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Home My WebLink AboutWATERFIELD P.U.D., 2ND FILING - FINAL - 7-95D - SUBMITTAL DOCUMENTS - ROUND 3 - DRAINAGE REPORTt� �� t�� I� _ � I� ram.=E�>T-'��t�ET�`nt�rra�::. 1�'are`yl ,3.-, :..,: , ;.. i - Q',.• Waterflleld P.U.D. Second Filing Proposed Construction Sequence ID Task Name 99 4Au2 Qtr 4, 1999 Qtr 1, 2000 Qtr 2, 2000 Qtr 3, 2000 1 1 4, 2000 Qtr 1, 2001 Qtr 2, 2001 SeOct Nov Dec Jan Feb Mar A r Ma Jun Jul AugSep 1 Overlot Grading 3/1 � V 5/31 Oct Nov Dec Jan Feb Mar A r Ma Jun, 2 i 3 Wind Erosion Control 4/1 5/31 4 Soil Roughening I i 5 Perimeter Barrier 6 7 Rainfall Erosion Control i I 311 j 11/30 8 Silt Fence Barriers i 9 Inlet Filters 1 I 10 Asphalt/Concrete Paving i 11 i i 12 Vegetative 3/1 11/30 13 Temporary Seed Planting i i Task Summary ^ Rolled Up Progress - watefiield_ec_schedule.mpp Split Rolled Up Task External Tasks Date: Fri 7/30/99 Progress Rolled Up Split Project 1 Summary WMMMEW Milestone ♦ Rolled Up Milestone O _ Paae 1 WATERFIELD P.U.D. SECOND FILING EROSION CONTROL COST ESTIMATE 08/03/99 F ' OPTION #1 Item No. Method Unit 1. Reseed/Much Acre OPTION #2 Item No. Method Unit 1. Gravel Filter Each 2. Silt Fence L. F. 3. Hay or Straw Dry Mulch Acre 4. Seeding (Native) Acre 5. Straw Bale Barrier Each Erosion Control estimate.xls t Quantity Unit Cost Total Cost 51 800 $40,800.00 Subtotal $40,800.00 Contingency (50%) $20,400.00 TOTAL $61,200.00 Quantilly Unit Cost Total Cost 4 300 $1,200.00 2630 3 $7,890.00 79 500 $39,500.00 10 300 $3,000.00 5 150 $750.00 Subtotal $52,340.00 Contingency (50%) $26,170.00 TOTAL $78,510.00 N UM Final Drainage & BEYOND ENGINE ERING Erosion Control Study Waterfield A U.D., Second Filing REFERENCES Storm Drainage Design Criteria and Construction Standards, City of Fort Collins, Colorado (Revised January 1997). 2. Drainage Criteria Manual, Urban Drainage and Flood Control District, Wright - McLaughlin Engineers, Denver, Colorado, March 1969. 3. Final Drainage Report for Waterfield P U D First Filing, Fort Collins, Colorado, prepared by Northern Engineering Services, Inc., October 20, 1998. 4. Final Drainage Report for Waterfield P U D , Second Filing, Fort Collins, Colorado, prepared by Northern Engineering Services, Inc., November 17, 1997. 5. Preliminary Drainage Report for Waterfield P U D , Fort Collins, Colorado, prepared by Northern Engineering Services, Inc., January 21, 1997. Ground Water Investigation of the Waterfield P.U.D. Site, prepared by Riverside Technology, Inc., May, 1998. 7. Jurisdictional Wetlands Delineation Survey for the Country Club Farms L L C . Larimer County, Colorado; by Riverside Technology, Inc., January 1996. 8. Preliminary Subsurface Exploration Report Country Club Farms/Bull Run Vine Drive and Summit View, LarJmer County Colorado, by Earth Engineering Consultants, October 8, 1997. 9. Cooper Slough Boxelder Creek Master Drainageway Planning Study, prepared by Simons, Li & Associates, Inc., August 1981. 9 \\FCS1\PROJECTTC0088Wdmin\ftnal drainage report.doc NO43M Final Drainage & BE YON D E N G IN E E R ING Erosion Control Study Waterfield P. U.D., Second Filing 6.0 CONCLUSIONS 6.1 Compliance with Standards All computations contained within this report have been completed in compliance with the City of Fort Collins Storm Drainage Design Criteria. 6.2 Drainage Concept The proposed drainage concepts presented in this study and shown on the final drainage and erosion control plans adequately provide for the conveyance and detention of developed runoff from the proposed development. 6.3 Erosion Control Concept The proposed erosion control concepts presented in this study and shown on the final drainage and erosion control plans provide adequate measures to control rain and wind erosion from this site. 8 \\FCS1TROJECTTC0088Wdmin\final drainage reportdoc NOLTE Final Drainage & BE Y O N D E N G IN E E R ING Erosion Control Study Waterfield P. U.D., Second Filing 5.0 EROSION CONTROL 5.1 General Concept The Waterfield P.U.D., Second Filing is in the Moderate Rainfall and Moderate Wind Erodibility zones per City of Fort Collins zone maps. Until the disturbed ground is vegetated, the potential exists for erosion problems during and after construction v 5.2 Specific Detail Upon commencement of overlot grading, silt fence must be installed as shown on the Drainage and Erosion Control Plan (See Back Pocket). Following completion of the overlot grading all areas that will not be paved shall be mulched and seeded. Upon completion of the roads, straw bale check dams and inlet protection shall be installed. All construction activities must also comply with the State of Colorado permitting process for Storm water Discharges Associated with Construction Activity. A Colorado Department of Health NPDES Permit will be required before any construction grading can begin. 7 \TCSI\PROJECTTC0088\Wdmin\final drainage reportdoe NOLTE ' a E Y O N D E N G I N E E R I N G Final Drainage & Erosion Control Study Waterfield AU.D., Second Filing Per the approved Waterfield First Filing utility plans, Pond #301 has a volume of approximately 14.7 acre-ft, and 100-year water surface elevation of 4949.3. The historic release rate is 3.00 cfs. Pond #301 will discharge through piping to the south side of Vine Drive. Pond #321 will be utilized for runoff from both the First and Second Filings. The pond has a storage volume of approximately 12.9 acre-ft up to approximate elevation 4951.6. Pond 4321 appears to have a high water line at approximately 4950.0. From the existing topography, the pond appears to overtop at approximate elevation 4952.0. 4.4 Water Quality Pond Design In order to maintain the quality of the existing wetlands, Pond #1 will be utilized for water quality enhancement prior to releasing storm water runoff to the wetlands. Pond #1 has been designed using criteria outlined in the Urban Drainage and Flood Control District Drainage Criteria Manual (Volume 3). Pond #1 shall be vegetated with wetland type plants and was sized to reflect a wetland basin. The water quality capture volume of the pond is 0.48 acre-ft and has a bottom elevation of 4951.0. The water will overtop the pond at elevation 4953.0 and sheet flow to the existing wetlands. Refer to Appendix E for water quality pond calculations. 6 A\FCSI\PROJECnFC0088Wdmin\fina1 drainage report.doc S �O�Final Drainage & 8 E Y O N D E N G I N E E R I N G Erosion Control Study Waterfield A U.D., Second Filing basins and they will continue to drain into the Larimer and Weld Canal. The 2- year flow is less than one (1) cfs while the 100-year flow is approximately 1.3 cfs. Basins 101-104 will drain directly to the existing wetlands area and pond. The developed flows will be conveyed to the pond by curb and gutter, storm drain pipe and a grass -lined swale. Basins 201-208 will drain directly to the existing wetlands area and pond. Basins 201-204 and 207-208 concentrate at design points 203, 204, 207 and 208. The ' developed flows are captured by two (2) 20' Type "R" curb inlets and conveyed to Water Quality Pond #1. Basins 205 and 206 concentrate at design points 205 ' and 206. The developed flows from the basins are captured by a 10' Type "R" inlet and conveyed to Water Quality Pond #1. The flows are released to the ' existing wetlands from Pond #1 by sheet flow. Basins 301-304 concentrate at design points 301-304. The developed flows are released from the street through a sidewalk chase and sheet flow to Detention Pond #301. The combined 100-year release is 19.39 cfs. Basins 401-404 concentrate at design points 401-404. The developed flows are ' released from the street through a sidewalk chase and sheet flow to Detention Pond #301. The combined 100-year release is 15.48 cfs. Basin 501 contains existing Pond #301 and the future school site and associated development. The basin will continue to sheet flow to Pond #301 until the school site is developed. 4.3 Detention Pond Design Detention Pond #301, designed and built with Waterfield P.U.D., First Filing, will be utilized for detention of the storm water runoff from the Second Filing. The existing wetlands area and pond (Pond #321) will also be utilized for detaining developed storm water runoff. 5 \\FCSI\PROJECTFC0088Wdmin\final drainage report.doc � NOLTE BE VON O E N G IN E E R ING 1 Final Drainage.& Erosion Control Study Waterfield A U.D., Second Filing rate of 0.9 cfs. H3 generally drains from west to east to an existing irrigation lateral and has a 2-year release rate of 1.0 cfs. Historic Basin H4 contains 74.3 acres and drains to the existing wetlands area and pond. The calculated 2-year historic release from this basin is 12.3 cfs. Basin H5 at the southeast corner of the Waterfield P.U.D. site. It contains 20.2 acres and drains towards the intersection of Vine Dr. and Summit View Dr. H5 has a 2-year historic release rate of 3.3 cfs. Basin H6 is located in the southwest corner of the site and drains directly to Lake Canal. This basin historically releases to the canal at a rate of 7.6 cfs for the 2- year storm. 4.0 DEVELOPED DRAINAGE CONDITIONS 4.1 General Concept In general, developed flows from the northern half of the site will drain to the existing wetlands area and pond (designated Pond #321 by Northern Engineering). The drainage will be detained in the wetlands and then released at a rate of 4.4 cfs to existing Pond #301 (designated by Northern Engineering), which was designed and built with Waterfield P.U.D. First Filing. The developed runoff from the southern portion of the site will flow directly to existing .Pond #301. According to the approved Waterfield First Filing utility plans, the historic release from Pond #301 is 3.00 cfs. The historic basin located north of the Waterfield site contains approximately 76 acres and releases at an historic rate of 31.3 cfs. This flow was used to approximate the theoretical overtopping of the Larimer and Weld Canal and has also been used in the developed flow calculations for sizing the storm drain pipe and inlets located at the intersection of Wood Duck Dr. and Merganser Dr. 4.2 Basin Description Basins OS1 and OS2 are located in the northern portion of the site and comprise less than one (1) acre. There will not be any grading or development within these 4\\FCSI\PROJEC71FC0088\Admin\final drainage repon.doc NICCTE B EYON D E N G IN E E R ING Final Drainage & Erosion Control Study Waterfield A U.D., Second Filing The detention ponds were sized using a modified version of the EPA Storm Water Management Model software (SWMM) known as MODSWMM. The software routes hydrographs through user defined "conveyance elements" while accounting for infiltration losses in pervious areas, surface retention, overland flow and gutter flow. Other design calculations, such as: inlet capacity, street capacity and riprap requirements were completed in conformance with design procedures set forth in the City of Fort Collins Storm Drainage Design Criteria and Construction Standards and the Urban Storm Drainage Criteria Manual by the Urban Drainage and Flood Control District. 3.0 HISTORIC DRAINAGE BASINS ' 3.1 Major Basin Description The site is located within the Cooper Slough Drainage Basin, which has been studied previously in the Cooper Slough Boxelder Creek Master Drainageivay ' Planning Study, prepared by Simons, Li & Associates. The Larimer and Weld Canal runs along the north property line and the Lake Canal is located at the southwest corner of the site. 3.2 Sub -basin Description ' Historic flows generally drain from north to south and eventually drain to Lake Canal. In general, no offsite drainage enters the site. Considering the entire ' Waterfield P.U.D. site, there are six (6) historic basins (See Appendix A). ' Historic Basin HI is located in the northern part of the Waterfield P.U.D. site and drains generally from west to east to an existing irrigation lateral. The historic 2- year release is 1.6 cfs. Basins H2 and H3 are located in the northeast comer of the 1 site. H2 drains to the Latimer and Weld Canal, and has an historic 2-year release 3 \\FCSI\PROJECnFC0088\Admin\final drainage repon.doe NOLTE BEYOND ENGINEERING Final Drainage & Erosion Control Study Waterfield P. U.D., Second Filing A Final Drainage Report for Waterfield P.U.D., First Filing was submitted by Northern Engineering on October 20, 1998 and approved by the City of Fort Collins. Also, a Preliminary Drainage Report for Waterfield. P.U.D. was submitted by Northern Engineering on January 21, 1997. Other reports and studies include the Ground Water Investigation of the Waterfield P. U.D. Site, prepared by Riverside Technology, Inc. in May 1998, as well as the Jurisdictional Wetlands Delineation Survey for the Country Club Farms L.L.C., prepared by Riverside Technology in January 1996. Earth Engineering Consults prepared a Preliminary Subsurface Exploration Report in October 1997. 2.0 METHODOLOGY 2.1 Compliance with Standards This Final Drainage & Erosion Control Study was prepared in accordance with the requirements and procedures for design set forth in the City of Fort Collins Storm Drainage Design Criteria and Construction Standards (Revised January 1997) and Urban Storm Drainage Criteria Manual by the Urban Drainage and Flood Control District. 2.2 Analytical Methods The Rational Method is widely accepted for design problems involving small drainage areas (<160 acres) and short times of concentration. Mathematically, it relates peak discharge to the runoff coefficient, rainfall intensity, and drainage area. Runoff coefficients and rainfall intensity data were obtained from the City of Fort Collins Storm Drainage Design Criteria and Construction Standards. The Rational Method was used to calculate 2- and 100-year developed flows. 2 \\FCSI\PROJEC7\FC0088Wdmin\final drainage report.doc NC47 E Final Drainage & e E'Y o N D E N G IN E E R ING Erosion Control Study Waterfield P. U.D., Second Filing 1.0 INTRODUCTION 1.1 Site Location The proposed Waterfield P.U.D., Second Filing is located in the northern part of Fort Collins at the northwest corner of East Vine Drive (County Road 48) and Summit View Drive (County Road 9E). More particularly, the site is located in Section 5, Township 7 North, Range 68 West of the 6`h Principal Meridian, Larimer County, Colorado. Please see Vicinity Map — Figure 1. 1.2 Existing Site Description The site for the Waterfield P.U.D., Second Filing contains approximately 92.8 acres and has been used for agricultural purposes. The site also contains a wetlands area of approximately 11.50 acres. The site generally slopes from north to south at grades ranging from 1% to 5%. The native soils consist of brown and light brown sandy lean clay underlain by predominately silt soils (to depth of approximately 14 feet). These soils are underlain by granular and essentially granular soils (to depth of approximately 15 feet). 1.3 Proposed Project Description The proposed development includes 106 single family homes, a day care, convenience store, school site and associated development. Approximately 42 acres will be dedicated to the City of Fort Collins as Open Space, which includes the designated wetlands area. 1.4 Previous Reports and Studies ' The initial submittal for the Final Drainage Report for Waterfield P.U.D., Second Filing was submitted to the City of Fort Collins by Northern Engineering Services, Inc. in November of 1997. 1 \\FCSI\FROJECTW0088\Admin\final drainage report.doc NEW INNER INNER W11EEW SEEMS WINNER REEEII - z GGIRE, -1 EGIIIE—f LIME: 16: SD SERVER: FC'. 7- Section 6 1 inch = 1000 ft Y DWG XREFS: TB8511 dwa - - Section 32 I I Section 5 I I I Section 4 Latimer and Weld Canal e ind j t g c / � arstFi F l f � First Filing � Plummer School Northern Railroad E. Vine Drive Lake Canal Section 8 NOS WATERFIELD P.U.D., SECOND FILING SHEET NUMBER VICINITY MAP 1 DETOND ENGINEERING FIGURE 1 OF 1 SHEETS 470 S. LINK LANE PLAZA97.FORT COLLINS, co. E.COM PREPARED FOR: COLORADO LAND SOURCE, INC. DATE SUBMITTED: 07/28/99 ,we NUMBER 970.221.2400 TEL 970.221.2415 FAX VVWW.NOLTE.COM FC00$$ 1 NCU E Final Drainage & Erosion Control Study BEYOND E N O I N E E R I N G' Waterfield P. U.D., Second Filing APPENDIX A - HISTORIC SITE HYDROLOGY APPENDIX B - DEVELOPED SITE HYDROLOGY APPENDIX C - STORM DRAIN SYSTEM DESIGN APPENDIX D - DETENTION POND DESIGN APPENDIX E - WATER QUALITY POND DESIGN APPENDIX F - CHARTS, TABLES AND GRAPHS POCKET - Drainage and Erosion Control Plan and Details (Sheets 10-15 of 32) I( ii \\FCSI\PROJECT\FC0088Wdmin\finaldrainanereport.doc NCUM Final Drainage & BEYOND ENGINEERING Erosion Control Study Waterfield AU.D., Second Filing TABLE OF CONTENTS PAGE ' 1.0. INTRODUCTION............................................................................................................1 1.1 Site Location.........................................................................................................I 1.2 Existing Site Description......................................................................................1 1.3 Proposed Project Description................................................................................1 1.4 Previous Reports and Studies................................................................................I ' 2.0 METHODOLOGY...................................................................................:.......................2 2.1 Compliance with Standards..................................................................................2 ' 2.2 Analytical Methods...............................................................................................2 3.0 HISTORIC DRAINAGE CONDITIONS.........................................................................3 ' 3.1 Major Basin Description.......................................................................................3 3.2 Sub -basin Description.....................................................................................: 3 4.0 DEVELOPED DRAINAGE CONDITIONS....................................................................4 4.1 General Concept....................................................................................................4 4.2 Basin Description..................................................................................................4 4.3 Detention Pond Design.........................................................................................5 4.4 Water Quality Pond Design..................................................................................6 5.0 EROSION CONTROL.....................................................................................................7 5.1 General Concept....................................................................................................7 5.2 Specific Detail.......................................................................................................7 6.0 CONCLUSIONS...............................................................................................................8 6.1 Compliance with Standards..................................................................................8 6.2 Drainage Concept..................................................................................................8 6.3 Erosion Control Concept.......................................................................................8 REFERENCES.......................................................................................I...............I..........9 i \\FCS1\PROJECT\FC0088\rldmin\final drainage report.doc BEY ON D E N G IN E E R ING August 3, 1999 FC0088 Mr. Basil Hamdan City of Fort Collins Stormwater Utility P.O. Box 580 Fort Collins, CO 80522 RE: Waterfield P.U.D., Second Filing Final Drainage and Erosion Control Study Dear Mr. Hamdan: We are pleased to submit the "Waterfield P.U.D., Second Filing Final Drainage and Erosion Control Study" for your review. It represents a study of the existing and proposed storm water characteristics of the project site. This report was prepared in compliance with technical criteria set forth in the Storm Drainage Design Criteria and Construction Standards (revised January 1997) for the City of Fort Collins. If you have any questions, please call. Sincerely, NOLTE ASSOCIATES, INC. 432 S. LINK LANE FORT COLLINS. CO 80524 970.22 1 .2400 TEL 970.221.2415 FAX WWW.NOLTE.COM < a S E q / O A, � C e o fr9'49- �_ W ".�.+Gi14ESY a S� 44 N:\F00088\Admin\final drainage report AeF.doc ` a WATERFIELD P.U.D., SECOND FILING FINAL DRAINAGE & EROSION CONTROL STUDY for :. QI -d' U our ;: a.::: 8101 E. Prentice Avenue Suite M180 Englewood, Colorado 80111 M Nolte Associates, Inc. 432 Link Lane Fort Collins, Colorado 80524 (970) 221-2400 August 1999 WATERFIELD P.U.D., SECOND FILING FINAL DRAINAGE & EROSION CONTROL STUDY BEYOND ENGINEERING