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HomeMy WebLinkAboutCAMPUS WEST THEATRE REDEVELOPMENT - PDP - 23-04B - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORT1 4 \ STORM DRAIN HYDRAULICANALYSIS:. . Project Title: CAMPUS WEST REDEVELOPMENT Catchment ID: PROPOSED CONDITIONS *Output Determined by STORM CAD Hydraulic Modeling Program, Haestad Methods, Inc. Q19 (Minor Storm) Peak Runoff Rate = 5.11 c.f.s. Upstream Downstream Length Section Cop AVerage Upstream IDown'stream Constructed Slope Dlectrarge ,Upstream HGL Upstream Energy Dovmstresm HGL Downstream Energy Node Node (0) Slxe (ere) Velocity Invert t Invert Elevation (MU (de) (1t) Grade (1U Grade (81s) Elevation (8) 00 (M AREA INLET MANHOLE 35.00 15Inch 6.46 6.00 5.024.00 2 5,023.66 0.0100D0 6.11 8.024.92 6.025.35 5,024.68 5,026.03 MANHOLE EXISTING INLET 25.00 18 inch 12.92 7.08 5.023.55 r 5,022.65 0.040000 8.11 8,024.47 5,024.90 5,023.15 5,024.37 Outlet: EXISTING INLET Junction: MANHOLE Inlet: AREA INLET Rim: Rim: 5,026.28 ft Rim: 5,021.25 ft .00 ft ft Sump: 5,022.55 ft Sump: 5,023.55 ft Sump:: 55,0211.0 5,028.00 • � 1 Ill .(I) ill � !Il Pipe: 15" RCP Station ft Up Invert: 5,023.55 ft' Dn Invert: 5,022.55 ft Length: 25.00 ft Size: 15 inch 51027.00 5p026.00 5,025.00 Elevation ft 51024.00 59023.00 5,022.00 5,021.00 H�-70 Pipe: 15" RCP Up Invert: 5,024.00 ft Dn Invert: 5,023.65 ft Length: 35.00 ft Size: 15 inch 0100 (Major Storm) Peak Runoff Rate =11.96 c•f.s. Upstream Downstream Length SeeBon Average Upstream Downstream ConasuoW Moherge Upstream Upstream Dovmstrearn Downstream We Node (ft) Stre (ds) Velocity Invert Invert Slope (da) HGL Energy HGL Energy I I 10MMcItyl (ft) Elevatlon I Elevation (Rift) (1g Grade (It) Grade (10 (1U tlq 00 AREA INLET MANHOLE I W.001 15 kWh 8.48 9.76 5,024.00 1 6.023.65 0.010000 11.N 6,026.72 8,028.19 5,025.62 51026.99 MANHOLE EXISTING INLET 25.D0 161nch 12.92 10.43 5,023.661 5022.65 0.040DD0 11.96 5,024.77 8,02626 6,023.58 5,025.47 Outlet: EXISTING Rim: 5,026.28 ft Sump: 5,022.55 ft Inlet: AREA INLET INL-Lgtion: MANHOLERim: 5,026.25 ft Rim: 5,02.7.25 ft Sump: 5,021.00 ft Sump: 5,023.55 ft 5, 028.00 Pipe: 15" RCP Up Invert: 5,023.55 ft Dn Invert: 5,022.55 ft Length: 25.00 ft Size: 15 inch AREA INLET MANHOLE EXISTING INLET ;1027.00 i,026.00 i, 025.00 i, 024.00 023.00 �,022.00 11021.00 70 Elevation ft Pipe: 15" RCP Up Invert: 5,024.00 ft Dn Invert: 5,023.65 ft Length: 35.00 ft Size: 15 inch 11 r i1 \�u � X>Z = io�z-2�IN2 = 1191 Fi.2 r�fixL.�vM \HEogEtICAI CAPAGIT�I \S �Q ml\*lmvM pc-:Pzr1 1N 1_d•1` \15. Sol-7•07t S.= 0.02 F \. E I-EV. drr GaAT E EL-E�-©S�TE'E �Zaq�+C6 r.�. 1 1.3 2 33•1 4 5 FLOW INTO INLET PER SO. FT. OF OPEN AREA (CFS/FT2) Figure 5-3 CAPACITY OF GRATED INLET IN SUMP (From: Wright -McLaughlin Engineers, 1969) . �oR M\NoR ©U25tGN= S•I1 cF5 a (�.3gc.F.S• LA AMV1b VQo� �\G. 5-3. U6p�H1 0.20E - FoR MASoe. Qtob. \1•q(a c7S QoEs\au= \\.9b cFs = 14.95c.F•S. `a 1�1.95cFS 1 MAY 19a4 5-11 DESIGN CRITERIA f City of Fort Collins Rainfall Intensity -Duration -Frequency Table for using the Rational Method (31 minutes - 60 minutes) Figure 3-1 b Duration (minutes) 2-year Intensity in/hr 10-year Intensity in/hr 100-year Intensity in/hr 31.00 1.27 2.16 4.42 32.00 1.24 2.12 4.33 33.00 1.22 2.08 4.24 34.00 1.19 2.04 4.16 35.00 1.17 2.00 4.08 36.00 1.15 1.96 4.01 37.00 1.13 1.93 3.93 38.00 1.11 1.89 3.87 39.00 1.09 1.86 3.80 40.00 1.07 1.83 3.74 41.00 1.05 1.80 3.68 42.00 1.04 1.77 3.62 43.00 1.02 1.74 3.56 44.00 1.01 1.72 3.51 45.00 0.99 1.69 3.46 46.00 0.98 1.67 3.41 47.00 0.96 1.64 3.36 48.00 0.95 1.62 3.31 49.00 0.94 1.60 3.27 50.00 0.92 1.58 3.23 51.00 0.91 1.56 3.18 52.00 0.90 1.54 3.14 53.00 0.89 1.52 3.10 54.00 0.88 1.50 3.07 55.00 0.87 1.48 3.03 56.00 0.86 1.47 2.99 57.00 0.85 1.45 2.96 58.00 0.84 1.43 2.92 59.00 0.83 1.42 2.89 60.00 0.82 . 0 2.8 No Text SECTION 3. HYDROLOGY STAND' 1S 3.1 General Design Storms All drainage systems have to take into consideration two separate and distinct drainage Problems. The first is the initial storm which occurs at fairly regular intervals, usually based on the two to ten-year storm, depending on land use. The second is the major storm which is usually based on an infrequent storm, such as the 100-year storm. In some instances the major storm routing will not be the same as the initial storm. In this case, a complete set of drainage plans shall be submitted for each storm system. 3.1.1 Initial Storm Provisions As stated before, the initial storm shall be based on the two to ten-year storm. The objectives of such drainage system planning are to minimize inconvenience, to protect against recurring minor damage and to reduce maintenance costs in order to create an orderly drainage system at a reasonable cost for the urban resident. The initial storm drainage system may include such facilities as curb and gutter, storm sewer and open drainageways, and detention facilities. 3.1.2 Major Storm Provisions The major storm shall be considered the 100-year storm. The objectives of the major storm planning are to eliminate substantial property damage or loss of life. Major drainage systems may include storm sewers, open drainageways, and detention facilities. The correlation between the initial and major storm system shall be analyzed to insure a well coordinated drainage system. 3.1.3 Storm Frequency The initial and major storm design frequencies shall not be less than those found in the following table: Table 3-1 DESIGN STORM FREQUENCIES Land Use or Zoninat Design Storm Return Period Initial Storm Major Storm Residential: (RE,RL,RLP,RP,ML,RM,RMP, RLM,MM RH).............................. Business: 2-year 100-year (I M,BP,HB( 5C IL,IP,IG)................. Public 0-year lOp-j, a " Building Areas ...................... Parks, Greenbelts, etc 10-year ear ...................... Open Channels & Drainageways 2-year 100 year Detention Facilities -- 100-year -- 100-year HSee Table 3-2 for zoning definitions 3.1.4 Rainfall Intensities The rainfall intensities to be used in the computation of runoff shall be obtained from the Rainfall Intensity Duration Curves for the City of Fort Collins, included in these specifications as Figure 3.1. 3.1.5 Runoff Computations Storm Runoff computations for both the initial and major storm shall comply with the criteria set forth in Section 3.2 "Analysis Methodology.,, All runoff calculations made in the design of both initial and major drainage systems shall be included with the storm drainage plans in the form of a Drainage Report. Reports submitted for approval should have a typed narrative with computations and maps in a legible form. May 1984 Revised January 1997 Design Criteria 3-1 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: CAMPUS WEST REDEVELOPMENT Catchment ID: PROPOSED CONDITIONS - (100-yr. STORM) I. Catchment Hydrologic Data Catchment ID = Area = 2.03 Acres Percent Imperviousness = 75.77 % NRCS Soil Type = C A, B, C, or D 11. Rainfall Information I (Inch/hr) = Cl • Pt 1(C2 + Td)•CS Design Storm Return Period, Tr = 100 years (input return period for design storm) Cl = 28.50 (input the value of C1) C2= 10.00 (input the value of C2) C3= 0.786 (input the value of C3) P1= 2.86 inches (input one-hr precipitation -see Sheet "Design Info") Ill. Analysis of Flow Time (Time of Concentration) for a Catchment Runaff Coefficient, C = 0.71 Overide Runoff Coefficient, C = (ender an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C-5 = 0.58 Overids 5-yr. Runoff Coefficient, C = (enter an overide C-5 value if desired, or leave blank to accept calculated CS.) Il70 Illustration 'ILEGEM lteaeh 1 ttov ;;k2 Elav Dhatlol Csaoluorni Bem� NRCSy� Meadow rFred a: Paved Areas ShallowI Paved Swales Lawn Ground W erwa (Sheet Flow) 2.5 �F 10 15 M Calculations: Reach Slope Length Syr NRCS Flow Flow ID S L Runoff Convey- Velocity Time Coeff ante V Tf fUR R C-5 fps minutes input input output input output output Overland 0.0250 45 0.58 0.16 4.63 1 1 0.0115 485 20.00 Computed 2.14 1 3.77 2 3 4 5 Sum 530 To = 8.40 Regional Tc = 12.94 Peak Runoff Prediction using Computed To adiction using Regional Tc Rainfall Intensity at Tc, I = 8.26 inch/hr Rainfall Intensity at Tc, I = 6.95 inch/hr Peak Flowrate, Qp = 11.96 cfs Peak Flowrete, Qp = 10.05 cfs CALCULATION OF A PEAK RUNOFF.USING, RATIONAL METHOD - Project Title: CAMPUS WEST REDEVELOPMENT Catchment ID: PROPOSED CONDITIONS - (10-yr. STORM) 1. Catchment Hydrologic Data Catchment ID = Area = 2.03 Acres Percent Imperviousness = 75.77 % NRCS Soil Type = C A, B, C, or D 11. Rainfall Information I (InclWhr) = C1 ' P11(C2 + Td)•C3 Design Storm Return Period, Tr = 10 years C1 = 28.50 C2= 10.00 C3= 0.786 P1= 1.40 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 precipihation—see Sheat `Design Info") Ill. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.62 Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C-5 = 0.58 Ovende 5-yr. Runoff Coefficient, C = (enter an overide C5 value if desired, or leave blank to accept calculated C-5.) Illustration Heach 3 13eaeh 1 overland t� LEGEND Bqomdng Reach WMning Bow NRCS Lend Heavy Tillage/ Short Grassed Paved Areas & Type Meadow Field Pasture/Swalesl MGtmund Shallow Paved Swales Lawns WaterwaysSheet Fl Con nce 2.5 0�7 10 15 20 WA Calculations: Reach Slope Length Syr NRCS Flow Flow ID S L Runoff Convey- Velocity Time Coeff ante V Tf Will ft C-5 fps minutes Input_ input Output Input output output Overland 0.0250 45 0.58 0.16 4.63 1 0.0115 485 20.00 Computed 2.14 3.77 2 3 4 5 Sum 530 Tc = 8.40 Regional Tc = 12.94 Peak Runoff Prediction using Computed Tc edletion using Regional Tc Rainfall Intensity at Tc, I = 4.04 inchlhr Rainfall Intensity at Tc, I = 3.40 inch/hr Peak Flowrate, Qp = 5.11 efs Peak Fiowrate, Qp = 4.29 efs '"Area -Weighting for Percent Imperviousness.Calculation Project Title: CAMPUS WEST REDEVELOPMENT Catchment ID: PROPOSED CONDITIONS Illustration t.� Svlrarta 3 Instructions: For each catchment subarea, carter values for A and I. Plow Direcdi 4 -- C14eh, car Boaoday Subarea Area Imperviousness Product ID (square feet) (percent) A r Axl input input input output Landscape 14,000 0 0 Drives/Walks 33,002 90 2,970,180 Gravel 0 40 , -Roof 41,532 90 3,737,880 Sum:J 88,534 sum: 6,708,060 Area -Weighted Percent Impervlousness (cam AUsum A) = 75.77 'See Table RO3 for Inperviousness-based values. DRAINAGE CALCULATIONS AND HYDRA ULIC ANAL YSIS VICINITY MAP N \ G G - G .) rtsr viw sr wmH ort / MOBY ARENA I W ElJ2ABETN STREET 1 `-- SITE COLORADO STATE I UNIVERSfTY W MAIN CAMPUS - uamsnr Luc to — sanx ae .Esravw w ED I y € S uar000 ae G € � � F711 ■[sr mia sr jf v.ven a alma+ cr SCALE: 1" = 500' CAMPUS WEST REDEVELOPMENT 1325 WEST ELIZABETH STREET FORT COLLINS, COLORADO BEING A PORTION OF THE SOUTHEAST QUARTER OF SECTION 15, TOWNSHIP 7 NORTH, RANGE 69 WEST OF THE 6TH P.M., CITY OF FORT COLLINS, COUNTY OF LARIMER, STATE OF COLORADO Engineering, Inc. December 15, 2005 Proiect No. GRD - 524 - 05 Mr. Basil Y. Harridan, P. E. Stormwater Utility 700 Wood Street P. O. Box 580 Fort Collins, Colorado 80522 - 0580 Re: Campus West Redevelopment Fort Collins, Colorado Dear Mr. Hamdan. This is to advise that the standard City of Fort Collins drainage report and onsite storm water detention requirements do not apply to this site. The reason that the drainage report and onsite storm water detention requirements do not apply is that the site has been previously developed and that virtually the entire site (95%f) has been impervious surface consisting of either structure or pavement. The redevelopment of the site is to consist of removal of the existing structures and pavement in order to construct new structures, parking areas, access drives and instal new landscaping. The redeveloped site is to reduce the amount of impervious surface to 85%± of the total site area. The site surface coverage for the prior developed condition and the proposed redevelopment are as follows. Site as Established prior to 2005 Impervious Surface (structures, pavement, walkways, etc.): 86,790 sq. ft. 94.9% Pervious Surface (lawns, landscaped areas, gravel surfacing, etc.): 4,665 sq. ft. 05.1% Total Site 91,455 sq. ft. 100% Site as Proposed for Redevelopment Impervious Surface (structures, pavement, walkways, etc.): 77,520 sq. ft. 84.8% Pervious Surface (lawns, landscaped areas, gravel surfacing, etc.): 13,935 sq. ft. 15.2% Total Site 91,455 sq. ft. 100% Exhibits are attached to provide the basis of determining the extent of the impervious and pervious ground coverage for the prior and proposed conditions. We sincerely appreciate your consideration of this matter. If you should have any questions, please feel free to contact this office. ..nnnnnmrrnn,,,_ Respec Ily s mitted, MES NER ngineering, Inc. Dennis R. Messner, President Civil Engineering Consultants 150 E. 29th Street, Suite 270 Loveland, Colorado 80538 (970) 663-2221 • DRAINAGE INVESTIGATION SEDIMENT EROSION CONTROL REPORT for CAMPUS WEST REDEVELOPMENT 1325 W. ELIZABETH STREET FORT COLLINS.) COLORADO Prepared for: Kenney & Associates, LLC 209 E. 4`b Street Loveland, Colorado 80537 December 2005 Project No. GRD - 524 - 05 Prepared by: 150 East 29"^ Street, Suite 270 Loveland, Colorado 80538-2765 Telephone: (970) 663-2221