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HomeMy WebLinkAboutDrainage Reports - 09/15/1995t. �o final �� � Report A �� SHEAR ccwm �i I Finial Drainage and Erosion Control Report for THE COTTAGES AT MIRAMONT P.U.D. Fort Collins, Colorado Prepared for: ALBRECHT HOMES 4836 South College Avenue Suite 10 Fort Collins, Colorado 80525 y Prepared by: SHEAR ENGINEERING CORPORATION Project No: 1410-01-94 DATE: August, 1995 4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 226-5334 August 22, 1995 Project No. 1410-01-94 Basil Hamdan City of Fort Collins Storm Water Utility P.O. Box 580 Ft. Collins, Colorado 80522 Re: Cottages at Miramont P.U.D.; Fort Collins, Colorado Dear Basil, Enclosed, please find the Final Drainage and Erosion Control Report for Cottages at Miramont P.U.D. The hydrology data and the hydraulic analysis presented in this report complies with the requirements of the City of Fort Collins Storm Drainage Criteria Manual; dated March, 1984, and the Erosion Control Reference Manual. The report and plan have been revised per your comments dated July 31, 1995. rase call me or Mark Oberschmidt at 226-5334. BWS / meo CC. Bill Albrecht 1 4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 226-5334 • : ? t�i i � � J��t 9� J JL. lie • �.� Ei ii i��i u x F _ ' OpY WYlW1•TO11.O � PAGE 1 The Cottages at Miramont P.U.D. Final Drainage and Erosion Control Report INTRODUCTION: The Cottages at Miramont P.U.D. is contained within an area considered with the Amended Oak/Cottonwood Farm Overall Drainage Study. More specifically, this is the area which contributes storm water runoff to Detention Pond #313 as defined in the Amended Oak/Cottonwood Farm Overall Drainage Study. Although this report has been specifically prepared' for the Cottages at Niramont P.U.D., several known proposed projects, adjacent to this one, are considered with this report because of the direct relationship to the projects, all of which contribute to detention pond #313 which was detailed with final design parameters in the Final Drainage and Erosion Control Report for The. Courtyards at ' Miramont P.U.D., Second Filing. The projects considered and referenced in this report include: * Oak Hill Apartments P.U.D. * lvliramont Fitness and Tennis Center * The Courtyards at Miramont P.U.D., Second Filing * The Courtyards at Miramont P.U.D., First Filing The Oak Hill Apartments P.U.D. Final Drainage and Erosion Control Report was prepared by RBD Inc., Consulting Engineers. Final conclusions which relate to the Oak Hill Apartments P.U.D. have been closely coordinated with RBD, Inc. and included in this report. Reference to conclusions presented with the Final Drainage and Erosion Control Report for the Oak Hill Apartments P.U.D. will be clearly identified in this report when referenced. The Final Drainage and Erosion Control Report for Miramont Fitness and Tennis Center was submitted on September, 1994 and was approved by the City of Fort Collins Storm Water Utility. The report was prepared by Water, Waste & Land, Inc. Final conclusions which relate to the Miramont Fitness and Tennis Center have been closely coordinated with Water, Waste & Land, Inc. and included in this report. Reference to conclusions presented with the Final Drainage and Erosion Control Report for Miramont Fitness and Tennis Center will be clearly identified in this report when referenced. The Courtyards at Miramont. P.U.D. First and Second Filing has been approved by the City of Fort Collins and are currently under construction. Final conclusions which relate to the The Courtyards at Miramont P.U.D. First and Second Filing are based primarily on the approved reports and design. The Amended Oak/Cottonwood Farm Overall Drainage Study is being prepared by RBD Inc., Consulting Engineers simultaneously with this proposal. The Amended Oak/Cottonwood Farm Overall Drainage Study is the primary reference for the storm water management design for The Cottages at Miramont P.U.D. Reference to conclusions presented with the Amended Oak/Cottonwood Farm Overall Drainage Study will be clearly identified in this report when referenced. PAGE 2 The Cottages at Miramont P.U.D. Final Drainage and Erosion Control Report L GENERAL LOCATION AND DESCRIPTION: A. Location 1. The Cottages at Miramont P.U.D. is located in the East One Half (1/2) of Section 1, Township 6 North, Range 69 West of the 6th P.M., City of Fort Collins, County of Larimer, State of Colorado.. 2. More specifically, The Cottages at Miramont P.U.D. is located on the east side of Boardwalk Drive, approximately three quarters (3/4) of a mile South of Harmony Road. The project is east of the Upper Meadow at Miramont and west of the Collinwood assisted living facility (Oakridge West P.U.D. First Filing). 3. The Cottages at Miramont P.U.D. is P.U.D., on the north by Miramont Oakridge West P.U.D. First Filing, Miramont P.U.D., Second Filing B. Description of Property bounded on the west by Oak Hill Apartments Fitness and Tennis Center on the east by and on the south by The Courtyards at 1. The 2.23 acres site (The Cottages at Miramont P.U.D.) is currently vacant land covered with native vegetation. 2. Development of the property will consist of the construction of sixteen (16) single family residences and the infrastructure to service them. 3. The site will be accessed from the extension of Rule Drive from Lemay Avenue. IL DRAINAGE BASINS AND SUB -BASINS: A. Major Basin Description 1. -The Cottages at Miramont. P.U.D. is located in the McClelland -Mail Creek Drainage Basin as delineated on the City of Fort Collins Storm Water Basin Map. a. The Basin fee rate for this basin is $3,717.00 per gross acre according to the development fee section of the City of Fort Collins Development Manual. b. Our understanding is that the above mentioned fees may be reduced with the provision for detention. Detention has been provided for this site with the Miramont Overall Drainage Plan (ODP). Refer to following discussion in the Sub -Basin description section. The amount of impervious area created by the development may also affect Basin fees. PAGE 3 The Cottages at Miramont P.U.D. Final Drainage and Erosion Control Report II. DRAINAGE BASINS AND SUB -BASINS: B. Sub -Basin Description 1. The Cottages at Miramont P.U.D. is contained within Basin 208 of the Amended Oak/Cottonwood Farm Overall Drainage Plan (ODP). -- ... 2. There is a detention pond identified in the Amended-Ozk/Cottonwood Farm Overall Drainage- Plan located downstream of the. Cottages at Miramont P.U.D. project which was defined for all projects within Basin 208 of the ODP including Cottages at Miramont P.U.D. a. The pond is designated as pond #313 of the Amended Oak/Cottonwood Farm Overall Drainage Study. b. This pond is located within the -limits of Tract D of the Courtyards at Miramont P.U.D., Second Filing, a plat recorded in Latimer County records. Tract D and the detention pond is currently owned by Oak Farm, Inc., A Colorado Corporation. c. The existing detention pond was originally designed by RBD, Inc. in association with the Upper Meadow -at Miramont, Second Filing. The .pond was constructed based on the original Oak/Cottonwood Farm Overall Drainage Study. It was constructed with additionalvolume requirements for irrigation purposes. It was constructed in association with the Upper Meadow at Miramont, Second Filing. d. Preliminary Pond volume requirements and- water surface elevation data were provided on the Utility Plan titled "Detention Pond and Erosion Control Plan" for Upper Meadow at Miramont P.U.D., Second Filing, prepared by RBD, Inc., dated June 7, 1993, RBD Project No. 504-003. e. Amendments to the Oak/Cottonwood Farm Overall Drainage Study during the design phase of the Courtyards at Miramont P.-U.D., Second Filing, indicated a need for additional volume than was originally identified. The :additional volume was provided during earthwork operations for Phase 1 construction of theCourtyards at Miramont P.U.D., Second Filing. 3. All stormwater from the projects which contribute -to detention pond #313, are conveyed to the existing irrigation/detention pond. The drainage design for the Fitness and Tennis Center, Oak Hill Apartments, the Cottages at Miramont P.U.D. and the Courtyards at Miramont P.U.D., have been well coordinated to allow. the conveyanceof storm water from these projects to detention pond #313 according to the requirements of the Amended Oak/Cottonwood Farm Overall Drainage Study. PAGE 4 The Cottages at Miramont P.U.D. Final Drainage and Erosion Control Report H. DRAINAGE BASINS AND SUB -BASINS: B. Sub -Basin Description 4. Our understanding from the review of the drainage reports available, is that allowable storm water release rates are very strictly controlled in this area. a. , The Amended Oak/Cottonwood Farm Overall Drainage Study _indicates that maximum allowable release rates for this area are as follows: * 0.20 cfs/acre for the 10-year storm * 0.50 cfs/acre for the 100-year storm. The total required detention volumes, as well as the allowable release rate for detention pond #313, have been summarized and are presented in subsequent sections of this report, as well as on the Drainage and Erosion Control Plan located in Appendix III (stuffer envelope) of this report. These summaries are consistent with the final conclusions presented in the Amended Oak/Cottonwood Farm Overall Drainage Study and the Final Drainage and Erosion Control Study for Oak Hill Apartments P.U.D. 5. Some offsite flows will -be conveyed through the site from the Miramont Tennis and Fitness Center. This subbasin is designated as sub -basin OS-1 on the Drainage and Erosion Control plan. Subbasin OS-1 contains approximately 0.13 acres. 6. The majority of the site (Sub -basin Ia) contributes stormwater to a low point located in the southeast portion of the site. Sub -basin la contains approximately 2.0 acres. 7. The remainder of the site (approximately 0.23 acres of grassed area) contributes stormwater directly to Courtyards at Miramont Second Filing. III DRAINAGE DESIGN CRITERIA: A. Regulations 1. Design Criteria from the City of Fort Collins Drainage . Criteria Manual were utilized in the design and preparation of the Drainage and Erosion Control Plan. 2. Supplemental drainage design criteria specified in the Amended Oak/Cottonwood Farm Overall Drainage Study was also utilized. 3. Erosion control measures and design conform to the requirements of the City of Fort Collins Erosion Control Reference Manual. PAGE 5 The Cottages at Miramont P.U.D. Final Drainage and Erosion Control Report III DRAINAGE DESIGN CRITERIA: B. Development Criteria Reference and Constraints 1. The following drainage reports were considered in the final drainage design and calculations for The Cottages at Miramont P.U.D.: -- a. Oak/Cottonwood Farm Overall Drainage Study; RBD, Inc.; dated May 4, 1992; RBD Project No: 504-001. b.. Amended 'Oak/Cottonwood Farm Overall Drainage Study; RBD, Inc.; dated August 16, 1994; ,RBD Project No: 504-001. c. Preliminary Drainage Report for Oak Hill Apartments P.U.D.; RBD, Inc.; dated February 7, 1994; RBD Project No: 088-010. d. Final Drainage and Erosion Control Report for Oak Hill Apartments P.U.D.; RBD, Inc.; dated May, 1994; RBD Project No: 088-010. e. Preliminary Drainage and -Erosion Control Report for Courtyards at Miramont P.U.D. (Phases I-V) and The Cottages at Miramont P.U.D. (Phase VI); Shear Engineering Corporation; Project No: 1410=01-94; Dated: March, 1994. f. Final Drainage and Erosion Control Report for Miramont Fitness and Tennis Center; Water, Waste and Land; dated -September 12, 1994; WWL Project No: 402. g. Master Drainage Study for the Oakridge Business Park. h. Drainage and Erosion Control Report for Oakridge West P.U.D. First Filing. i. The Final Drainage and Erosion Control Report for Courtyards at Miramont Second Filing; Shear Engineering Corporation; Project No: 1410-01-94; Dated October, 1994. 2. The property to the north, Miramont Fitness and Tennis Center. has received Final Approval. Therefore, grading along the northern property line of the Cottages At Miramont will match the proposed contours of the Miramont Fitness and Tennis Center. 3. The property to the south, Courtyards at Miramont Second Filing, is, currently under construction. Grading along the southern property line of the Cottages at Miramont will match the proposed contours of Courtyards at Miramont Second Filing. 4. The property to the west, Oak Hill Apartments P.U.D., is currently under review. Grading along the western property line of the Cottages at Miramont will match the proposed contours of Oak Hill Apartments P.U.D. PAGE 6 The Cottages at Miramont P.U.D. Final Drainage and Erosion Control Report III DRAINAGE DESIGN CRITERIA: B. Development Criteria Reference -and Constraints (continued) 5. The property to the east, Collinwood (Oakridge West P..U.D. • First Filing), is developed and limits the amount of grading that can be performed along the eastern property line of the Cottages at Miramont P.U.D. C. Hydrological Criteria 1. The Rainfall -Intensity -Duration curves for the City of Fort Collins were used (Figure 3.3.1-1, attached in Appendix H for reference), in conjunction with the "Rational Method" for determining peak flows at various concentration points. D. Hydraulic Criteria 1. Street capacity references provided in the City of Fort Collins Drainage Criteria Manual and street capacity exhibits which were prepared by this office, based on the Mannings equation, were utilized. 2. Drainage -channel capacities are based on -the Mannings Equation. The Mannings coefficients are as suggested by City of Fort Collins Drainage Criteria Manual. IV DRAINAGE FACILITY DESIGN: A. General Concept 1. Stormwater runoff from the site will be conveyed to the southeast corner of the property via a combination of a. Overland flow. b. Gutter flow. 2. No detention will be provided on the site as the Cottages at Miramont will contribute stormwater to the regional pond (Pond 313) located just south of the project in Tract D of the Courtyards at Miramont Second Filing. Pond 313 is sized for contributions from the Cottages At Miramont P.U.D. along with the other projects mentioned in the introduction of this report. 3. No storm sewer is provided on the site as the outlet device located at concentration point A has more than enough capacity to handle the peak flows to concentration point A. PAGE 7 The Cottages at Miramont P.U.D. Final Drainage and Erosion Control Report IV DRAINAGE FACILITY DESIGN: B. Specific Details: 1. Specific design details and final design calculations have been provided with this submittal of the Final Drainage and Erosion Control Report and Utility Plans for the Cottages at Miramont P.U.D.. 2. The existing irrigation/detention pond, which will service the Courtyards , and Cottages at Miramont P.U.D., the Oak Hill Apartments P.U.D. and the Miramont Fitness and Tennis Center, is identified on the Amended- Oak/Cottonwood Farm Overall Drainage Study as pond #313. a. The pond was originally designed and constructed in conjunction with the Upper Meadow at Miramont P.U.D., Second Filing. Reference: "Detention Pond and Erosion Control Plan" for Upper Meadow at Miramont P.U.D., Second Filing (Sheet 1 of 1) prepared by RBD, Inc. dated June 7, 1993, Project No. 504-003. ii.- Preliminary detention pond volume requirements were based on- the original Oak/Cottonwood Farm Overall Drainage Study; RBD, Inc.; dated May 4, 1992; RBD Project No: 504-001. iii. Final detention pond requirements were determined based on actual contributing design areas and are presented in the most current Amended Oak/Cottonwood Farm Overall Drainage Study. b. The existing irrigation/detention pond was constructed in 1993. The plans for the pond indicate that the pond would first be constructed as an interim pond which would be an irrigation/retention pond. The ultimate pond would act as an irrigation/detention pond. The -following- represents summary data which was presented on the 'Detention Pond and Erosion Control Plan" for Upper Meadow at Miramont P.U.D., Second Filing (Sheet 1 of 1). L The interim pond is proposed to have 6.7 acre feet of irrigation volume. ii. The ultimate pond is proposed to have 2.7 acre feet of irrigation volume. iii. The ultimate pond is proposed to have 4.0 acre feet of detention volume. c. The Amended Oak/Cottonwood Farm Overall Drainage Study indicates a 4.60 acre-foot detention requirement based on the SWMM model. , Refer to the Amended Oak/Cottonwood Farm Overall Drainage Study and the Appendix of the Final Drainage and Erosion Control Study for the Oak Hill Apartments P.U.D.; Sheet 10 -Site Hydrology. d. The existing pond detention storage volume is 4.20 acre-feet -based on actual volume verification provided by RBD, Inc. Consulting Engineers. Refer to the Appendix of the Final Drainage and Erosion Control Study for the Oak Hill Apartments P.U.D.; Sheet 10 - Site Hydrology. PAGE 8 The Cottages at Miramont P.U.D. Final Drainage and Erosion Control Report IV DRAINAGE FACILITY DESIGN: B. Specific Details (continued): 2. e. Detention pond #313 required additional volume due to actual volume requirement determination. Additional detention pond grading requirements to- -provide -die additional volume were shown on the Final Grading -Plan , Sheet 11 of 13 of the Utility Plans for Courtyards at Miramont P.U.D., Second Filing. The pond expansion provided 4.75 ac-ft of detention storage volume. The detention pond design stage -storage curve is included in Appendix A of this report for reference. The detention pond will also act as an irrigation facility for this site, the open space greenbelt areas on the west side of Boardwalk Drive, and for future development to the south and east. A pump house and necessary infrastructure _ is -under construction to distribute the irrigation water as needed. L Construction of the pump house will not be associated with the The Cottages at Miramont P.U.D. ii. Maintenance of the detention/irrigation pond will be the responsibility of the owner of the tract on which the pond is located. This includes the pump house. 3. A 4' wide curb opening will be provided at the southeast corner of the site (Concentration Point A) to convey the stormwater runoff from the site into Tract A of the Courtyards at Miramont P.U.D., Second Filing. a. Tract A of the Courtyards at Miramont P.U.D. Second Filing is designated as a Utility, Drainage, and Access easement on the final plat of Courtyards at Miramont P.U.D., Second Filing. b. The peak 100 year or major flow at Concentration Point A is 14.45 cfs. Refer to pages 1, la, and.2 in the drainage calculations located in Appendix I. c. The capacity of the 4' wide curb opening is 24.29 'cfs. Refer to page 3 in the drainage calculations -located in Appendix I. d. The peak 10 year or minor storm flow at Concentration Point A is 6.64 cfs. Refer to pages 1, la, and 2 in the drainage calculations located in Appendix I. e. The street capacity at Concentration Point A for the minor storm is 7.29 cfs. This is based on the capacity of the private drive up to the top of the curb on the low side of the private drive. Refer to page 4 in the drainage calculations located in Appendix L PAGE 9 The Cottages at Miramont P.U.D. Final Drainage and Erosion Control Report IV DRAINAGE FACILITY DESIGN:- B. Specific Details (continued): 2. f. The top of the curb on the low side of the private drive should not be overtopped as the stormwater will be releasing through the 4' curb cut located at the low point (Concentration Point A). The capacity of the curb cut -is more than 1 1/2 times greater than the peak flow to concentration point. 3. A low flow channel along with a grassed swale will convey the stormwater from the curb cut located at the low point on the private drive of Cottages at Miramont through tract A of Courtyards at Miramont P.U.D. Second Filing and into the private drive of Courtyards at Miramont P.U.D. Second Filing. a. The slope of the low flow channel is 0.5%. Refer to the Final Grading plan for Courtyards at Miramont•P.U.D. Second Filing sheet 11 included in the stuffier envelope. b. The peak 100 year flow (Q100) at the outfall of the swale into the private drive of Courtyards at Miramont Second Filing is-14.98 cfs. One hundred and thirty threepercent of the -peak -flow (Q100*133) is 19.92 cfs. Refer to page 5 in the drainage calculations located in Appendix I. c. The capacity of the low flow channel and the grassed swale at the outfall of the swale into the private drive of Courtyards at Miramont Second Filing is 31.0 cfs (Section A -A). d. The capacity of the low flow channel and the grassed swale out in the wider portion of Tract A is 33.2 cfs (Section B-B). Refer to pages Sa and 5b in the drainage calculations located in Appendix I. e. The swale is capable of handling the stormwater generated by the development of The Cottages at Miramont P.U.D. PAGE 10 The Cottages at Miramont P.U.D. Final Drainage and Erosion Control Report IV DRAINAGE FACILITY DESIGN: B. Specific Details (continued): 4. Peak flows and street capacities at the various points in the Cottages were determined. The following table summarizes the results of these calculations. Refer pages 4, 4a, 4b and 4c, and 6 - 9 in the drainage calculations located in Appendix I —The street capacities are based on typical sections (20' flowline to flowline). Concentration Q100 Minor Storm Major. Storm Notes Point Capacity Capacity cfs cfs cfs A 14.45 7.29 NA Curb Cut provided B 9.56 7.29 147.33 C 4.77 7.29 NA D 4.03 7:29 NA E 2.25 7.29 NA 5. A small -berm has been provided along the east side of the property to ensure that all the flows are conveyed to the outlet at concentration Point A. Refer to section A -A on the Master Grading plan (Sheet 6 of 10). 6. Stormwater runoff from the Cottages leaves the site at -the southeast corner and is conveyed to the detention pond via the streets in Courtyards at Miramont P.U.D. The streets have adequate flow capacity to handle the flows -from the Cottages. Refer to the calculations located at the end of Appendix I which were done with the Final Drainage and Erosion Control Report for Courtyards at Miramont Second Filing. a The peak 100 - year flow at concentration point B is 32.37 cfs. b. The contributing area used in the determination of the peak flows to Concentration Point B included all of the Cottages at Miramont. c. The capacity of the streets in the Second Filing is 92.5 cfs. This is based on a flow depth up to the top of curb on the high side of the road. 7. Maintenance of the open space areas within the limits of the Cottages at Miramont P.U.D. will be the responsibility of the Homeowners Association. PAGE 11 The Cottages at Miramont P.U.D. Final Drainage and Erosion Control Report V. EROSION CONTROL DESIGN CRITERIA: A. Regulations 1. Design Criteria from the City of Fort Collins Erosion Control Reference Manual were utilized. VI. EROSION CONTROL FACILITY DESIGN: A. General Concept: 1. The Cottages at Miramont P.U.D. lies within the Moderate Wind Erodibility Zone per the City of Fort Collins Erodibility Zone Map. a. According to the criteria of the City of Fort Collins Erosion Control Reference Manual for Construction sites, the Erosion control performance standard has been calculated and appropriate erosion control measures identified for the control of erosion during and after construction. 2. -Erosion control measures are specified on the Drainage and Erosion Control Plan attached in Appendix III-(stuffer envelope). These measures will -effectively reduce the amount of soil erosion potential created -during the construction of the project. a. Maintenance of erosion control devices, both onsite and offsite, will remain the responsibility of the developer until the subdivision is totally developed. B. Specific Details 1. Silt fence will be installed along the eastern property lines. 2. A gravel filter will be provided at the 4' curb cut. PAGE 12 The Cottages at Miramont P.U.D. Final Drainage and Erosion Control Report VIL EROSION CONTROL SECURITY DEPOSIT: A. An erosion control security deposit is required in accordance with City of Fort Collins policy (Chapter 7, . Section C : SECURITY; page 7.23 of the City of Fort Collins Development Manual). In no instance shall the amount of the security be less than $1000.00. 1. According to current City of Fort Collins policy; the erosion control security deposit is figured based on the larger amount of 1.5 times the estimated cost of installing the approved -erosion control measures or 1.5 times the cost to re -vegetate the anticipated area to be disturbed by construction.activity. a The cost to install the proposed erosion control devices for the Courtyards at Miramont P.U.D., Second Filing is $1,255.00. 1.5 times this estimate is $ 1,882.50. i. unit prices have been provided by Connell Resources. b. Based on current data provided by the City of Fort Collins Storm Water Utility, and based on an actual anticipated net affected disturbed area during construction of, the The Cottages at- Miramont P.U.D. (approximately..2.22 acres) we estimate that the cost to re -vegetate the disturbed area will be $1,430.00 ($650.00 per acre x 2.20-acres). 1.5 times the cost to re -vegetate the disturbed area is $2,145.00. i. The 2.22 acres is the actual area of the The Cottages at Miramont P.U.D., housing project. I The $650.00 per acre for re -seeding sites of less than 10 acres was quoted to us by the City of Fort Collins Storm Water Utility staff. 2. The erosion control security deposit amount required for this project will be $2,145.00. See the Erosion Control Security Deposit Requirements document located in Appendix III (stuffer envelope). 3. The erosion control security deposit is reimbursable. PAGE 13 The Cottages at Miramont P.U.D. Final Drainage and Erosion Control Report VM. VARIANCE FROM CITY STANDARDS A. Variance from City of Fort Collins requirements 1. There will be no requests for variances from the City of Fort Collins Storm Drainage Design Criteria. IX. CONCLUSIONS: A. Compliance with Standards: 1. All drainage design and calculations conform with the criteria and requirements of the City of Fort Collins Storm Drainage Criteria. 2. Proposed erosion control measures conform with generally accepted erosion control measures and the City of Fort Collins Erosion Control reference manual. B: Drainage Concept: 1. The design of the drainage infrastructure for The Cottages at Miramont P.U.D. and the Courtyards-at-Miramont Second Filing P.U.D. effectively controls any increase in storm water runoff due to the development of The Cottages at-Miramont P:U.D.. 2. The erosion control measures specified will effectively reduce erosion potential. during and after construction. PAGE 14 The Cottages at Miramont P.U.D. Final Drainage and Erosion Control Report 14 1. City of Fort Collins Storm Drainage Design Criteria Manual 2. Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual. 3. City of Fort Collins Erosion Control .Reference Manual; prepared by Hydrodynamics, Inc.; dated January 1991. 4. Oak/Cottonwood-Farm Overall Drainage Study; RBD, Inc.; dated May 4, 1992; RBD Project No: 504-001 5. Amended Oak/Cottonwood Farm Overall Drainage Study; -RBD, Inc.; dated August 16, 1994; RBD Project No: 504-001. 6. Final Drainage Report for Oak Hill Apartments P.U.D.; RBD, Inc.; dated May 2, 1994; RBD Project No: 088-010. 7. Final Drainage and Erosion Control Report for Oak Hill Apartments P.U.D.; RBD, Inc.; dated May, 1994; RBD Project No: 088-010. 8. Preliminary Drainage and. Erosion Control Report for Courtyards at Miramont P.U.D. (Phases I - V) and The Cottages at Miramont P.U.D. (Phase VI); Shear Engineering Corporation; Project No: 1410-01-94; Dated: March, 1994. 9. Final Drainage and Erosion Control Report for Miramont Fitness and Tennis Center; Water, Waste and Land; dated July 18, 1994 WWL Project No: 402. 10. "Detention Pond and Erosion Control Plan" for Upper Meadow at Miramont P.U.D., Second Filing (Sheet 1 of 1) prepared by RBD, Inc. dated June 7, 1993, Project No. 504-003 11. Master Drainage Study for the Oakridge Business Park; RBD, Inc.; dated September, 1990. . 12. Final Drainage and Erosion Control Report for Courtyards at Miramont P.U.D., Second Filing; Shear Engineering Corporation; Project No: 1410-01-94; Dated: October, 1994. APPENDIX I Storm Drainage Calculations Erosion Control Calculations FLOW SUMMARY FOR COTTAGES AT MIRAMONT DESIGN SUB AREA C2 C10 C100 Tc Tc 22 I10 I100 Q2 Q10 Q100 DESIGN POINT BASIN 2,10 100 ac. min. min iph iph iph cfe cfa cfe f lffftft 4f1f1f4f 114t♦ f4ff♦ tflf♦ tfff♦ ♦fff! if Yff ♦f 44f ftfff fft4f 4f tff ttYff if t44 11f!! A Ia & OS-1 2.13 0.76 0.76 0.95 12.50 10.00 2.34 4.10 7.14 3.79 6.64 14.45 CURB CUT B Ib-Id & OS-1 1.41 0.76 0.76 0.95 12.50 10.00 2.34 4.10 7.14 2.51 4.39 9.56 STREET C Ic 0.54 0.76 0.76 0.95 5.00 5.00 3.29 5.64 9.30 1.35 2.31 4.77 STREET D Id 0.53 0.76 0.76 0..95 10:00 8.00 2.54 4.45 8,00 1.02 1.79 4.03 STREET B Ie 0.28 0.76 0.76 0.95' -9.50 7.00 2.62 4.57 8.44 0.55 0.97 2.25 STREET i ra"—PARMBY A)60 vAr.0 � •��QiS — �. � 15�,��N l� _ —_—� GATE 1 2 SZ c Art/ . _ = �1 O�k,�,g_ -a� =--Z�Z3_ss. - rs�� q =1O-Z�4 -- 4 [jFF51TE Gor1}��1 u�lin {rco -/A --- - - ---- - 5 — 47(D +� �tt�lr>>s -_-Gt J jr �SO\b- G�1 - ----- - — a c 7 — 0 % 10 CC. »i4tmar1t— 9 �NSv�C co�1�,r,l��k,nc Ar«. Sybbs�N tc -----� =--Z=0 �,c _ LZj:GAS sue__— n _ -PN,LLI )- SIM __.c. - 0,03 17.�. - 18 V1.05�.6.Sra�'\CO.o3i CO.Lu� Q.Og 0.6b0 D_ � 61 10 20 ID 12 13 14 1s 16 21 (1sa,-is 310,5b sF — 22 - 23 - d.135c 24 25 p,06� 0 zu� t (0 \o t 6 -n) p;Se� t .a" SUB -BASIN SURFACE CHARACTERISTICS STREETS ASPHALT CONCRETE GRAVEL LOTS ROOFS LAWNS SANDY SOIL FLAT < 20, AVERAGE 2 - 7% STEEP > 7! LAWNS HEAVY SOIL SHEAR ENGINEERING CORPORATION COMPOSITE RUNOFF COEFFICIENT FOR SUBBASIN OS-1 PAGE :lA PROJECT :COTTAGES AT MIRAMONT PROJ.NO. :1410-01-94 DATE: 04/20/95 LOCATION :RULE DRIVE BY: MEO FILE :COTAMCOF NOTES OS-1 SUB -BASIN Ia . RUNOFF COEF. AREA C C*A (acres) 0.100 0.950 0.095 0.000 0.950 0.000 0.000 0.500 0.000 0.000 0.950 0.000 0.000 0.100 0.000 0.000 0.150 0.000 0.000 0.200 0.000 RUNOFF COEF. AREA C C*A (acres) 0.730 0.950 0.694 0.000 0.950 0.000 0.000 0.500 0.000 1.210 0.670 0.811 0.000 0.950 0.000 0.000 0.100 0.000 0.000 0.150 0.000 0.000 0.200 0.000 FLAT .< 294 0.030 -0.200 0.006 0.060 0.200 0.012 AVERAGE 2 - 7% 0.000 0.250 0.000 0.000 0.250 0.000 STEEP > 7% 0.000 0.350 0.000 0.000 0.350 0.000 TOTAL AREA 0.130 0.101 2.000 1.516 C2 C10 C100 C2 C10 C100 COMPOSITE C VALUE 0.777 0.777 0.971 0.758 0.758 0.948 OVERALL COMPOSITE C VALUE FOR CONTRIBUTING AREA TO CP 'A' C = 0.7592488 C100 = 0.949061 SAY 0.76 SAY 0.95 0 SHEAR ENGINEERING CORPORATION PAGE 2 FLOW TO CONCENTRATION POINT A FROM SUBBASIN Is & OS-1 PROTECT: COTTAGES AT MIRAMONT DATE 04/20/95 FILE: COTAMRUN PROD. NO.1410-01-94 NOTES: BY HBO AREA (A)= 2.130 ACRES RUNOFF CORP. (C) 2 YEAR 10 YEAR 100 YEAR C = 0.76 0.76 0.95 SEE SPREAD SHEET ATTACHED ON PAGE 1 TIME OF CONCENTRATION (Tc) OVERLAND TRAVEL TIME (Ti) LENGTH 32 PENT SLOPE = 3.69 It 2 YEAR 10 YEAR 100 YEAR C 0.05 0.10 0.40 Ti (min)= 7.22 6.88 4.81 TRAVEL TIME (TO =L/(60+V) FLOW TYPE L (ft) 31 S (4) - 0.51 GUTTER L (ft) 183 S (4) - 0.5 GUTTER L (ft) = 63 S (4) - 2.01 GUTTER L (ft) = 212 S (t) - 0.62 GUTTER L (ft) = 30 S (4) = 0.5 GUTTER L (ft) =? S (4) =? ? L (ft) =? S (4) =? ? NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 Tc =Ti+TOTAL TRAVEL TIME 2 YEAR 10 YEAR 100 YEAR Tc (min)= 12.47 12.13 10.06 USE Tc = 12.5 12.5 10 INTENSITY (I) (iph) 2 YEAR 10 YEAR 100 YEAR I = 2.34 4.10 7.14 NOTE: INTENSITIES TAKEN FROM FIGURE 3-1 RUNOFF (Q= CIA) (cfe) V (fps) = 1.5 Tt(min)= 0.34 V (fps) = 1..5 Tt(min)= 2.03 V (fps) = 2.83 Tt(min)= 0.37 V (fps) = 1.63 Tt(min)= 2_17 V (fps) - 1.5 Tt(min)= 0.33 V (fps) =? Tt(min)= 0.00 V (fps) =? Tt(min)= 0.00 TOTAL TRAVEL TIME (min) = 5.25 2 YEAR 10 YEAR 100 YEAR Q = 3.79 6.64 14.45 CONCLUDE:SIZE CURB CUT TO HANDLE Q100 AND CONVEY OVER GRASS TO TRACT A OF COURTYARDS AT MIRAMONT SECOND FILING SEE PAGE 3 CHECK STREET CAPACITY SEE PAGES 4 & 4A Ckoc, 1 SouCZ PREPAREDBY Y DA E ZU SJ 2 -- --4— _ _ 5- f �— 1 G Wb G-- -- — --- '� = OlZ — --- —----------- --- 10 0,3Z,6 11 13 14 l 1c ----- 19 20 21 22 23 24 25 26 27 - ----- --- 2G --- ---- ------ - --- -- - -- ---------- ---------- ----- it -- --- 10 _ 11 12 13 14 - 15 16 PP."ZRAM B7 0 11 i DATE SLD Cc�" G�YJ�•, ONCA :Sr-C�VO'h1 41 cs Id1D-d1-CA Reu,s�a g11�{t3 Glvoo © A = 1A . 4 c(�s _ Q-z, 3,-1 S cis. _- (blrvo,r Sto)rm,---- -lbw --Qr i'° -- o- 1-)-Sc Pie 4A A.9 L l�, 5>< '(' II,.bS-- —wh <<Z,z� (.So) 0 1�2 0)Z 111h�o,r S� r� - F�oU ���°-tD�----o>� _curb _QY_v__}•1��_����-----__ D 17_ I _ �3:sa R 3 = o,wi-a 1S 20 ' ------- 2t l415 posso cs -11 )4A'S A Snp,)-t p&AM is oN )_oV3SlDE_wwc-'4 22- ----- - b1SG-\aE5 E EVgr1oYJ or °P Q'--(7_gy-k ON H)b14SIDE 23_-CP's-- c)p°-- Zhe -cZra _s1u�� _sv-b__�s__rvt ytae� 24 1 I UU- 25 _ A� C-)°:-- 1 o`a Is 26 2, i low s �e L�rb W \� htive S��\� 1�erh Q' �d 2 phi o Reo AljCs u v 0 J 6 E'er 6N 'NQ' + = r. r ppsoo N [rj FJ � C CL + a N J J a o- ^ � � N N `— 5 — v Ln fl M + P 11 (� go N v N / Q y Pi 11 41 nj C� ,^1f1 r M r? O (y a (T T 4a 'y/j_]_44cT� 1J 'f 17"; rhWAas Lg Ti4y o i��« �o a.6 s cl r1to �eye,� s}orm Wile/ Avi,y, 50 See SoC,r)0,. 1i'li 6N (>rlJ,. f)ky4 ja�t _!A T� All I t I #+ r rr1 ! Il 1 15, -r �1 Y 1 y{ I . �- 71 * Si r l a T I +k, I } h —17 e .odo - l I i -TT 1 } - -•i . -.- . } � 1•—i-- T � r �{- j —F- iT 7-� Zt, -i rt-�ti 1 1 I i -! 3 1 .. i _ TH I 1 I 1 1_ 1 UD r Tz - -r- - - - ,- - , L 1 r PAGE XC) :53 CcA-A-,,s�, (F;;IJMBY (Z 3 4 6 z\ LoiA w\ Q- A 8 46 -C A�- 10 --- --- 11- ALAOL cv�- %191A--- ,�,-eA) 12 3 14 15 16 17 18 19 20 ZA4 .00- 6,3 21 10 22--G1�ou� SWe)e jej Llp- 23 21 -S 25 26 27 O\C 28 SHEAR ENGINEERING CORPORATION PAGE SA CHANNEL CAPACITY PROTECT NAME: COTTAGES W MIRAMONT DATE: 06/19/95 PROJECT NO. 1410-01-94 BY : MEO SWALE DESCRIPTION: SWALE IN TRACT A OF COURTYARDS SECTION A -A - LOCATED IN NARROW SECTION OF TRACT A FILE: COTCHAN CAPACITY OF TRIANGULAR OR TRAPEZOIDAL CHANNEL CONTRIBUTING AREA PEAK 100 YEAR PLOW @ OUTFALL FROM COTTAGES 14.45 CFS 2.13 PEAK 100 YEAR FLOW ® CP B IN COURTYARDS 32.37 CPS 5.51 CONTRIBUTING AREA TO CP B IN COURTYARDS INCLUDES COTTAGES CHANNEL CONFIGURATION: TRAPEZOIDAL DESIGN FLOW (c£s) 19.92 CHANNEL LINING: GRASS W/ VALLEY PAN REFER TO PAGE 5 Da Db Dc Sc n W I (ft) (ft) (ft) ____ (t) ____ _____ (ft) ____ (ft) ____ ____ 5.00 _-__ 5.00 1.250 0.50 0.028 3.00 0.25 0.25 = LEFT BANK SLOPE 0.25 = RIGHT BANK SLOPE DEPTH WIDTH AREA PERIM R 2/3 Sc 1/2 Q V (s.f.) (ft) (G.f.) _______ (ft) _______ (A/P) _______ _______ (cfs) _______ (ft/sec) _______ _______ -1.25 _______ 13.00 10.00 13.31 0.83 0.07 31.02 3.10 1.00 11.00 7.00 11.25 0.73 0.07 19.15 2.74 0.75 9.00 4.50 9.18 0.62 0.07 10.49 2.33 0.50 7.00 2.50 7.12" 0:50 0.07 4.67 1.87 0.25 5.00 1.00 5.06 0.34 0.07 1.27 1.27 1.02 11.16 7.22 11.41 0.74 0.07 19.99 2.77 rrr+rr+rxtxrttrrrrrrrrrrrrrr+r+rxxxttt+rr+rrxrxrrttrtrrrrr++rrr+rrrtrr+r SHEAR ENGINEERING CORPORATION PAGE SB CHANNEL CAPACITY PROJECT NAME: COTTAGES N MIRAMONT DATE: 06/19/95 PROJECT NO. 1410-01-94 BY : MSO SWALB DESCRIPTION: SWALE IN TRACT A OF COURTYARDS SECTION B-B - LOCATED IN WIDE SECTION OF TRACT A FILE: COTCHAN CAPACITY OF TRIANGULAR OR TRAPEZOIDAL CHANNEL CONTRIBUTING AREA PEAK 100 YEAR PLOW 0 OUTPALL FROM COTTAGES = 14.45 CPS 2.13 PEAK 100 YEAR PLOW W CP B IN COURTYARDS = 32.37 CPS 5.51 CONTRIBUTING AREA TO CP B IN COURTYARDS INCLUDES COTTAGES CHANNEL CONFIGURATION: TRAPEZOIDAL DESIGN FLOW (cfe) 19.92 CHANNEL LINING: GRASS WA VALLEY PAN REFER TO PAGE 5 Da Db Dc Sc n W I (ft) (ft) (ft) M ----- (ft) ---- (ft) ---- ---- 10.00 ---- 10.00 ---- 1.000 ---- 0.50 0.028 3.00 0.25 0.10 - LEFT BANK SLOPE 0.10 - RIGHT BANK SLOPE DEPTH WIDTH AREA PERIM R 2/3 Sc 1-/2 Q V (s.f.) (ft) (s.f.) (ft) (A/P) ------- ------- (cfe) ------- (ft/sec) ------- ------- 1.00 ------- 23.00 ------- 13..00 ------- 23.20 0.68 0.07 33.25 2.56 0.75 18.00 7.88 18.07 0.57 0.07 16.98 2.16 0.50 13.00 4.00 13.05 0.45 0.07 6.82 1.71 0.25 8.00 1.38 8.02 0.31 0.07 1.59 1.16 0.00 3.00 0.00 3.00 0.00 0.07 0.00 0.00 0.80 19.00 8.80 19.08 0.60 0.07 19.71 2.24 kTt4f tftffTTfYf Tfff Yf tTf TffTtfffftfTtfiffllfffttffftf tfiff tffftf tfffffiTTft E Yj o � v � SHEAR ENGINEERING CORPORATION PAGE 6 FLOW TO CONCENTRATION POINT B FROM SUBBASIN Ib-Id & OS-1 PROJECT: COTTAGES AT MIRAMONT DATE O8/10/95 FILE: COTAMRUN PROJ. NO.1410-01-94 NOTES: BY MEO AREA (A)= 1.410 ACRES RUNOFF COEF. (C) _2 YEAR 10 YEAR 100 YEAR C 0.76 0.76 0.95 SEE SPREAD SHEET ATTACHED ON PAGE 1 TIME OF CONCENTRATION (Tc) OVERLAND TRAVEL TIME (Ti) LENGTH 32 FEET SLOPE 3.69 k 2 YEAR 10 YEAR 100 YEAR C = 0.05 0.10 0.40 Ti (min)= 7.22 6.88 4.81 TRAVEL TIME (Tt) =L/(60*V) FLOW TYPE L (ft) = 31 S (k) = 0.51 GUTTER L (ft) = 24 S (k) = 2.00 GUTTER L (ft) = 230 S (k) = 0.50 'GUTTER L (ft) = 31.4 S (k) = 1.1 GUTTER L (ft) = 24 S (k) = 2 GUTTER L (ft) = 183 S (k) = 0.50 GUTTER L (ft) _? S (k) _? _ ? NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 Tc =Ti+TOTAL TRAVEL TIME 2 YEAR 10 YEAR 100 YEAR Tc (min)= 12.69 12.34 10.28 USE Tc = 12.5 12.5 10 INTENSITY (I) (iph) 2 YEAR 10 YEAR 100 YEAR I = 2.34 4.10 7.14 NOTE: INTENSITIES TAKEN FROM FIGURE 3-1 RUNOFF (Qa CIA) (cfe)- 2 YEAR 10 YEAR 100 YEAR Q = 2.51 4.39 9.56 CONCLUDE:CHECK STREET CAPACITY AT B V (fps) = 1.5 Tt(min)= 0.34 V (fps) = 2.83 Tt(min)= 0.14 V (fps) a 1.5 Tt(min)- 2.56 V (fps) _. 2.07 Tt(min)- 0.25 V (fps) a 2.83 Tt(min)= 0.14 V (fps) = 1.5 Tt(min)= 2.03 V (fps) =1- Tt(min)- 0.00 TOTAL TRAVEL TIME (min) = 5.47 SHEAR ENGINRBRING CORPORATION PAGE 7 FLOW TO CONCENTRATION POINT C FROM SUBBASIN Ic PROJECT: COTTAGES AT MIRAMONT DATE O8/10/95 FILE: COTAMRUN PROD. NO.1410-01-94 NOTES: BY MBO AREA (A)= 0.540 ACRES RUNOFF CORP. (C) 2 YEAR 10 YEAR 100 YEAR C = 0.76 0.76 0.95 SEE SPREAD SHEET ATTACHED ON PAGE 1 TIME OF CONCENTRATION (Tc) OVERLAND TRAVEL TIME (Ti) HA LENGTH 0 PERT SLOPE = 0.00 t 2 YEAR 10 YEAR 100 YEAR C 0.05 0.10 0.40 Ti (min)= 0.00 0.00 0.00 TRAVEL TIME (TO =L/(60*V) FLOW TYPE L (ft) = 49 S (t) = 1.00 GRASSED SWALR L (ft) = 265 S (t) = 0.5 GUTTER L (ft) - S (t) _ L (£t) = S L (ft) = S L (£t) S L (ft) = S (t) = NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 Tc =Ti+TOTAL TRAVEL TIME 2 YEAR 10 YEAR 100 YEAR Tc (min)= 3.46 3.46 3.46 USE Tc = 5 5 5 INTENSITY (I) (iph) 2 YEAR 10 YEAR 100 YEAR I = 3.29 5.64 9.30 NOTE: INTENSITIES TAKEN FROM FIGURE 3-1 RUNOFF (Q= CIA) (Cfs) 2 YEAR 10 YEAR 100 YEAR Q = 1.35 2.31 4.77 CONCLUDE:CHECK STREET CAPACITY AT C V (fps) = 1.58 Tt(min)= 0.52 V (fps) - 1.50 Tt(min)= 2.94 V (fps) = Tt(min)= 0.00 V (fps) = Tt(min)= 0.00 V (fps) = Tt(min)= 0.00 V (fps) = Tt(min)= 0.00 V (fps) = Tt(min)= 0.00 TOTAL TRAVEL TIME (min) = 3.46 SHEAR ENGINEERING CORPORATION PAGE a FLOW TO CONCENTRATION POINT D FROM SUBBASIN Id PROJECT: COTTAGES AT MIRAMONT DATE 08/10/95 FILE: COTAMRUN PROD. HO.1410-01-94 NOTES: BY MEO AREA (A)= 0.530 ACRES RUNOFF CORP. (C) 2 YEAR 10-YEAR 100 YEAR C = 0.76 0.76 0.95 SHE SPREAD SHEET ATTACHED ON PAGE 1 TIME OF CONCENTRATION (Tc) OVERLAND TRAVEL TIME (Ti) LENGTH = 32 FEET SLOPE 3.69 4 2 YEAR 10 YEAR 100 YEAR C = 0.05 0.10 0.40 Ti (min)= 7.22 6.88 4.81 TRAVEL TIME (It)=L/(60*V) PLOW TYPE L (ft) - 31 S (4) - 0.51 GUTTER L (ft) = 24 S (4) - 2.00 GUTTER L (ft) = 230 S (4) - 0.50 GOITER L (ft) _? S (4) =7 ? L (ft) _? S (4) =7 ? L (ft) _? S (4) _? ? L (ft) _? S (4) _? ? NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 Tc =Ti+TOTAL TRAVEL TIME 2 YEAR 10 YEAR 100 YEAR Tc (min)= 10.26 9.92 7.85 USE Tc = 10 10 8 INTENSITY (I) (iph) 2 YEAR 10 YEAR 100 YEAR I = 2.54 4.45 8.00 NOTE: INTENSITIES TAKEN FROM FIGURE 3-1 RUNOFF (Q= CIA) (cfe) 2 YEAR 10 YEAR 100 YEAR Q = 1.02 1.79 4.03 CONCLUDE:CHECK STREET CAPACITY AT D V (fps) = 1.5 Tt(min)= 0.34 V (fps) = 2.83 Tt(min)= 0.14 V (fps) = 1.5 Tt(min)= 2.56 V (fps) _? Tt(min)= 0.00 V-,(fps) _? Tt(min)= 0.00 V (fps) _? Tt(min)= 0.00 V (fps) _? Tt(min)- 0.00 TOTAL TRAVEL TIME (min) = 3.04 SHEAR ENGINEERING CORPORATION PAGE 9 FLOW TO CONCENTRATION POINT E FROM SUBBASIN Is PROJECT: COTTAGES AT MIRAMONT DATE 08/17/95 FILE: COTAMRUN PROJ. NO.1410-01-94 NOTES: BY MHO AREA (A)- 0.280 ACRES RUNOFF COEF. (C) 2 YEAR 10 YEAR 100 YEAR C = 0.76 0.76 0.95 SHE SPREAD SHEET ATTACHED ON PAGE 1 TIME OF CONCENTRATION (TO OVERLAND TRAVEL TIME (Ti) LENGTH 32 FEET SLOPE = 3.69 t 2 YEAR 10 YEAR. 100 YEAR C = 0.05 0.10 0.40 Ti (min)= 7.22 6.86 4.81 TRAVEL TIME (Tt) =L/(60*V) FLOW TYPE L (ft) -= 24 S (t) - 2.00 GUTTER V (fps) = 2.83 Tt(min)- 0.14 L (ft) 16 S (t) = 1.00 GUTTER V (fps) = 2.00 Tt(min)= 0.13 L (ft) = 183 S (t) = 0.50 GUTTER V (fps) = 1.50 Tt(min)= 2.03 L (ft) _? S (t) _?" ? V (fps) _? Tt(min)= 0.00 L (ft) _? S (t) _? ? V (fps) _? Tt(min)= 0.00 L (ft) _? S (t) _? ? V (fps) _? Tt(min)= 0.00 L (ft) _? S (t) _? ? V (fps) _? Tt(min)= 0.00 NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) = 2.31 Tc -Ti+TOTAL TRAVEL TIME 2 YEAR 10 YEAR 100 YEAR Tc (min)- 9.53 9.18 7.12 USE Tc - 9.5 9.5 7 INTENSITY (I) (iph) 2 YEAR 10 YEAR 100 YEAR I = 2.62 4.57 8.44 NOTE: INTENSITIES TAKEN FROM FIGURE 3-1 RUNOFF (Q= CIA) (cfs) 2 YEAR 10 YEAR 100 YEAR Q = 0.56 0.97 2.25 CONCLUDE:CHECK STREET CAPACITY AT E iio i C6Ur\'��c.t'�\, �vc,tn�oNL too, .`•`; REfc-RET\1cE c7Nl ; EeDnvE 6ieJ, I aI � `i9 2 �i eti = , S I 4L — arve\uU1Qs c �YG �h es h,�r�r�e`vL 3 Slu;�ur<, n _ rr C \\ 3,Z•C6 L,4 TlG,�y. SCGow\ J\1\h \\ 6 Ro ,A - `d0U -4 -i �112� t�nZx41 33�307 5� = G,i6 �� 8 IAouIZr s IJ w - 54 Lol -; I z 9 'h L�� s /Zx 10 7u}�1 d� rc. 11 cwa Aye = -Z2 M3 12 C oSL% `c, 13 14 C,`s �X.�,s } 0,417- = ,zg _, 6I cc,i, ka�es 'd = 644 5�e , ,3. 15 16 17 G 13 2 '( RgVCL P R-r'A r d.Urr-, N W WERLAN'D 19 2`?U L 1= I "e C Assuane,d Go}}e, Flow V 20 L-i:: . 2°lo C.iassume. Gv'• T,- 1=l = -L9' s = I,4� 21 ZlU L�= (� 4 0w Grf serA Sw-le_ VC 3,0 � ,.s - I, 1- 122 2z6 Lr `' I i-7°I( GU4,' ) , 23 O 3310 Lx 0!5°lo 2`1 O 10'� Lf u"!�2`1 (use ON C, F)uv 25 2s �a (.e_` crc toe - ��� �clF �L = 12.54 \_"_I .. "— . -f 1_\1 i'i'.I .-I..i lI -Jf -. ._ 'Y k—/'. I r,'ll a J: ,J 169 6�e1 E�2ErvcE a�ILY SHEAR ENGINEERING CORPORATION PAGE 4A FLOW TO CONCENTRATION POINT B FROM SUBBASIN lb PROJECT: COURTYARDS AT MIRAMONT AT MIRAMONT DATE 10/OS/94 PILE: MIRARUN PROJ. NO.1410-01-94 NOTES: BY MHO AREA (A). 5.510 ACRES RUNOFF -COBS. (C) 2 YEAR 10 YEAR 100 YEAR C . 0.71 0.71 0.89 SEE PAGE 4 TIME OF CONCENTRATION (TO ' OVERLAND TRAVEL TIME (Ti) NOT APPLICABLE LENGTH . 10 PERT SLOPS ,. 0.00 4 2 YEAR 10 YEAR 100 YEAR C . 0.00 0.00 0.00 Ti (min).- 0.00 0.00 0.00 TRAVEL TIME (TO .L/(60*V) PLOW TYPE L (ft) 270 S (%) . _1.00 GUTTER V (fps) . 2.00 Tt(min). 2.25 L (ft) . 250 S (t) . 2.00 GUTTER V (fps) . 2.80 Tt(min). 1.49 L (ft) . 210 S (t) . 4.00 GRASSED SWALE V (fps) . 3.00 Tt.(min). 1.17 L (ft) . 226 S-(4) . 2.12 GUTTER V (fps) -= 2.10 Tt(min). 1.79 L (ft) . 526 S (4) . 0.50 GUTTER V (fps) . 1:50 Tt(min). 5.84 L (ft) . 0 8 (t) . 0.00 GUTTER - V (fps) . 0.00 Tt(min). 0.00 L (ft) . 0 S (t) 0.00 COTTER V (fps) . 0.00 Tt(min). 0.00 NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) . 12.54 Tc -Ti+TOTAL TRAVEL TIME 2 YEAR 10 YEAR 100, YEAR ' Tc (min). 12.54 12.54 12.54 USE Tc . 12.5 12.5 12.5 INTENSITY (I) (iph) 2 YEAR SO YEAR 100 YEAR I 2.34 4.15 6.60 NOTE: INTENSITIES TAKEN FROM FIGURE 3-1 RUNOFF (Q. CIA) (cfe) 2 YEAR SO YEAR 100 YEAR Q . 9.15 16.24 32.37 CONCLUDE: INSTALL: CURB OPENING TO HANDLE Q100 +'0�2 �EY61�E�CE ONt�{ Pt.G[ h:D. PREPARED,, m� GOyrii. �c.r�i1� Cra irl\rcrx.or�� Sc�n�t� 1'��\nti 5 DATE V-Z-2A4 141G�o1�S4 1 O Re,nse.,l le�s)4d vlwU = 3Z.,3] 3 e V Gc1..�i% 4 E� t d fO P CU�:�� = 6, ��' CVc�•c�,\� = 1,42� 14ar,vzoNI AL 5 "(r Z�lo d'roi� .., .. C—lei �a Yes✓ o� e v�b eve 6 A = x ,35 = 1,5 3f P = 5 + 9 - BIZ �sn Ne 4i-3 10 Olb 11 12 4 I �wr.r�� se. Sln �� o 7 to 0,1 IN 13 QcS = 23,22 < 30,16-7 14 N G1rGh'i� wic�>, �U Iv 15 = )0 Y .3e, ,s 12 ; 1� IZ �2c� - 1,��6U x J,�i X 67 1c 19 = 49, 6 3 GT 5 JZ�3] dk 20 21 a>`1c,�v�c. Ns� ��� . 10 . .Wo\e :. Gvrb GCS C.ic� (�J Lo \� 1 22 w j t �le� = 6`1 A 7 CFr,0Wr 23 .6i.`6� , (REA R�\ 25 �G I -- 27 t : y_i I i j. i 1' ,. 1� I I I ,'I . , I it � 1t n '.i._I f r r �, i' -i I t ♦ 1 i t 'Nli r r 1. .:; - ✓• 4-1 j.. 1. Y 1t 1 l I 1- -� 1 i ... ! 1 �/ r i It d' � 1 I, r f f �, � i � I I b i ✓l 44, 41 tj �f a r ,.o: 1 1 I f. J- ✓. I �``,, r f t q �l � � l t -, -t 1 r; -4 L� . i " l r 1 r g V. i l v1 1 In 01 :—rX 11 Iti f IN N !-r r I- j , i i II 1 1 I 0 �1 L �' All Ir,r u 't( I t I l N. 1 Y r us-- . '^ t2 r ti o" Ly L-, � r M o. ^ 11 11 1 ,c_rM Q S I -•• `tp �• •: — i :• tiJ 111.00 N� N :Q•�••• �.. U± •- N ID Y Y •Q V ,?. ••� .z a W ¢' > co M O w 0 C] m L � W > 0 u W C im 'n.. i I �I I ti I� I fill -- t - nF-' r _ I , -COU} I I � -• r �- t +-'- -i - 1 1 -r� � i I I r , �t --� --lit 1- -1� 1 I 11' �� - -1 I� 1 ,••I - 1. ,I� i - I { ! I 14. I _ I °' II .'e -,--- I ITt I j ?VLSI III'I,, 1 IIIi JI No Text CONSTRUCTION SEQUENCE PROJECT: THE COTTAGES AT MIRAMONT STANDARD FORM C SEQUENCE FOR 19 ONLY COMPLETED BY:MEO/Shear Engineering Corp: Indicate by. use of.a,bar.line or symbols when erosion control measures will be installed. Major modifications to an approved schedule may require submitting a new schedule forapproval by -the City Engineer. Year 95 96 Month S' O N D J F M A M J J A S O OVERLOT GRADING *** *** *** WIND EROSION CONTROL * Soil Roughening *** RAINFALL EROSION CONTROL STRUCTURAL: * Sediment Trap/Basin * Inlet Filters * Straw Barriers *** *** Silt Fence Barriers *** *** Asphalt/Concrete.Paving *** VEGETATIVE: * Permanent Seed Planting * Sod Installation STRUCTURES: INSTALLED BY: OWNER MAINTAINED BY: OWNER VEGETATION/MULCBING CONTRACTOR: OWNER DATE PREPARED:0808/ 8/95 DATE SUBMITTED: 08/18/95 APPROVED BY THE CITY OF FORT COLLINS ON: RAINFALL PERFORMANCE STANDARD EVALUATION STANDARD FORM A PROJECT: Co�i-4,5es �,Ifiirti,rs,os3� COMPLETED BY: DATE: DEVELOPED SUBBA$IN ERODIBILITY ZONE Asb (ac) Lsb (ft) Ssb Lb (feet) Sb M PS M �00 MARCH 1991 8-14 DESIGN CRITERIA EFFECTIVENESS CALCULATIONS PROJECT: Co i T A GES mqvr\6,A STANDARD FORM B COMPLETED BY: �E,0 DATE: Erosion Control C-Factor P-Factor Method Value Value Comment U S 1,0 Gyz,vc\ MAJOR PS SUB AREA BASIN ($) BASIN (Ac) CALCULATIONS Arc., =-0;73�C, SoJ� = 16x,o3= OM 0, 452� = �0;,73(I,0) } �Q,���C1�o) l,l�,�0,���zzt 6,S�0-� CFY P) 100 C— �,y5Z4x,3�o��]XIU� MARCH 1991 8-15 DESIGN CRITERIA August 21, 1995 Project No. 1410-01-94 Basil Hamdan City of Fort Collins Storm Water Utility P.O. Box 580 Ft. Collins, Colorado 80522 Re: The Cottages at Miramont P.U.D.; Fort Collins, Colorado Dear Basil, Attached is the erosion control security deposit estimate for The Cottages at Miramont P.U.D.. ESTIMATE 1: 280 LF of silt fence at $3.50 per LF $ 980.00 1 Gravel inlet Filter at $75.00 each 75.00 TOTAL ESTIMATED COST: S 1,255.00 x 1.50 $19882.50 ESTIMATE 2: re -vegetate the disturbed area of 2.20 acres at.$650.00 per acre $ 1,430.00 TOTAL ESTIMATED COST: $ 19430.00 x 1.50 S 29145.00 The total required erosion control security deposit will be $ 2,145.00. If you have any questions, please call at 226-5334. Brian W. Shear P.l Shear Engineering BW S / meo cc: Albrecht Homes 4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 226-5334 o Imm000 o wwlninin Ln WWCID CID W 0 mmmm000000 o a �w���mininin w W W W W W W CO CO W W 0 w0mmmmmmmmmmoo0 . . . . . . . . . . . . . . . . o www�rwwwwwwwwlnlnln M W W W W W W W W W W W W 0 W W O nooa,commmmmmmmo,mmmmmmm . . . . . : . . . . . . . . . . . . . . O w w -it w w w w -it .0 w w w w w orw w w w w N W W W W W W W W W W W W OD W W W W W W W O 0 m v M W W WWr-nnnnnnnnnnn W OD-00 00 00 W O O w w w w w w w w w w w w w w w w w w w w w w w w w w A rl W W W W W W W W W W W W W W W 00 00 CO W OD W 00 W W 00 W O W NMwtoLnt11010W%DWt01�nnnnnnl-nnW W W O W W W W W W W CO W W OD-00 W CO W W W W W W W W W W W W U O 1D O N M w w. Ln u1 U1 1f1 t0.1D 1D t0 10 10.t0 ,10 t0 10.n n n n n n t W M w w w w w w w w- w .w'w z W-WW co WWWWW.WWWWWWWCID WW'WWW00WWW N ►-7 O w mriNMM1 w1 wL)U nU1U)U. . .. 1101010t01010 . 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M M_ M M M M W W W CO W M W OD -,M W W.OD W:;W' W:WZW- W`W,;W*W W W W W W O O MNW W m0r1N.NMMMwwwvv-0m 0Inmw%Dww 174 . . . . . . . . . . . . . . . . . a M 0el.4.-1HNNNNNNNNNNNNNNNNNNNNN W W W W W W W W W W W W O0 W CO CO CO CO CO W W W W W W W W a In In1nmNMwlnlannnODWWmmmmm.mo00000 a. . . . . . . . . . . . : . . . . . . . ... . . . . . la N mOOrIr1Hririrl'iriHrlr1rlr1r1ririrlrNIVNNNN n CO W CO CO W W W CO W W 00 W OD W W W W CO W MOD W W W W w ".t." 0 wU)OMU110 CO W 0%000rlAAT404NNNMC'1MMM1'M 1..1 . . . . . . -. . . . . . . . . . . . . . . . . . . N W m0000000.-1rl.4Hr-I Hrlrlr- HArlrlrlrlrirl n n W 0o W W W W W W W CO CO CO CO CO CO CO. CO CO CO CO W W W W In WN W rlwU)nn W mm00rlrirlrlrlN_N.NMMMMM rl 10 W W mmmmmmmm0000000-00`O:0o000 nnnnnnnnnnnWWWWWWWWWWWWWWW 010M0-Wn0%0rlNMMw-W1n1n1nln%DWW%0nn%D%D%D rl wlonnnnWOOWWWWWWOOWW.WOD: WWWWWWW nnnnnnn"rnnnnrnnnrrr;nnrNnnn In a.0w10n W W nnn1010101nwwMMNNm%Owriml0 O ONNNNNNNNNNNNNNNo No NNo NeirlrIr100 nnnnnnnnnnnnnnnnnnnnnnnnnn 3Ex-4 00000000000000000000000000 OUP 00000000000000000000000000 Azw riNMwlnlnn W mOriNMwlfllon W mOlnOlf10ln0 w W rleirlrlrlrlrieirlrlNNMM� wln a Table 88 C-Factors and P-Factors for Evaluating EFF Values. Treatment C-Factor P-Factor BARE SOIL Packedand smooth................................................................ 1.00 Freshlydisked......................................................................... 1.00. . Roughirregular surface........................................................... 1.00 SEDIMENT BASIN/TRAP................................................................. 1.00 STRAW BALE BARRIER, GRAVEL FILTER, SAND BAG ........................ 1.00 SILT FENCE BARRIER..................................................................... 1.00 ASPHALT/CONCRETE-PAVEMENT...................................6...........6... 0.01 ESTABLISHED DRY LAND, (NATIVE)..GRASS ............................ See Fig. 8-A SODGRASS................................................................................. 0.01 TEMPORARY VEGETATION/COVER CROPS .................................... 0.4512' HYDRAULIC MULCH @ 2 TONS/ACRE ............... 6........................... 0.1013' SOIL SEALANT ............... ...................................................... 0.01-0.60(•) EROSION CONTROL MATS/BLANKETS............................................ 0.10 GRAVEL MULCH Mulch shall consist of gravel havingg-a diameter of approximately 1 /4" to 1 1 /2" and applied at a rate of at least 135 tons/acre.............. 0.05 1.00 0.90 0.90 0.50"' 0.80 0.50 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 HAY OR STRAW DRY. MULCH After olantina crass seed, apply mulch at a rate of 2 tons/acre (minimum) and adequately anchor, tack or crimp material into the soil. Slope (%) 1 to 05.................................................. ... ........................0.06 1.00 6 to 10..............................................:............................... 0.06 1.00 11 to 15............................................................................. 0.07 1.00 1.6. to 20..............................................................................0.11 1.00 21 to 25.............................................................................. 0.14 1.00 25 ............................ to 33............................................. ....0.17 1.00 > 33.......................................................................... 0.20 1.00 NOTE:'. Use of other C-Factor or P-Factor values reported in this table must be substantiated by documentation. (1) Must be constructed as the first step in overlot grading. (2) Assumes planting by dates identified in Table 11-4, thus dry or hydraulic mulches are not required. (3) Hydraulic mulches shall be used only between March 15 and May 15 unless irrigated. (4) Value used must be substantiated by documentation. - MARCH 1991 8-6 DESIGN CRITERIA APPENDIX II Backup Diagrams and Exhibits Table 3-3; Rational Method Runoff Coefficients for Composite Analysis Table 3-4; Rational Method Frequency Adjustment Factors Figure 3-2; Estimate of Average Flow Velocity for Use with the Rational Formula Figure 3-1; City of Ft. Collins Rainfall Intensity Duration Curve Table 4-1 - Initial Storm - Street Runoff Encroachment Table 4-2 - Major Storm - Street Runoff Encroachment R-M-P Medium Density Planned Residential District — designation for medium density areas planned as a unit (PUD) to provide a variation in use and building placements with a minimum lot area of 6,000 square feet. R-L-M Low Density Multiple Family District — areas containing low density multiple family unifortone family orther use in th-Ltwo family d el lingsstrictwand 9 000 squaot area of re O 00 are feet forsquare multiple -family dwellings. M-L Low. Density Mobile Home District — designation for areas for mobile home parks containing independent mobile homes not exceeding 6 units per acre. M-M Medium Density Mobile Home District — designation for areas of mobile home parks containing independent mobile homes not exceeding 12 units per acre. B G General Business District — district designation for downtown business areas, including a variety of permitted uses, with minimum lot areas equal to 1 /2 of the total floor area of the building. B-P Planned Business District-- designates areas planned; as .unit:developments to., provide business services while protecting the surrounding residential areas with minumum lot areas the same as R-M. terea of automobile -orientated gsi- H-B •sBDis suan tfloor eof the building. Hises wh a minimum lot area equal to of tot B-L Limited Business District — designates areas for neighborhood convenience' centers, including a variety of community uses with minimum lot areas equal to two times the total floor area of the building. C Commercial District —designates areas of commercial, service and storage areas. I-L Limited Industrial District —designates areas of light industrial uses with a minimum area of lot equal to two times the total floor area of the building not to be less than 20,000 square feet. 612 Industrial Park District _ designates light industrial park areas containing controlled. industrial uses with minimum lot areas equal to two times the total floor area -of the building not to be less than 20,000 square feet. I-G General Industrial District — designates areas -of major industrial development. T Transition District— designates -areas which are in a transitional stage with regard to ultimate -development. For current and more explicit definitions of land uses and zoning classifications, refer to the Code of the City of Fort Collins,. Chapters 99 and 11 S. Table 3-3 ' ' RATIONAL METHOD RUNOFF COEFFICIENTS FOR COMPOSITE ANALYSIS Runoff Coefficient Character of Surface Streets, Parking Lots,'Drives: 0.95 Asphalt'........::..................................................... .. 0.95 Concrete. .................................................... 0.50 Gravel............................................................ 0.95 Roofs.......................................................................................................... Lawns, Sandy Soil: 0.15 Flat <2% `......................................:................... 0. Average 2 to 7%.......................................................... ........................ 0.20 Steep>7%............:.................................................. Lawns',.Heavy Soil: 0.25 Flat<2% ............... :...................... ...............................::..:....:..:......:..... 0.2 Average2 to 7% ................................................................................... . .0.35 --..., Steep >7%......... :..................................................... .......................... MAY 1984 3-4 DESIGN CRITERIA 3.1.7 Time of Concentration In order to use the Rainfall Intensity Duration Curve, the time of concentration must be known. This can be determined either by the following equation or the "Overland Time of Flow Curves" from the Urban Storm Drainage Criteria Manual, included in this report (See Figure 3-2). Tc =1.87 (�1' iz S Where Tc =Time of Concentration, minutes S = Slope of Basin, % C = Rational Method Runoff Coefficient D = Length of Basin, feet C, = Frequency Adjustment Factor Time of concentration calculations should reflect channel -and storm sewer velocities as well as overland flow times. 3.1:8 Adjustment for Infrequent Storms The preceding variables are based on the initial storm, that is, the two to ten year storms. For -storms withhigher intensitiesan,adjustment,of the runoff coefficient is required because of the lessening° amount of) infiltration; depression retention, and other losses that have a proportionally smaller effect on storm -runoff. These frequency adjustment factors are found in Table 3-4. Table 3-4 RATIONAL METHOD FREQUENCY ADJUSTMENT FACTORS Storm Return Period Frequency Factor (years) q 2 to 10 1.00 11 t025 1.10 26 to 50 1.20 51 to 100 1.25 Note: The product of C times Ct shall not exceed 1.00 3.2 Analysis Methodology The methods presented in this section will be instituted for use in the determination and/or verification of runoff at specific design points in the drainage system. These methods are (1), the Rational Method and (2) the .Colorado,Urban Hydrograph, Procedure (CUHP). Other computer methods, such as SWMM, STORM; and HEC' 1' are:allowable.if:results are not radically different than these two. Where applicable, drai'nage-systems proposed for construction should provide the minimum protection as determined by the methodology so mentioned above. 3.2.1 Rational Method For drainage, basins of 200 acres or less, the runoff may be calculated by the Rational Method, which is essentially the following equation: Q=C,CIA Where Q = Flow Quantity, cfs A =Total Area of Basin, acres C, = Storm Frequency Adjustment Factor (See Section 3.1.8) C = Runoff Coefficient (See Section 3.1.6) I =Rainfall Intensity, inches per hour, (See Section3.1.4) 3.2.2 Colorado Urban Hydrograph Procedure For basins larger than 200 acres, the design storm runoffshould be_ana!yzed by deriving synthetic unit hydrographs. It is recommended that the . Colorado Urban Hydrograph Procedure be used for such analysis. This procedure is detailed in the Urban Storm Drainage Criteria Manual, Volume 1, Section 4. MAY 1984 3-5 DESIGN CRITERIA DRAINAGE CRITERIA MANUAL RUNOFF 5C 3C I-- 20 z w 0 Ir w a 10 z w IL 5 w m 3 Z) 0 0 2 I W H 3 1 5 .1 AV ■rNIP /A/I0 1111IM A■■ FAME I It■■O e■■■® �ee�r�■MFAM Mr.1111 �■���ee■■e■� �����ii�ii�iisi��■iviiiis 2: .3 .5 1 2 3 5 10 20 VELOCITY IN- FEET PER SECOND FIGURE 3-2. ESTIMATE OF AVERAGE FLOW VELOCITY FOR USE WITH THE RATIONAL FORMULA. *MOST FREQUENTLY OCCURRING"UNDEVELOPED" LAND SURFACES IN THE DENVER REGION. REFERENCE: "Urban. Hydrology . For. Small- Watersheds" -Technical Release, No. 55, USDA, SCS Jan. 1§75. 5 =1-84 URBAN DRAINAGE & FLOOD CONTROL DISTRICT AVERAGE FLOW VELOCITY FOR USE WITH RATIONAL METHOD PROM FIGURE 3-2 SLOPE VELOCITY (fp0) 4 FOREST FALLOW SHORT BARB GRASSED PAVED/ GRASS GROUND WATERWAY GOITER r rrrtrrrrrrtrrrrtrrrrrrrrrrrrrrrrerr ttrtrrererrrrrrrrrrrrerrrrr 0.5 0.18 0.33 0.50 0.70 1.11 1.50 0.6 0.19 0.36 0.54 0.75 1.22 1.61 0.7 0.20 0.38 0.5E 0.82 1.33 1.72 0.8 0.22 0.41 0.62 0.85 1.41 1.80 0.9 _0.23 0.44 0.66 0.92 1.51 1.88 1.0 0.24 0.46 0.70 0.98 1.5E 2.00 1.5 0.28 0.54 0.82 1.21 1.83 2.36 2.0 0.35 0.65 1.00 1.47 2.16 2.83 2.5 0.38- 0.73 .. 1.12: 1.58. 2.39: 3.10 3-.0 0.43 0.60 1.26 1.72 2.61 3.40 3.5 0.46 0.85 1.37 1.85 2.80 3.67 4.0 0.50 0.93 1.47 1.94 3.00 4.00 4.5 0.52 0.97 1.54 2.04 3.17 4.18 5.0 0.54 1.05 1.64 2.19 3.37 4.45 5.5 6.0 6.5 7.0 7.5 8.0 0.5 9.0 9.5 10.0 No Text a PORT COLLINS RAINFALL INTENSITY CURVE DATA FOR CITY OF PORT COLLINS PIG 3-1 INTERPRETED DECEMBER 21, 1992 BY MARK OEBRSCHMIDT SHEAR ENGINEERING CORPORATION INTENSITIES IN RED ARE BASED. ON STRAIGHT LINE INTERPOLATION BY MARK OBBRSCHMIDT ON MARCH 9, 1995_ 2 .5 10 25 50 100 TIME YEAR YEAR YEAR YEAR YEAR YEAR rrtrr:rrrrrtrrrrrr:rrrsrr:rrrrrrrrtrrrerrrrrrrrrrrtrr:tr rrrrrrr 5 3.29 4.70 :5.64 7.02 7.95 9.30 6 3.14 4.49 5.402 6.716 7.63 8.868' 7 2.99 4.28 5.164 6.412 7.31 8.436 8 2.84 4.07 4.926 6.109 6.99 6.004 9 2.69 3:86, 4.688 •: 5.804 + 6..67. E. 7.572 :. 10 2.54 3.65 4.45 5.50 6.35- 7.14 11 2.46 3.534 4.31 5.32 6.138 6.924 12 2.38 3.418 4.17 5.14 5.926 6.708 13 2.3 3.302 4.03 4.96 5.714 6.492 14 2.22 3.186- 3.89 4.76 5.502 6.276 15 2.14 3.07 3..75 4.60 5.29 6.06 16 2.082 2.986 3.65 4.48 5.152 5.89 17 2.024 2.902 3.55 4.36 5.014 5.72 18 1.966 2.818 3.45 4.24 4.876 5.55 19 1.908 2.734 3:35 4.12 4.738 5.38 20 1.85 2.65 3.25 4.00 4.60 5.21 21 1.606 2.588 3.174 3.900 4.496 5.094 22 1.762 2.526- 3.098 3.816 4.392 4.979 23 1.718 2.464 3.022 3.724 4.288 4.862 24 1.674 2.402" 2.946 3.632 4.184 4.746 25 1.63 2.34 2.87 3.54. 4.08 4.63 26 1.598 2.294 2.816 3.466 3.998 4.544 27 1.566 2.248 2.762 3.392 3.916 4.458 28 1.534 2.202-• 2.708'-. _3:318::' 3:834 A .372 29 1.502 2.156 2.654 3.244 3.752 4.286 30 1.47 2.11 2.60 3.17 3.67 4.20 35 1.32 1.92 2.38 2.88 3.35 3.81 40 1:20 1.76 2.19 2.67 3.08 3.60 45 1.12 1.62 2.02 2.46 2.84 3.28 50 1.04 1.51 1.87 2.27 2.65 3.02 ' 55 0.97 1.40 1.73 2.12 2.46 2.80 60 0.90 1.32 1.62 1.99 2.32 2.60 65 0.88 1.24 1.52 1.84 2.18 2.43 70 0.82 1.18 1.44 1.72 2.05 2.30 75 0.79 1.11 1.38 1.62. .1.93 2.17 - 80 0.74 1.07 1.30 1.53 1.82 2.07 85 0.70 1.00 1.23 1.46 1.73 1.96 90 0.69 0.97 1.20 1.40 1.67 1.87 95 0.64 0.91 1.13 1.32 1.59 1.77 100 0.61 0.88 1.09 1.27 1.51 1.70 105 0.60 0.83 1.04 1.22 1.46 1.63 110 0.57 0.80 1.00 1.18 1.40 1.67 115 0.54 0.78 0.96 1.14 1.33 1.50 120 0.52 0.76 0.91 1.10 1.19 1.44 4.2.2.1 Street Encroachment The encroachment of gutter flow on the street for the initial storm runoff shall not ex- ceed the specifications set forth in Table 4-1. A storm drainage system shall begin Where the encroachment reaches the limits found in this table. Table 4-1 INITIAL STORM —,STREET RUNOFF ENCROACHMENT Street Classification Maximum Encroachment Local (includes places, alleys, No curb -topping. t Flow may spread to marginal access) crown of street Collector No curb -topping. t Flow spread must leave at least one lane width free of water Major Arterial No curb -topping. t Flow spread must leave at least one-half (1 /2) of roadway width tree of water in each direction t Where no curbing exists, encroachment shall not extend over property lines. 4.2.2.2Theoretical Capacity Once the allowable pavement encroachment has been established, theoretical gutter capacity shall be computed using the following revised Manning's equation for flow in shallow triangular channels: 0-0.56ZS'2yerj n Where 0 = Theoretical -Gutter Capacity, cfs y — Depth of Flow at Face of Gutter, feet n = Roughness Coefficient S =Channel Slope, Ieet/feet Z = Reciprocal of Cross Slope, feet/feet A nomograph based on the previous equation has been developed and is included in Figure 4-1. The graph is applicable for all -gutter configurations. An "n" value of 0.016 shall be used for all calculations involving street runoff. 4.2.2.3 Allowable Gutter Flow In order to calculate the -actual flow rate allowable; the theoretical capacity shall be multiplied by a reduction factor. These factors are determined by the curve in Figure 4-2 entitled "Reduction Factors foriAllowable;.Gutter Capacity". The allowable gutter flow calculated thusly is the value:to%be used.,in the drainage system calculations. MAY 1984 4-2 DESIGN CRITERIA 4.2.3 Major Storms The determination of the allowable street flow due to the major storm shall be based on the following criteria: • Theoretical capacity based on allowable depth and inundated area. • Reduced allowable flow due to velocity conditions. 4.2.3.1 Street Encroachment Table 4-2 sets forth the allowable street inundation for the major storm runoff. Table 4-2 MAJOR.STORM — STREET RUNOFF ENCROACHMENT street Gawficatlon Maximum Encroachment Local (includes places, alleys, Residential dwellings, public, marginal access & collector) commercial, and industrial buildings shall not be inundated atthe ground line unless buildings are flood proofed: The depth of water over the crown shall not exceed 6 inches. Arterial and Major Arterial Residential dwellings, public, commercial and industrial buildings shall not be. inundated at the ground line unless buildings are flood proofed. Depth of water at the street crown shall not exceed 6 inches to allow operation of emergency vehicles. The depth of water over the gutter flowline shall not exceed 18 inches. In some cases, the 18 inch depth over the gutter flowline is more restrictive than the 6 inch depth over the street crown. For these conditions, the most restrictive of the two criteria shall govern. 4.2.3.2Theoritical Capacity Manning's equation shall be used to calculate the theoretical runoff -carrying capac- ity based on the allowable street inundation. The equation will be as follows: 0=1.486R213S'"2A n, Where Q = Capacity; cfs n = Roughness Coefficient R=Hydraulic Radius, A/P S=Slope, Ieet/feet A = Area, feet Appropriate "n" values can be found in.Table 4-3. Any values not listed should be located in the Geological Survey Water Supply Paper, 1849. Table 4-3 MANNING'S ROUGHNESS COEFFICIENTS FOR STREET SURFACES Surface' Roughness Coefficient Gutter& Street......:............................................................... 0.016 . - DryRubble........................................................................... 0.035 .. Mowed Kentucky Bluegrass ................................................. .0.035 Rough Stony Field w/Weeds':...:.:...:..................................... . 0.040 ' Sidewalk & Driveway ............. :..:........:......... .:........................ 0.016 MAY 1984 4-5 DESIGN CRITERIA APPENDIX III Portions of the Overall Drainage Study for Oak /Cottonwoods Farm - McClellands Basin OVERALL DRAINAGE STUDY OAK/COTTONWOOD FARM - McCLELLANDS BASIN FORT COLLINS, COLORADO GENERAL LOCATION AND DESCRIPTION A. Location The Oak/Cottonwood Farm development is located in the southeast part of Fort Collins, immediately south of Harmony Road and west of Lemay Avenue. The Oak/Cottonwood Farm development consists of approximately 271.7 acres occupying the east half of Section 1, Township 6 North, Range 69 West, of the 6th Principal Meridian. See the Overall Drainage Plan in the back pocket of this report. This study will deal only with the area within the McClellands Basin, or all of the area north of the Mail Creek Irrigation Ditch. The areas south of the Mail Creek Irrigation Ditch will be addressed under a separate study. B. Description of Property The Oak/Cottonwood Farm site contains two existing churches and assorted retail businesses along Harmony Road, and an existing psychiatric hospital along Lemay Avenue. The remainder of the existing site, prior to the start of construction of the.single family developments, consisted of cultivated farmland and natural grasses. The Mail Creek Irrigation Canal runs across the center of the site from northwest to southeast. Topography.. north of the Mail Creek irrigation canal is generally sloping from northwest to southeast at approximately 1.4% . Topography south of theMail Creek: irrigation canal is generally sloping from north to south at approximately 5.7%. Mail Creek and Fossil Creek is located in the southern part of the development, generally running from west to east. A small portion of the site,, planned for residential development, is located south of Mail Creek Three separate single family developments have been designed and construction started within the Oak/Cottonwood Farm development; The Upper Meadow at Miramont First and Second Filings, and Castleridge P.U.D.. Four other developments have been proposed within this Overall development, and either Final or Preliminary plans submitted to the City for review; Miramont Third Filing, Oak Hill Apartments, Tennis Center, and the Courtyards at Miramont. The developments mentioned above have been shown schematically on the overall Drainage Plan included in 1)v site within the McClellands Basin. The adjacent Oakridge development utilized SWMM modeling for the 10 year and 100 year storm events with a different model for each storm event. Due to the number of existing and proposed detention facilities within this portion of the subject site, and the need to determine the size of the future detention ponds, a new SWMM model was developed for the Oak/Cottonwood Farm site. The 2, 5, 10, 25, 50, and 100 year rainfall events, which were obtained from the City of Fort Collins and required to be run by the City, were run for a new single SWMM model developed for the site. The new SWMM model was not. incorporated into the existing Oakridge site SWMM model. D. Hydraulic Criteria , All calculations- with this report -have been prepared :n accordance with the City of Fort Collins Storm Drainage Criteria. E. Variances from Criteria No variances are being sought for the Oak/Cottonwood Farm site. DRAINAGE FACILITY DESIGN - OVERALL DRAINAGE STUDY FOR OAK/COTTONWOOD FARM A. General Concept As development continues to occurs within the Oak/Cottonwood Farm site, the drainage concepts shown on the, Overall Drainage Plan in the back pocket of this report should be followed. Specific detention requir,ements.exist,inthe-McClellands Basin, where as the Mail Creek Basin and the Fossil Creek Basins allow for undetained storm water runoff directly to Mail Creek and to Fossil Creek. B. Specific Details To the East of the Oak/Cottonwood , Farm property, within the McClellands Basin, is the Oakridge Business Park and Residential Community. The appendix includes portions of the text from the Master Drainage Study for the Oakridge Business Park. Three existing 36" pipes lie beneath Lemay Avenue, approximately 3000 feet south of Harmony Road, which in effect direct the Oak/Cottonwood Farm storm water runoff to the Oakridge property. Within the Oakridge development, the Storm Water Management Model (SWMM) was utilized to model the 3 pipes, the SWMM model was also calibrated to release runoff from this property at a target design rate for the site. Once the SWMM model was calibrated for the existing developments within the study area, the study area was evaluated in reference to the required 0.5 cfs per acre ,100 year storm event, release rate. Future detention pond sites were planned with the Client to the best extent possible in order to determine how the study area would drain. Each detention pond system was modeled with a release rate of 0.5 cfs per acre during a 100 year storm event. The off -site residential neighborhood to the west of the Oak/Cottonwood Farm site drains southeasterly and through the first planned development in the oak/Cottonwood Farm: site,. *Tlhe extent of this off -site area was estimated to be 14.75 acres,per;the Mail Creek Hydrologic Information drawing by Water Engineering &Technology, Inc. dated 2-29-90. For this report, it has been assumed that the separation between the Mail Creek Basin and the McClellands Basin has been shown correctly on the Mail Creek Hydrologic Information drawing. Per a conversation with the City Stormwater Utility, it was learned that within the Mail Creek Basin it was assumed during storm events that the Mail Creek Ditch is flowing full and land above the Ditch will sheet flow storm water directly over the Ditch and downstream to Mail Creek. Per meeting with John Moen (Ditch Rider of the Mail Creek Ditch) the Mail Creek irrigation ditch has no available capacity for storm water runoff and during a storm event storm water runoff sheet flows directly over the Mail Creek irrigation ditch. This off -site storm water runoff from the 14.75 acres of existing residential neighborhood only has a minor impact to the Oak/Cottonwood Farm site and these off -site flows are collected in the First Filing development as discussed later in this report. Included on the Overall Drainage Plan is a summary table of the proposed detention ponds. their required capacities, and their maximum allowable release rates (Summarized below). The detention pond capacities were sized with the anticipated type of development contributory to the ponds at the time of this report. As the development of these sites progresses to final design, the SWMM model should be updated to finalize the size of each detention pond per its final type of development. Outflow from each pond shall utilize a rating curve based on the ultimate pond configuration. The rating curves for detention ponds 321 (Associated with Miramont First Filing), and Detention pond 340 (Associated partly with Miramont Second Filing) have been included in the model with this update. 5 detention volume available within basin 204 based on field verification is 3.4 ac.-ft.. Because the existing available volume is greater than the required volume per the SWMM Model, this method of modeling Basin 204 is adequate. Element 307 - Pace and Builders Square (Basin 203) Per the Harmony Market 2nd Filing drainage report, the designed release rate at this location is 6 cfs. No SWMM model rating curves are available for the detention ponds existing within this basin. For the SWMM modeling herein, a conveyance element was derived which modeled the maximum release rate of 6 cfs occurring from this basin, and caused water over and above this release rate to be•detained at the'upstream end of the conveyance element: This�way of'modeling-the 'existing facilities enables the model to realize the intended release rate at this location so the downstream system analysis can be completed utilizing the full upstream impact. Per the SWMM Model output, the water detained at conveyance element 307 is 5.3 ac.ft.. The actual detention volume available within basin 203 based on field verification is 8.0 ac.-ft.. Because the existing available volume is greater than the required volume per the SWMM Model, this method of modeling Basin 203 is adequate. Element 303 - Church Site (Basin 205) No SWMM model rating curves are available for the detention pond existing within this basin. For the SWMM modeling herein, a conveyance element was derived which modeled the maximum release rate of 0.5 cfs/acre occurring from this basin per the criteria within the McClellands Basin, and caused water over and above this release rate to be detained at the upstream end of the conveyance element. This way of modeling the existing facilities enables the model to realize the intended release rate at this location so the downstream system analysis can be completed utilizing the full upstream impact. ` The actual detention volume available within basin 205 by a field verification is outside the scope of this project. Element 311 - Collinswood Treatment Complex (Basin 207) No SWMM model rating curves are available forthe detention pond existing within this basin. For the SWMM modeling herein, a conveyance element was derived which modeled the maximum 7 existing 36" culverts under Lemay Avenue, a second drainage system was master planned along Boardwalk. A series of storm sewers and open channels was constructed along Boardwalk from the existing 36" storm sewers under Lemay Avenue, upstream to Oakridge Drive. A detention pond was planned and partially constructed for the property in the northwest corner of the Oak/Cottonwood Farm site with an 18" e storm sewer outlet to release runoff at the required 0.5 cfs per acre. On the Overall Drainage Plan a storm sewer system has been shown in Boardwalk Drive to transport the northwestern detention pond outlet flows to the downstream storm sewer and open channel system. This system was built according to this overall plan. At the time of this update, Detention pond 322 will outlet onto Boardwalk Drive and be conveyed by curb and gutter to the storm sewer system (a combination of pipes and open channels). An,agreement between GT Land and Front Range Baptist Church exists that' limits the release from basin 202 to 5.57 cfs for the 10 year storm event and 11.45 cfs for the 100 year storm event (Based on the capacity of Boardwalk Drive Curb and Gutter). Detention pond 321 will outlet on the west side of Boardwalk and be conveyed downstream to Lemay Avenue by the same series of pipes and open channels. A copy of this agreement has been included in the appendix of this report. The storm sewer system in Boardwalk Drive was sized to carry the 25 year storm runoff event due to the location of the proposed high and low points in Boardwalk Drive. As storm events occur greater than the 25 year storm event, minor ponding is planned to occur at the low points. In the event the storm sewer systems become plugged, overflow swales have been provided to redirect storm water runoff to the proposed open channel system to safely convey storm water runoff to the proposed detention pond number 340 and the existing 36" culverts under Lemay Avenues In order to achieve the required 0.5 cfs per acre release at the existing 36" culverts under Lemay Avenue, detention pond number 340 is planned immediately upstream of the 36" culverts. During final design of this detention pond, the hydraulics of the connection from the detention pond to the existing 36" culverts will need to be worked out to ensure the 0.5 cfs per acre release rate is riot exceeded. A preliminary rating curve based on the proposed ultimate design of this pond has been included in the model, and the calculations are included in the appendix of this report. The rating curve included is based on the existing 36" pipes under Lemay being built according to plan, and that rating curve is a preliminary design only. As pond 340 is finalized, these existing 36" culverts will need to be reevaluated and the new rating curves based on 0 go e an emergency overflow outlet in the event the outlet structure and pipe become plugged. All on -site drainage facilities will be maintained by a homeowners association, or other entity created by the developer. The City of Fort Collins will maintain the storm sewer systems located within dedicated right-of-ways. REFERENCES 1. Storm Drainage Design Criteria and Construction Standards by the City of Fort Collins, Colorado, May 1984. 2. Erosion Control Reference Manual for Construction Sites by the City of Fort Collins, Colorado, January 1991. 3. Master Drainage Study for the Oakridge Business Park in Fort Collins, Colorado, by RBD Inc., September 1990. 4. Final Drainage and Erosion Control Study for The Upper Meadow at Miramont First Filing, Fort Collins, Colorado, by RBD, Inc., November 10, 1992. 5. Final Drainage and Erosion Control Study for The Upper Meadow at Miramont Second Filing, Fort Collins, Colorado, by RBD, Inc. 6. Final Drainage and Erosion Control Study for Castleridge at Miramont First Filing, Fort Collins, Colorado, by RBD, Inc., October 7, 1993. 7. Preliminary Design Report for Mail Creek Stability Study, by Lidstone and Anderson-& TST, Inc., January 28, 1994. 8. Preliminary Drainage and Erosion Control Study for Miramont 3rd Phase P.U.D., Fort Collins, Colorado, by RBD, Inc., February 4, 1994. 9. Final Drainage and Erosion Control Study for Miramont P.U.D. Third Filing, Fort Collins, Colorado, by RBD, Inc., April 4, 1994. 10. Preliminary Drainage and Erosion Control Plan for the Oak Hill Apartments, Fort Collins, Colorado, by RBD, Inc., February 4, 1994 11 CLIENT 1ntQ 1Z �M/71�h' 1 1JOB NO. p l �NO PROJECT j ' � '�ti I � �'� CALCULATIONS FOR �� KA M �^ �� pp��I I -I ¢ ['1nCI Engineering Consultants MADE BY Sd_ DATE4��CHECNED By DATE -SHEET I ID OF _ ._��u1MA.t r ' I f �,— �co� Y4wtcE 77 _. Y 3oz - - �. M CLIENT 1UOPOI(K IA/6H L JOBNO. Soy-00 / RNC PROJECT COTTONWOOD CALCULATIONS FOR SWMM rnoDE� Engineering Consultants MADE BY KLOL DATE Y y 92 CHECKED BY -DATE SHEET _11 OF DETZ=K ir//n/6" Cpl YA,VeF'' "RaM67E4s �.;. f-. 01J10TIIOR C.6N . 'swb LEFT' R115 r a I ,r .0 -. . CONVEY AAlCE TYfE. 6TA/ NI .. FFrfr!-�FuLL CJiF,W'tZ ... t:CEmE.vT _ ',_. D1Art1E7SR SiOE.So/� ,S/GE SloA`, 3Z0 .. cifnim ,Soo 1350 .0050 y 7 /,2S o OiIO o 0 073.. / 2Sw�L_ eae F 3z! 3Z2 PfPE ' /,SO 70. 4100 0 D O!3` /,SOr 3Z3_.. FIFE 6So' . Lsoo o(!o o 0 o13 /.So 324-- —YIP — 1Za�... ,0050 :6-7 - p- -- OII3- --- 3.00 .. (23YR. D"E57JJI6u) 3Z5- CHAVAAE J/"v Y20 .00.0 3,00I i - 3ZG PIPE - 3,So /00 .0050 O O .013 3.so (25YR 0ES16rJ) -- 327--- _. -. CHANOFR __y.00 750. .DOS, 4 4-_ .035 3.00 ---.._ _.__I 320 PIPE /,75 100 10100 O 0 .013 A75, (25 YR DES1(qro) 329 CHAeJNEz 5S.00 2yo .01256 y y .035 y,00 330 PIPE 1.s0 80 .005o O 0 1013 LSO (ZS YC DEs/cu) __7 331 PIPE - 3.00 80 .0050 -0 O .013 3.00 (25 YR DES/G.u) I LrAr' O.Ib 10 00/y6 O 0 .013 d,lo C'fzATu.lb C_I Ezv5' 341 'PIPS 5•Zn (ZD 0. jo QS d013 S. Zb � I � � CJENT` i _ I I _A w ID JCB NO.Z�G-�`_ PROJECT A A II p w MG^-,rf CAICUUTIONS FO:��T ��` I � y a Engineering Consultants MADE BYDATE`,!S CHECKED BY -DATE SHEET -OF .1LPY�.S 7n.. _ - � A�1 i4 P_... t- .. ., i� r•-'-i L t r..''..+-.-i�t µ 7-- I .. ... � - GIl..�MUf�.. I 7 O �1.1�.• K.. �..i r'- 1i, mod.:,. �/oWM � 1 ♦� I -�-lJ- f� I 1 ^ a r 1 ,1 yy 37,it3 'll 141 '49b 4-814�5- ':. 49�T ' • -j - . , ; � . I �� , vSS � 2664-,A91 � C-�. 08 2.3Z I -7 oLLa'v1�9 r^I ltil Jt ..T�-D .'LI:), � I 1 8r V Az5. 1 i � 122fGATl�nJ TA2i E� drop, -E 3.�5 i -7.85 nG.P'r- APPENDIX IV Stuffer Envelope Drainage and Erosion Control Plan Preliminary Drainage and Erosion Control Plan (Overall area; for reference) Final Grading Plan for Courtyards at Miramont Second Filing Erosion Control Security Deposit Requirements August 22, 1995 Project No: 1410-01-94 Re: EROSION CONTROL SECURITY DEPOSIT REQUIREMENTS: The Cottages at Miramont P.U.D.; Fort Collins, Colorado A. An erosion control security deposit is required in accordance with City of Fort Collins policy (Chapter 7, Section C : SECURITY; page 7.23 of the City of Fort Collins Development Manual). In no instance shall the amount of the security be less than $1000.00. 1. According to current City of Fort Collins policy, the erosion control security deposit is figured based on the larger amount of 1.5 times the estimated cost of installing the approved erosion control measures or 1.5 times the cost to re -vegetate the anticipated area to be disturbed by construction activity. a The cost to install the proposed erosion control devices for the Courtyards at Miramont P.U.D., Second Filing is $1,255.00. 1.5 times this estimate is $ 1,882.50. i. unit prices have been provided by Connell Resources. b. Based on current data provided by the City of Fort Collins Storm Water Utility, and based on an actual anticipated net affected disturbed area during construction of the The Cottages at Miramont P.U.D. (approximately 2.22 acres) we estimate that the cost to re -vegetate the disturbed area will be $1,430.00 ($650.00 per acre x 2.20 acres). 1.5 times the cost to re -vegetate the disturbed area is $2,145.00. i. The 2.22 acres is the actual area of the The Cottages at Miramont P.U.D., housing project. ii. The $650.00 per acre for re -seeding sites of less than 10 acres was quoted to us by the City of Fort Collins Storm Water Utility staff. CONCLUSION: The erosion control security deposit amount required for this project will be S 2,145.00. Because of the anticipated construction phasing, separate erosion control deposit amounts may be established for the phase to be constructed. 4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 226-5334 THE UPPER MEADOW j edt' LEGEND 6 i&2do• 33 DAMDESIGNATION 1 a a +L r SUB BAST BOUNDARY B 28 DESIGNATIONSUBBASIN 13 W' 1R���y ,., I:; y {' �c/ CONCENTRATION POEXT 33 6E �.o ° 13 PLOW DWCTION 13 9 w • 1 Ry 30 `� � ' = Cl C.�JT 1 _ , l / I ltl WOOD VARMS DETENTION POND 0 3 cre- � DESIGNATION 10 { ` 3 - t '� \\ L—`J� EROSION CONTROL LEGEND �' 11 � 1,� Y �• /y u naruEoPu rs P..D. : < �b�i 9J 2 '� , D r = GRAVEL INLET FILTER r 1 ' \ ..\ 4 '1 ` _� a SILT FENCE RIP RAP APRON e �410 �a. 'd^` AREA INLET FILTER STINGT •n D IRgTION 1 _ - / �, / ` y1 e1� CA1 2 STRAW BALE DIKE SPA GRADING AND DRAINAGE GENERAL_NOTE, I Thl City If[: Cofliry, still Ell by mit,waild, r I PPrr-Ids^qIIIII d,mt nl Hi In pF- AOm ra Lixr—�\ \ 3 �, A a '_ 17 i. ll; ��J _ �— Pfe" II] Midl v" m11n, ni 1. �duun.r � Hu°atild in �.�: MEMN x. �hYe m e - - pH »aN uc suN or -, -,121 we ¢\ � 3 \ \ \r -^\ I I I - z2 J ( _ ( �' MIRAMONT �� p + caomo CE co I.n a 10 y w.�r ALL 1xiEnS r P!aldc 1U WOMI[S-I .YIe Mm OML D SauL Pn Colwtl 101,(M N1 AwtlbiN: / m. UPILEee OTHEM PROPOSED PARK 3 \ \ / - ��J TENNIS 1 w sexi er"em 112 s «OrEO ZONED rp Vi\ _� _� _' 23 - y I CENTER J ♦\ = `""rD. N,ww . US ,��ISSAil s Fin A PARCEL P off\ \ - ( —J 1 UUU UUU \\\ '�V� a �ch"ImwendWI umkd9ne.• tloe1. 11 \ 24 - V . 0 � \ \ a cdoi a ,yu,� dem, d' rmid.d ro w.A, w.w J B° FAiW l WwmAIar or / / I vew•mw..�Aimsr wN All PARK OR ULT/-PAM/LY jo , rYY," mm a P° � en• e H ry� ti \`I rs .rswualm 1 � R.1 ,BOY / / y�B� _ -IAnn® a=IMF, r. N ra�o ta»�r to er dr.-a s .I. 9 1� I 1 EXISTING 1 DETENTION POND I---� POND PHASE VII C' A II _ rm1 couwwooc 2.. r.r � NET r \ \ II ZONED bp I �' I THE COTTAGES AT MIRAMONT P.U.D. '\ --4I I (PHASE M) ..♦ C �I I li ' I FUTURE wF9 EVELOPMFJVT I - 'P 0 L - Jfi S1pIN4EWER— Ii 11 YN eIOrMERS i LEMAY AVENUE At / \ / MIRAMONT PHASE VI REVISIONS Date tew Droea uwm _ AUDI SHEAR ENGINEERWG CORPORAI'fON """ PPELDIINARY VASTER DRAINAGE AND EROSION CONTROL PUN �srn �p T N NO Of "" -- h °i"°"" E.1a Book cn.cL.a aws. _ ALBRECHT HOMES E838 S0. COLLEGE AYE, SUITE t2. EORT coulHs. coLORADo COURTYARDS AT MIRAMONT P.U.D. �.a1p. 1 R 1410-01-94 _ r - 1w Approved firs _ _ _ PHONE: (303) 226-53U (303) 226-aa51 FORT COLLINS COLORADO Mill FOR REFERENCE ONLY