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HomeMy WebLinkAboutDrainage Reports - 05/10/2002I 1 [l 1 1 n L 1 1 1 Report R G C� L U �/ t� January 8, 2002 We ----f-s=� � JAN 2 4 2002 JR Project 39067.17 II Mr. Basil Hamdan,*:'"` City of Fort Collins Stormwater Utility 700 Wood Street J•R ENGINEERING Fort Collins, CO 80521 A Subsidiary of Westrian RE: New Belgium Brewery Administrative Change #6, Expansion of the Brew House Dear Basil: This letter is intended to be an update to the New Belgium Brewery Administrative Change #6 — Expansion of the Brew House, the update will include revision to the temporary parking lot. The original Administrative Change #6 shows a temporary parking lot on the east side of the site constructed of crushed gravel. This parking lot has been revised in size and surface material. A surface of constructed rotomilled asphalt is proposed. The changes to the parking lot required an increase in area to Basin E from 5.84 acres to 6.36 acres. The runoff coefficient was also increased from 0.74 to 0.77 for the 100-year event. Effectiveness calculations have been updated to reflect these changes. All calculations used for drainage design are attached. The Drainage and Erosion Control plan sheet has been revised and includes a drainage summary table, detention pond summary table, Basin E boundary changes, and the new temporary parking lot location. This plan sheet is also attached. A design variance is requested to allow for less than 1 foot of freeboard between the 100-year WSEL and the spill elevation in the proposed Detention Pond E. The actual freeboard of Pond E is 0.74 foot. This difference in freeboard allows for significantly more volume available for detention. All surrounding buildings will have finished floor elevations a minimum of 1 foot above the 100-year spill elevation. Thank you for your time in consideration of this submittal. Please contact me with any questions or concerns you may have. Sincerely, ;� /0 - Mark West, E.I. Design Engineer Cc: Sheri Wamhoff, Chris Wesche Attachments John Tufte, P.E. Project Engineer LJ 2620 East Prospect Road, Suite 190, Fort Collins, CO 80525 970-491-9888 • Fax: 970-491-9984 • w ..jrengineering.com I 1 I 1 1 1 1 HYDRAULIC CALCULATIONS IJAN 2 4 2002 <1 .,_.. ,. , . . I RUNOFF COEFFICIENTS & % IMPERVIOUS LOCATION: New Belgium Brew House Expansion PROJECT NO: 39067.17 COMPUTATIONS BY: M. West DATE: 1/8/02 Recommended Runoff Coefficients from Table 3-3 of City of Fort Collins Design Criteria Recommended % Impervious from Urban Storm Drainage Criteria Manual Streets, parking lots, sidewalks (asphalt) Rotomill Asphalt Roofs Lawns (2 to 7%, heavy soil) Runoff coefficient C % Impervious 0.95 95 0.75 75 0.95 95 0.25 25 JR Engineering 2620 E. Prospect Rd., Ste. 190 Fort Collins, CO 8525 SUBBASIN DESIGNATION TOTAL AREA (ac.) TOTAL AREA (sq.ft) ROOF AREA (sq.ft) HARD SURFACE AREA (sq.ft) GRAVEL AREA (sq.ft) LANDSCAPE AREA (sq.ft) RUNOFF COEFF. (C) % Impervious Comments D 0.75 32,823 0 10,507 a 22,316 0.47 47 Revised E 6.36 277,000 55,415 61,865 39,534 120,186 0.62 62 Revised e 2.04 88,682 18,235 35,351 0 35,096 0.67 67 Portion of Basin E Equations - Calculated C coefficients & % Impervious are area weighted C=£(Ci Ai) /At Ci = runoff coefficient for specific area, Ai Al = areas of surface with runoff coefficient of Ci n = number of different surfaces to consider At = total area over which C is applicable; the sum of all Ai's Note: Sub -basin a is the portion of Sub -basin E used to determine flows in the trickle channel 8ow.xls I � B ,) 0§ �k §b `k� / / \ } \\\@ E \ \ \ ƒ/\ E SmEA ± 0 a. L)Z� 22�¥/ 22| 2 s =/2 ! k£�~ mmm ) {«s ]/a00 2:: \ m \ / \ \ 2\ & { \ ! ){ 1 C O_ ' Z 0 H N H ~ Z z K W O Z w LL U ' O LL O N LU O N a K W ' O x 3 ' a c0 � o II U z O ' Up�F o i. 0 w O �¢ p 1 W V% c N d m Q NA N f N 0 V C C O a M V N LL N m N m 0 W W2 J_ N N fm0 V m S 6 c> w U 7 M O N II � r ao V y m o m O m ao m E r e LL 10 < d W 2 > a Q S m m m m U E O � � 2 o 0 0 m N N _ G C O (� O o m W N JL tmp O a _ J F Z m m N N N N N _ o N O N N N = L g ��s W O g m U s� n M O N � N G G V Q z m ❑ w m m m ? H � Q 00 °4Q oa O N e i U) j J N 1 J � U U zZ O Q + n m � II U II II W N N 2 U U LL m � U o C _N n .E v o N m C m a E cU) cc .. ) + `o E E E E U b / \ §z E \\\b 5m5A ) ui Z� 22 Va 2 s =)2 :: #zr ^ k£0 mmm f¥y co \ \ k= / k \ }} ;f } JR Engineering 2620 E. Prospect Rd., Ste. 190 Fort Collins, CO 80525 1 1 1 1 1 RATIONAL METHOD PEAK RUNOFF (City of Fort Collins, 2-Yr Storm) LOCATION: New Belgium Brew House Expansion PROJECT NO: 39067.17 COMPUTATIONS BY: M. West DATE: 1 /8/02 2 yr storm, Cf = 1.00 DIRECT RUNOFF CARRY OVER TOTAL REMARKS Tributary Sub -basin A (ac) C Cf tc (min) i (in/hr) Q (2) (cfs) from Design Point Q (2) (cfs) Q(2)tot (cfs) D 0.75 0.47 7.3 2.50 0.89 0.89 Revised E 6.36 0.62 11.4 2.11 8.29 8.29 Revised e 2.04 0.67 8.2 2.40 3.29 3.29 Portion of Basin E flowxls Q=CfCiA Q = peak discharge (cfs) C = runoff coefficient Cf = frequency adjustment factor i = rainfall intensity (in/hr) from City of Fort Collins OF curve (4/16/99) A = drainage area (acres) i = 24.2211 (10+tc)oJ JR Engineering 2620 E. Prospect Rd., Ste. 190 Fort Collins, CO 80525 RATIONAL METHOD PEAK RUNOFF (City of Fort Collins, 10-Yr Storm) LOCATION: New Belgium Brew House Expansion PROJECT NO: 39067.17 COMPUTATIONS BY: M. West DATE: 1 /8/02 10 yr storm, Cf = 1.00 DIRECT RUNOFF CARRY OVER TOTAL REMARKS Tributary Sub -basin A (ac) C Cf tc (min) i (in/hr) Q (10) (cfs) from Design Point Q (10) (cfs) Q(10)tot (cfs) D 0.75 0.47 7.3 4.26 1.52 1.52 Revised E 6.36 0.62 11.4 3.60 14.16 14.16 Revised e 2.04 0.67 8.2 4.11 1 5.63 5.63 Portion of Basin E Q=CfCiA Q = peak discharge (cfs) C = runoff coefficient Cf = frequency adjustment factor i = rainfall intensity (in/hr) from City of Fort Collins IDF curve (4/16/99) A = drainage area (acres) i = 41.44 / (10+ tc)0.7974 flow.xls JR Engineering 2620 E. Prospect Rd., Ste. 190 Fort Collins, CO 80525 RATIONAL METHOD PEAK RUNOFF (City of Fort Collins, 100-Yr Storm) LOCATION: New Belgium Brew House Expansion PROJECT NO: 39067.17 COMPUTATIONS BY: M. West DATE: 1/8/02 100 yr storm, Cf = 1.25 DIRECT RUNOFF CARRY OVER TOTAL REMARKS Area Design. A (ac) C Cf tc (min) i (in/hr) Q (100) (cfs) from Design Point Q (100) (cfs) Q(100)tot (cfs) D 0.75 0.59 6.4 9.08 4.05 4.05 Revised E 6.36 0.77 10.2 7.69 37.78 37.78 Revised e 2.04 0.84 6.9 8.88 15.21 15.21 Portion of Basin E Q=CiA Q = peak discharge (cfs) C = runoff coefficient i = rainfall intensity (in/hr) from City of Fort Collins IDF curve (4/16/99) A = drainage area (acres) i = 84.682 / (10+ tC)0.797s flow.xls 1 } a ' y W Q o Zcql G a W ti 0 0 x ' 3 Eu W ao � N ' a°3p 0 zM�00 1 11 w C N N C W w w m E m a') o 0 c 0 0 0 a a0 N � G t�7 V M LO d O N <O O w Lo Q O w 01 r) f`7 N U O co Cl) d O C V N 0) u r C M ? N C M ? N 0 r ad o o L U o 0 0 v c0 c0 O o 6 U v 04 m (q U o 0 0 d LO(� - h Cl) O A Q O O N C R W R 5 a o w 0) a a vJ JR Engineering POND E - DETENTION VOLUME CALCULATIONS Rational Volumetric (FAA) Method 100-Year Event LOCATION: New Belgium Brew House Expansion PROJECT NO: 39067.17 COMPUTATIONS BY: M. West DATE: 1 /8/02 Equations: Area trib. to pond = 6.36 Developed flow = QD = CIA C (100) = 0.77 Vol. In = Vi = T C I A = T Qo Developed C A = 4.91 Vol. Out = Vo =K Qao T Release rate, QPo = 1.15 storage=S=Vi -Vo K= 1 Rainfall intensity from City of Fort Collins IDF Curve with updated (3.67") rainfall acre acre cfs (from fig 2.1) Storm Duration, T (min) Rainfall Intensity, I (in/hr) Qo (cfs) Vol. In Vi (ft) Vol. Out Vo (ft) Storage S (ft) Storage S (ac-ft) 5 9.95 48.9 14657 345 14312 0.33 10 7.77 38.1 22881 690 22191 0.51 20 5.62 27.6 33119 1380 31739 0.73 30 4.47 21.9 39494 2070 37424 0.86 40 3.74 18.4 44074 2760 41314 0.95 50 3.23 15.9 47637 3450 44187 1.01 60 2.86 14.0 50551 4140 46411 1.07 70 2.57 12.6 53019 4830 48189 1.11 80 2.34 11.5 55161 5520 49641 1.14 90 2.15 10.6 57055 6210 50845 1.17 100 1.99 9.8 58754 6900 51854 1.19 110 1.86 9.1 60297 7590 52707 1.21 120 1.75 8.6 61710 8280 53430 1.23 130 1.65 8.1 63016 8970 54046 1.24 140 1.56 7.6 64231 9660 54571 1.25 150 1.48 7.3 65366 10350 55016 1.26 160 1.41 6.9 66433 11040 55393 1.27 170 1.35 6.6 67440 11730 55710 1.28 180 1.29 6.3 68393 12420 55973 1.28 190 1.24 6.1 69299 13110 56189 1.29 fl ow. xl s, FAA-100yr-POND E I JR Engineering L� 1 1 1 11 1 200 1.19 5.8 70163 13800 56363 1.29 210 1.15 5.6 70988 14490 56498 1.30 220 1.11 5.4 71778 15180 56598 1.30 230 1.07 5.3 72537 15870 56667 1.30 240 1.04 5.1 73266 16560 56706 1.30 250 1.00 4.9 73968 17250 56718 1.30 260 0.97 4.8 74646 17940 56706 1.30 270 0.95 4.6 75301 18630 56671 1.30 280 0.92 4.5 75935 19320 56615 1.30 290 0.90 4.4 76549 20010 56539 1.30 300 0.87 4.3 77145 20700 56445 1.30 310 0.85 4.2 77723 21390 56333 1.29 Required Storage Volume: 56718 ft' 1.30 acre-ft Iflow.xls,FAA-100yr-PONDE JR Engineering WATER QUALITY CAPTURE VOLUME SUMMARY FOR EXTENDED DETENTION LOCATION: New Belgium Brew House Expansion PROJECT NO: 39067.17 COMPUTATIONS BY: M. West DATE: 1/8/02 Guidelines from Urban Strom Drainage Criterial Manual, September 1999 (Referenced figures are attached at the end of this section) Use 40-hour brim -full volume drain time for extended detention basin Water quality Capture Volume, WQCV = 1.0 * (0.91 * i3 - 1.19 * i2 + 0.78i) Design Volume: Vol = WQCV/12 * Area * 1.2 MAJOR BASIN Trib. area (acres) Impervious Ratio, la % Impervious I = la/100 WQCV (watershed inches) Design Volume, Vol. (ac-ft) POND E 6.36 62 0.62 0.24 0.15 flow.xls,1/8/02,9:04 AM 11 Pond E Proposed Detention Pond - Stage/Storage LOCATION: New Belgium Brew House Expansion PROJECT NO: 39067.17 COMPUTATIONS BY: M. West DATE: 1/8/02 100-yr WSEL- top of berm - V = 1/3 d (A + B + sgrt(A'B)) where V = volume between contours, ft3 d = depth between contours, ft A = surface area of contour POND NAME Stage (ft). Surface Area (ft) Incremental Storage (ac-ft) Total Storage (ac-ft) 4946 0 4947 16156 0.12 0.12 4948 24495 0.46 0.59 4949.00 33050 0.66 1.25 4949.26 35170 0.20 1.45 4950 41204 0.85 2.10 WQCV = 100-YR Detention Volume = Total required volume = 0.15 ac-ft 1.30 ac-ft 1.45 ac-ft flow.xls I ' Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility ' POND E LOCATION: New Belgium Brew House Expansion PROJECT NO: 39067.17 COMPUTATIONS BY: M. West DATE: I/8/02 ' 1. Basin Storage Volume A) Tributary Area's Imperviousness Ratio (i=la/l00) ' B) Contributing Watershed Area (Area) C) Water Quality Capture Volume (WQCV) ' (WQCV = 1.0 * (0.91 * i3 - 1.19 * iZ + 0.78i) ) D) Design Volume: Vol = WQCV/12 * Area * 1.2 2. Outlet Works ' A) Outlet Type (Check One) B) Depth at Outlet Above Lowest Perforations (H) C) Required Maxiumum Outlet Area per Row, (Ao) (Figure EDB-3) ' D) Perforation Dimensions (enter one only) i) Circular Perforation Diamter OR ii) 2" Height Rectangular Perforation Width ' E) Number of Columns (nc, See Table 6a-1 for Maximum) F) Actual Design Outlet Area per Row (Ao) ' G) Number of Rows (nr) H) Total outlet Area (Aoj ' 3. Trash Rack A) Needed Open Area: ' A, = 0.5 * (Figure 7 Value) * Ao, B) Type of Outlet Opening (Check One) C) For 2", or Smaller, Round Opening (Ref: Figure 6a) ' 1) Width of Trash Rack and Concrete Opening (W. o) from Table 6a-1 ii) Height of Trash Rack Screen (HTR) ' = H - 2" for Flange of top support iii) Type of Screen Based on Depth H) Describe if "other" iv) Screen Opening Slot Dimension, ' Describe if "other" v) Spacing of Support Rod (O.C.) Type and Size of Support rod (Ref: Table 6a-2) la = 62 % i = 0.6177 A = 6.36 acres WQCV = 0.24 watershed inches Vol. = 0.15 ac-ft x Orifice Plate Perforated Riser Pipe Other: H=. 3 ft Ao = 0.25 square inches D = 9116 inches, OR W = inches nc = 1 number Ao = 0.25 square inches nr = 9 number Aot = 2.25 square inches At = 76.5 square inches x < 2" Diameter Round 2" High Rectangular Other: WW.0 = 6 inches HTR = 34 inches 0 x S.S. #93 VE Wire (US Filter) Other: x 0.139" (US Filter) Other: 3/4 inches #156 VEE ' Page 1 1 1 1 1 vi) Type and size of Holding Frame (Ref: Table 6a-2) D) For 2" High Rectangular Opening (Refer to Figure 6b): 1) Width of rectangular Opening (W) W = ii) Width of Perforated Plate Opening (Wconc=W+12") Wwnc = iii) Width of Trashrack Opening (Wopening) Wopening = from Table 6b-1 iv) Height of Trash Rack Screen (HTR) HTR = v) Type of Screen (based on Detph H) (Describe if "other) vi) Cross -bar Spacing (Based on Table 6b-1, KlempTM KPP Grating). Describe if "other" vii) Minimum Bearing Bar Size (KlempTM Series, Table 6b-2) (Based on depth of WQCV surcharge) 4. Detention Basin length to width ratio 5. Pre -sedimentation Forebay Basin - Enter design values (N/A) A) Volume (5 to 10% of the Design Volume in 1 D) B) Surface Area C) Connector Pipe Diameter (Size to drain this volume in 5-minutes under inlet control) D) Paved/Hard Bottom and Sides 6. Two -Stage Design (N/A) 3/8" x 1.0" flat bar inches inches inches inches KlempTM KPP Series Aluminum Other: inches Other: 1 (L/W) acre-feet acres inches yes/no A) Top Stage (DWo = 2' minumum) DWo = feet B) Bottom Stage (DBs = DWo + 1.5' min, DWo + 3.0' max. Storage = 5% to 15% of Total WQCV) C) Micro Pool (Minimum Depth = the Larger of 0.5"Top Stage Depth or 2.5 feet) D) Total Volume: Vol,,, = Storage from 5A + 6A + 6B Must be > Design Volume in 1 D 7. Basin Side Slopes (Z, horizontal distance per unit vertical) Minimum Z = 4, flatter preferred 8. Dam Embankment Side Slopes (Z, horizontal distance per unit vertical) Minimum Z = 4, flatter preferred 9. Vegetation (Check the method or describe "other") Storage = acre-feet DBs = feet Storage = acre-feet Surf. Area = acres Depth = feet Storage = acre-feet Surf. Area = acres Vol,', = 0 acre-feet Z = 20 (horizontal/vertical) Z = 4 (horizontal/vertical) x_ Native Grass _ Irrigation Turf Grass Other: f Page 2 EFFECTIVENESS CALCULATIONS I 1 11 1 [1 1 11 ' JR Engineering, Ltd. 2620 E. Prospect Rd., Ste. 190, Fort Collins, CO 80525 ' RAINFALL PERFORMANCE STANDARD EVALUATION PROJECT: New Belgium Brew House Expansion STANDARD FORM A COMPLETED BY: M. West DATE: 08-Jan-02 DEVELOPED ERODIBILITY Asb Lsb Ssb Ai • Li Ai • S1 Lb Sb PS SUBBASIN(s) ZONE (AC) (FT) (%) (FT) D MODERATE 0.75 1 275 0.7 207.2 0.5 E 6.36 690 0.6 4387.7 3.5 Total 1 1 7.11 1 4594.96 4.07 646 0.6 1 73.8% Asb = Sub -basin area Lsb = Sub -basin flow path length Ssb = Sub -basin slope ' Lb = Average flow path length = sum(Ai Li)/sum(Ai) Sb =Average slope = sum(Ai Si)/Sum (Ai) ' PS is taken from Table 8-a (Table 1,1, Erosion Control Reference Manual) by interpolation. An Erosion Control Plan will be developed to contain PS% of the rainfall sedimentation that would normally flow off a bare ground site during a 10-year, or less, precipitation event. 1 d tErosion.xls ' JR Engineering 2620 E. Prospect Rd., Ste. 190, Fort Collins, CO 80525 1 1 1 1 1 EFFECTIVENESS CALCULATIONS PROJECT: New Belgium Brew House Expansion STANDARD FORM B COMPLETED BY: M. West DATE: 08-Jan-02 EROSION CONTROL C-FACTOR P-FACTOR METHOD VALUE VALUE COMMENT BARE SOIL 1.00 1.00 SMOOTH CONDITION ROUGHENED GROUND 1.00 0.90 ROADS/WALKS 0.01 1.00 GRAVEL FILTERS 1.00 0.80 PLACED AT INLETS SILT FENCE 1.00 0.50 SEDIMENT TRAP 1.00 0.50 STRAW MULCH (S = 1-5%) 0.06 1.00 FROM TABLE 8B STRAW BARRIERS 1.00 0.80 EFF = (1-C* P)* 100 MAJOR SUB BASIN AREA EROSION CONTROL METHODS BASIN BASIN (Ac) D 0.75 ROADS/WALKS 0.24 Ac. ROUGHENED GR. 0.00 Ac. STRAW/MULCH 0.51 Ac. GRAVEL FILTER NET C-FACTOR 0.04 NET P-FACTOR 0.80 EFF = (I-C*P)*100 = 96.5% E 6.36 ROADSIWALKS 2.33 Ac. ROUGHENED GR. 1.27 Ac. STRAW/MULCH 2.76 Ac. GRAVEL FILTER NET C-FACTOR 0.23 NET P-FACTOR 0.78 EFF = (1-C *P)* 100 = 82.0% ' TOTAL AREA = 7.11 ac TOTAL EFF = 83.5% (E (basin area * eff) / total area REQUIRED PS = 73.8% ' Since 83. %5 > 73.8%, the proposed plan is o.k. 1 ' erosion.xls 40, B REM OEM � REM EROSW AND MOMENT CONTROL NOTES 1. DURING CONSTRUCTED. PROPOSED POND SELL SERVE AS SEDIMENT BASIN. ME SEDIMENT BASINS AND SEDIMENT MAE SPACE BE CONSTRUCTED NITNIX 5 DAYS OF COMMENCEMENTW REM AOXG ALL RUNOET SXALL BE DIRECTED TO ME FARM AND MAP ASMACH AS POSSIBLE THROUGH POT`ME U yGRADING. TER COMPLETED BE PAVING AND A MAJOR PORTION OF PERMANENT LANDSCAPING THE GRAVEL FILTER B MROA MAY BE REMOWD EME BASINS MEN CMAPPROVAL. SEDIMENT THEN MAY E REMOVED THEM E BASINS AND IRA µD TRUE POND GRADING CONSTRUCTOR MAY CUR, 2 TEMPORARYALL SNEEEDED TODIRECT RUNOFT' TO ME SEDIMENT TASIDY AND M4YNiMAP SM ME PW NCEDNM HAY MADE GREEN DMLS 3. TIE SRRM RIVER SYSTEM SHALL M CONSTRUCTED AS 5OX1 AS PDS9BLE AFTER ROUGH GRADING MATH NI£T5 BEING IMMEDIATELY PROTECTED BY HAY SALE FILTERS INLETS IN AREAS MNICH HAVE BEEN PATED BUT LANDSCAPING IS NOT COMPLETE SHALL BE PROTECTED MIN GRAVEL AND ORDERED" FILTERS. A. ALL LANDSCAPED AREAS OUTSIDE BE THE CONSTRUCTION DISTURBANCE ZONE SHNL BE REVEGETATED PER W DSGK SPECIFICATIONS AS SON AS POS901£ AFTER GRADING IS COIPIETE. ALL SEEDED AREAS SHALL M MULCHED ON MATTED. S ALL PAVED AREAS OUTSIDE THE CONSTRUCTOR DISTURBANCE ZONE SHALL BE CATERED MM GRAVEL OR PAWD REM A MINIMUM BY H UFT OR PAREMENT AS SE AFTER CRMONG AS POSSIBLE. B. ALL DISTURBED AREAS WiMR THAN 1/3 ACRE OR AS DIRECTED BY ME ON OUTSIDE THE CONSTRUCTION DISTURBANCE ZONE WHICH HAW NOT BEEN PROTECTED FARM wDSON WITHIN 2 WEXS CP GRADING SHALL BE COMMON FwaDMS. 7. CONTRACTOR SHALL BE RESPCRSINE TO APPEY FW INY OMAN APPLICAUKE EFFORTS. a ME CONTRACTOR SHALL FNONAE AT LEAST 1 WIXCLE DIAGRAMS; CON1Pa FACILITY. ENE CONTRACTOR SHALE SUBMIT A POUR w101 Mu ASSURE USAGE OF MIS FAULTY BY ALL VEHICLES LEAVING THE SHE ME OETULS PROVIDED OUR THIS SHI B. CONTRACTOR SHALL MAINTAIN AIL TEMPORARY ARGUES CONTROL FACNTES IN WLG XCMGING DICER UNTIL SUCH TIME AS PERMANENT FACILDES ARE IN RACE AND ME CM HAS APPROVED THEIR REMOVAL. 10. SET FENCE ON ME IDUNNILL SIDE OF AM DISTURBED AREA SMLL BE CONSTRUCTED "MIN 5 DAYS CE COMMENCEMENT OF SR MEASURE, 11. 'JUTE MATTI W APPROVED EWAL WALL ME INSTALLED M MWES GREATER THAN P.I. wR _',-----------mom - r SPARROW ' r �'`` w; I I ICIPOND D 1.1 7 ` ` EXISTING 17EW BEI-mm BRENERY EF- � B B � f R�in xu amp MAN awt AC \ter mmwNr Rose r� I 1 1 AREA "to�F t I I �I I CrOUNWIT SUMP I l / -�REM REM11 CONSTRUCTION SEQUENCE woaT. B.. ww,I ..... _ RAMMANA NA "tow Now AwMwUEA, to My MONTH 1 1 X Rod EE. O� IMP g LRMItAANAA RPhRAI SAI INIMAN dew ttow NEAR, RoMw SAw 0, wo tow AplfyCaleq R.MN M Nwwov MM AN Wwwo, IRROME WHSITCMN 11 mqsRRRRX ........ - ua,ewL¢ a 1T. HONE® WatATaAIUG"M mrlxAGlGe a wTE R.e.ERn AARI"MD BY CITY G FORT COLLINS ON r III II I I dIT , I IIII J II II#III C I IlllTSIM ill I II IIII � IL-1) sm 9t D1:T31 � Rc;'119Tp[ya 7]5123 DESIGN POINT AREA DESIG MEA AGES Clo nIW Tc (la) MN 1 TO (100) EEN 0 (10) f35 0 (1CO) us A 4 118 DJB 11 Sm 10.1 55 2} 1C B B 103 U56 I 0]0 z3.o 1 10.0 03s I- C C 0.55 095 1.00 9.B 9.6 RL D D 0.)5 0.47 0.5B ITS 0.4 1.3 {.1 E E 1 B.OB i 0.1 0." 11.4 i 10.2 14.2 1�.1 F F I p 3g 1 0.29 0.36 13.8 1 13.6 0 i9 J.91 RETENTION POND V SUMMARY RETENTION REQUIRED M ACR. REIFNTIdN FRONDED B.ER ACRE. 1W YR M'31 amist MAX RELEASE RAZE 0.0 6S REVISED DETENTION POND 'E' SUMMARY nI 0.15 AC FT. 100-YR DETENTION REWIRED 1.30 AG FT. TOTAL OET EI n011 PROMOm 1.{S AC.R. 100 YR INSIDE 4;NW;Um I RELEASE RATE 1.15 Cis �Mz < �a D. No v8a:A. 0�O�az;Xo�go L E y 50 25 0 50 100 4 w p o SCALE: 1' - 50' 0. p a LEGEND EXISTING EASEMENTS u 8 ----" _------ EXISTING CONTOURS �Wzy ' - -wo- - - EXISTING INDEX CONTOURS j1j BE EIOSnNG EDGE OF PAVEMENT Z g���EEE - - - - - - - - - EXISTING FLOMLINE 1 EXISTING DRAINAGE PIPE z t PROPOSED CONTOURS 490- PROPOSED INDEX CONTOURS W PROPOSED FLONUNE QDESIGN POINT n ASIN DESIGNATION MINOR STIXtM RUNOFF COEFFICIENT AREA IN ACRES n _ _ _ _ _ _ _ BASIN BOUNDARY � o SILT FENCE m ® 51. TEMPORARY GRAVEL CONSTRUCTION ENTRANCE ® _ GRAVEL FILTER 100-YR WATER SURFACE r� -+ ELEVATION DETENTION AREA UT SIT PREPAIED WCfII TE SEEM ARpNSICN CF ffia�wo� O REVISED REVISED } Z z } Z w� O W F CJ 0- Ir Z M ND M BF1Wf Q' A EYMIIO DD O 0 a City of Fort Collins, Colorado C) UTILITY PLAN APPROVAL (n of Z Q APPROVED: J Q W W Glr Gaze" DOSE W "� W CHEERED BY: W W Z IPm. A ww..ow UMIy Dete CHECKED BY: W m a TCW S wwtR UGRy Dine Z Z r Q CHECKED BY: lr Pmb i RVMIm pule Q CHECKED BY: Tellk GBM.M Dm. SHEET >e OF 10 DIECKED BY: BMe JOB No. 39067.17