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Home My WebLink AboutHARMONY MARKET PUD, 7TH FILING, GOLDEN CORRAL - PRELIMINARY & FINAL - 54-87Y - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTFINAL DRAINAGE AND EROSION CONTROL STUDY FOR ARMONY MARKET P.U.D. SEVENTH FILING FORT COLLINS, COLORADO FINAL DRAINAGE AND EROSION CONTROL STUDY FOR HARMONY MARKET P.U.D. SEVENTH FILING FORT COLLINS, COLORADO June 26, 1994 Prepared for: G C Development Corporation P.O. Box 29511 Raleigh, North Carolina 27626 Prepared by: RBD, Inc. Engineering Consultants 209 South Meldrum Fort Collins, Colorado 80521 (303) 482-6368 RBD Job No. 633-001 OISOINC. Engineering Consultants 209 S. Meldrum Fort Collins. Colorado 80521 303/482-5922 FAX: 303/482-6368 June 26, 1994 Mr. Glen Schlueter City of Fort Collins Utility Services Stormwater 235 Mathews Fort Collins, Colorado 80522 RE: FINAL DRAINAGE AND EROSION CONTROL STUDY FOR THE HARMONY MARKET P.U.D. SEVENTH FILING Dear Glen: We are pleased to submit to you, for your review and approval, this Final Drainage and Erosion Control Study for the Harmony Market P.U.D. Seventh Filing. All computations within this report have been completed in compliance with the City of Fort Collins Storm Drainage Design Criteria. We appreciate your time and consideration in reviewing this submittal. Please call if you have any questions. Respectfully, RBD Inc. Engineering Consultants Preby: by: s / zel-e F David K. Delaney, P.E. Kevin W. Gingery, P.E. Project Engineer Water Resources Project Manager cc: Bill Kozar Denver 303/458-5526 TABLE OF CONTENTS DESCRIPTION PAGE GENERAL LOCATION AND DESCRIPTION ......................... 1 Location 1 Description of Property . . ...... .... ........... ....... .... 1 DRAINAGE BASINS 1 ......................................... Major Basin Description ....... .... ....... .... ... .... .... 1 Sub -Basin Description ................................... 2 DRAINAGE DESIGN CRITERIA ... ... . . . . .... ....... . . . ... . .. . .. 2 Regulations.......................................... 2 Development Criteria Reference and Constraints ................. 2 Hydrological Criteria .................................... 3 Hydraulic Criteria ...................................... 3 Variances from Criteria .................................. 3 DRAINAGE FACILITY DESIGN ... ....... ................ . ....... 3 General Concept ....... . .... .. . ....... .. . ..... . .. . . . . . 3 Specific Details....................................... 3 EROSION CONTROL ........................................ 4 General Concept ... ......... . ... ... ........ ....... ... . 4 Specific Details ....................................... 4 CONCLUSIONS 5 ........................................... Compliance with Standards ............................... Drainage Concept ..................................... 5 5 Erosion Control Concept ................................. 5 REFERENCES............................................. 6 APPENDIX VICINITY MAP 1 HYDROLOGY 2 EXCERPTS FROM FINAL DRAINAGE REPORTS for HARMONY MARKET P.U.D. SECOND AND THIRD FILINGS 4 EROSION CONTROL 18 TABLES AND FIGURES 22 DRAINAGE AND EROSION CONTROL PLAN pocket FINAL DRAINAGE AND EROSION CONTROL STUDY FOR THE HARMONY MARKET P.U.D. SEVENTH FILING FORT COLLINS, COLORADO I. GENERAL LOCATION AND DESCRIPTION A. Location The Harmony Market P.U.D. is located immediately south of Harmony Road between Boardwalk Drive and Lemay Avenue. More specifically, this site is located in the Northeast quarter of Section 1, Township 6 North, Range 69 West of the 6th Principal Meridian, City of Fort Collins, Larimer County, Colorado. The Seventh Filing of Harmony Market P.U.D. is located along the south side of Harmony Road west of its intersection with Lemay Avenue. 01 B. Description of Property The existing Harmony Market P.U.D. has been developed in several phases and contains a Pace Warehouse, Builders Square, Steeles Market, 01 First Bank, and a Jiffy Lube. The First Bank of Westland is currently in the process of upgrading their site from its interim to final plan. INThe Harmony Market P.U.D. Seventh Filing site contains approximately 1.489 acres and is currently undeveloped. An existing access off Harmony Road borders the site to the west and is fully developed. An _ interior temporary access road runs along the south property line and a currently undeveloped parcel lies to the east. The proposed use for the subject site is as a restaurant. ll. DRAINAGE BASINS A. Major Basin Description The project site is located within the McClellands Basin. No major drainageway exists within the Harmony Market P.U.D. development or immediately downstream within the Oak/Cottonwood Farm site. A I it IR B. Sub -Basin Description Flows from the site, in a developed condition, were included as part of the overall drainage study for two prior developments within the Harmony Market P.U.D.; Builders Square (Second Filing) [11, and Steeles Market (Third Filing) [2]. Portions of those reports are included in the Appendix. Historic flows for the study site were divided into two sub -basins. Basin 1 of the site is part of Basin C of the Second Filing and Basin 2 was included in Basin E of the Third Filing. Flows from the study site basins enter existing detention ponds located to the south in the parking lots of the above mentioned developments. No offsite flows cross the study site. III. DRAINAGE DESIGN CRITERIA A. Regulations The City of Fort Collins Storm Drainage Design Criteria [3] is being used for this study. B. Development Criteria Reference and Constraints itThe Seventh Filing of Harmony Market P.U.D. is a portion of Basin C and Basin E as described in the Harmony Market P.U.D. Second & Third itFilings Final Drainage Reports. The existing drainage basins contain detention ponds with release rates dictated by the capacity of downstream facilities at the Oakridge West it P.U.D. First Filing. This downstream development has a drainage release requirement of 0.2 cfs/acre for the maximum 100 year release rate. The existing detention pond in Basin C of the Second Filing and Basin E of the Third Filing conform to this requirement with the study site being fully developed. In the Harmony Market P.U.D. Third Filing Final Drainage Report, the detention pond for Basin E was sized for fully developed storm water runoff at 2.83 ac.-ft. An interim pond grading plan was constructed per the correspondence contained in sheets 13 to 17 in the Appendix, providing 2.77 ac.-ft. of detention volume until development of additional pads in Basin E necessitated final pond grading. The final pond grading will need to be completed in conjunction with this site. 4 � it C. Hvdroloaical Criteria The Rational Method is being used to determine run-off peak flows from the study site. Rainfall criteria for this study was obtained from the City of Fort Collins [3] and is included in the Appendix. The 10- and 100-year 14 rainfall criteria was utilized to determine the planned developed flows. IND. Hydraulic Criteria All calculations within this study have been prepared in accordance with the City of Fort Collins Drainage Criteria. E. Variances from Criteria No variances are being sought for the subject site drainage. IV. DRAINAGE FACILITY DESIGN A. General Concept All on -site developed flows for the study site will be conveyed by parking lot sheet flow and gutter flow across the southern access and drain into the existing storm sewer system and related detention pond of either Steeles Market or Builders Square. Developed runoff from the subject site was included in sizing of the existing detention ponds, therefore; no on -site detention is intended for the site. Included in the back. pocket of this report is the Drainage and Erosion Control Plan for the subject site. B. Specific Details Basin 1 is comprised of asphalt parking and driveways, half of the restaurant building, and landscaping. Basin 1's storm water runoff is proposed to outlet onto the Builders Square access roadway and sheet flow to the existing storm sewer system and related Detention Pond C. Basin 2 also contains asphalt parking and driveways, half of the building area, and landscaping. Developed flows from Basin 2 outlet onto the access roadway for Steeles Market and sheet flow to Detention Pond E and related storm sewer system. The 100 year water surface limit of Ponds C & E are cross hatched on the included Drainage and Erosion Wcontrol Plan. Detention Pond E is currently at an interim stage of development. Additional site grading will be required to increase its current detention volume of 2.77 ac.-ft. to its final required volume of 2.83 ac.-ft. as determined in the Harmony Market P.U.D. Third Filing Final Drainage Report. V. EROSION CONTROL A. General. Concept The Harmony Market P.U.D. Seventh Filing lies within the Moderate Rainfall and Wind Erodibility Zone per the City of Fort Collins zone maps. The potential exists for erosion problems during construction of the parking/driveways and landscaped areas until the disturbed ground is paved or revegetated. Thus the new improvements will be subjected to both wind and rainfall erosion. Per the City of Fort Collins Erosion Control Reference Manual for Construction Sites [4] and related calculations in the appendix, the erosion control performance standard for the subject site is 81.28 %. From the calculations in the appendix, the effectiveness of the proposed erosion control plan is 99.5 %. It is anticipated that the construction duration of this project will be less than 6 weeks due to the limited arnount of work to be completed, therefore the erosion control plan as specifically detailed below, should meet the City of Fort Collins requirements. B. Specific Details If the curb, gutter, and asphalt are not installed within six weeks after overlot grading begins, then these improvements should not be included in the erosion control effectiveness calculations. Given the size and scope of work to be completed for this construction project, we anticipate that installation of the curb, gutter, asphalt, and landscaping can be completed within six weeks after construction begins. As a first step in the construction process, the subject site will have a silt fence installed along the east, south, and west perimeter of the property to prevent construction sediment from leaving the site. After the overlot grading and utility installation has been completed, the parking/driveway surfaces will receive the curb, gutter, and pavement surfaces. After installation of the curb, gutter, and pavement surfaces, 4 14 the permanent landscaping surfaces (grass sod) will be installed to protect the bare ground. Once all of the improvements have been completed, the sediment fence can be removed from the construction site. VII. CONCLUSIONS A. Comoliance with Standards All computations within this report have been completed in compliance with the City of Fort Collins Storm Drainage Design Criteria. B. Drainage Concept The proposed drainage concepts presented in this report and shown on the Drainage and Erosion Control Plan are in compliance with the City of Fort Collins drainage criteria. The developed storm water runoff from Basin 1 will be collected in an existing detention facility on the adjacent Builders Square site, and developed runoff from Basin 2 will be collected in the existing detention pond on the adjacent Steeles Market site. The flows will be conveyed downstream as is currently occurring with historic drainage from the subject site. C. Erosion Control Concept The proposed erosion control plan adequately provides for the control of wind and rainfall erosion from the study site. Through the construction sequence and proposed erosion control measures, the City of Fort Collins performance standards will be met. The proposed erosion control concepts presented in this report and shown on the Erosion Control Plan are in compliance with the City of Fort Collins erosion control criteria. 67 REFERENCES 1. RBD Inc., Harmony Market P.Q.D. Second Filing Final Drainage Report, Total Site Preliminary - Revised Drainage Report, Fort Collins, Colorado, August 13, 1990. 2. RBD Inc., Harmony Market P.U.D. Third Filing Final Drainage Report Total Site Preliminary - Revised Drainage Report Fort Collins Colorado, August 30, 1990. 3. City of Fort Collins, Storm Drainage Design Criteria and Construction Standards, May 1984, Revised 1992. 4. City of Fort Collins, Erosion Control Reference Manual for construction Sites, January 1992. 0 VICINITY MAP � VICINITY MAP ■ SCALE: 1 "=2000'