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Home My WebLink AboutEAST VINE STREETS FACILITY PUD AMENDED FINAL - 30 91D - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTAMMENDED FINAL DRAINAGE AND STORM WATER QUALITY STUDY EAST VINE STREETS FACILITY P.U.D. PHASE TWO FINAL CITY OF FORT COLLINS October 2, 1998 Prepared for: Client: Vaught Frye Architects, P.C. 1113 Stoney Hill Drive Fort Collins, Colorado 80525 Owner: City of Fort Collins Streets Department 700 Wood Street Fort Collins, Colorado 80522 Prepared by: The Sear -Brown Group 209 South Meldrum Street Fort Collins, Colorado 80521 (970) 482-5922 Project Number: 183-047 I 1 1 THE SEAR -BROWN GROUP Standards in Excellence The Sw-amwv Gravy Fort Collins Streets Facility 183-047 Storm Drainage System Preliminary Design (Fort Collins) Designer. SLG Storm: 2 yr Cf = 1.00 Design Point Basin(s) to (min) tci (min) C x Cf Intensity (inthr) Area (so) Remarks Length (it) U/S D.P. Type Time (min) Direct (ds) Other (cis) Total (cis) Slope M Type/ ttFL Capacity (cis) Design (cis) Slope N Diameter (in) Capacity (cis) Design (cis) Velocity (fl/s) 1 2 ] 4 Ie Ia 5 7 s a 10 11 12 13 14 148 14b 15 10 /s 17 1s 21 22 23 Individual Basins 1 H 22.0 22.0 0.61 1.73 4.36 4.6 4.6 0.50 L 1 4lQ 4.0 0.75 18 9.1 0.6 2.6 2 48-1 22.1 22.1 0.95 1.73 0.59 1.0 1.0 0.50 L 1 1.0 0.75 15 5.6 3 48-2 6.2 6.2 0.95 3.02 1.76 5.0 5.0 0.77 L 1 5.0 0.75 24 19.6 4 4B-3 5.8 5.8 0.95 3.08 0.79 2.3 2.3 0.89 L 2 2.3 0.75 18 9.1 5 0-1 7.6 7.6 0.95 2.82 3.17 8.5 8.5 0.89 L 2 13 8.5 0.75 18 9.1 6 O-2 68.0 6&0 0.25 0.54 1.23 0.3 0.3 0.43 L 2 5.7 0.3 0.75 18 9.1 7 88 99 1010 ggregated Basins 2 3 5 6 7 8 9 10 Notes: 1. Column 4a idemcies the type of channel used to calculate the velocity for the travel time calculations 2. Column 14a identifies whether the street is a main arterial, collector, or local street for use in the street capacity calculations. 3. For final design submittals, channel 8 pipe velocities are shown elsewhere in this report. ] sep" M M M M M M The Sear -Brown Group Fort Collins Streets Facility Time of Concentration (Fort Collins) Designer: SLG Storm: 100 yr Cf= 1.25 tl = 1.870.1 - C x COW(1/2) S"(1/3) tc= ti+I 183-047 tc Remarks Basin Area C C x Cf Length Slope ti Length Slope Velocity tL (ac) M M (min) (ft) M MIS) (min) (min) 1 2 3 3a 4 5 6 7 7a 8 9 10 11 12 H 4.36 0.61 0.76 60 1.70 4.1 1290 PA 0.50 1.34 16.1 20.2 B-1 0.59 0.95 1.00 180 1.10 2.4 1480 PA 0.50 1.34 18.5 20.9 B-2 1.76 0.95 1.00 190 1.30 2.4 267 PA 0.77 1.67 2.7 5.0 4B-3 0.79 0.95 1.00 130 0.77 2.3 250 PA 0.89 1.80 2.3 5.0 0-1 3.17 0.95 1.00 490 0.92 4.3 135 PA 0.89 1.80 1.3 5.5 0-2 1.23 0.25 0.31 460 0.83 33.6 1925 GW 0.43 1.01 31.8 65.4 Note: Column 7a codes the channel type for velocity calculations. PA = Paved Area, PL = Pasture& Lawns, GW = Grassed Waterway 30-Sep-98 I m Sill Fort Collins Streets Facility Storm Dminade System Prelhminary Desian Designer SLG Storm: 100 yr Cf = 1.25 (Fort Collins) 183-047 Design Basin(s) tc tC C z CI Intensity Area Remarks Length U/S D.Pl Time Direct Other Total Slope Type/ Capacity Design Slope Diameter Capacity Design Velocity Point (min) (ft) Type (min) (min) (iNhr) (ac) (cis) (ds) (cts) M #FL (cis) (l M (in) Ids) WS) ON 1 2 3 4 4a 4b 5 7 8 9 10 11 12 f3 14 /4a 14b 15 19 18 17 1s 21 22 23 Individual Basins 1 H 2O.2 20.2 0.76 5.15 4.36 17.1 17.1 0.50 L 1 17.1 0.75 18 9.1 2 4B-1 20.9 20.9 1.00 5.05 0.59 3.0 3.0 0.50 L 1 3.0 0.75 15 5.6 3 48-2 5.0 5.0 1.00 9.29 1.76 16.3 16.3 0.77 L 1 16.3 1.70 24 29.5 4 48-3 5.0 5.0 1.00 9.30 0.79 7.3 7.3 0.89 L 2 7.3 0.75 21 13.7 5 O-1 5.5 5.5 1.00 9.04 3.17 28.7 28.7 0.89 L 2 i 28.7 0.75 21 13.7 6 0-2 65.4 65.4 0.31 2.43 1.23 0.9 0.9 0.43 L 2 0.9 0.75 18 9.1 77 88 99 10 10 ggregated Basins 2 3 5 6 7 8 9 10 Notes: 1. Column 4a identifies the type of channel used to calculate the velocity for the travel time calculations 2. Column 14a identifies whether the street is a main arterial, collector, or twat street for use in the street capacity calculations. 3. For final design submittals, channel a pipe velocities are shown elsewhere in this report. 3PSel I 1 11 1 t 1 STORM SEWER SYSTEM 0 L Fort Collins Streets Facility SLG 09/30/98 Peak Discharge for Storm Sewer System Basin 0-1 4B-3 4B-2 Area (ac) 3.17 0.79 1.76 Tc (min) 7.6 5.8 6.2 Intensity in/hr) 2.82 3.08 3.02 C x Cf 0.95 0.95 0.95 Area'C (ac) 3.01 0.75 1.67 Td (min) = 7.6 5.8 6.2 Q (cfs) = 17t05' 14.21 14.89 Q1 (cfs) M W1ffZ,74 9.39 9.84 Q2 (cfs) _ 5i7$ 4.82 5.05 Used Q = i(C2A2'td/Tc2+C1Al) Storm Sewer System Design and Flow Analysis us James Guo August1994 M M M FC Streets Facility S. Gentry 9/23/98 Pipe Manhole From Manhole To Distance Invert Up Invert Down Rim Depth Land Slope 1 PLUG Al 18.21 4950.92 4950.86 4955.35 4.43 -0.0081 2 Al Al 328.82 4950.71 4949.56 4955.50 3.29 0.0046 3 Al OLD PLUG 174.49 4949.41 4948.99 4954.00 3.09 0.0057 4 OLD PLUG 4953.00 51 1 1 1 0.00 r� 1 ' STORM SEWER SYSTEM DESIGN USING UDSEWER MODEL Developed by Civil Eng. Dept, U. of Colorado at Denver Metro Denver Cities/Counties & UDFCD Pool Fund Study ' USER:RDB-Fort Collins -Colorado ............................................... ON DATA 09-30-1998 AT TIME 09:14:12 VERSION=01-17-1997 ' *** PROJECT TITLE :Fort Collins Streets Facility *** RETURN PERIOD OF FLOOD IS 2 YEARS (Design flow hydrology not calculated using UDSEWER) ' *** SUMMARY OF HYDRAULICS AT MANHOLES MANHOLE CNTRBTING RAINFALL RAINFALL DESIGN GROUND WATER COMMENTS ' ID NUMBER AREA * C DURATION INTENSITY PEAK FLOW ELEVATION ELEVATION MINUTES INCH/HR CFS FEET FEET -------------- 0.01 17.05 4952.75 4950.95 OK 1.00 17.05 4954.49 4952.21 OK ' 2.00 11.27 4955.67 4953.46 OK 3.00 11.27 4955.67 4953.56 OK OK MEANS WATER ELEVATION IS LOWER THAN GROUND ELEVATION ' *** SUMMARY OF SEWER HYDRAULICS NOTE: THE GIVEN FLOW DEPTH -TO -SEWER SIZE RATIO= .8 ------------------------------------------------------------------------------- SEWER MAMHOLE NUMBER SEWER REQUIRED SUGGESTED EXISTING ' ID NUMBER UPSTREAM DNSTREAM SHAPE DIA(RISE) DIA(RISE) DIA(RISE) WIDTH --__-'----_---ID-NO. ID NO_---___ - (IN)_(FT) (IN) (FT) (IN) (FT) (FT) 1.00 1.00 0.01 ROUND 29.01 30.00 24.00 0.00 ' 2.00 2.00 1.00 ROUND 23.14 24.00 0.00 0.00 3.00 3.00 2.00 ROUND 23.14 24.00 0.00 0.00 DIMENSION UNITS FOR ROUND AND ARCH SEWER ARE IN INCHES DIMENSION UNITS FOR BOX SEWER ARE IN FEET ' REQUIRED DIAMETER WAS DETERMINED BY SEWER HYDRAULIC CAPACITY. SUGGESTED DIAMETER WAS DETERMINED BY COMMERCIALLY AVAILABLE SIZE. FOR A NEW SEWER, FLOW WAS ANALYZED BY THE SUGGESTED SEWER SIZE; OTHERWISE, EXISITNG SIZE WAS USED SEWER DESIGN FLOW NORMAL NORAML CRITIC CRITIC FULL FROUDE COMMENT ID FLOW 0 FULL Q DEPTH VLCITY DEPTH VLCITY VLCITY NO. NUMBER CFS CFS FEET FPS FEET FPS FPS ------------------------------------------------------------------------------- 1.0 17.0 10.3 2.00 5.43 1.49 6.80 5.43 0.00 V-OK 2.0 11.3 12.5 1.49 4.49 1.20 5.72 3.59 0.66 V-OK 3.0 11.3 12.5 1.49 4.49 1.20 5.72 3.59 0.66 V-OK ' FROUDE NUMBER=O INDICATES THAT A PRESSURED FLOW OCCURS ---------------------------------------------------------------------- SEWER SLOPE INVERT ELEVATION BURIED DEPTH COMMENTS ' ID NUMBER UPSTREAM DNSTREAM UPSTREAM DNSTREAM X (FT) (FT) (FT) (FT) 1.00 0.24 4949.41 4948.95 3.08 1.80 NO 2.00 0.35 4950.71 4949.56 2.96 2.93 OK 3.00 0.35 4950.92 4950.86 2.75 2.81 OK OK MEANS BURIED DEPTH IS GREATER THAN REQUIRED SOIL COVER OF 2 FEET ' *** SUMMARY OF HYDRAULIC GRADIENT LINE ALONG SEWERS ------------------------------------------------------------------------------- SEWER SEWER SURCHARGED CROWN ELEVATION WATER ELEVATION FLOW ' ID NUMBER LENGTH LENGTH UPSTREAM DNSTREAM UPSTREAM DNSTREAM CONDITION FEET FEET FEET FEET FEET FEET 1.00 193.04 193.04 4951.41 4950.95 4952.21 4950.95 PRSS'ED 2.00 328.82 328.82 4952.71 4951.56 4953.46 4952.21 PRSSIED I PA ' 3.00 18.21 18.21 4952.92 4952.86 4953.56 4953.46 PRSS'ED PRSS'ED=PRESSURED FLOW; JUMP=POSSIBLE HYDRAULIC JUMP; SUBCR=SUBCRITICAL FLOW ' *** SUMMARY OF ENERGY GRADIENT LINE ALONG SEWERS ---------- -- ------ --------------------------------------------------------- UPST MANHOLE SEWER JUNCTURE LOSSES DOWNST MANHOLE ' SEWER MANHOLE ENERGY ID NO ID NO. ELEV FT --------------------------------------------------------------------------- FRCTION BEND BEND LATERAL LATERAL MANHOLE FT K COEF LOSS FT K COEF LOSS FT ID ENERGY FT 1.0 1.00 4952.67 1.72 0.25 0.00 0.00 0.00 0.01 4950.95 2.0 2.00 4953.66 0.94 0.25 0.05 0.00 0.00 1.00 4952.67 3.0 3.00 4953.76 0.05 0.25 0.05 0.00 0.00 2.00 4953.66 BEND LOSS =BEND K* FLOWING FULL VHEAD IN SEWER. LATERAL LOSS= OUTFLOW FULL VHEAD-JCT LOSS K*INFLOW FULL VHEAD ' FRICTION LOSS=O MEANS IT IS NEGLIGIBLE OR POSSIBLE ERROR DUE TO JUMP. FRICTION LOSS INCLUDES SEWER INVERT DROP AT MANHOLE NOTICE: VHEAD DENOTES THE VELOCITY HEAD OF FULL FLOW CONDITION. A MINIMUM JUCTION LOSS OF 0.05 FT WOULD BE INTRODUCED UNLESS LATERAL K=O. FRICTION LOSS WAS ESTIMATED BY BACKWATER CURVE COMPUTATIONS. II II L 1 1 I I I I 7 WATER QUALITY PONDS I I I I 1 II r THE SEAR -BROWN GROUP Protect: F+- fOL` Project No. 1$3 -0'q? By: Checked: Date: �� g Sheet of x - &L 14.1a Ll o .19 i a . oo 0.TS7 3.01 0.95- o.--s L �7b O -7- H U, 39 O • cat a . to O-;. I.23 0•ZS G,31 4a-1 a.s9 0.95 O,s1� b.z1 3.55 THE SEAR -BROWN GROUP FULL -SERVICE DESIGN PROFESSIONALS FORMERLY RBI), INC. 209 SOUTH MELDRUM FORT COLLINS, COLORADO 80521-2603 970.482.5922 FAX:970-482-6368 October 2, 1998 Mr. Basil Hamdon City of Fort Collins Utility Services Stormwater 700 Wood Street Fort Collins, Colorado 80521 RE: Amended Final Drainage, Erosion and Storm Water Quality Study for the East Vine Streets Facility P.U.D. Phase Two Final Dear Basil: We are pleased to submit to you, for your review and approval, this Amended Final Drainage, Erosion and Storm Water Quality Study for the East Vine Streets Facility P.U.D., Phase One Final. All computations within this addendum have been completed in compliance with the City of Fort Collins Storm Drainage Design Criteria. We appreciate your time and consideration in reviewing this submittal. Please call if you have any questions. Sincerely, The Sear -Brown Group Serena Gentry, E.I.T. jap 0. Project ngineer Ictti Q�Nce ��% UJ Z a 73 �•'••.....•••6C?� l Terry Project Manager NEW YORK • PENNSYLVANIA COLORADO•UTAH STANDARDS IN EXCELLENCE EQUAL OPPORTUNITY EMPLOYER Table Rating Table for Circular Channel 1Project Description Project File cAprogram files\haestad\fmw\fcstree.fm2 Worksheet basin a ' Flow Element Circular Channel Method Manning's Formula Solve For Discharge Constant Data 1 Mannings Coefficient 0.013 Channel Slope 0.005000 ft/ft Diameter 6.00 in ' Minimum Maximum Increment Depth 0.00 0.50 0.05 ft Rating Table Depth (ft) Discharge (cfs) Velocity ON 0.00 0.00 0.00 0.05 0.01 0.81 0.10 0.03 1.24 0.15 0.08 1.57 ' 0.20 0.13 1.82 0.25 0.20 2.02 0.30 0.27 2.17 0.35 0.33 2.26 0.40 0.39 2.30 0.45 0.42 2.27 ' 0.50 0.40 2.02 II 09/30/98 FlowMaster v5.13 12:09:12 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 11 I I Table Rating Table for Rectangular Channel rroiect me c:Nprogram nies%naestaavmwvcstree.Tmz Worksheet basin b Flow Element Rectangular Channel Method Manning's Formula Solve For Discharge Constant Data Mannings Coefficient 0.012 Channel Slope 0.004400 ft/ft Bottom Width 1.50 ft minimum maximum increment Depth 0 0.92 0. 10 ft sting Table Depth Discharge Velocity (ft) (cfs) (ft/s) 0.00 0.00 0.00 0.10 0.24 1.63 0.20 0.72 2.40 0.30 1.32 2.94 0.40 2.01 3.35 0.50 2.76 3.68 0.60 3.55 3.95 0.70 4.38 4.17 0.80 5.24 4.36 0.90 6.11 4.53 09/30/98 FlowMaster v5.13 ' 06:53:21 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 OF Tables for use with Hydro Pond Duration (min) 5 10 20 30 40 50 60 80 100 120 150 180 MOF_\C; Fort Collins 3.25 2.52 1.83 1.47 1.22 1.04 0.91 0.74 0.61 0.52 0.43 0.39 Greeley 3.62 2.81 2.00 1.64 1.34 1.16 1.04 0.80 0.67 0.58 0.49 0.42 Loveland 3.50 2.70 2.00 1.61 1.35 1.15 1.00 0.80 0.65 0.53 0.43 0.39 5-YEAR: Greeley 5.19 4.02 2.86 2.35 1.92 1.66 1.49 1.14 0.94 0.80 0.66 0.56 Westminster 4.90 3.90 2.75 2.25 1.90 1.60 1.35 1.15 1.02 0.85 0.74 0.65 10- YEAR: Fort Collins 5.60 4.40 3.22 2.60 2.18 1.85 1.62 1.30 1.10 0.91 0.75 0.65 Greeley 6.12 4.75 3.38 2.78 2.27 1.96 1.76 1.47 1.20 0.96 0.78 0.67 I..oveland 5.70 4.50 3.35 2.70 2.25 1.95 1.70 1.35 1.15 0.97 0.75 0.65 :t5-YEAR: i.;reeley 7.31 5.67 4.03 3.22 2.70 2.34 2.10 1.61 1.30 1.14 0.93 0.80 Ioveland 7.15 5.50 4.00 3.30 2.70 2.35 2.05 1.65 1.40 1.20 0.95 0.85 50-YEAR: Greeley 8.73 6.78 4.81 3.97 3.23 2.80 2.51 1.91 1.58 1.30 1.10 0.92 Ioveland 8.30 6.40 4.65 3.70 3.10 2.65 2.40 1.95 1.70 1.40 1.10 0.95 100-YEAR: i of t Collins 9.00 7.20 5.18 4.17 3.50 3.00 2.61 2.06 1.70 1.45 1.19 1.05 iDreeley 9.67 7.51 5.34 4.39 3.59 3.10 2.78 2.16 1.79 1.50 1.23 1.05 Loveland 9.40 7.15 5.40 4.35 3.60 3.05 2.70 2.14 1.80 1.60 1.35 1.10 Westminster 9.48 7.32 5.30 4.28 3.60 3.10 2.71 2.15 1.80 1.55 1.29 1.15 11"M Bmwn (;r" nh 24-Sep-98 1.00 Y 0 0.96 U L 0.92 N 0.88 O Figure 1. Peak Flow Adjustment Factor For FAA Method I'` Opo=peak outflow from the pond ! Opi=peak inflow to the pond 1 i i •i i r-_- •. i i U.UO W 0.4 Opo/Opi Ratio . • 0.75 II --------------------------- DETENTION POND SIZING BY FAA METHOD Developed by Civil Eng. Dept., U. of Colorado Supported by Denver Metro Cities/Counties Pool Fund Study Denver Urban Drainage and Flood Control District, Colorado USER=Kevin Gingery------------ . ... ..................... EXECUTED ON 09-30-1998 AT TIME 14:53:51 PROJECT TITLE: Fort Collins Streets Facility - Water Quality Pond A **** DRAINAGE BASIN DESCRIPTION BASIN ID NUMBER = 1.00 BASIN AREA (acre)= 20.36 RUNOFF COEF = 0.86 ***** DESIGN RAINFALL STATISTICS DESIGN RETURN PERIOD (YEARS) = 2.00 INTENSITY (IN/HR) -DURATION (MIN) TABLE IS GIVEN DURATION 5 10 20 30 40 50 60 80 100 120 150 180 INTENSITY 3.3 2.5 1.8 1.5 1.2 1.0 0.9 0.7 0.6 0.5 0.4 0.4 ***** POND OUTFLOW CHARACTERISTICS: MAXIMUM ALLOWABLE RELEASE RATE = 1.5 CFS OUTFLOW ADJUSTMENT FACTOR = 1 AVERAGE RELEASE RATE = 1.5 CFS AVERAGE RELEASE RATE = MAXIMUM RELEASE RATE * ADJUSTMENT FACTOR. ***** COMPUTATION OF POND SIZE ---------------------------- RAINFALL RAINFALL INFLOW DURATION INTENSITY VOLUME MINUTE INCH/HR ACRE -FT 0.00 0.00 0.00 5.00 3.25 0.40 10.00 2.52 0.61 15.00 2.18 0.79 20.00 1.83 0.89 25.00 1.65 1.00 30.00 1.47 1.07 35.00 1.35 1.14 40.00 1.22 1.19 45.00 1.13 1.24 50.00 1.04 1.26 55.00 0.98 1.30 60.00 0.91 1.33 65.00 0.87 1.37 70.00 0.83 1.40 75.00 0.78 1.43 80.00 0.74 1.44 85.00 0.71 1.46 90.00 0.68 1.48 ----------------- OUTFLOW REQUIRED VOLUME STORAGE ACRE -FT ACRE -FT 0.00 0.00 0.01 0.38 0.02 0.59 0.03 0.76 0.04 0.85 0.05 0.95 0.06 1.01 0.07 1.07 0.08 1.10 0.09 1.14 0.10 1.16 0.11 1.19 0.12 1.20 0.13 1.24 0.14 1.26 0.15 1.27 0.17 1.27 0.18 1.29 0.19 1.29 95.00 0.64 1.48 0.20 1.29 100.00 0.61 1.48 0.21 1.28 105.00 0.59 1.50 0.22 1.28 110.00 0.57 1.51 0.23 1.28 115.00 0.54 1.52 0.24 1.28 120.00 0.52 1.52 0.25 1.27 ----------------------------------------------------- THE REQUIRED POND SIZE = 1.291422 ACRE -FT THE RAINFALL DURATION FOR THE ABOVE POND STORAGE= 90 MINUTES ***** GEOMETRIES OF AN EQUIVALENT CIRCULAR POND ----------------------------------------------------- STAGE CONTOUR CONTOUR POND POND (DEPTH) DIAMETER AREA SIDE SLP STORAGE FEET ----------------------------------------------------- FEET ACRE FT/FT ACRE -FT 0.00 21.06 0.01 110.00 0.00 0.50 131.06 0.31 110.00 0.08 1.00 241.06 1.05 110.00 0.42 1.50 351.06 2.22 110.00 1.24 2.00 461.06 3.83 110.00 2.75 2.50 ----------------------------------------------------- 571.06 5.88 110.00 5.18 L L II I I --------------------------- DETENTION POND SIZING BY FAA METHOD Developed by Civil Eng. Dept., U. of Colorado Supported by Denver Metro Cities/Counties Pool Fund Study Denver Urban Drainage and Flood Control District, Colorado ---------------------------------------------------------------------- USER=Kevin Gingery........................................................... EXECUTED ON 09-30-1998 AT TIME 15:07:44 PROJECT TITLE: Fort Collins Streets Facility - Water Quality Basin B **** DRAINAGE BASIN DESCRIPTION BASIN ID NUMBER = 2.00 BASIN AREA (acre)= 6.21 RUNOFF COEF = 0.57 ***** DESIGN RAINFALL STATISTICS DESIGN RETURN PERIOD (YEARS) = 2.00 INTENSITY (IN/HR) -DURATION (MIN) TABLE IS GIVEN DURATION 5 10 20 30 40 50 60 60 100 120 150 180 INTENSITY 3.3 2.5 1.8 1.5 1.2 1.0 0.9 0.7 0.6 0.5 0.4 0.4 ***** POND OUTFLOW CHARACTERISTICS: MAXIMUM ALLOWABLE RELEASE RATE _ .3 CFS OUTFLOW ADJUSTMENT FACTOR = 1 AVERAGE RELEASE RATE _ .3 CFS AVERAGE RELEASE RATE = MAXIMUM RELEASE RATE * ADJUSTMENT FACTOR. ***** COMPUTATION OF POND SIZE ----------------------------------------------------- RAINFALL RAINFALL INFLOW OUTFLOW REQUIRED DURATION INTENSITY VOLUME VOLUME STORAGE MINUTE INCH/HR ACRE -FT ACRE -FT ACRE -FT __ -------------------- 0.00 0.00 0.00 0.00 0.00 5.00 3.25 0.08 0.00 0.08 10.00 2.52 0.12 0.00 0.12 15.00 2.18 0.16 0.01 0.15 20.00 1.83 0.18 0.01 0.17 25.00 1.65 0.20 0.01 0.19 30.00 1.47 0.22 0.01 0.20 35.00 1.35 0.23 0.01 0.22 40.00 1.22 0.24 0.02 0.22 45.00 1.13 0.25 0.02 0.23 50.00 1.04 0.26 0.02 0.23 55.00 0.98 0.26 0.02 0.24 60.00 0.91 0.27 0.02 0.24 65.00 0.87 0.28 0.03 0.25 70.00 0.83 0.26 0.03 0.25 75.00 0.78 0.29 0.03 0.26 80.00 0.74 0.29 0.03 0.26 85.00 0.71 0.30 0.04 0.26 90.00 0.68 0.30 0.04 0.26 95.00 0.64 0.30 0.04 0.26 100.00 0.61 0.30 0.04 0.26 105.00 0.59 0.30 0.04 0.26 110.00 0.57 0.31 0.05 0.26 115.00 0.54 0.31 0.05 0.26 120.00 0.52 0.31 0.05 0.26 ----------------------------------------------------- THE REQUIRED POND SIZE _ .2614721 ACRE -FT THE RAINFALL DURATION FOR THE ABOVE POND STORAGE= 90 MINUTES ***** GEOMETRIES OF AN EQUIVALENT CIRCULAR POND ----------------------------------------------------- STAGE CONTOUR CONTOUR POND POND (DEPTH) DIAMETER AREA SIDE SLP STORAGE FEET ----------------------------------------------------- FEET ACRE FT/FT ACRE -FT 0.00 0.00 0.00 87.00 0.00 0.50 87.00 0.14 87.00 0.03 1.00 174.00 0.55 87.00 0.20 1.50 261.00 1.23 87.00 0.65 2.00 348.00 2.18 87.00 1.50 2.50 ----------------------------------------------------- 435.00 3.41 87.00 2.90 THE SEAR -BROWN GROUP Project: ' Project No. IS 3 -C)"4 By: S ' Checked: / Date: 9 ! C36 g Sheet of c�U4.a-� +4 Uo L = 1.29 Ac-4+ 3so; 5.:2 , 3so 5 s9sa L L= %3oEA+6 + r4a3 Vo L 76) 99-3 c� c 4(o, J. U (o Come Uo L = n. ;z �, 6,C--;- Ua L - li DETENTION POND I -I- 1 11 1 1 Table of Contents ' I. General........................................................................................................................I A. Location.................................................................................................................. 1 B. Description of Phase 2 Improvements.................................................................... 1 II. Drainage Basins and Sub-basins................................................................................. 1 III. Drainage Facility Design............................................................................................ 1 A. Lot 2 Drainage Improvements................................................................................ 2 ' B. Lot 4B Drainage Improvements.............................................................................. 2 C. Water Quality Ponds............................................................................................... 2 ' D. Detention Pond........................................................................................................ 2 APPENDIX..................................................................................................................... 3 THE SEAR -BROWN GROUP Project: 'F+- (lli'U 3h� El•Project No. By: Checked: Date: hp' Sheet of �- _ -�e� - �c �•� -i a� iJ0 _. i /no - d Ant& C,_ pi-f Oct 29.6 o .sCo lb. Lol Q-� 1.23 d.�vl U.38 415- 1 6.s�i I,U o.s9 3 9 3 (�73.9�- C�.Lo3 Table ' Rating Table for Circular Channel 'Project Description Project File cAprogram files\haestad\fmw\fcstree.fm2 ' Worksheet detention outlet Flow Element Circular Channel Method Manning's Formula Solve For Discharge Constant Data Mannings Coefficient 0.013 Channel Slope 0.000700 ft/ft Diameter 18.00 in Input Data Minimum Maximum Increment ' Depth 0.00 1.50 0.10 -77 'Rating Table Depth (ft) Discharge (cfs) Velocity (ft/s) 0.00 0.00 0.00 ' 0.10 0.02 0.49 0.20 0.11 0.76 0.30 0.24 0.97 0.40 0.43 1.14 0.50 0.67 1.29 0.60 0.94 1.42 0.70 - 1.23 1.53 0.80 1.55 1.61 0.90 1.87 1.69 1.00 2.18 1.74 ' 1.10 2.47 1.78 1.20 2.72 1.79 1.30 1.40 2.90 2.99 1.78 1.74 1.50 2.78 1.57 1 09/30/98 FlowMaster v5.13 ' 12:10:34 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 ----------- - DETENTION POND SIZING BY FAA METHOD Developed by ' Civil Eng. Dept., U. of Colorado Supported by Denver Metro Cities/Counties Pool Fund Study Denver Urban Drainage and Flood Control District, Colorado ------------------ USER=Kevin Gingery........................................................... EXECUTED ON 09-30-1998 AT TIME 19:25:21 ' PROJECT TITLE: Fort Collins Street Facility - Detention Pond **** DRAINAGE BASIN DESCRIPTION ' BASIN ID NUMBER = 3.00 BASIN AREA (acre)= 37.93 RUNOFF COEF = 0.63 ***** DESIGN RAINFALL STATISTICS DESIGN RETURN PERIOD (YEARS) = 100.00 INTENSITY (IN/HR) -DURATION (MIN) TABLE IS GIVEN DURATION 5 10 20 30 40 50 60 80 100 120 150 180 INTENSITY 9.0 7.2 5.2 4.2 3.5 3.0 2.6 2.1 1.7 1.5 1.2 1.0 ***** POND OUTFLOW CHARACTERISTICS: MAXIMUM ALLOWABLE RELEASE RATE = 10.5 CFS ' OUTFLOW ADJUSTMENT FACTOR = 1 AVERAGE RELEASE RATE = 10.5 CFS AVERAGE RELEASE RATE = MAXIMUM RELEASE RATE * ADJUSTMENT FACTOR. ***** COMPUTATION OF POND SIZE RAINFALL RAINFALL INFLOW OUTFLOW REQUIRED DURATION INTENSITY VOLUME VOLUME STORAGE MINUTE INCH/HR ACRE -FT ACRE -FT ACRE -FT 0.00 0.00 0.00 0.00 0.00 5.00 9.00 1.49 0.07 1.42 10.00 7.20 2.39 0.14 2.24 15.00 6.19 3.08 0.22 2.86 ' 20.00 5.18 3.44 0.29 3.15 25.00 4.68 3.88 0.36 3.52 30.00 4.17 4.15 0.43 3.72 35.00 3.84 4.45 0.51 3.95 40.00 3.50 4.65 0.58 4.07 45.00 3.25 4.85 0.65 4.20 50.00 3.00 4.98 0.72 4.26 55.00 2.80 5.12 0.80 4.32 ' 60.00 2.61 5.20 0.87 4.33 65.00 2.47 5.33 0.94 4.39 70.00 2.34 5.42 1.01 4.41 75.00 2.20 5.47 1.08 4.39 80.00 2.06 5.47 1.16 4.31 85.00 1.97 5.56 1.23 4.33 90.00 1.88 5.62 1.30 4.31 ' 95.00 1.79 5.64 1.37 4.27 100.00 1.70 5.64 1.45 4.20 ----------------------------------------------------- THE REQUIRED POND SIZE = 4.412304 ACRE -FT THE RAINFALL DURATION FOR THE ABOVE POND STORAGE= 70 MINUTES ***** GEOMETRIES OF AN EQUIVALENT CIRCULAR POND ----------------------------------------------------- STAGE CONTOUR CONTOUR POND POND (DEPTH) DIAMETER AREA SIDE SLP STORAGE FEET ----------------------------------------------------- FEET ACRE FT/FT ACRE -FT 0.00 0.00 0.00 100.00 0.00 0.50 100.00 0.18 100.00 0.05 1.00 200.00 0.72 100.00 0.27 1.50 300.00 1.62 100.00 0.86 2.00 400.00 2.88 100.00 1.98 2.50 500.00 4.51 100.00 3.83 3.00 600.00 6.49 100.00 6.58 ----------------------------------------------------- ❑0.00 3.83 3 THE SEAR -BROWN GROUP Pro)ect: '• ''�$r CPro)ect No. By; S Checked: Date: Sheet of AMENDED FINAL DRAINAGE, EROSION AND STORM WATER QUALITY STUDY FOR THE EAST VINE STREETS FACILITY P.U.D., PHASE TWO FINAL I. General This amendment addresses the changes made in relation to the Final Drainage, Erosion and Storm Water Quality Study for the East Vine Streets Facility P.U.D., Phase One Final Report. This amended final consists of Phase Two improvements in Lots 1, 2, and 4B. Lot 4 was divided into two lots in a revised plat submitted by Muller Engineering for the Colorado Department of Transportation (CDOT). CDOT will own Lot 4A and have access to the City of Fort Collins' Lot 4B streets facilities. A. Location The site is situate in the North ''/z of Section 12, Township 7 North, Range 69 West of the 6`h Principle Meridian, City of Fort Collins, Larimer County, Colorado. A Description of Phase 2 Improvements Lot 2 improvements include a new parking lot and renovated building. Lot 1 improvements will incorporated a large vehicle covered parking building, a small building for paint storage and mixing, a vehicle wash bay and various utility changes. Lot 4B will have a sand/salt storage dome and an ice slicer building. II. Drainage Basins and Sub -basins No major drainageway exists on the site. The property being improved lies within --- the Dry Creek Basin. The site is not impacted by the 100-year flood plain. Historic drainage patterns on the site are generally west to east. The first phase of planning included preliminary sub -basin delineation for the entire 32.8 acres. Sub - basin `H' has more lawn area than was considered in the Phase One Final Drainage Report. Lot 4B will be paved and Lot 1 remains mostly impervious. III. Drainage Facility Design The City of Fort Collins Storm Drainage Design Criteria is being used for the site. The improvements of this second phase of development stay within the limits imposed by the preliminary design of the site and construction of the first phase. The first phase construction included water quality ponds and a detention basin sized for the complete development of the site. This second phase will complete the construction of Water Quality Pond `A', the extension of an existing storm sewer west to drain Lot 413, and other surface drainage features such as cross pans. The design calculations for runoff and the storm sewer line extension are attached in the Appendix. The runoff for sub -basin `H' concentrated at Point 1 is less than what was calculated in the Phase 1 Final Report. A. Lot 2 Drainage Improvements Lot 2 is contained within Sub -basin `H'. A two -foot trickle channel will drain the grass lawn area from the building to the proposed parking lot. Surface runoff continues to flow along cross pans and curb and gutter in the parking lot. A six- foot cross pan carries runoff across the paved access area east of the parking lot to the northeast corner of the pavement. Rain falling in the access road north of the building and lawn of Lot 2 flows northeast into the proposed curb and gutter, then east to concentration point 1. A curb break opens to a new four -foot trickle pan in the water quality pond. The pan will end at an existing outlet pipe to the detention basin. B. Lot 4B Drainage Improvements ' The existing 24-inch storm sewer that was stubbed out from the area inlet in Lot 1 will be extended west to convey 2-year storm flows from new area inlets at the ' south corners of Lot 4B. Six-foot cross pans run along the east and west lot lines to the area inlets. Another cross pan drains the area between the inlets along the north side of the access road. The sub -basin in the north section of Lot 4B will be unchanged from historic conditions. An existing swale north of the property boundary will continue to flow east to the new curb and gutter in Lot 2. I 1 C. Water Quality Ponds Water quality pond A currently contains wetlands and therefore is not able to be regraded. With the development of Lot 4B, the volume of water for a 2-year storm directed to this basin (1.29 ac-ft) is greater than the current volume of the water quality pond (1.05 ac-ft) according to calculations by the FAA method. These calculations included the upsizing of the current 6-inch outlet pipe to a 12- inch pipe. _However, the emergency weir at the east end of the pond will direct _ any overflow directly to the detention pond. Water quality pond B is sufficient to handle the volume of water from a 2-year storm even with the development of Lot 4B. The calculations for the water quality ponds are located in the Appendix. D. Detention Pond The current size of the detention pond is less than what is needed for the volume of water from the 100-year storm. Therefore, regrading the pond is necessary. Calculations for the detention pond with the new gradation along with the new gradation plan are located in the Appendix. 2 I 1 APPENDIX 1 I 1 I [J 1 I 1 i I 0 .1 HYDROLOGY M M M M The Sear -Brown Group Fort Collins Streets Facility Composite Rational Method Runoff Coefficients (Fort Collins) Designer SLG Surface Impervious I Pervious C 0.951 0.25 W = i = = = M M 183-047 Basin Area Percent Impervious PercentRunoff Pervious Coefficient Remarks Total Impervious (ac) (ac) C H 4.36 2.24 51.4% 48.6% 0.61 413-1 0.59 0.59 100.0% 0.0% 0.95 413-2 1.76 1.76 100.0% 0.0% 0.95 46-3 0.79 0.79 100.0% 0.0% 0.95 0-1 3.17 3.17 100.0% 0.0% 0.95 0-2 1.23 0.00 0.0% 100.0% 0.25 7 8 9 10 30-Sep-98 M M = = = = = = M The Sear -Brown Group Fort Collins Streets Facility Time of Concentration Designer. Storm: Cf = I (Fort Collins) ti = 1.870.1 - C x CflD"(1/2) SLG S^(1/3) 2 yr 1.00 tc = ti + tL 183-047 SUB -BASIN DATA INITIAIJOVE LAND TIME TFURECTIME tc Remarks Basin Area C C x Cf Length Slope ti Length Slope Velocity tL (ac) (ft) N (min) (ft) N (ft/s) (min) (min) 1 2 3 3a 4 5 6 7 7a 8 9 10 11 12 H 4.36 0.61 0.61 60 1.70 6.0 1290 PA 0.50 1.34 16.1 22.0 Lot 2 B-1 0.59 0.95 0.95 180 1.10 3.6 1480 PA 0.50 1.34 18.5 22.1 Lot 4B - North 13-2 1.76 0.95 0.95 190 1.30 3.5 267 PA 0.77 1.67 2.7 6.2 Lot 4B - East 13-3 0.79 0.95 0.95 130 0.77 3.5 250 PA 0.89 1.80 2.3 5.8 Lot 4B - West 0-1 3.17 0.95 0.95 490 0.92 6.4 135 PA 0.89 1.80 1.3 7.6 Lot 4A 0-2 1.23 0.25 0.25 460 0.83 36.3 1925 GW 0.43 1.01 31.8 68.0 North of All Lots Note: Column 7a codes the channel type for velocity calculations. PA = Paved Area, PL = Pasture& Lawns, GW = Grassed Waterway 30-Sep-98