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HomeMy WebLinkAbout4._EngineeringReportAppx_04162021STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTST ST ST ST ST ST ST STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTST B A S I N 1 0 0AREA= 0.39 ACC = 0.54B A S I N 1 0 1AREA= 0.08 ACC = 0.73BASIN 102AREA= 0.70 ACC = 0 . 5 7BASIN 103AREA= 0.68 ACC = 0 . 5 8 BASIN 104AREA= 0.90 ACC = 0.58 BASIN 105AREA= 0.98 ACC = 0.56 B A S I N 1 0 6AREA= 0.98 ACC = 0 . 5 0BASIN 107A R E A = 1 . 4 4 A C C = 0 . 5 7 4715 47104710 470547050'40'80'120'APRIL 2021PARKVIEW CROSSINGSSTORMWATER DRAINAGE BASINS Apr 09, 2021 - 11:13amCAD FILE: M:\193211\Drawings\FIGURES\Storm Basins.dwg 1OF 1 Existing SituationMinimum VolumeLand Use Open LandArea 10.71 AcresStorm DurationIntensity Future Runoff Rate Runoff VolumeRelease RateRelease VolumeRequired StorageSlope 2 %(Minutes) (in/hr) Q=CiA (cfs) (cf) (cfs) (cf) (cf)C= 0.2012 1.82 9.767024 0.000 0 7,024Overland Flow Distance 300 ft14 1.65 8.837414 0.000 0 7,414Time of Concentration23min16 1.51 8.097768 0.000 0 7,768Design Storm Frequency 10 year (Table I-3)18 1.40 7.508095 0.000 0 8,095Intensity at Tc 1.19 in/hr (Figure I-3)20 1.31 7.008399 0.000 0 8,399Peak Runoff Rate 2.547 cfs22 1.23 6.588684 0.000 0 8,68424 1.16 6.228953 0.000 0 8,953Proposed Situation26 1.10 5.909207 0.000 0 9,207Land Use Residential28 1.05 5.629449 0.000 0 9,449Area 10.71 Acres30 1.00 5.389680 0.000 0 9,680Slope 1.5 %32 0.96 5.169901 0.000 0 9,901 *C= 0.5034 0.93 4.9610114 2.547 306 9,808Overland Flow Distance 300 ft36 0.89 4.7810318 2.547 611 9,707Time of Concentration17min38 0.86 4.6110515 2.547 917 9,598Design Storm Frequency 10 year (Table I-3)40 0.83 4.4610706 2.547 1,222 9,48342 0.81 4.3210890 2.547 1,528 9,362Intensity at Tc 1.45 in/hr 10-yr (Figure I-3)44 0.78 4.1911069 2.547 1,834 9,2352.35 in/hr 100-yr (Figure I-3)46 0.76 4.0711242 2.547 2,139 9,10348 0.74 3.9611411 2.547 2,445 8,966Peak Runoff Rate 7.79 cfs 10-yr50 0.72 3.8611575 2.547 2,751 8,82512.60 cfs 100-yr52 0.70 3.7611735 2.547 3,056 8,67954 0.69 3.6711891 2.547 3,362 8,529Percent Impervious50%56 0.67 3.5812044 2.547 3,667 8,37658 0.65 3.5012192 2.547 3,973 8,219Runoff Treatment Volume 9719 cf60 0.64 3.4312338 2.547 4,279 8,059(RTV)62 0.63 3.3512480 2.547 4,584 7,89664 0.61 3.2912620 2.547 4,890 7,73066 0.60 3.2212756 2.547 5,196 7,56168 0.59 3.1612890 2.547 5,501 7,38970 0.58 3.1013022 2.547 5,807 7,215Weir Flowrate2.547 cfs72 0.57 3.0413151 2.547 6,112 7,038Weir Width3.5inches74 0.56 2.9913278 2.547 6,418 6,860*10-yr Detention Volume Required - 9901 cfPARKVIEW CROSSINGSDETENTION RELEASE RATEL:\193211\Computations\ON-SITE STORM.xls Pond Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Friday, 04 / 9 / 2021 Pond No. 2 - POND 5B Pond Data Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 4699.00 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 4699.00 2,921 0 0 1.00 4700.00 3,804 3,352 3,352 2.00 4701.00 4,787 4,286 7,638 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)= 0.00 0.00 0.00 0.00 Span (in)= 0.00 0.00 0.00 0.00 No. Barrels = 0 0 0 0 Invert El. (ft)= 0.00 0.00 0.00 0.00 Length (ft)= 0.00 0.00 0.00 0.00 Slope (%)= 0.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No Crest Len (ft)= 0.29 4.00 0.00 0.00 Crest El. (ft)= 4699.01 4700.50 0.00 0.00 Weir Coeff.= 3.33 3.33 3.33 3.33 Weir Type = Rect Ciplti --- --- Multi-Stage = No No No No Exfil.(in/hr)= 0.000 (by Contour) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 Stage (ft) 0.00 4699.00 0.20 4699.20 0.40 4699.40 0.60 4699.60 0.80 4699.80 1.00 4700.00 1.20 4700.20 1.40 4700.40 1.60 4700.60 1.80 4700.80 2.00 4701.00 Elev (ft) Discharge (cfs) Stage / Discharge Total Q Pond Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Friday, 04 / 9 / 2021 Pond No. 2 - POND 5B Pond Data Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 4699.00 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 4699.00 4,542 0 0 1.00 4700.00 5,952 5,231 5,231 2.00 4701.00 7,462 6,692 11,923 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)= 0.00 0.00 0.00 0.00 Span (in)= 0.00 0.00 0.00 0.00 No. Barrels = 0 0 0 0 Invert El. (ft)= 0.00 0.00 0.00 0.00 Length (ft)= 0.00 0.00 0.00 0.00 Slope (%)= 0.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No Crest Len (ft)= 0.29 4.00 0.00 0.00 Crest El. (ft)= 4699.01 4700.50 0.00 0.00 Weir Coeff.= 3.33 3.33 3.33 3.33 Weir Type = Rect Ciplti --- --- Multi-Stage = No No No No Exfil.(in/hr)= 0.000 (by Contour) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 Stage (ft) 0.00 4699.00 0.20 4699.20 0.40 4699.40 0.60 4699.60 0.80 4699.80 1.00 4700.00 1.20 4700.20 1.40 4700.40 1.60 4700.60 1.80 4700.80 2.00 4701.00 Elev (ft) Discharge (cfs) Stage / Discharge Total Q 0.90 0.50 0.20 Note: Coefficients obtained from CoB Design Standards Table I-1 BASIN 100 Post-Development Weighted C-Value (Cw) Area Runoff (Acres) Coefficient Calculations Asphalt/Concrete 0.06 0.90 0.05 Dense Residential 0.31 0.50 0.16 Open Land 0.02 0.20 0.00 Totals 0.39 0.21 Cw =0.54 BASIN 101 Post-Development Weighted C-Value (Cw) Area Runoff (Acres) Coefficient Calculations Asphalt/Concrete 0.06 0.90 0.06 Open Land 0.02 0.20 0.00 Totals 0.08 0.06 Cw =0.73 BASIN 102 Post-Development Weighted C-Value (Cw) Area Runoff (Acres) Coefficient Calculations Asphalt/Concrete 0.20 0.90 0.18 Dense Residential 0.40 0.50 0.20 Open Land 0.10 0.20 0.02 Totals 0.70 0.40 Cw =0.57 BASIN 103 Post-Development Weighted C-Value (Cw) Area Runoff (Acres) Coefficient Calculations Asphalt/Concrete 0.17 0.90 0.15 Dense Residential 0.46 0.50 0.23 Open Land 0.05 0.20 0.01 Totals 0.68 0.39 Cw =0.58 MAJOR SUBDIVISION Weighted Runoff Coefficients PARKVIEW CROSSINGS Asphalt/Concrete Dense Residential Open Land L:\193211\Computations\Stormwater Calculations.xls BASIN 104 Post-Development Weighted C-Value (Cw) Area Runoff (Acres) Coefficient Calculations Asphalt/Concrete 0.27 0.90 0.24 Dense Residential 0.51 0.50 0.26 Open Land 0.12 0.20 0.02 Totals 0.90 0.52 Cw =0.58 BASIN 105 Post-Development Weighted C-Value (Cw) Area Runoff (Acres) Coefficient Calculations Asphalt/Concrete 0.24 0.90 0.22 Dense Residential 0.61 0.50 0.31 Open Land 0.13 0.20 0.03 Totals 0.98 0.55 Cw =0.56 BASIN 106 Post-Development Weighted C-Value (Cw) Area Runoff (Acres) Coefficient Calculations Dense Residential 0.98 0.50 0.49 Totals 0.98 0.49 Cw =0.50 BASIN 107 Post-Development Weighted C-Value (Cw) Area Runoff (Acres) Coefficient Calculations Asphalt/Concrete 0.45 0.90 0.41 Dense Residential 0.72 0.50 0.36 Open Land 0.27 0.20 0.05 Totals 1.44 0.82 Cw =0.57 EXISTING POND 5B Post-Development Weighted C-Value (Cw) Area Runoff (Acres) Coefficient Calculations Existing (4G/4H) 3.71 0.51 1.89 Proposed 7.00 0.49 3.43 Totals 10.71 5.32 Cw =0.50 L:\193211\Computations\Stormwater Calculations.xls Storm Drain Inlet ID#Basin 10-Yr Flow (cfs) 25-Yr Flow (cfs) 100-Yr Flow (cfs) SDI-100 100 0.43 0.52 0.70 SDI-102 102 0.60 0.72 0.97 SDI-103 103 0.54 0.64 0.86 SDI-104 104 0.78 0.94 1.27 SDI-105 105 0.74 0.89 1.20 SDI-106 107 1.03 1.25 1.66 PARKVIEW CROSSINGS MAJOR SUBDIVISION SDI FLOWS Label Inlet TypeDischarge (ft³/s)Spread (ft)Gutter Width (ft)Road Slope (%)Gutter Cross Slope (%)Road Cross Slope (%)Grate Width (ft)Grate Length (ft) Grate TypeCurb Opening Length (ft)Opening Height (ft)Inlet Efficiency (%)Water Depth at Curb (in)100 - 25YR SAG 0.52 4.7 1.5 1.00% 6.25% 3.00% 1.46 2.94 Curved Vaned 2.75 0.5 100 2.3100 - 100YR SAG 0.70 5.6 1.5 1.00% 6.25% 3.00% 1.46 2.94 Curved Vaned 2.75 0.5 100 2.6102 - 25YR ON GRADE 0.72 4.9 1.5 0.70% 6.25% 3.00% 1.46 2.94 Curved Vaned 2.75 0.5 82.4 2.4102 - 100YR ON GRADE 0.97 5.6 1.5 0.70% 6.25% 3.00% 1.46 2.94 Curved Vaned 2.75 0.5 80.0 2.6103 - 25YR ON GRADE 0.64 4.7 1.5 0.70% 6.25% 3.00% 1.46 2.94 Curved Vaned 2.75 0.5 84.0 2.3103- 100YR ON GRADE 0.86 5.7 1.5 0.70% 6.25% 3.00% 1.46 2.94 Curved Vaned 2.75 0.5 80.2 2.6104 - 25YR ON GRADE 0.94 5.1 1.5 1.00% 6.25% 3.00% 1.46 2.94 Curved Vaned 2.75 0.5 79.0 2.4104 - 100YR ON GRADE 1.27 5.8 1.5 1.00% 6.25% 3.00% 1.46 2.94 Curved Vaned 2.75 0.5 73.6 2.7105 - 25YR ON GRADE 0.89 5.0 1.5 1.00% 6.25% 3.00% 1.46 2.94 Curved Vaned 2.75 0.5 79.3 2.4105 - 100YR ON GRADE 1.20 5.7 1.5 1.00% 6.25% 3.00% 1.46 2.94 Curved Vaned 2.75 0.5 74.5 2.6106 - 25YR SAG 1.25 7.8 1.5 0.70% 6.25% 3.00% 1.46 2.94 Curved Vaned 2.75 0.5 100 3.4106 - 100YRSAG1.669.31.50.70%6.25%3.00%1.462.94Curved Vaned2.750.51003.9PARKVIEW CROSSINGSSTORM DRAIN INLET SPREAD CALCSMAJOR SUBDIVISION Equations Used: Qp = C i A (Modified Rational Method) i = a * (DURATION) ^ -(b) (City of Bozeman) Overland Flow tc=((1.8)*(1.1-C)*(D^(1/2)))/(S^(1/3)) (City of Bozeman) Gutter Flow V=3.28*k*(S^(1/2), where k=0.618 (paved) (FHWA HEC 22, Eqn 3-4) BASIN 100 Basin Area (ac): 0.39 Post-Dev C (weighted): 0.54 Overland Distance (ft): 130 Storm Event Intensity Overland Slope (%): 1.8 (yr) (in/hr) A B Gutter Flow Distance (ft): 115.0 2 1.03 0.36 0.6 Gutter Flow Slope (%): 1.0 5 1.60 0.52 0.64 Post-Dev. Tc (min): 10.3 10 2.01 0.64 0.65 Storm Event (yr): 2 10 25 100 25 2.40 0.78 0.64 Storm Coeff. A: 0.36 0.64 0.78 1.01 50 2.94 0.92 0.66 Storm Coeff. B: 0.60 0.65 0.64 0.67 100 3.28 1.01 0.67 Composite C: 0.54 0.54 0.54 0.54 Storm Intensity (in/hr): 1.03 2.01 2.40 3.28 Post-Dev Qp (cfs):0.22 0.43 0.52 0.70 BASIN 101 Basin Area (ac): 0.08 Post-Dev C (weighted): 0.73 Overland Distance (ft): 30 Overland Slope (%): 2.0 Storm Event Intensity Gutter Flow Distance (ft): 115.0 (yr) (in/hr) A B Gutter Flow Slope (%): 1.0 2 1.88 0.36 0.6 Post-Dev. Tc (min): 3.8 5 3.03 0.52 0.64 Storm Event (yr): 2 10 25 100 10 3.83 0.64 0.65 Storm Coeff. A: 0.36 0.64 0.78 1.01 25 4.54 0.78 0.64 Storm Coeff. B: 0.60 0.65 0.64 0.67 50 5.66 0.92 0.66 Composite C: 0.73 0.73 0.73 0.73 100 6.38 1.01 0.67 Storm Intensity (in/hr): 1.88 3.83 4.54 6.38 Post-Dev Qp (cfs):0.12 0.24 0.28 0.40 BASIN 102 Basin Area (ac): 0.70 Post-Dev C (weighted): 0.57 Overland Distance (ft): 190 Overland Slope (%): 1.4 Storm Event Intensity Gutter Flow Distance (ft): 470.0 (yr) (in/hr) A B Gutter Flow Slope (%): 0.7 2 0.79 0.36 0.6 Post-Dev. Tc (min): 16.3 5 1.20 0.52 0.64 Storm Event (yr): 2 10 25 100 10 1.49 0.64 0.65 Storm Coeff. A: 0.36 0.64 0.78 1.01 25 1.79 0.78 0.64 Storm Coeff. B: 0.60 0.65 0.64 0.67 50 2.17 0.92 0.66 Composite C: 0.57 0.57 0.57 0.57 100 2.41 1.01 0.67 Storm Intensity (in/hr): 0.79 1.49 1.79 2.41 Post-Dev Qp (cfs):0.31 0.60 0.72 0.97 BASIN 103 Basin Area (ac): 0.68 Post-Dev C (weighted): 0.58 Overland Distance (ft): 280 Overland Slope (%): 1.2 Storm Event Intensity Gutter Flow Distance (ft): 405.0 (yr) (in/hr) A B Gutter Flow Slope (%): 0.7 2 0.72 0.36 0.6 Post-Dev. Tc (min): 18.8 5 1.09 0.52 0.64 Storm Event (yr): 2 10 25 100 10 1.36 0.64 0.65 Storm Coeff. A: 0.36 0.64 0.78 1.01 25 1.64 0.78 0.64 Storm Coeff. B: 0.60 0.65 0.64 0.67 50 1.98 0.92 0.66 Composite C: 0.58 0.58 0.58 0.58 100 2.20 1.01 0.67 Storm Intensity (in/hr): 0.72 1.36 1.64 2.20 Post-Dev Qp (cfs):0.28 0.54 0.64 0.86 PARKVIEW CROSSINGS POST-DEVELOPMENT SUB BASIN FLOWS MAJOR SUBDIVISION Storm Coeff. (i) Storm Coeff. (i) Storm Coeff. (i) Storm Coeff. (i) L:\193211\Computations\Stormwater Calculations.xls BASIN 104 Basin Area (ac): 0.90 Post-Dev C (weighted): 0.58 Overland Distance (ft): 300 Overland Slope (%): 2.0 Storm Event Intensity Gutter Flow Distance (ft): 400.0 (yr) (in/hr) A B Gutter Flow Slope (%): 1.0 2 0.79 0.36 0.6 Post-Dev. Tc (min): 16.2 5 1.20 0.52 0.64 Storm Event (yr): 2 10 25 100 10 1.50 0.64 0.65 Storm Coeff. A: 0.36 0.64 0.78 1.01 25 1.81 0.78 0.64 Storm Coeff. B: 0.60 0.65 0.64 0.67 50 2.19 0.92 0.66 Composite C: 0.58 0.58 0.58 0.58 100 2.43 1.01 0.67 Storm Intensity (in/hr): 0.79 1.50 1.81 2.43 Post-Dev Qp (cfs):0.41 0.78 0.94 1.27 BASIN 105 Basin Area (ac): 0.98 Post-Dev C: 0.56 Overland Distance (ft): 300 Overland Slope (%): 2.0 Storm Event Intensity Gutter Flow Distance (ft): 670.0 (yr) (in/hr) A B Gutter Flow Slope (%): 1.0 2 0.72 0.36 0.6 Post-Dev. Tc (min): 18.9 5 1.09 0.52 0.64 Storm Event (yr): 2 10 25 100 10 1.36 0.64 0.65 Storm Coeff. A: 0.36 0.64 0.78 1.01 25 1.63 0.78 0.64 Storm Coeff. B: 0.60 0.65 0.64 0.67 50 1.97 0.92 0.66 Composite C: 0.56 0.56 0.56 0.56 100 2.19 1.01 0.67 Storm Intensity (in/hr): 0.72 1.36 1.63 2.19 Post-Dev Qp (cfs):0.39 0.74 0.89 1.20 BASIN 106 Basin Area (ac): 0.98 Post-Dev C: 0.50 Overland Distance (ft): 200 Overland Slope (%): 2.0 Storm Event Intensity Gutter Flow Distance (ft): 0.0 (yr) (in/hr) A B Gutter Flow Slope (%): 0.0 2 0.94 0.36 0.6 Post-Dev. Tc (min): 12.1 5 1.45 0.52 0.64 Storm Event (yr): 2 10 25 100 10 1.81 0.64 0.65 Storm Coeff. A: 0.36 0.64 0.78 1.01 25 2.17 0.78 0.64 Storm Coeff. B: 0.60 0.65 0.64 0.67 50 2.64 0.92 0.66 Composite C: 0.50 0.50 0.50 0.50 100 2.95 1.01 0.67 Storm Intensity (in/hr): 0.94 1.81 2.17 2.95 Post-Dev Qp (cfs):0.46 0.89 1.06 1.45 BASIN 107 Basin Area (ac): 1.44 Post-Dev C: 0.57 Overland Distance (ft): 300 Overland Slope (%): 1.0 Storm Event Intensity Gutter Flow Distance (ft): 465.0 (yr) (in/hr) A B Gutter Flow Slope (%): 0.7 2 0.67 0.36 0.6 Post-Dev. Tc (min): 21.1 5 1.01 0.52 0.64 Storm Event (yr): 2 10 25 100 10 1.26 0.64 0.65 Storm Coeff. A: 0.36 0.64 0.78 1.01 25 1.52 0.78 0.64 Storm Coeff. B: 0.60 0.65 0.64 0.67 50 1.83 0.92 0.66 Composite C: 0.57 0.57 0.57 0.57 100 2.03 1.01 0.67 Storm Intensity (in/hr): 0.67 1.26 1.52 2.03 Post-Dev Qp (cfs):0.55 1.03 1.25 1.66 Storm Coeff. (i) Storm Coeff. (i) Storm Coeff. (i) Storm Coeff. (i) L:\193211\Computations\Stormwater Calculations.xls