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Home My WebLink AboutRIGDEN FARM FILING SIX, TRACT Z, SINGLE FAMILY ATTACHED - PDP - PDP140009 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORT (3)Project: Tract Z Multi-Family Project Number: 13-2449 Basin Area (SF) AREA (AC) Landscape Paved Roof Percent Impervious A1 42,151 0.97 9,583 19,166 14,810 77% A2 20,828 0.48 1,861 11,160 7,807 87% A3 32,705 0.75 22,938 1,763 8,004 27% A4 17,156 0.39 10,122 464 6,570 37% A5 15,831 0.36 9,979 1,116 4,736 34% Total 128,671 2.95 54,483 33,669 41,927 55.5% Proposed Design 6/12/2014 Olsson Associates Copyright 2014 A1 A4 A3 A2 A5 Project Title: Catchment ID: Illustration Instructions: For each catchment subarea, enter values for A and C. Subarea Area Runoff Product ID acres Coeff. A C* CA input input input output Pavement 0.43 100.00 43.00 Roof 0.36 90.00 32.40 Landscape 0.18 0.00 0.00 Porous 40.00 0.00 Sum: 0.97 Sum: 75.40 Area-Weighted Runoff Coefficient (sum CA/sum A) = 77.73 *See sheet "Design Info" for inperviousness-based runoff coefficient values. Area-Weighting for Runoff Coefficient Calculation 132449_Runoff Calcs, Weighted C 6/12/2014, 3:24 PM Project Title: Catchment ID: I. Catchment Hydrologic Data Catchment ID = A1 Area = 0.97 Acres Percent Imperviousness = 75.40 % NRCS Soil Type = B A, B, C, or D II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3 Design Storm Return Period, Tr = 2 years (input return period for design storm) C1 = 28.50 (input the value of C1) C2= 10.00 (input the value of C2) C3= 0.786 (input the value of C3) P1= 0.85 inches (input one-hr precipitation--see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.51 Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C-5 = 0.54 Overide 5-yr. Runoff Coefficient, C = (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration NRCS Land Heavy Tillage/ Short Nearly Grassed Type Meadow Field Pasture/ Bare Swales/ Lawns Ground Waterways Conveyance 2.5 5 7 10 15 Calculations: Reach Slope Length 5-yr NRCS Flow Flow ID S L Runoff Convey- Velocity Time Coeff ance V Tf ft/ft ft C-5 fps minutes input input output input output output Overland 0.0100 25 0.54 N/A 0.08 5.02 1 0.0100 359 20.00 2.00 2.99 2 3 4 5 384 Computed Tc = 8.01 Regional Tc = 12.13 User-Entered Tc = 8.01 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = 2.51 inch/hr Peak Flowrate, Qp = 1.24 cfs Rainfall Intensity at Regional Tc, I = 2.13 inch/hr Peak Flowrate, Qp = 1.06 cfs Rainfall Intensity at User-Defined Tc, I = 2.51 inch/hr Peak Flowrate, Qp = 1.24 cfs (Sheet Flow) 20 Shallow Paved Swales Sum CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Rigden Farm Filing Six, Tract Z MF A1 Paved Areas & 132449_Runoff Calcs, Tc and PeakQ 6/12/2014, 3:25 PM Sheet 1 of 1 Designer: Company: Date: Project: Location: 1. Design Discharge for 2-Year Return Period Q2 = 1.26 cfs 2. Hydraulic Residence Time A) : Length of Grass Swale LS = 55.7 ft B) Calculated Residence Time (based on design velocity below) THR = 1.5 minutes 3. Longitudinal Slope (vertical distance per unit horizontal) A) Available Slope (based on site constraints) Savail = 0.020 ft / ft B) Design Slope SD = 0.020 ft / ft 4. Swale Geometry A) Channel Side Slopes (Z = 4 min., horiz. distance per unit vertical) Z = 4.00 ft / ft B) Bottom Width of Swale (enter 0 for triangular section) WB = 4.50 ft 5. Vegetation A) Type of Planting (seed vs. sod, affects vegetal retardance factor) 6. Design Velocity (0.186 ft / s maximum for desirable 5-minute residence time) V2 = 0.61 ft / s 7. Design Flow Depth (1 foot maximum) D2 = 0.35 ft A) Flow Area A2 = 2.1 sq ft B) Top Width of Swale WT = 7.3 ft C) Froude Number (0.50 maximum) F = 0.20 D) Hydraulic Radius RH = 0.28 E) Velocity-Hydraulic Radius Product for Vegetal Retardance VR = 0.17 F) Manning's n (based on SCS vegetal retardance curve D for sodded grass) n = 0.144 G) Cumulative Height of Grade Control Structures Required HD = 0.00 ft 8. Underdrain (Is an underdrain necessary?) 9. Soil Preparation (Describe soil amendment) 10. Irrigation Notes: Sandy loam shall be amended to the existing ground as needed. Design Procedure Form: Grass Swale (GS) Scott Zey Olsson Associates June 12, 2014 Rigden Farm Filign Six, Tract Z Fort Collins, Colorado Choose One Temporary Permanent Choose One Grass From Seed Grass From Sod Choose One YES NO Grass Swale, GS 6/12/2014, 3:25 PM Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Type of Permeable Pavement Section A) What type of section of permeable pavement is used? (Based on the land use and activities, proximity to adjacent structures and soil characteristics.) B) What type of wearing course? 2. Required Storage Volume A) Effective Imperviousness of Area Tributary to Permeable Pavement, Ia Ia = 87.0 % B) Tributary Area's Imperviousness Ratio (I = Ia / 100) i = 0.870 C) Tributary Watershed Area ATotal = 20,828 sq ft (including area of permeable pavement system) D) Area of Permeable Pavement System APPS = 6,967 sq ft (Minimum recommended permeable pavement area = 6314 sq ft) E) Impervious Tributary Ratio RT = 1.7 (Contributing Imperviuos Area / Permeable Pavement Ratio) F) Water Quality Capture Volume (WQCV) Based on 12-hour Drain Time WQCV = 524 cu ft (WQCV = (0.8 * (0.91 * i3 - 1.19 * i2 + 0.78 * i) / 12) * Area) G) Is flood control volume being added? H) Total Volume Needed VTotal = cu ft 3. Depth of Reservoir A) Minimum Depth of Reservoir Dmin = 6.0 inches (Minimum recommended depth is 6 inches) B) Is the slope of the reservoir/subgrade interface equal to 0%? C) Porosity (Porous Gravel Pavement < 0.3, Others < 0.40) P = 0.40 D) Slope of the Base Course/Subgrade Interface S = 0.020 ft / ft E) Length Between Lateral Flow Barriers (max = 18.79 ft.) L = 18.8 ft F) Volume Provided Based on Depth of Base Course V = 639 cu ft Flat or Stepped: V = P * ((Dmin-1)/12) * Area Sloped: V = P * [(Dmin - (Dmin - 6*SL-1)) / 12] * Area Volume assumes uniform slope & lateral flow barrier spacing. Calculate the volume of each cell individually when this varies. 4. Lateral Flow Barriers A) Type of Lateral Flow Barriers B) Number of Permeable Pavement Cells Cells = 10 5. Perimeter Barrier A) Is a perimeter barrier provided on all sides of the pavement system? (Recommeded for PICP, concrete grid pavement, or for any no-infiltration section.) Rigden Farm Filing Six, Tract Z MF Fort Collins, Colorado Design Procedure Form: Permeable Pavement Systems (PPS) SSZ Olsson Associates June 12, 2014 Choose One No Infiltration Partial Infiltration Section Full Infiltration Section Choose One YES NO Choose One YES- Flat or Stepped Installation NO- Sloped Installation Choose One Sheet 2 of 2 Designer: Company: Date: Project: Location: 6. Filter Material and Underdrain System A) Is the underdrain placed below a 6-inch thick layer of CDOT Class C filter material? B) Diameter of Slotted Pipe (slot dimensions per Table PPs-2) C) Distance from the Lowest Elevation of the Storage Volume y = 0.7 ft (i.e. the bottom of the base course to the center of the orifice) 7. Impermeable Geomembrane Liner and Geotextile Separator Fabric A) Is there a minimum 30 mil thick impermeable PVC geomembrane liner on the bottom and sides of the basin, extending up to the top of the base course? B) CDOT Class B Separator Fabric 8. Outlet (Assumes each cell has similar area, subgrade slope, and length between lateral barriers (unless subgrade is flat). Calculate cells individually where this varies.) A) Depth of WQCV in the Reservoir DWQCV = 4.50 inches (Elevation of the Flood Control Outlet) B) Diameter of Orifice for 12-hour Drain Time DOrifice = 0.66 inches (Use a minimum orifice diameter of 3/8-inches) Notes: Rigden Farm Filing Six, Tract Z MF Design Procedure Form: Permeable Pavement Systems (PPS) SSZ Olsson Associates June 12, 2014 Fort Collins, Colorado Choose One YES NO Choose One 4-inch 6-inch Choose One Choose One YES NO Placed above the liner Placed above and below the liner N/A Permeable Pavement Calc2.0, PPS 6/12/2014, 3:27 PM BUILDING #3 5-PLEX BUILDING #4 3-PLEX BUILDING #7 8-PLEX CELL 1 CELL 2 CELL 3 CELL 4 CELL 5 CELL 6 CELL 7 CELL 8 CELL 9 CELL 10 C C PERMEABLE PAVEMENT NOTES FIGURE 1 PERMEABLE PAVEMENT UNDERDRAIN PLAN FORT COLLINS 2014 R EXHIBIT TEL 970.461.7733 Loveland, CO 80538 Suite 160 PERMEABLE PAVEMENT 5285 McWhinney Boulevard UNDERDRAIN DETAIL R 1 PERMEABLE PAVEMENT SECTION D-D PERMEABLE PAVEMENT SECTION C-C EXHIBIT TEL 970.461.7733 Loveland, CO 80538 Suite 160 PERMEABLE PAVEMENT 5285 McWhinney Boulevard CROSS SECTIONS R 2 Concrete Walls PVC geomembrane installed normal to flow N/A- Flat installation Other (Describe): Choose One YES NO Choose One PICP Concrete Grid Pavement Pervious Concrete Porous Gravel Permeable Pavement Calc2.0, PPS 6/12/2014, 3:27 PM