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HomeMy WebLinkAboutHACIENDA HIGGINS-MARQUEZ - PDP/FDP - FDP120022 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTi ---5-'�--�---D----D- --.� ZA- �rf LU LU H U) Y O O /J 4 1 I I 5046, �504 .�6 - - - TW = 47.11 BW = 46.48 MULBERRY STREET ------------------- I I --5047 I I I 1 I I 5048 I j ra0 I I ------0 —GAD o I -1 0.26 0.25 h0� // 40 0.47 TF = 5049.27 I // // 0.09 0.08 0.36 r00 I // I 0• A _ � /E TW = 48.66 7TW = 45.04 BW = 45.15-- BW = 44.70 TW = 48.23 TW = 46.76 BW = 45.03 BW = 44.93 SCALE VERTICAL: 1"= NIA HORIZONTAL: 1"= 20' DESIGNER: JCB l Engineering SUBMITTAL DATE: DECEMBER 12, 2012 PROJ. MGR: SME PREPARED FOR: WILLIAM H. HIGGINS LEGEND 5124 EXISTING 1' CONTOUR 0 0 EXISTING INLET 5 +90� EXISTING SPOT ELEVATION BAlAREA (AC1 X BASIN DESIGNATION XXXX X.XX 2 - YEAR RUNOFF COEFFICIENT 100 - YEAR RUNOFF COEFFICIENT BASIN BOUNDARY DESIGN POINT 0-101 —100- PROPOSED FLOW DIRECTION —5124— PROPOSED 1' CONTOUR PROPOSED CONCRETE PROPOSED DECK PROPOSED RETAINING WALL ,1h +� PROPOSED SPOT ELEVATION NOTES 1. ALL SPOT ELEVATIONS ARE 5OXX.XX 2. SPOT ELEVATIONS ADJACENT TO THE BUILDING ARE TO FINISHED DIRT GRADE. A3 A O z mn. zn « HIGGINS PROPERTY GRADING AND DRAINAGE PLAN SHEET 1 OF 1 SHEETS PROJECT NUMBER B12030 11 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Higgins Property Catchment ID: Basin B, 100-year Discharge for Swale B and Offsite Design I. Catchment Hydrologic Data Catchment ID = B Area = 0.09 Acres Percent Imperviousness = 2.00 % NRCS Sal Type = C A, B, C, or D IL Rainfall Information I (inch/hr) = C1 . Pi /(C2 + Td)^C3 Design Storm Return Period, Tr = 100 years C1 = 28.50 C2= 10.00 C3= 0.793 P1= 2.91 inches (input return period for design storm) (input the value of Cl) (input the value of C2) (input the value of C3) (input one-hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.41 Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C-5 = 0.14 Overide 5-yr. Runoff Coefficient, C = (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Beach 3 Illustration overland LEG [teach 1 flAw $END �� Flow Duvctfor Caichauat B.�.daay NRCS Land Hea TiIla e/ Near' Grassed Paved Areas 8 Type Meadow Field aP:Sht0,rrta/] Barre Swales/ Shallow Paved Swales Ground Waterways (Sheet Flow) Conve nce 2.5 00 10 15 20 a Calculations: Reach Slope Length 5-yr NRCS Flow Flow ID S L Runoff Convey- Velocity Time Coeff ance V Tf ft/ft It C-5 fps minutes input input output input output output Overland 0.0690 54 0.14 0.13 6.68 1 2 3 4 5 Sum 54 Computed Tc = 6.68 Regional Tc = 10.30 Peak Runoff Prediction using Computed Tc diction using Regional To Rainfall Intensity at Tc, I = 8.90 inch/hr Rainfall Intensity at Tc, I = 7.62 inch/hr Peak Flowrate, Qp = 0.31 cis Peak Flowrate, Op = 0.26 cfs Higgins - UD Rational Basin B 100yr STORM B.As, Tc and PeakQ 12/11/2012, 4:12 PM II CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD n Project Title: Higgins Property Catchment ID: Basin B, 2-year Discharge for Offsite Design I. Catchment Hydrologic Data Catchment ID = B Area = 0.09 Acres Percent Imperviousness = 2.00 % NRCS Soil Type = C A, B. C, or D II. Rainfall Information I (inch/hr) = C1 ` P1 /(C2 + Td)AC3 Design Storm Return Period, Tr = 2 years C1 = 28.50 C2= 10.00 C3= 0.786 P1= 0.82 inches (input return period for design storm) (input the value of Cl) (input the value of C2) (input the value of C3) (input one-hr precipitation --see Sheet "Design Info") Ill. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.06 Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C-5 = 0.14 Overide 5-yr. Runoff Coefficient, C = (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration ' Reach I flow Reach 2 Catchasaat Boundary NRCS Land Heavy Tillage! Short Nearly Grassed Paved Areas & Type Meadow Field Pasture/ Bare Swale:/ Shallow Paved Swales Lawns Ground Waterwa (Sheet Flow) Conveyance H 2.5 0�7 10 15 20 Calculations: Reach Sloe Length 5-yr NRCS Flow Flow ID S L Runoff Convey- Velocity Time Coeff ance V Tf fvft ft C-5 fps minutes input input output input output output Overland 0.0690 54 0.14 0.13 6.68 1 2 3 4 5 Sum 54 Computed Regional Tc = 10.30 Peak Runoff Prediction using Computed Tc diction using Regional Tc Rainfall Intensity at Tc, I = 2,56 inch/hr Rainfall Intensity at Tc, I = 2.19 inch/hr Peak Flowrate, Op = 0.01 Cis Peak Flowrate, Op = 0.01 cfs Higgins - LID Rational Basin 6 2yr STORM Bads, Tc and PeakO 1211112012, 4:13 PM CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Higgins Property Catchment ID: Basin A, 100-year Runoff I. Catchment Hydrologic Data Catchment ID = A Area = 0.26 Acres Percent Imperviousness = 75.00 % NRCS Soil Type = C A, B, C, or D II. Rainfall Information I (inch/hr) = C1 • P1 /(C2 +Td)AC3 Design Storm Return Period, Tr = 100 years C1 = 28.50 C2= 10.00 C3= 0.786 P1= 2.91 inches (input return period for design storm) (input the value of Cl) (input the value of C2) (input the value of C3) (input one-hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.66 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 ICI ooerland LE.GG� Beach 1 Hory Q Reach 2 i7ow Diaxctiot Caiehment Reach 3 NRCS Land Hea Ti% e/ Short Nearly Grassed Paved Areas & Type Meadow Fie d Pasture/ Bare Swalesl Shallow Paved Swales Lawns Ground Waterways (Sheet Flow) Conveyance 2.5 �5 �7 10 151 20 Ia Calculations: Reach Slope Length 5- r NRCS Flow Flow ID S L Runoff Convey- Velocity Time Coeff ante V Tf ft/ft ft C-5 fps minutes input input output input output output Overland 0.0200 8 0.54 0.06 2.28 1 0,0200 126 15.00 2.12 0.99 2 3 4 tEE 5 1 I I I Sum 134 Computed Tc = 3.27 Regional Tc = 10.74 Peak Runoff Prediction using Computed Tc diction using Regional Tc Rainfall Intensity at Tc, 1 = 10.87 inch Rainfall Intensity at Tc, I = 7.65 inch/hr Peak Flowrate, Op = 135 cfs Peak Flowrate, Op = 1.30 cfs Higgins - UD Rational Basin A 100yr STORM A.xls, To and PeakO 12/11/2012, 4:13 PM 11 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Higgins Property Catchment ID: Basin A, 2-year Discharge 1. Catchment Hydrologic Data Catchment ID = A Area = 0.26 Acres Percent Imperviousness = 30.10 % NRCS Soil Type = C A, B, C, or D IL Rainfall Information I (inch/hr) = C1 ' P1 /(C2 + Td)AC3 Design Storm Return Period, Tr = 2 years C1 = 28.50 C2= 10.00 C3= 0.786 P1= 0.82 inches (input return period for design storm) (input the value of C1) (input the value of C2) (input the value of C3) (input one-hr precipitation --see Sheet "Design Info") Ill. 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 Reach 2 Reach 3 �` awerland Reach 1 flow J Begiol' Flow Dimtim Catchment NRCS Land 9 of Short Nearl YType GrassedPaved Areas 8 [He8v,Llla adow Field Pasture/ Bare Swales/ Shallow Paved Swales Lawns Ground Waterways (Sheet Flow) Conveyance 2.5 �5 �7 10 15 20 Im 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 0.0200 8 0.54 0.06 2.28 1 0,0200 126 15.00 2.12 0.99 2 3 4 5 Sum 134 Computed Tc = 3.26 Regional Tc = 10.74 Peak Runoff Prediction using Computed Tc diction using Regional Tc Rainfall Intensity at Tc, I = 3.06 inch/hr Rainfall Intensity at Tc, I = 2.16 inch/hr Peak Flowrate, Qp = 0.40 cis Peak Flowrate, Qp = 0.28 cfs Higgins - UD Rational Basin A 2yr STORM A.As, Tc and PeakQ 12/11/2012, 4:13 PM CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Higgins Property Catchment ID: Basin EX, Existing 100-year Discharge I. Catchment Hydrologic Data Catchment ID = EX Area = 0.34 Acres Percent Imperviousness = 2.00 % NRCS Soil Type = C A, B, C, or D II. Rainfall Information I (inch/hr) = C1 * P1 /(C2 +Td)AC3 Design Storm Return Period, Tr = 100 years C1 = 28.50 C2= 10.00 C3= 0.793 P1= 2.91 inches (input return period for design storm) (input the value of C1) (input the value of C2) (input the value of C3) (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 = 0.16 Overide 5-yr. Runoff Coefficient, C = (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration Reach I Saw© B� Reach 2 catchment Reach 3 NRCS Land Hea Tillage/ Short I Nearly Grassed Paved Areas & Type Mead w Field Pasture/ Bare Swales/ Shallow Paved Swales Lawns Ground Waterways (Sheet Flow) Conve nce 2.5 �5 �7 10 15 20 ZN Calculations: Reach Slope Length 5-yr NRCS Flow Flow 10 S L Runoff Convey- Velocity Time Coeff ante V Tf ft/ft ft C-5 fps minutes input input output input output output Overland 0.0100 176 0.16 0.13 22.44 1 2 3 15 Sum 176 Computed Tc = 22.44 Regional Tc = 10.98 Peak Runoff Prediction using Computed Tc diction using Regional Tc Rainfall Intensity at Tc, I = 5.25 inch/hr Rainfall Intensity at Tc, 1 = 7.42 inch/hr Peak Flowrate, Op = 0,92 cfs Peak Flowrate, Op = 1.30 cfs Higgins - UD Rational Basin Existing 100yr Existing.tds, Tc and PeakO 12/1112012, 4:14 PM 11 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Higgins Property Catchment ID: Basin EX. Existing 2-year Discharge I. Catchment Hydrologic Data Catchment ID = EX Area = 0.34 Acres Percent Imperviousness = 2.00 % NRCS Soil Type = C A, B, C, or D II. Rainfall Information I (inch/hr) = Ct " P1 /(C2 + Td)AC3 Design Storm Return Period, Tr = 2 years C1 = 28.50 C2= 10.00 C3= 0,786 P1= 0.82 inches (input return period for design storm) (input the value of Cl) (input the value of C2) (input the value of C3) (input one-hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.06 Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C-5 = 0,16 Overide 5-yr. Runoff Coefficient, C = (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration Rearh 3 neaiati Raub 8av O B Catchment Bocmdary NRCS Land Hea Tdla e/ Short Nearl Grassed Paved Areas 8 Type Meadow Field Pasture' Bare Swale,/ Shallow Paved Swales Lawns Ground Waterways (Sheet Flow) Conveyance 2.5 �5 �7 10 15 20 91 Calculations: Reach Slope Length 5-yr NRCS Flow Flow ID S L Runoff Convey- Velocity Time Coeff ante V Tf ft/ft ft C-5 fps minutes input input output input output output Overland 0.0100 176 0.16 0.13 22,44 1 2 Wsum 176 Computed Tc = 22A4 Regional To = 10.98 Peak Runoff Prediction using Computed Tc diction using Regional Tc Rainfall Intensity at Tc, I = 1.52 inch/hr Rainfall Intensity at Tc, I = 2.14 inch/hr Peak Flowrate, Op = 0.03 cfs Peak Flowrate, Qp = 0.04 cfs Higgins - UD Rational Basin Usting 2yr E)asting.tds, Tc and PeakQ 1211112012, 4:14 PM BLUE SKY Engineering Erosion Control Erosion and Sediment Control devices will be implemented on the site as needed. It is anticipated that onsite runoff will be contained by straw wattles surrounding the site. Inlet protection will be placed adjacent to the inlets north of the site on Mulberry Street. Summary Due to the size of this small site, the proposed development of the site will have minimal impact to the stormwater. The runoff from the site is less than what would typically be expected for a residential site, therefore no on site detention or downstream improvements are included with this project. If you have any questions, please contact me at 970-217-7420 or seliason@bluesky- engineer.com. Sincerely, Blue Sky Engineering Sam Eliason, P.E. 1501 Academy Cr_ Sure 2�14 1 for Collins, CO 80524 1 070-217-7420 1 www.biuesky-engineer.com A��BLUE SKY Engineering December 11, 2012 Mr. Glen Schleuter Stormwater Department City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80521 RE: Drainage Letter for Higgins Property Project #B 12030 Dear Glen, We have prepared this drainage letter for Higgins Property for your review and approval. The existing property is an undeveloped 14,970 square -foot lot on the southeast side of the intersection of Cook Street and Mulberry Street. The site is located in the Canal Importation Drainage Basin. This project proposes to develop a single family residence on the property. The following is a summary of the impacts to the drainage systems on and off the site. In addition, supporting calculations and a drainage exhibit have been attached. Runoff The existing site (Basin EX) drains to the southeast and has 0.03 cfs and 0.63 cfs of runoff leaving the site in the 2-year and 100-year storms, respectively. In the developed condition, approximately 0.26 acres drains to Cook Street and Mulberry Street. The area draining to the streets is defined as Basin A and will have 0.40 cfs and 1.85 cfs of runoff leaving the site in the 2- year and 100-year storms, respectively. The area draining to the southeast following the historic drainage pattern is defined as Basin B and contains no new imperviousness from the historic site. Basin B will have 0.01 cfs and 0.31 cfs of runoff leaving the site in the 2-year and 100-year storms, respectively. Detention Storage The entire site is estimated to be approximately 25% impervious when built out. Residential development typically runs approximately 40% imperviousness based on UDFCD Figure RO-3. Due to the differnece between typical and developed percent imperviousness, the size of the site, and the difficulty in providing detention we are not proposing any detention storage with this project. Water Quality The small site and proximity to adjacent storm sewer make it very difficult to provide typical water quality. The residential site will have an area of non paved surfaces at the front and rear of the lot. These areas will intercept the stormwater runoff that comes from the roof, driveway, and patio areas and provide some water quality via "disconnected impervious areas" and the grass swales to convey the runoff. This is the extent of water quality that we are proposing. 1501 Acodemy Ct. Suite 204 1 Fort Collins, CO 80524 1 97C-217-7420 1 wAwN bluesky-engineer.Com