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Home My WebLink AboutLANDMARK APARTMENTS EXPANSION - PDP - PDP120031 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTPROSPECT ROAD CALL UnUTY NonnCATION CENTER OF COLORADO 1-800.922-1987 L 2-BUSINESS DAYS IN ADVANCE BEFORE YOU DIG. GRADE. OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. 1 O51 1.40 0.32 1 30 60 SCALE: I" = 30' ® I > .� AR FIRST C SME£LY FIRST SUBDI PIS/ON I � \ n DRAINAGE A EROSION CONTROL LEGEND QI DESIGN POINT BASIN 10 0.60 0.4 5-YR RUNOFF COEFFICIENT AREA IN ACRES Row DIRECTION BASIN BOUNDARY '- EXISTING PIPES PROPOSED STORM PIPE "' 4905"" EXISTNG 5' CONTOUR EXISTING 1' CONTOUR —4905— PROPOSED 5CONTOUR PROPOSED V CONTOUR O SF SF— SILT FENCE VEHICLE TRACKING CONTROL PAO CW O CONCRETE WASHOUT AREA WI ®' WATTLE WATTLE B CID-3 INLET PROTECTION w3 GUTTER PROTECTION W♦ WATTLE FILTER NOTES 1. REFER TO SHEET 2 FOR EROSION CONTROL NOTES 2. REFER TO THE GRADING PLAN FOR STORM SEWER CONSTRUCTION INFORMATION. IN I \ \ I\ CIP-3 1 \ � i t \ / 'AR lnlGK-C. SHE \/\ - FIRST SUBDII/l ON \ 00 \. \' ! i A ENBURG DRIVE --� 6• SOIL COVER 8• GRANULAR BEDDING D - d50 a STATE CLAS919CATON FOR NOMINAL STONE SITE. IF RP -RAP TO BE GROUTED: GROUT MALL BE IN ACCORDANCE TO ASTM: C1107-1-ATEST REASON. GROUT STALL BE MBRATED IN FLACE. TOPS CF EXPoYD PoP-RAP MLL BE %ET BRUSHED AMID CLEANED OF GROUT TO EXPOSE Rip -RAP COLOR. S SMALLER, THAN INTERMEDIATE ROCK Cgo RIPRAP w9rwAnrW GIVEN sm DIMENSION 6Y1i141I (INCRE5i fixom") TYPE LL 70-100 12 ,-70 9 6^ 35-50 6 2-10 2 TYPE L 70-100 15 0-70 12 9•• 05-50 9 2-10 3 TYPE M 70-100 21 so-7o a 12 1 50 2 2-10 TYPE H 100 lO $ 70 2♦ Is 3 s0 19 2-10 6 TYPE w 100 42 50-70 w 2♦ ysg 12 2—w 9 ••BURY TYPES M. AND L WTH NATIVE TOP Bpi AND REVEGETATE TO PROTECT FROM WMOAUS1 CONSTRUCNON RIPRAP DRAWING DRAWING. Steel or Filter FrbHa Wood Post Boaldilled Trench ' Filter Fabric Attach Securely o Post Steel w Wood Post Cwnpacted Backfdl Runoff II11U BJ p 1I1 — - 1 W W 1 Dills III=1T nI_rf- 10•MIN 1W�1-ILB-111 III 1-U�11-UI Approximately III IJ 4 Xd Trench W 1-I II L ITI IT_I IMAM— 1 D1 1 H 1Ll IJ 1 1�n-Z 1-1--T_ SECTION VIEW General Note. 1. The roximure tributary area M limited to 0.25 acres per 100 feet of fence 2. Inspect and repair face after each etwm event Remora sediment Men on e half of tee height of the fence has been filled Removed sediment shall be deposited in on area tributary to a sediment basin or other filtering measure VTC SILT FENCE EROSION CONTROL GENERAL NOTES: I INSPECT AND REPAIR GRAVEL FILTERS AFTER EACH STORM EVENT. REMOVE SEDIMENT WHEN ONE HALF OF THE FILTER DEPTH HAS BEEN FILLED. REMOVED SEDIMENT SHALL BE DEPOSITED IN AN AREA TRIBUTARY TO A SEDIMENT BASIN OR OTHER FILTERING MEASURE, 2. EROSION CONTROL MAINTENANCE 15 THE RESPONSIBILITY OF THE DEVELOPER. VEHICLE TRACKING CONTROL w 0 City of Fort Collins, Colorado UTILITY PLAN APPROVAL APPROVED CT, En9neer Date SHEET CHECKED BY wntr n wmleea]er mnuy Onee CHECKED BY: Slorm.aln Utility Date CHECKED BY: Pn,.. E Renremia, once 7 OF 9 CHECKED BY. Troths Engineer Dote CHECKED BY: Job No. 223-04 Dole No Text APPENDIX A VICINITY MAP A 5. REFERENCES 1. City of Fort Collins, "Storm Drainage Criteria Manual", (SDCM), dated March 1999. 3. RBD, Inc. Engineering Consultants, "Final Drainage and Erosion Control Study for the Hamlet at Miramont P.U.D.", dated March 29, 1996. 2. Urban Drainage and Flood Control District, "Urban Storm Drainage Criteria Manual", Volumes 1 and 2, dated June 2001, and Volume 3 dated September 2001. 4 A summary of the drainage patterns within each basin is provided in the following paragraphs. Basin I (2.52 acres) is located in the northern portion of the site. Runoff from this basin will be collected in the proposed storm pipe and conveyed to the proposed Water Quality Pond 1 and be released into the existing drainage way. Basin 1 runoff is 8.3 cfs for the 10-year minor storm and 23.1 cfs for the 100-year major storm. Runoff from offsite Basins OSI and OS2 will flow into Basin I and be conveyed into the existing drainage way as this flow has historically done. Water quality extended detention will not be provided for this flow. Basin 2 (0.39 acres) is located in the south eastern portion of the site. Runoff from this basin will flow through the parking lot and into Water Quality Pond 2 and be released into the existing drainage way. Basin 2 runoff is 1.5 cfs for the 10-year storm and 3.8 cfs for the 100-year storm. 4.3. Drainage Summary The proposed development has been divided into two subbasins which correlate to the - two proposed water quality ponds. Runoff from all subbasins will be routed to the existing drainage way on site. The runoff will then flow south off site eventually entering the Poudre River. c 3. DRAINAGE DESIGN CRITERIA 3.1. Regulations This report was prepared to meet or exceed the "City of Fort Collins Storm Drainage Design Criteria Manual" specifications. Where applicable, the criteria established in the "Urban Storm Drainage Criteria Manual" (UDFCD), 2001 has been used. 3.2. Development Criteria Reference and Constraints The runoff from this site has been routed to conform to the requirements of the City Stormwater Department. Neither stormwater detention nor extended water quality detention are proposed for this site. 3.3. Hydrologic Criteria Runoff computations were prepared for the 10-year minor and 100-year major storm frequencies utilizing the Rational Method. All hydrologic calculations associated with the basins are included in Appendix B of this report. 3.4. Hydraulic Criteria All hydraulic calculations within this report have been prepared in accordance with the City of Fort Collins Drainage Criteria and are included in Appendix B of this report. There are private storm sewer improvements proposed with this project which will be sized with the final drainage report for this site. All basins will be collected in water quality ponds and released into the existing drainage way. 4. DRAINAGE FACILITY DESIGN 4.1. General Concept The runoff from the proposed development will flow through the parking lots, enter private storm pipe and into water quality extended detention ponds. Runoff will then be released into the existing drainage way on site. No water quantity detention is provided for this development. Refer to the preliminary drainage plan in Appendix A. 4.2. Specific Flow Routing 2 1. GENERAL LOCATION AND DESCRIPTION 1.1. Location The proposed Landmark Apartments is located in Fort Collins near the southeast corner of the intersection of Prospect Road and Shields Street. This project is located in the Northwest Quarter of Section Twenty three, Township Seven North, Range Sixty-nine West of the Sixth Principal Meridian, in the City of Fort Collins, Larimer County, Colorado. The site is bounded on the north by Prospect Road, on the west by existing Landmark apartments and residential development, on the south by undeveloped property and on the east by existing residential development. See the Vicinity Map in Appendix A. 1.2. Description of Property The project consists of approximately 3 acres of land with a drainage way that flows through the southwest portion of the site contained within a separate parcel of land. The proposed improvements on this site consist of 32 units in six buildings with associated drives, walks, and parking. Access is obtained on the south from the existing Landmark Apartments development. No portion of the proposed project is within a designated floodplain area. Existing drainage patterns are to the south into the existing drainage way at approximately 4% to 10%. 2. DRAINAGE BASINS AND SUB -BASINS 2.1. Major Basin Description The proposed development does not appear to be located within any City mapped Drainage Basin based on mapping provided on the City website. The site appears to belong in the Spring Creek Drainage Basin. Water Quality extended detention is provided on site for this site and water quantity detention it being provided by a downstream detention pond. 2.2. Sub -basin Description The site currently drains from north to south, with an existing slope of approximately 4% to 10%. With existing drainage patterns, runoff sheet flows into the existing drainage way that bisects the site and is conveyed downstream, eventually entering the Poudre River. TABLE OF CONTENTS TABLEOF CONTENTS............................................................................................................... iii GENERAL LOCATION AND DESCRIPTION 1.1 Location...................................................................................................................1 1.2 Description of Property............................................................................................I 2. DRAINAGE BASINS AND SUB -BASINS 2.1 Major Basin Description..........................................................................................1 2.2 Sub -Basin Description............................................................................................. I 3. DRAINAGE DESIGN CRITERIA 3.1 Regulations..............................................................................................................2 3.2 Development Criteria Reference and Constraints...................................................2 3.3 Hydrologic Criteria..................................................................................................2 3.4 Hydraulic Criteria....................................................................................................2 4. DRAINAGE FACILITY DESIGN 4.1 General Concept......................................................................................................2 4.2 Specific Flow Routing.............................................................................................3 4.3 Drainage Summary ..................................................................................................3 5. REFERENCES....................................................................................................................4 APPENDICES A Vicinity Map B Hydrologic & Hydraulic Computations C Excerpts from Previous Reports C Figures and Tables in North Star design 700 Automation Drive, Unit I Windsor, CO 80550 Phone:970-686-6939 Fax:970-686-1188 November 20, 2012 Wes Lemarque City of Fort Collins Stormwater 700 Wood Street Fort Collins, CO 80522-0580 RE: Preliminary Drainage Report for Landmark Apartments Dear Wes, I am pleased to submit for your review and approval, this Preliminary Drainage Report for Landmark Apartments. I certify that this report for the drainage design of Landmark Apartments was prepared in accordance with the criteria in the City of Fort Collins Storm Drainage Manual. I appreciate your time and consideration in reviewing this submittal. Please call if you have any questions. Sincerely, Patricia Kroetch, PE PRELIMINARY DRAINAGE REPORT Wful LANDMARK APARTMENTS Prepared for: The Neenan Company 2607 Midpoint Drive Fort Collins, CO 80522 Prepared by: North Star Design 700 Automation Drive, Unit I Windsor, Colorado 80550 (970)686-6939 November 20, 2012 Job Number 223-04