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HomeMy WebLinkAboutDrainage Reports - 04/06/2022City of Fort Collins Approved Plans Approved by: Date: Dan Mogen 04/06/2022 3/15/22 Appendix A APPENDIX A SITE DESCRIPTIONS, CHARACTERISTICS, & REFERENCES FORT COLLINS STORMWATER CRITERIA MANUAL Hydrology Standards (Ch. 5) 3.0 Rational Method 3.4 Intensity-Duration-Frequency Curves for Rational Method Page 8 Table 3.4-1. IDF Table for Rational Method Duration (min) Intensity 2-year (in/hr) Intensity 10-year (in/hr) Intensity 100-year (in/hr) Duration (min) Intensity 2-year (in/hr) Intensity 10-year (in/hr) Intensity 100-year (in/hr) 5 2.85 4.87 9.95 39 1.09 1.86 3.8 6 2.67 4.56 9.31 40 1.07 1.83 3.74 7 2.52 4.31 8.80 41 1.05 1.80 3.68 8 2.40 4.10 8.38 42 1.04 1.77 3.62 9 2.30 3.93 8.03 43 1.02 1.74 3.56 10 2.21 3.78 7.72 44 1.01 1.72 3.51 11 2.13 3.63 7.42 45 0.99 1.69 3.46 12 2.05 3.50 7.16 46 0.98 1.67 3.41 13 1.98 3.39 6.92 47 0.96 1.64 3.36 14 1.92 3.29 6.71 48 0.95 1.62 3.31 15 1.87 3.19 6.52 49 0.94 1.6 3.27 16 1.81 3.08 6.30 50 0.92 1.58 3.23 17 1.75 2.99 6.10 51 0.91 1.56 3.18 18 1.70 2.90 5.92 52 0.9 1.54 3.14 19 1.65 2.82 5.75 53 0.89 1.52 3.10 20 1.61 2.74 5.60 54 0.88 1.50 3.07 21 1.56 2.67 5.46 55 0.87 1.48 3.03 22 1.53 2.61 5.32 56 0.86 1.47 2.99 23 1.49 2.55 5.20 57 0.85 1.45 2.96 24 1.46 2.49 5.09 58 0.84 1.43 2.92 25 1.43 2.44 4.98 59 0.83 1.42 2.89 26 1.4 2.39 4.87 60 0.82 1.4 2.86 27 1.37 2.34 4.78 65 0.78 1.32 2.71 28 1.34 2.29 4.69 70 0.73 1.25 2.59 29 1.32 2.25 4.60 75 0.70 1.19 2.48 30 1.30 2.21 4.52 80 0.66 1.14 2.38 31 1.27 2.16 4.42 85 0.64 1.09 2.29 32 1.24 2.12 4.33 90 0.61 1.05 2.21 33 1.22 2.08 4.24 95 0.58 1.01 2.13 34 1.19 2.04 4.16 100 0.56 0.97 2.06 35 1.17 2.00 4.08 105 0.54 0.94 2.00 36 1.15 1.96 4.01 110 0.52 0.91 1.94 37 1.16 1.93 3.93 115 0.51 0.88 1.88 38 1.11 1.89 3.87 120 0.49 0.86 1.84 FORT COLLINS STORMWATER CRITERIA MANUAL Hydrology Standards (Ch. 5) 3.0 Rational Method 3.4 Intensity-Duration-Frequency Curves for Rational Method Page 9 Figure 3.4-1. Rainfall IDF Curve – Fort Collins Fi g u r e 2 . D e p t h t o g r o u n d w a t e r o v e r t i m e a t N o r t h f i e l d m o n i t o r i n g p o i n t s ( i n f e e t ) . Da t e MW - 1 MW - 2 PZ - 1 PZ - 2 PZ - 3 PZ - 4 PZ - 5 PZ - 6 PZ - 7 7/ 2 7 / 2 0 1 7 3 . 8 5 . 3 4 . 7 4 . 6 5 . 1 5 . 0 6 . 0 6 . 8 7 . 2 9/ 1 9 / 2 0 1 7 4 . 0 5 . 7 5 . 2 4 . 7 5 . 8 5 . 3 7 . 0 6 . 7 7 . 3 10 / 1 9 / 2 0 1 7 4 . 0 5 . 6 5 . 0 4 . 6 5 . 9 5 . 1 7 . 1 6 . 6 7 . 3 2/ 1 2 / 2 0 1 8 5 . 7 7 . 0 6 . 8 6 . 2 7 . 5 6 . 5 8 . 8 8 . 0 8 . 9 6/ 7 / 2 0 1 8 3 . 7 5 . 2 4 . 4 4 . 6 4 . 4 5 . 3 5 . 1 7 . 2 7 . 0 2/ 1 5 / 2 0 1 9 6 . 5 7 . 4 7 . 6 7 . 3 9 . 7 6/ 6 / 2 0 1 9 3 . 8 5 . 5 4 . 5 4 . 4 5 . 3 6 . 9 7 . 5 0 1 2 3 4 5 6 7 8 9 10 6/ 1 / 2 0 1 7 8 / 3 1 / 2 0 1 7 1 1 / 3 0 / 2 0 1 7 3 / 1 / 2 0 1 8 6 / 1 / 2 0 1 8 8 / 3 1 / 2 0 1 8 1 1 / 3 0 / 2 0 1 8 3 / 2 / 2 0 1 9 6 / 1 / 2 0 1 9 8 / 3 1 / 2 0 1 9 Depth to Water (feet) Da t e MW -1 MW -2 PZ -1 PZ -2 PZ -3 PZ -4 PZ -5 PZ -6 PZ -7 6/ 2 5 / 2 0 1 9 Mi l l e r G r o u n d w a t e r E n g i n e e r i n g , LL C Appendix B APPENDIX B SWMM INPUT/OUTPUT Northfield Mercy Housing PROPOSED DRAINAGE SUMMARY Design Engineer: A. Bartel Design Firm: Highland Development Services Project Number:21-1037-00 Date: SWMM INPUT SUMMARY TABLE D1 D1 3.15 137,252 48.5% 581 236 1.34% D2 D2 0.07 3,228 100.0% 113 29 1.62% D5 D5 0.81 35,339 40.7% 363 97 1.00% D6 D6 0.16 6,832 42.5% 172 40 1.08% D7 D7 1.91 83,096 69.8% 762 109 0.84% D8 D8 0.28 11,992 7.6% 58 206 7.84% D9 D9 2.50 108,741 3.9% 629 173 1.03% D8+D9 D8+D9 2.77 120,732 4.3% 629 173 1.03% E6 E5, E6 1.15 50,017 81.8% 502 100 0.50% E8 E7, E8 1.35 58,860 67.8% 497 118 0.50% Slope %Length (ft) Width (ft) October 13, 2021 SWMM SUBCATCHMENT BASIN ID TRIBUTARY SUB-BASINS AREA (acres) AREA (sq ft) Percent Impervious 21-1037-00 Rational Calcs (FC).xlsx Page 7 of 7 Highland Development Services Appendix C APPENDIX C RATIONAL CALCULATIONS Design Engineer: Design Firm: Project Number: Date: APPROVED VS PROPOSED SUMMARY TABLE NF Approved (D1-D14) NFC Proposed (D1-D9) NF Approved NFC Proposed NF Approved NFC Proposed NF Approved NFC Proposed NF Approved NFC Proposed NF Approved NFC Proposed POND D 9.21 9.18 41.3% 38.8% 44.51 44.65 1.71 1.64 4949.54 4949.52 0.32 0.34 1. Northfield Approved area and % Impervious taken from Northfield Rational Calcs, dated October 15, 2019. 2. Northfield Peak Runoff was obtained from the EPA SWMM model output in the "Final Drainage Report for Northfield" dated February 26, 2020. 3. Northfield Commons Peak Runoff was obtained from the EPA SWM model in this report. 4. Northfield Commons Spill Depth includes 8 cfs additional flow from Alta Vista Main St. Northfield Commons DEVELOPED PEAK RUNOFF Area (acres) % Impervious A. Bartel Highland Development Services 21-1037-00 October 13, 2021 Peak Runoff (cfs)100-yr Detention Volume (ac-ft)100-yr WSE Spill Depth (ft) 21-1037-00 Rational Calcs (FC).xlsx Page 6 of 7 Highland Development Services Design Engineer: Design Firm: Project Number: Date: BASIN SUMMARY TABLE C2-10 C100 tc 2 yr (min) tc 100-yr (min) I2 (in/hr) I100 (in/hr) Q2 (cfs) Q100 (cfs) D1 D1 3.15 48.5% 0.61 0.76 10.42 8.73 2.18 8.13 4.19 19.54 D2 D2 0.07 100.0% 0.95 1.00 5.00 5.00 2.85 9.95 0.20 0.74 D3 D3 0.07 100.0% 0.95 1.00 5.00 5.00 2.85 9.95 0.20 0.74 D4 D4 0.24 17.2% 0.38 0.48 7.68 6.90 2.44 8.82 0.22 1.00 D9 D9 2.50 3.9% 0.28 0.35 11.42 11.03 2.10 7.42 1.47 6.50 D1-D4&D9 Standard WQ 3.53 30.1% 6.28 28.51 D5 D5 0.81 40.7% 0.57 0.71 6.05 5.52 2.63 9.43 1.21 5.41 D6 D6 0.16 42.5% 0.58 0.73 5.75 5.00 2.67 9.95 0.24 1.13 D7 D7 1.91 69.8% 0.76 0.95 10.20 8.54 2.20 8.20 3.18 14.85 D8 D8 0.28 7.6% 0.31 0.39 5.69 5.13 2.68 9.62 0.23 1.02 D5-D8 RAIN GARDEN 2.88 55.5% 4.86 22.41 D Total 9.18 11.14 50.92 October 13, 2021 DESIGN POINT Runoff Coefficient Time of Concentration Rainfaill Intensity AREA (acres) TRIBUTARY SUB-BASIN Peak Runoff % IMPERVIOUS Northfield Commons DEVELOPED PEAK RUNOFF A. Bartel Highland Development Services 21-1037-00 21-1037-00 Rational Calcs (FC).xlsx Page 5 of 7 Highland Development Services October 13 October 13 October 13 October 13 Appendix D APPENDIX D DETENTION POND CALCULATIONS October 13 October 13 Highland Development Services October 13 Highland Development Services October 13 Appendix E APPENDIX E INLET CALCULATIONS NF Commons TYPE C AREA INLET SIZING CALCULATION Design Engineer: Design Firm: Project Number: Date: DESIGN CRITERIA EQUATIONS: Q i = Grate Capacity w/o Reduction Factor (cfs) C = Orifice Discharge Coefficient = 0.67 A = Orifice area (ft2) - Open Area of Grate G = Gravitational Constant (32.2 ft/s2) H = Allowed Head on Grate, Ponding Depth (ft) Grate Dimensions and Information: 3 ft 3 ft 0.65 sqft/sqft 50% 5.85 sqft Allowed Head (ft) Inlet Capacity (Qi, cfs) Inlet Capacity w/ Reduction Factor (Qg, cfs) 0.25 15.73 7.86 0.50 22.24 11.12 1.00 31.45 15.73 1.50 38.52 19.26 2.00 44.48 22.24 INLET SIZING CALCULATIONS Inlet ID: Design Flow Rate (Q 100 , cfs): Allowed Head (H , ft): Inlet Capacity (Qg, cfs) Inlet-D05 (DP D4)1.00 0.5 11.12 Width (W ): A. Bartel Highland Development Services 21-1037-00 September 8, 2021 Apply Reduction Factor for the Allowable Capacity. Assumed Capacity per Head Allowed Inlet Grate Open Area (A ): Reduction Factor (F ): Opening Ratio (R ): Length (L ): Page2 Appendix F APPENDIX F LOW IMPACT DEVELOPMENT CALCULATIONS