Required Concentrated Flow- Energy Dissipation Provided Plantings Seed (Plan for frequent weed control) Sand Grown or Other High Infiltration Sod Choose One YES NO YES NO Major Basin B - Raingarden.xlsm, RG 9/9/2022, 9:21 AM Area treated by Stormtech LID Pond (ac)4.78 Area treated by Rain Garden (ac)2.15 Total LID (ac)6.93 *Total Drainage Area (ac)9.24 % Treated by LID 75.00% % Treated by ODP Pond and Detention Pond A - Brookfield 25.00% LID SUMMARY TABLE *Includes Major Basin A, Major Basin B, Basin BF1, Sub-Basin ODP2, and Sub-Basin ODP3. Excludes Sub-Basin ODP1. BUILDING 2 BUILDING 4BUILDING 5BUILDING 6BUILDING 7BUILDING 8SUITES &MAIL LOUNGEBUILDING 3BUILDING 1 UDMONITO R I NG WE L L TRAFFIC R AT E D ST ST ST ST ST ST STSTSTSTSTD D D DD D DD D D H2OGAS GAS VAULT ELEC V.P. S S ST PRECISION DRIVE BROOKFIELD DRIVELE FEVER DRIVE CINQUEFOIL LANERAIN GARDEN OVERFLOW OUTFALL RAIN GARDEN FLAT AREA = 2,119 SQ. FT. (1,350 SQ. FT. MINIMUM) 38 MC-4500 STORMTECH ISOLATOR CHAMBERS WATER QUALITY BASIN W/ WEIR LANDSCAPE DRAIN (TYP.) LANDSCAPE DRAIN (TYP.) LANDSCAPE DRAIN (TYP.) LANDSCAPE DRAIN (TYP.) LANDSCAPE DRAIN (TYP.) AREA INLET AREA INLET AREA INLET AREA INLET AREA INLET TYPE R INLET TYPE R INLET TYPE R INLET AREA INLET EXISTING TYPE R INLET EMERGENCY OVERFLOW PATH AREA INLET FOREBAY TOTAL DRAINAGE AREA TOTAL DRAINAGE AREA TOTAL DRAINAGE AREA TOTAL DRAINAGE AREA LID EXHIBIT FORT COLLINS, CO THE SAVOY E N G I N E E R N GI EHTRON R N 09.09.2022 P:\514-003\DWG\DRNG\514-003_LID.DWG Area treated by Stormtech LID Pond (ac)4.78 Area treated by Rain Garden (ac)2.15 Total LID (ac)6.93 *Total Drainage Area (ac)9.24 % Treated by LID 75.00% % Treated by ODP Pond and Detention Pond A - Brookfield 25.00% NOTES: 1.Refer to The Savoy - Utility Plans for additional clarification on basin breakdowns, grading, and utility sizing. 2.Buildings 3 - 6 have storm drains along the R.O.W for anticipated roof leader connections. LID SUMMARY AND LEGEND: *Includes Major Basin A, Major Basin B, Basin BF1, Sub-Basin ODP2, and Sub-Basin ODP3. Excludes Sub-Basin ODP1 NORTH ( IN FEET ) 0 1 INCH = 80 FEET 80 80 160 240 NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY APPENDIX APPENDIX D EROSION CONTROL REPORT NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY EROSION CONTROL REPORT EROSION CONTROL REPORT A comprehensive Erosion and Sediment Control Plan (along with associated details) will be included with the final construction drawings. It should be noted; however, any such Erosion and Sediment Control Plan serves only as a general guide to the Contractor. Staging and/or phasing of the BMPs depicted, and additional or different BMPs from those included may be necessary during construction, or as required by the authorities having jurisdiction. It shall be the responsibility of the Contractor to ensure erosion control measures are properly maintained and followed. The Erosion and Sediment Control Plan is intended to be a living document, constantly adapting to site conditions and needs. The Contractor shall update the location of BMPs as they are installed, removed, or modified in conjunction with construction activities. It is imperative to appropriately reflect the current site conditions at all times. The Erosion and Sediment Control Plan shall address both temporary measures to be implemented during construction, as well as permanent erosion control protection. Best Management Practices from the Volume 3, Chapter 7 – Construction BMPs will be utilized. Measures may include, but are not limited to, silt fencing and/or wattles along the disturbed perimeter, gutter protection in the adjacent roadways, and inlet protection at existing and proposed storm inlets. Vehicle tracking control pads, spill containment and clean-up procedures, designated concrete washout areas, dumpsters, and job site restrooms shall also be provided by the Contractor. Grading and Erosion Control Notes can be found on Sheet CS2 of the Utility Plans. The Final Utility Plans will also contain a full-size Erosion Control Plan as well as a separate sheet dedicated to Erosion Control Details. In addition to this report and the referenced plan sheets, the Contractor shall be aware of, and adhere to, the applicable requirements outlined in any existing Development Agreement(s) of record, as well as the Development Agreement, to be recorded prior to issuance of the Development Construction Permit. Also, the Site Contractor for this project may be required to secure a Stormwater Construction General Permit from the Colorado Department of Public Health and Environment (CDPHE), Water Quality Control Division – Stormwater Program, before commencing any earth disturbing activities. Prior to securing said permit, the Site Contractor shall develop a comprehensive Storm Water Management Plan (SWMP) pursuant to CDPHE requirements and guidelines. The SWMP will further describe and document the ongoing activities, inspections, and maintenance of construction BMPs. NNORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY APPENDIX APPENDIX E EXCERPTS FROM PREVIOUS REPORTS AND USDA SOILS REPORT May 9, 2014 FINAL DRAINAGE REPORT FOR MILESTONE APARTMENTS Fort Collins, Colorado Prepared for: Milestone, Terra Vida II LLP 1400 16th Street, 6th Floor Denver, Colorado 80202 Prepared by: 200 South College Avenue, Suite 10 Fort Collins, Colorado 80524 Phone: 970.221.4158 Fax: 970.221.4159 www.northernengineering.com Project Number: 514-002  This Drainage Report is consciously provided as a PDF. Please consider the environment before printing this document in its entirety. When a hard copy is absolutely necessary, we recommend double-sided printing. Milestone Apartments Final Drainage Report 7 2. The offsite detention/water quality pond, referred to as the “ODP Pond”, currently under review with the Banner Health Medical Campus, will be constructed just to the northeast of the site. The pond has been designed to incorporate all necessary detention, water quality, and L.I.D. (Low Impact Design) requirements for the north portion (Basin 1 - 3.88 acres) of the Terra Vida 2 site. Please see the Banner Health Master Drainage Exhibit provided in Appendix C. The portion of the Terra Vida 2 site that was anticipated to drain to the “ODP Pond” is identified on this exhibit as “Basin 4”. There will be 0.16 acres less than originally anticipated draining to the “ODP Pond” from the Terra Vida 2 site. It is noted that the offsite ODP Pond was previously agreed to by City Stormwater to provide all water quality and L.I.D. measures for both the Terra Vida 2 site, noted as “Tract I” in the Banner Health Medical Campus project, as well as “Tract K” (just northeast of the Terra Vida 2 site) and “Tract M” (just east of the Terra Vida 2 site). 3. The offsite storm sewer system in Precision Drive, which was recently constructed, will receive and convey storm runoff from the south portion of the Terra Vida Site (5.67 acres). Please see the Precision Drive Drainage Exhibit, provided in Appendix D (excerpt from approved Final Drainage Report submitted as “Presidio Apartments”, now referred to as “Terra Vida 1 Apartments”, Ref. 6). The portion of the Terra Vida 2 site that was anticipated to drain to the previously approved Precision Drive storm sewer system is identified in this exhibit as “Basin 1”, “Basin 2”, and a portion of “Basin 3”. There will be 0.13 acres more than originally anticipated draining to the Precision Drive storm sewer system from the Terra Vida 2 site. 4. A list of tables and figures used within this report can be found in the Table of Contents at the front of the document. The tables and figures are located within the sections to which the content best applies. 5. The drainage patterns anticipated for proposed drainage basins are described below. Basins 1A and 1B Basins 1A and 1B will consist of apartment complex development. These basins will generally drain via parking and drive curb and gutter to inlets and an internal storm drain system. This system will tie to the offsite storm line system currently under review with the Banner Health Medical Campus. This offsite storm system will convey runoff to the offsite detention/water quality pond, referred to as the “ODP Pond”, currently under construction with the Banner Health Medical Campus, just to the northeast of the site. Basin 2 Basin 2 rooftops and landscaped areas. This basin will generally drain via sheet flow into the Lady Mood Drive R.O.W. Runoff will be collected in the existing Lady Moon Drive storm sewer system and directed to the existing offsite detention pond within the Willow Brook Subdivision. Basins 3A - 3D Basins 3A through 3D will consist of apartment complex development. These basins will generally drain via parking and drive curb and gutter to inlets and an internal storm drain system. This system will tie to the offsite storm line system in Precision Drive, which was recently constructed and will drain to the existing offsite detention pond within the Willow Brook Subdivision. September 20, 2013 FINAL DRAINAGE AND EROSION CONTROL REPORT BANNER HEALTH MEDICAL CAMPUS Fort Collins, Colorado Prepared for: Banner Health 1801 16th Street Greeley, CO 80631 Prepared by: 200 South College Avenue, Suite 10 Fort Collins, Colorado 80524 Phone: 970.221.4158 Fax: 970.221.4159 www.northernengineering.com Project Number: 306-003  This Drainage Report is consciously provided as a PDF. Please consider the environment before printing this document in its entirety. When a hard copy is absolutely necessary, we recommend double-sided printing. PRIVATE DR. RD RD RD RD RD RD RD HY DHY DHY DHY DG G T S T S FESHYD HY DHY DGAS GASFESFESFESFESFESFESFES R R D D D D D D DD D D D D D LOT ONE HARMONY TECHNOLOGY PARK, SECOND FILING LOT TWO HARMONY TECHNOLOGY PARK, SECOND FILING LOT TWO HARMONY TECHNOLOGY PARK, SECOND FILING PRECISION DRIVE OWNER: ANDERSON, KATHRYN JOY WINCHESTER, ELSIE A / SUSAN P BILL RAY II / LUCAS, SHERI W OWNER: CHANDLER, J THOMAS OWNER: CHANDLER, J THOMAS TRACT E BROOKFIELD PARCEL V PART B PARCEL VII HY DFESFES V.P.V.P. V.P.V.P. V.P. V.P. V.P. V.P. V.P. V.P. V.P. V.P. V.P. V.P.V.P.FES FE SC.O. LID LID PROPOSED STORM LINE PROPOSED STORM LINE TOTAL VOLUME~2.62 AC-FT POND AREA~38,288 SF / 0.90 ACRES 100 YR. RELEASE RATE 9.30 CFS TOTAL VOLUME~3.92 AC-FT SURFACE AREA 48,207 SF / 1.10 AC 100 YR. RELEASE RATE 0.7 CFS FOSSIL CREEK RESERVO IR INLET D ITCH IRR IGAT ION D ITCH ACCESS ROAD PROPOSED PLD SECTION WITH UNDERDRAIN O-1 5.10 O-2 5.90 PROPOSED STORM LINE 1 2 3 4 12 16 17 13 19 21 22 14 6 7 8 10 9b 11 18 9a 5 1 3.40 2 2.55 3 0.58 5 0.65 9a 1.08 9b 0.55 10 0.59 6 0.64 7 0.33 8 0.47 4 0.50 12 1.65 16 0.50 13 3.44 14 2.57 17 4.01 18 2.33 19 1.56 21 0.21 22 0.52 15 1.61 11 0.39 20 1.05 15 20 PROPOSED HELIPAD HARMONY ROAD LADY MOON DR.CINQUEFOIL LANELE FEV E R D R.CINQUEFOIL LANELADY MOON DR.TIMBERWOOD DR.CINQUEFOIL LANEFULL BUILD FULL BUILD FULL BUILD FULL BUILD FULL BUILD FULL BUILD PROPOSED BUILDING TRACT K TRACT I TRACT M PROPOSED BUILDING H-1 1.05 H-1 POND 1 POND 2 ODP POND O-1 O-2 O-3 O-3 23.79 NORTH ( IN FEET ) 1 inch = ft. Feet0100100 100 200 300 KEYMAP HARMONY ROAD BROOKFIELD DRIVELE FEVER DRIVE TIMBERWOOD DRIVE LADY MOON DR.CINQUEFOIL LANECALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. CALL UTILITY NOTIFICATION CENTER OF COLORADO Know what's below. before you dig.Call R Date Date Date Date Date DateAPPROVED: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: City Engineer Water & Wastewater Utility Stormwater Utility Parks & Recreation Traffic Engineer Environmental Planner City of Fort Collins, Colorado UTILITY PLAN APPROVAL EXHIBIT MASTER DRAINAGE C600 FOR DRAINAGE REVIEW ONLY. NOT FOR CONSTRUCTION. FORT COLLINS, COLORADO BANNER HEALTH MEDICAL CAMPUS SEPTEMBER 20, 2013 SHEET HARMONY RD. & LADY MOON DR. BOULDER ASSOCIATES ARCHITECTS 1426 PEARL ST., SUITE 300 BOULDER, CO 303.499.7795 OF 60 FINAL PLAN ODP POND CONTRIBUTIONS IMAGO TRACT I IMAGO TRACT K IMAGO TRACT M ODP POND TOTAL IMAGO TRACT I 100-YEAR RELEASE RATE VOLUME TO ODP POND (CFS) 1.0 AC-FT 25.1 10.0 1.1 AC-FT 5.5 AC-FT 1.4 AC-FT IMAGO TOTAL 8.0 AC-FT 9.0 AC-FT BANNER HEALTH MEDICAL CAMPUS EASEMENT AREA (SQFT)(ACRES) 23,433 0.538 187,464 4.304 4.842210,897 LEGEND: 4953 PROPOSED CONTOUR 93 PROPOSED STORM SEWER PROPOSED SWALE EXISTING CONTOUR PROPOSED CURB & GUTTERPROPERTY BOUNDARY PROPOSED INLET ADESIGN POINT FLOW ARROW DRAINAGE BASIN LABEL BASIN DESIGNATION BASIN AREA (AC) DRAINAGE BASIN BOUNDARY PROPOSED SWALE SECTION AA B2 1.45 ac 1.REFER TO THE "FINAL DRAINAGE REPORT FOR BANNER HEALTH MEDICAL CAMPUS" BY NORTHERN ENGINEERING FOR ADDITIONAL INFORMATION. 2.THE FINISHED FLOOR ELEVATIONS SHOWN ARE THE MINIMUM ELEVATIONS REQUIRED FOR PROTECTION FROM THE 100-YEAR STORM. 3.FULL BUILD AS SHOWN IS PROVIDED FOR REFERENCE ONLY TO INDICATE ULTIMATE BASIN IMPERVIOUSNESS AND BOUNDARY AREAS. NOTES: 2 FtCollins-100yr pond2 13.00 82.79 2221 1 0 3 FtCollins-100yr mh6 23.79 90 2976 1.0 0 4 FtCollins-100yr mh4 5.16 80 1498 1 0 5 FtCollins-100yr mh6 5.9 85 1030 1 0 7 FtCollins-100yr mh3 5.15 70 747 1 0 [SUBAREAS] ;;Subcatchment N-Imperv N-Perv S-Imperv S-Perv PctZero RouteTo PctRouted ;;-------------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- 1 .016 .25 .1 .3 0 OUTLET 2 .016 .25 .1 .3 0 OUTLET 3 .016 .25 .1 .3 0 OUTLET 4 .016 .25 .1 .3 0 OUTLET 5 .016 .25 .1 .3 0 OUTLET 7 .016 .25 .1 .3 0 OUTLET [INFILTRATION] ;;Subcatchment Param1 Param2 Param3 Param4 Param5 ;;-------------- ---------- ---------- ---------- ---------- ---------- 1 .51 0.5 6.48 7 0 2 .51 0.5 6.48 7 0 3 .51 0.5 6.48 7 0 4 .51 0.5 6.48 7 0 5 .51 0.5 6.48 7 0 7 .51 0.5 6.48 7 0 [JUNCTIONS] ;;Name Elevation MaxDepth InitDepth SurDepth Aponded ;;-------------- ---------- ---------- ---------- ---------- ---------- mh2 101 10 0 10 0 mh3 99 10 0 10 0 mh5 98 0 0 0 0 mh4 101 10 0 10 0 mh6 97.5 0 0 0 0 [OUTFALLS] ;;Name Elevation Type Stage Data Gated Route To ;;-------------- ---------- ---------- ---------------- -------- ---------------- FCRID 96 FREE NO [STORAGE] ;;Name Elev. MaxDepth InitDepth Shape Curve Name/Params N/A Fevap Psi Ksat IMD ;;-------------- -------- ---------- ----------- ---------- ---------------------------- -------- -------- -------- -------- pond1 105 10 0 TABULAR pond1 0 0 pond2 105 10 0 TABULAR detpond2 0 0 pond3 97 10 0 TABULAR pond3 0 0 Final Drainage and Erosion Control Report for PRESIDIO APARTMENTS Fort Collins, Colorado December 21, 2009 Prepared for: Ken Kiken Milestone Development Group, LLC 1400 16th Street, 6th Floor Denver, Colorado 80202-1473 Prepared by: 200 South College Avenue, Suite 100 Fort Collins, Colorado 80524 Phone: 970.221.4158 Fax: 970.221.4159 www.northernengineering.com Project Number: 514-001 Presidio Apartments Final Drainage and Erosion Control Report 4 FIGURE 1 – Proposed Site Plan 8.0 Proposed Drainage Plan The developed site has been broken into eleven (11) developed drainage basins. Developed stormwater from the site will be conveyed primarily via gutter flow and through an on-site storm drain system into the landscape enhanced detention/water quality pond. Detention and water quality treatment of the adjacent half streets of Rock Creek Drive and Cinquefoil Lane has already been accommodated in existing facilities. Existing sump inlets in Cinquefoil Lane capture and convey flows from Rock Creek Drive and Cinquefoil Lane into the existing storm line system for the Brookfield subdivision. All drainage from the right-of-way of Precision Drive, as well as a small on-site basin (Basin 6, 0.35 acres), will be conveyed via a new storm line, which ties into the existing storm system for the Brookfield subdivision. (NOTE: said storm line within Precision Drive shall be constructed by the Overall Presidio Developer, not the Apartment Developer). The existing storm system conveys flows into the Brookfield detention/water quality pond. This pond was originally designed to accommodate flows from approximately 10-acres of future development. The Precision Drive right- of-way and assumed basins to the north of Precision Drive (see Future Precision Drive Drainage Basins Exhibit, Appendix E) are consistent with the assumptions made in the design of the Brookfield pond. Runoff volume and peak 100-year flow from the assumed basins to the north of, and including, Precision Drive will not exceed quantities assumed in the original design of the Brookfield pond. APPENDIX D PRECISION DRIVE DRAINAGE PLAN S D D S D D S ELEC S WV WVWV WV WV HY DD S WV WV ELEC SV.P. S S S V.P.V.P.S SV.P.V.P.V.P. V.P. S V.P. V.P.S S S S V.P. H2O S HY DELEC S X VAULT ELEC VAULT ELECVAULT CABLE V.P. X X ELEC VAULT ELEC WV WV S S WV WV D V.P.V.P. V.P.V.P. S WV WV S DX X X XXWS OXV.P.XXWSO S DD D S D D SSANI SANI SANI D DD S VAULT ELEC WV WV WV S VAULT ELECEEEEVAULT ELEC EEEE EW 8" W HY DWVWV 8" W 8" W 8" WHY DWV WV WVWV WV WWV WV 8" W WV WV 12" WFO FO FO FO FO FO FOCABLEELEC TTTTTG G G GGGASTT TTTT T T T TELE H2OGAS GAS VAULT ELEC VAULT ELECELEC E D FE SFES D VAULT ELEC V.P.WV.P.V.P. V.P. V.P. V.P.V.P. ST ST DSTSTSTSTSTSTSTSTST10" SS 10" SS 10" SS 10" SS10" SS8" SS12" SSSS18" SS8" SS 12" SS18" SS8" SS8" SSSSD D W 12" W 12" W 6" W12" W 12" W 8" WRR R R R R R R R ST 10 12 14 10 8 22 12 10 24 11 11 22 24 24 2424 8 6 12 HC HC HC 9 14 14 10 14 13 6 HC HC 7 HC 11 HC HC HC HC 4 12 5 8 18 GM GM GM GMGMGM GM GM GM GMEM EM EM EMEMEM EM EM EMEM TF TF TF TF TF TF TF TF TF 4 TF TF1 2 3 4 5 Drawn by:ATC Date Drawn:7.15.09 NORTH 0 1 inch = ft.( IN PRESIDIO FUTURE PRECISION DRIVE DRAINAGE BASINS TF TF TF TF TF TF TF TF TF TF TFPRESIDIO APARTMENTS SITE DETENTION POND REMAINS AS POND 236 IN UPDATED MASTER SWMM PRESIDIO APARTMENTS SITE WITHIN MASTER BASIN 36 5.1 ACRES OF BASIN 38 DRAINS TO POND 234 7.3 ACRES OF BASIN 36 DRAINS TO POND 234 6.3 ACRES OF BASIN 36 DRAINS TO POND 238 Drawn by:ATC Date Drawn:6.26.09 NORTH 0 1 inch = ft.( IN PRESIDIO MASTER DRAINAGE EXHIBIT This unofficial copy was downloaded on Dec-02-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Dec-02-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Dec-02-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Dec-02-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Dec-02-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA NORTHERNENGINEERING.COM | 970.221.4158 PRELIMINARY DRAINAGE REPORT: THE SAVOY FORT COLLINS | GREELEY APPENDIX MAP POCKET DR1 – DRAINAGE EXHIBIT BUILDING 2BUILDING 4BUILDING 5BUILDING 6BUILDING 7 BUILDING 8 SUITES &MAIL LOUNGEBUILDING 3BUILDING 1EVEVEVEVEVUDUDMONITORING WELL TRAFFIC RATEDSTSTSTSTSTSTSTSTSTSTSTSTSTST ST ST ST ST ST ST ST STDDDD DDDDDDDodp1SSSSSSSH2OSHYDELECSX X XSSANISANISANIWVWVWVGASH2OGASGASVAULTELECV.P.STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTST STSTSTSTST STSTDDDDDST ST ST ST STDD ODP1ODP2A1A3A5BF1A6A7A8A9A10A11B1B2B3B4B5B6ODP3odp2a7a8a10a11b2b3bf1ODP PONDDETENTIONPOND A -BROOKFIELDPRECISION DRIVEBROOKFIELD DRIVE LE FEVER DRIVECINQUEFOIL LANE NORTHERN LIGHTS DRIVE BROOKFIELD DRIVE odp3IMAGOENTERPRISES INC,4710 CINQUEFOIL LN,FORT COLLINSA4A2A12a2a315' DRAINAGEEASEMENTRAIN GARDENOVERFLOW OUTFALL RAIN GARDENFLAT AREA = 2,119 SQ. FT.(1,330 SQ. FT. MINIMUM)DRAINAGEEASEMENTLANDSCAPEDRAIN (TYP.)LANDSCAPEDRAIN (TYP.)LANDSCAPEDRAIN (TYP.)EXISTING 15'TYPE R INLETAREA INLETAREA INLETAREA INLETAREA INLETTYPE R INLETTYPE R INLETTYPE R INLETAREA INLETEXISTINGTYPE R INLETEMERGENCYOVERFLOWPATHSWALEEXISTING 36" RCPFOREBAYPROPOSED OFF-SITE STORM EASEMENTBY SEPARATE DOCUMENTFOREBAYAREA INLETSTORM DRAIN(TO BE UTILIZED FORROOF DRAIN CONNECTIONS)STORM DRAIN(TO BE UTILIZED FORROOF DRAIN CONNECTIONS)AREA INLETDRAINAGEEASEMENTLANDSCAPEDRAIN (TYP.)DRAINAGEEASEMENT38 MC-4500 STORMTECHISOLATOR CHAMBERSSheetTHE SAVOY These drawings are instruments of service provided by Northern Engineering Services, Inc. and are not to be used for any type of construction unless signed and sealed by a Professional Engineer in the employ of Northern Engineering Services, Inc.NOT FOR CO N S T R U C T I O N REVIEW SE T E N G I N E E R N GI EHTRON R N FORT COLLINS: 301 North Howes Street, Suite 100, 80521 GREELEY: 820 8th Street, 80631 970.221.4158 northernengineering.comof 12DR1DRAINAGE PLAN12CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOUDIG, GRADE, OR EXCAVATE FOR THE MARKING OFUNDERGROUND MEMBER UTILITIES.CALL UTILITY NOTIFICATION CENTER OFCOLORADOKnow what'sbelow.before you dig.CallRNORTH( IN FEET )01 INCH = 50 FEET5050100150PROPOSED CONTOUREXISTING STORM SEWERPROPOSED STORM SEWERPROPOSED SWALEEXISTING CONTOURPROPOSED CURB & GUTTER OVERLAND FLOWPROPOSED STORM INLETBASIN AREALID SUMMARY:STAaPROPOSED RIGHT-OF-WAYDESIGN POINTBASIN IDBASIN MINOR AND MAJOR C COEFFICIENTSLEGEND:1.REFER TO THE "PRELIMINARY DRAINAGE REPORT FOR THE SAVOY" BY NORTHERNENGINEERING DATED 09/14/2022 FOR ADDITIONAL INFORMATION.2.THE SAVOY WILL NOT BE PROVIDING ONSITE DETENTION. DETENTION IS BEINGPROVIDED AT ODP POND AND DETENTION POND A - BROOKFIELD.3.LID MEASURES ARE PROVIDED VIA STORMTECH ISOLATOR CHAMBERS AND RAINGARDEN.4.ALL PROPOSED ONSITE STORM SEWER AND STORMTECH SYSTEM ARE TO BEPRIVATELY OWNED AND MAINTAINED. ALL PROPOSED OFFSITE STORM SEWERSYSTEMS ARE PUBLICLY OWNED AND MAINTAINED.5.TEMPORARY AND LONG TERM EROSION PROTECTION WILL BE DESIGNED ANDSHOWN AT FIRST ROUND FDP.NOTES:CONCENTRATED FLOWBASIN DELINEATION PROPOSED UNDERDRAINUDBASINTOTALAREA(acres)Tc2(min)Tc100(min)C2C100Q2(cfs)Q100(cfs)A10.175.05.00.810.860.391.46A20.465.05.00.860.911.134.19A30.645.05.00.830.881.525.62A40.175.05.00.810.860.391.46A50.275.05.00.800.860.622.34A60.195.05.00.670.730.371.40A70.365.05.00.890.940.913.36A80.525.05.00.880.931.324.86A90.635.05.00.690.741.244.64A100.515.05.00.870.921.274.68A110.605.05.00.790.841.365.04A120.245.05.00.850.900.592.17ODP10.455.05.00.670.720.873.25ODP20.906.16.10.730.791.756.61ODP30.255.05.00.660.710.471.78B10.255.05.00.640.700.451.71B20.515.05.00.900.951.314.83B30.585.05.00.820.881.365.09B40.255.05.00.830.880.592.17B50.395.05.00.750.800.833.10B60.175.05.00.290.350.140.61BF11.1610.410.40.630.691.626.18Area treated by Stormtech LID Pond (ac)4.78Area treated by Rain Garden (ac)2.15Total LID (ac)6.93*Total Drainage Area (ac)9.24% Treated by LID75.00%% Treated by ODP Pond and Detention Pond A - Brookfield25.00%RUNOFF SUMMARY:*Includes Major Basin A, Major Basin B, Basin BF1, Sub-Basin ODP2,and Sub-Basin ODP3. Excludes Sub-Basin ODP1KEYMAP24'DR1