Loading...
HomeMy WebLinkAboutHARMONY RIDGE PUD, PHASE ONE - FINAL - 49-95B - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTFIGURE 1 HORS&700TH ROAD �ooQao T. T' q T 7 N .3 4 PROJECT LOCATION HARMONY ------ . .. .......... ----------- T 6 N Rt 6 \A"' 14 Q14 tz . ............. ----- . ...... . ..... . ...... T R 6N as VICINITY MAP SCALE 1 " = 2000' I 1.0 Introduction 1.1 Scope and Purpose This report presents the results of a final drainage evaluation for the Harmony Ridge P.U.D. A hydrologic analysis of the proposed development plan was completed to determine the location and magnitude of the storm runoff. The hydrologic data was then used to evaluate conveyance and detention facilities based on City criteria. 1.2 Proiect Location and Description The Harmony Ridge P.U.D. is a proposed combination townhome residential and single family residential site. This site is located in the East half of the Northwest Quarter of Section 3, T6N, R69W of the 6th Principal Meridian, Larimer County, Colorado. The site is bounded on the north by the future alignment of Harmony Road, on the east by The Ridge P.U.D., on the south by the Cathy Fromme Prairie, and on the west by unplatted vacant land. A vicinity map illustrating the project location is provided in Figure 1. The Harmony Ridge P.U.D. consists of approximately 31.4 acres. Approximately 22.3 acres is proposed for townhome units and the remaining 9.1 acres is proposed for low density single family lots. The development will consist of 22 building pads for townhomes with garages and 15 single family lots. The townhomes will be two story buildings with walkout basements. Seneca Street, Shadow Ridge Drive, Dusty Sage Drive, and Shadow Ridge Court are the only public streets in the development. All of the remaining streets within the townhome tracts will be private and will be maintained privately. 1.3 Previous Studies The "Preliminary Drainage Report for the Harmony Ridge P.U.D." (Stewart & Associates, Inc., September 18, 1995) was reviewed prior to the preparation of this report. Portions of the "Final Drainage Report for the Arapaho Farms Townhomes P.U.D." (RBD Inc., 1994) and the McClellands-Mail Creek Master Plan were reviewed for information pertinent to this development. TABLE OF CONTENTS 1.0 Introduction Page 1.1 Scope and Purpose..........................................................................................................1 1.2 Project Location and Description.....................................................................................1 1.3 Previous Studies..............................................................................................................1 2.0 Historic Conditions....................................................................................................................3 3.0 Developed Conditions Plan........................................................................................................4 3.1 Design Criteria................................................................................................................4 3.2 Drainage Plan Development............................................................................................ 5 3.2.1 Street Capacity ................................................................................................. 10 3.2.2 Storm Sewer Design......................................................................................... 10 3.2.3 Inlet Analysis...................................................................................................14 3.2.4 Channel, Spillway, and Riprap Design..............................................................14 3.2.5 Detention Pond Analysis...................................................................................17 3.3 Erosion Control............................................................................................................. 17 Fi ures Figure1 - Vicinity Map..........................................................................................................................2 Tables Table 1 - Hydrologic Calculations Worksheet......................................................................................7&8 Table 2 - Summary of Attenuated Runoff.................................................................................................9 Table 3 - Summary of Street Capacity Analysis......................................................................................11 Table 4 - Summary of Storm Sewer Design............................................................................................13 Table 5 - Summary of Inlet Analysis and Design....................................................................................15 Table6 - Summary of Riprap Design.....................................................................................................16 Table 7 - Summary of Detention Pond Analysis and Design....................................................................17 Technical ADDendices Appendix A - Rational Method Analysis Appendix B - Street Capacity Analysis Appendix C - Storm Sewer Design Appendix D - Inlet Analysis and Design Appendix E - Channel, Spillway, and Riprap Design Appendix F - Detention Pond Analysis Appendix G - Erosion Control Calculations Sheets Drainage & Erosion Control Plans July 14, 1997 Mr. Glen Schlueter City of Fort Collins Stormwater Department P.O. Box 580 Fort Collins, CO 80522 RE. Harmony Ridge P. U.D. Project No. 10-875-000 Dear Mr. Schlueter: We are pleased to submit this Final Drainage Report for the Harmony Ridge P.U.D. The report includes our evaluation of the proposed storm runoff interception and conveyance facilities, detention analysis, and erosion control plan. It should be noted that the preliminary report was prepared and submitted to the City by Stewart & Associates, Inc. (September 18, 1995). We believe this report meets the requirements for a final submittal and we look forward to your review and comment. If you should have any questions please feel free to contact us. Sincerely, TST, INC. CONSULTING ENGINEERS Donald N Taranto, P.E. SAS/DBL/jts ° ELSOI� � cG1S-�Elie'�es ° 15467 " David B. Lindsay TSTINC. 748 Whalers Way— Building D 102 Inverness Terrace East Consuiring Engineers Fort Collins. CO 80525 (970) 226-0557 Suite 105 Englewood, CO 80112 Metro Denver (303) 595-9103 (303) 792-0557 Fax (970) 226-0204 Fax (303) 792-9489 0 0 0 0 I 0 I FINAL DRAINAGE REPORT FOR HARMONY RIDGE P.U.D. Submitted to: CITY OF FORT COLLINS July 14, 1997