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Drainage Reports - 10/15/2009
OF City of Ft; :Colli ppro d Plans x • V Approved By. FORT COLL '. Date JD -)g-oa UNION PLACE FINAL DRAINAGE & EROSION CONTROL STUDY for Robert Ross, MA Merten Design Studio Boulder, CO a Nolte Associates, Inc. 1901 Sharp Point Drive, Suite A Fort Collins, Colorado 80525 . (970) 221-2400 ' October 8, 2009 UNION PLACE FINAL DRAINAGE & EROSION CONTROL STUDY for Robert Ross, AIA Merten Design Studio Boulder, CO M Nolte Associates, Inc. 1901 Sharp Point Drive, Suite A Fort Collins, Colorado 80525 (970) 222-2400 October 8, 2009 PROFESSIONAL ENGINEER'S CERTIFICATION I hereby certify that this Final Drainage and Erosion Control Study for Union Place was prepared by me or under my direct supervision in accordance with the provisions of the City of Fort Collins Storm Drainage Criteria for the owners thereof Samuel M. Eliason Registered Professional Engineer State of Colorado No. 38212 i ' Union Place BEYOND ENG IN EERING Final Drainage &Erosion Control Study , ' TABLE OF CONTENTS PAGE I. GENERAL PROJECT LOCATION AND DESCRIPTION ........................................... 1 ' A. Location...............::.......................................:.......................................................I B. Description of Property ........................................................................................ 1 ' H. DRAINAGE BASINS AND SUB-BASINS.................................................................... 2 A. Major Basin Description...................................................................................... 2 B. Sub -Basin Description......................................................................................... 3 ' III. DRAINAGE DESIGN CRITERIA.................................................................................. 3 A. Regulations...........................................................................................................3 ' B. Development Criteria Reference and Constraints ................................................ 4 C. Hydrological Criteria........................................................................................... 5 D. Hydraulic Criteria............................................................................................ 5 E. Variance Request................................................................................................. 9 IV. DRAINAGE FACILITY DESIGN.................................................................................. 9 A. General Concept9 ' ................................................................................................... B. Specific Details . . 13 V. CONCLUSIONS............................................................................................................14 ' A. Compliance with Standards............................................................................... 14 B. Drainage Concept ................:.....: C. Water Quality .....:............................................................................................... 15 ' VI. EROSION AND SEDIMENT CONTROL.................................................................... 15 V11. REFERENCES...............................................................................................................16 APPENDICES APPENDIX A - Runoff Calculations APPENDIX B - Detention Pond Analysis APPENDIX C - Open Channel and Street Capacity Analysis ' APPENDIX D - Storm Sewer and Inlet Capacity Analysis APPENDIX E - Erosion Control APPENDIX F - References & Previous Studies ' MAP POCKET —Drainage and Erosion Control Plans ' 1 N:\FCB0277\Drainage\Word\FCB0277_DrainageReport_Final3.doc i I I iI - f Awl- i I ' K �� I 4 lit.____ __^--•.. i �' a•- E4 i El 0.31 059 ` am it l .v TAT.-' Ti i 'TI EXISTING ' IRRIGATION I 1 DITCH ll l INFILTRATION TRENCH SEE SHEET GR04 FOR DETAILED INFORMATION Cl DETENTION POND CA, \C1 WESTWOODy' 0.49 as nsT POND; DRIVE I _DETENTION C OUTLET AND' 4g$4-n� I I SIDEWALK CHASE I ® 11 �� 7l 024 B1 Al_� r0.23 a" 1 0 I U -- TYPE R INLETS{ .� WEST WILLOX LANE Gil _ -_. �� - GI i - , ONE 1lMl111111 �� ./ a � 1 INFILTRATION TRENCH a SEE SHEET GR04 FOR----`-'r� 1 DETAILED INFORMATION � -4 11 A II �- A2 u -REFER TO NOTE 6 FOR REQUIRED yam\ RAIN GARDEN DIMENSIONS r� ti � � �y ■II� �A ff W.S, lj� r 1 1i ('' I! 't I Basin Area C2 C100 Q2 Q100 _ Basin Area C2 Cloo Qt Q100 acres c s c s acres c s c s AI 0.23 0.26 0.58 0.13 1.01 F3 0.33 0.34 0.60 0.32 1.96 A2 0.30 0.68 0.80 0.58 239 FA 121 0.49 0.68 1.17 5.67 A3 0.31 0.24 0.57 0.14 120 F 0.20 0- 0,58 0.15 1.13 Bl 0.24 0.54 0.71 0.31 1.44 _ G1 0.41 0.51. 0.69 0.44 2.08 B2 0.58 0.40 0.63 0.49 2.70 _ G2 0.27 0.42 0.64 0.24 1.29 B3 0.28 0.36 0.61 0.22 1 1.30 _ 11 0.23 0.66 0.79 0.43 1.81 C l 0.49 0.25 0.57 0.25 206 JI 0.10 U.67 0.19 1.37 1.54 C2 0.57 0.56 0.72 0.91 4.09 J2 0.26 0.66 0.75 0.45 1.94 C3 0.07 0.06 O51 0.01 028 PI 1.53 UD6 OSI 0.12 3.52 C4 0.18 0.32 0.60 0.13 0 R4 P2 11.81 0.06 Q51 _ 0.06. 2.05 I7 0.50 0.22 0.57 Q25 2.19 P3 0.19 0.08 0.52 0.04 0.83 El 0.31 0.69 0.81 0.61 2A8 M 0.90 0.59 0.74 1.17 5.09 E2 0.77 0.36 0.61 0.79 4,66 _ U 0.3G 0.06 0.51 0.01 0.36 '.DETENTION POND SUMMARY RO,00 Stontv Swr Sb'aw aw Area of Vulac R,l .Rate 100-year Depth D, Tnp-of- Not Pord Vo1me Rmcd W8I3. Bawd.. Berm Elt, OMbt P' na- r u4.40 Pond Ln IL30 2.26 4979.86 1.10 498230 Volme candled gom u ti,.wfilat 4978.76. ]veils area in basin P3. Pond P- Reginml41 5.58 Volare caboL.td 6om bottom ofpord at 497C& Does wtid;We aea it basin P3 PoM P - Reguwl 92 5.77 Vohane caL.L w Dom bottom of,w at s- _ 4976.8. Does ik iearea inbasin P3. Pard CI 0.07 0.49 0.07 0,20 4985,71 106 N/A N/A E3 u REFER TO NOTE 6 FOR REQUIRED ' RAIN GARDEN -" DIMENSIONS .J- C3 Da 0.S B3 D I G1\ G2 r F 0.27 n.s REFER TO NOTE 10 FOR REQUIRED RIPRAP DIMENSIONS w FUTURE SPILLWAY IN INTO MASON STREET I I ; L__J MODIFIED TYPE E R INLET TYPE R ,INLET a _ _ C F H �a�f a EESb 0.2J 0.N z P3 Y N000Y0 ' a a 1� Z Y 0.19 aoe p o as WILLOX o z Y CROSSING PUD D (McDONALDS) c w o s 9 TYPE 13 0.86 am INLET a] � �_ PJ POND P OUTLET Q_ YI, TO EXISTING 18" < iv STORM PIPE c CURB CHANNEL AND PERMANENT PUMP MAY BE REQUIRED AS PER W THE DEVELOPMENT AGREEMENT IF ' + Z /, < l i POND DOES NOT INFILTRATE. SEE V Q SHEET DT04 FOR DETAILS. a Pz�'1: J . M EXISTING STORM SEWER a Lu 24" RCP PER WILLOX CROSSING PUD Z Z 1 4a O cr ;zJ1 J2 .01 Ill _ an 0 Y �, ' l 1 PLUG EXISTING Z o n>o p,28 ae9 M1 Y II McDONALDS _ a7 z �I POND OUTLET Its o P l r All`( w� ml 2 w i 1 I �P belEXISTING DETENTION POND LTOS P2 i BE RE -GRADED AS ce o.81 am l PART OF POND P Q JI J2 ! it A` I ��JIM I< �I W E NOTES W W ,. SEE SHEET CVOI & CV02 FOR STANDARD EROSION AND z SEDIMENT CONTROL CONSTRUCTION PLAN NOTES o LEGEND m 2. REFER TO SHEETS GROt-GRO3 FOR CURB CUT AND SIDEWALK i CHASE LOCATIONS 3. SEE SHEET DR02 FOR SWALE SECTIONS.% X Xpl BASIN DESIGNATION 2 - YEAR RUNOFF COEFFICIENT - PROPOSED STORM DRAIN PIPE .. to n �9 R - BASIN AREA (ac.) i 10D - YEAR RUNOFF COEFFICIENT s 4. STORM SEWER AND INLET SIZES FOR REFERENCE ONLY. REFER _ - O PROPOSED STORM DRAIN INLET o S$ TO SHEETS SDO1 AND SD02 FOR STORM SEWER AND INLET SIZES. a all! M BASIN BOUNDARY - -Jt21- EXISTING 1 CONTOUR,' gP 4 5. REFER TO SHEET ECOI FOR EROSION CONTROL o m W 31 6. ME ROOFTOP OF EACH TRIPLEX GAGING URBAN PRAIRIE STREET •••••�•• FUTURE SPILLWAY - -5190- EXISTING 0 CONTOUR m ss a (LOCATED IN BASINS 82 AND B3) SHALL DRAIN TO A RAIN - -st24- PROPOSED 1' CONTOUR 1 WCE w n A BB GARDEN(5)'T IS AT LEAST 66 SWARE FEET, WITH A MAXIMUM THA DEPTH OF 6•. ® DESIGN POINT -5130- PROPOSED 5' CONTOUR City of Fort Collins, CO1078d0 7. RIPRAP DOWNSTREAM OF ALL STORM SEWER SHALL BE A 0 EXISTING STORM MANHOLE (PPIId1'Y PLAN APPROVAL MINIMUM SIZE OF TYPE L (9• MEAN PARTICLE SIZE BY WEIGHT) FOR _ ---► PROPOSED FLOW DIRECTION , A MINIMUM OF 8 FROM THE END OF FLARED END SECTION UNLESS A EXISTING STORM DRAIN INLET APPROVED: - LABELED. WRAP RIPRAP AROUND FLARED END SECTION Ala ^f , PROPOSED SWALE CROSS SECTION � EXISTING STORM DRAINPIPE I plJ 6Y�nca Date ACCORDING TO THE RIPRAP DETAIL ON SHEET DT04. . t ° T��jiItl -`ly-I PERMEABLE PAGERS EXISTING STORM DRAIN FES CHECKED BY: Tatar t Leknta Utility Date iTt `' .' CHECKED BY: numnatter Utility Date PERMEABLE PAVEMENT. DR01 1 °n ff rntxtEr CHECKED BY: Pub J, Deemtion Date 6 v 40 �a1rs 2' TO 6• ROCK RUBBLE '•arw/axa oecma CA - (SEE SHEET DT04 FOR DETAILS) wro CHECKED BY: 1E1MALALL1 0 - Tra18e blamear 'Date hw;Erwbk.� r•_40' TYPE L RIPRAP I HOES NOT 0 FO -APWMA(3Y M PlANS. - (SEE SHEET DTDI FOR DETAILS) I SIM PDa11T1EE E I¢maxsmE raa AC°mACY wp. caunErDaEss a Rtu+s CHECKED BY: .re xuxlnR _ Date F090277 I LIMIT DEPTH OF ROW 12' 2;� LANK ASPHALT/ CURB & CONCRETE PAVEMENT GUTTER SECTION Al N.T.S. UNIT DEPTH ROW 1 8' 2x 2x LAWN ASPHALT/ CURB & CONCRETE PAVEMENT GUTTER SECTION B1 N.T.S. LIMIT DEPTH OF ROW 2X - „• 4.5' 2x x SIDEWALK SEE DETAIL 4.5' 2 THIS. _ - - SIDEWALK -- SHEET ASPHALT/ CDNCRETE SEE DETAIL PAVEMENT CU«„�R I THIS SHEET SECTION C4 N.T.S. LIMIT DEPTH OF ROW 18' D;� 3x ax LAWN ASPHALT/ CURB & CONCRETE PAVEMENT CUTTER SECTION E1 N.T.S. LIMIT DEPTH OF ROW 2X 10 26' TO EDP (TYPICAL) 2x 15' 4.5' SIDEWALK 2;� !S.y �24 4W . 6:\ �/ 4.5' SEE DETAIL SIDEWALK SIDEWALK SHEET ASPHALT/ CONCRETE CURB AND SEE DETAIL PAVEMENT ` ASPHALT/ GUTTER 1 THIS CONCRETE PAVEMENT CURB & SHEET GUTTER SECTION B2 LIMIT DEPTH OF ROW a4• zx --m- zx 4.5' 4.5' SIDEWALK SEE DETAIL CURB AND ASPHALT/ CONCRETE SIDEWALI( 1 THIS GUTTER PAVEMENT SHEET SECTION 133 •J LIMIT DEPTH OF ROW Iz.7' 2x zx MIN. FAIN. 2x 2% CURB & GUTTER ASPHALT/ CONCRETE PAVEMENT SECTION C2 SECTION E2 TO EDP (TYPICAL) 7,V 5' 2x 4.5' 1.0, SIDEWALK ASPHALT/ CONCRETE PAVEMENT CURB & GUTTER SECTION E3 52 -�I 2-4x a ASPHALT/ 9DEWALK CONCRETE PAVEMENT CURB & GUTTER SECTION E4 & G1 REFER TO OPEN yriay CHANNEL/STREET- CAPACITY TABLE ; THIS SHEET SECTION Mel, B4b, B4c N.T.S. 4.5' SIDEWALK CURB WITH CURB CUT \ Q ALLOWABLE DEPTH OF FLOW = 0.75'�'5' DETAIL 1 f� 2.75' 2.75 45�55•, - DETAIL 2 N.T.S. wabk Cakuh l Opm Chw-USh Scion SmtiDn BwtKs) I33'Qjro Dopth of lonqudiul Sbpc Crass Slop.of rkpth Note Fbw Fb .. t % t 12'Aky S.tvowiIh R.2m Cuff AT AI-A2 3.1 0.36 0.6 3% 0.31 7-A3 5.2 0.36 0.6 3% 0.35 16' Aky Section wih R.Ibe Cwb BI BI 1.9 0.32 0.6 2% 0.21 EI EI 3.3 0.38 0.5 2.4% 0.29 B2 BI-B2 '5.3 1 0.6 2%b Sbook 6:1 ad 0.59 Urban Praae Stoo, 41 inSwak B3 B3 1.7 1 0.6 0.42 C4 C4 1.1 0.5 066 5s1am4.51 0.45 15'1.w Crown Aky C2 CI-C2 6.6 0.30 Assutm Pond C I a 0.56 0.6 2% b Swale Section belwem UAon Pnab li4a B, C 14.1 1.18 0.6 5.8.1 0.94 'Ibn Sstbn Von. Slrt I and Q:ktlbn Pohl PAh B, C 14.1 1.9 0.6 41 0.97 ihruuoSwab A4c B,C 14.1 0.95 0.6 14.4:1 an:1 d 20 0.96 Swale SeClmi Sowh Silt.fCnan 2% inStrcd, 4.5:1 and 100yr0uwnoy I.fSlrea EI-F2 8.9 11.59 0A 6:1 bawak U.36 ivda .wmak Swale Scdioo Sowh Sid,.MGen 2% b Street, 10:1 aid LcafSvcw F3 RbP3 M7 0.72 0.6 5:1 bawab 0.67 SoW SikofW&XLe E4 E4 7.5 6"owrcmxn 0.46 2% 0.60 SoMh SBCofW&.I. GI 2.8 6^aw;rc "o 0.5 r/o 0.43 City of Fort Collins, Colorado UTIMTV PLAN APPROVAL APPROVED: City b&- Date CHECKED BY: Lla ! ►aMaatu atlT1q t Dab CHECKED BY: SGTnwda DtWq Date CHECKED BY: Parb kRaeTntlm Deb CHECKED BY: naGc bsium Dab CHECKED BY: Dab Wz U g Q ~ J co a w Z O z Z cc 0 I1]:11iea SCA E Wxncu: t-.n tn@Mm t-.n o ' of e III $' Ira! i g l 1 aX Tr I. B3 g 6i II` 1 J a. L Sari WEST WILLO% LANE -Aa IP. - - __ IP IP I i - I p ^ I B ( 985 m 9B4 / I I \ 9 a g0 i 90 k I I I I '9MJ a —L--------- — _--- 1Weuox 1, \ ` - CROSSING PUD ITIP s GREEN ST. �\ (MGDONALDS) fl 9a / BE f -- , --F --rtr- / G Igo -Y99 - /----------� - LPL 9e ��\ 1 Si, I II 1 I m i — LFAf a SW I� Exlsnluc SIB I I IRRIGATION DITCH I�I I I 1 �� I�•-__GRE-_LEYI I TE A : EA EMEN T SF -` - I ,m `CONTRACIQR I'D j4 `w C T EXIS+',L71N ULS DUN OTKAC DNSUCTION WEGTWO gIG_�, I CTR.,,,y�• afilllVE se I9B7 I � I :--------- ._- ,. .-I. eA., \ // �I DETENTION POND P 4 A%.I DO NOT 1 _ _ _ DISTURB LRSAN PRAWE ST. BA \ / _ _ I I EXISTING q / U\ I I �• /; `it. N 60 PNND L I{I STAGESIO 1 I I `1 l : GRADING F w ! V AAT - It. z m gACTIV1TIES T' qe•., 1\ \..• ii '." z T I ES I I I mV : I i t 11 11 , x• 11 � I I I DO I lilt I \ I I � I I l i 9B2 _ 98 SF SF General Notes: SF SILT FENCE 1. The maximum tributary area is limited! to 0.25ac es per 100 feet of fence. 2. Inspect and repair fence after each Steel storm event. Remove sediment when StPost Filler Fabric one half of the height of the fence has WOSt been filled. Removed sediment shall be deposited in n a tributary to a sediment bosin orother filtering measure. BOCkfilled TrMCh 1/2' ® STRAW WATTLES - CONTRACTORS TO INSTALL WATTLES PER NANUFACTURERS SPECIFICATIONS filter Fabric W SLDPES. WATTLES $ROTA➢ BE -6' M. WATRE AFTER 3'- Altacll $eNrelY INSTALLED W CONTOUR WITH A $yDIyI \ 1 1 BTIACXCDpF STAKES HEFD018E to POYI DOWNWARD ANGLE AT THE END OF ME 1�I' \ (1.2m) Steel ROW !N ADDER i0 PREIENI COWING AT �,�E\ / O \ TAMPED UNTIL WRF/IROPE IS SHDG Wood Po31\ ME MID-YCDON A \ J' ��$Va�� 1\ 0 /1 W/ WATTLE Compacted BOckfill RUNNING LENGTHS OF WATTLES SHOULD BE ABUTTED FIRMLY TO ENSURE NO \ LEAKAGE AT THE ABUTMENTS, '1 Runoff L SPACING - DOWNSLOPADJACENT ROLLS SHAL .. P SECTION VIEW VEHICLE TRACKING CONTROL AMICµ SPACING FOR SLOPE INSTALLATIONS SHOULD BE \ _ TIGHTLY AB DETERMINED BY S'TE CONDITONS: SLOPE GRADIENT AND 1 SOIL ME ME THE MAIN FACTORS. A GOOD Approximately PULE-OF-iHUNB IS: T� 4 X4' french I SLOPES - 10 FEET APART 21 SLOPES - 20 FEET APART 3A SLOPES - 30 FEET APART y 1 0;1 SLOPES . 40 FEET APART, ETC. HOWEVER, ADJUSTMENTS MAY WINE 10 BE MADE FOR THE SOIL TYPE: FOR SOFT, LOAMY SOILS - ADJUST THE ROWS CLOSER TOGETHER; FOR HARD. ROCKY SOUS ADJUST THE ROWS NRiLER MART. INSTALLATION (A) WHEN INSTALLING RUNNING LENGTHS or WATTLES. BUTT ME SECOND WAITLE SIGNA Y AGAINST THE FIRST. DO NOT OVERLAP THE ENDS. STAKE THE WATTLES AT EACH END AND FOUR FONT CN CENTER, TOP EXAMPLE: P 25 Fair WATTLE USES 6 STAKES A 20 FOOT WATTLE USES 5 STAKES A 12 FONT WATTLE USES 4 STAKES STAKES SHOULD BE DRIVEN THROUGH ME MIDDLE OF THE WATTLE, LEASING 2 - 31NCHES OF THE STAKE PROTRUpNG Ali ME WATTLE. A LAW SEGMENT LOAD WILL TEND TO PICK THE WATTLE UP AND COULD PULL IT OFF THE STAKES IF THEY ARE DRIVEN Dam iW LOW. IT MAY BE NECESSARY TO MAKE A HOLE IN THE WATTLE WITH THE PICK END Cr YOUR MADDOX IN ORDER TO GET ME STAKE THROUGH THE STRAW, WEN STRAW Wr.lilEi ARE USED FOR FLAT GROUND APPLICATIONS, DRIK THE STAKES STRAIGHT 00WJ: MIEN INSTALLING WATTLES an SLOPES. DRRE THE STAKES PERPENDICULAR TO THE SLOPE. DRIVE TFU FIRST END STAKE Cr THE SECOND WATTLE AT AN ANGLE TOWARD THE FIRST WA11UE W ORDER TO HELP ABUT THEM TIGHTLY IOGEMEL IF YOU HAVE DIFFICULTY DRINNG THE STAKE INTO EXTREMELY HMO OR POCKY SLOPES. A PLOT BAR MAY BE NEEDED TO BEGIN THE STAKE HC E. STAKING: WE RECWMEND USING rW STAKE $, w 1/2' 10 5/8' REBAR, TO YWRE THE WATTLESBE SAKE TO USE A STAKE 'HA11S LONG ENWLN 10 PROTRWE YHRAL INCHES MORE THE WATTLE: Ir IS A LWO LENGTH FOR HARD. ROCK SOL FOR SOFT, LOAMY S0. USE A 2. $LANE FOR fJ2EAlER YWPIIY. THE OIAYERR OF THE STAKE $IIWLO BE APPPOAMI.if LY 1' Ew EASE Of MINING TNRWw THE WATTLE. IP INLET PROTECTION — GRAVEL LCtA�tIV V ass = B Dos _ O PROPOSED INLET FILTER ' O STRAW WATTLE BEa C B 5 sod 1 ---o-- SILT FENCE ESBA C VEHICLE TRACKING CONTROL `a0<' €� s --a99i-- EXISTING 1' CONTOUR W BSSo pbc. --ogaD-- EXISTING 5' CONTOUR IQ� EBB i PROPOSED V CONTOUR PROPOSED 5' CONTOUR 4 'Ou-4980— NODl1V0 " PROPOSED STORM PIPE O PROPOSED STORM DRAIN MANHOLE - O EXISTING STORM PIPE r 0 EXISTING STORM MANHOLE tD W EXISTING STORM DRAIN INLET O of e0 0' EXISTING STORM DRAIN FES W 1 LochNOTES m' 1. BEE SHEET CVD2 FEW STANDARD EROSION AND BECMENT COMITUX CMTRUCTIM NOTESL N 2. DETENTION POND P CAN ACT AS A TEMPORARY SEDIMENT POND WRING ULS 1— CONSTRUCTION. ME CBNTRACTOR SHALL INSI ME POND EVERY 1W0 Z Q WEEKS OR AFTER ANY SIGNIFICANT STORK EVENT AND MAKE RPAIRS OR C.EA11 CUT SEDIMENT AS NECESSARY. Q O W d SEED, MULCH, & FERTILIZER SEED MIX (ALL DISTURBED AREAS - EXCEPT AS NOTED ON LANDSCAPE PLAN) J ME FOLLOMTNg MIX RATER ARE FW DRILL SEEDING AND MILL NEED TO BE DOUBLED Q O FOR NWROSEECING ON BRMOCAST SEEDWG CC SPECIES SCIENTIRL NAME VARIETY x OF MIX LB/AC. PUS J Buffdograss BuNla docf older Tseako 444 8.4 Western wheotgress PaacaoJrvm IMN Amba 228 4.3 ^ ErrV r Z Slender WM1eatgrass ET X fmMJaaWule San Lub 159 3.0 Stints grams S.Wwouo curfoinds. Vaughn 13.2 2.5 O ' Blus gram. BautNwP y.a,, Hachlta 32 0.6 Sane dropseed SpyMou, XDtanWr O5 0.1 V � SssdMg rat-19.8 Ib/H., PLS Z O SEED MIXTURES FOR SITES WM DISMNCTNE SOIL PROBLEMS M.G., ALKALINITY. SALINHY OR HIGH WATER TABLE) SHOULD BE DEVELOPED BY A O TRAINED SPECIALIST. MULCH (ALL DISTURBED AREAS) co ONE OR MORE OF ME FOLLOWING MULCHES SHALL BE USED WM A PERENNIAL DRYLAND CRASS SEED MIXTURE, 0 ACCEPTABLE W EX _ MULCH DATES Cf USE APPLICATION RATE Z STRAW OR HAY AN. 01 - DEC. 31 2 TONS/ACRE z HYDRAUUC W PLI MAR. 15 - MAY 15 3/4 TONS/ACRE 1— 1— EROSION CW ROL - (MATS M BLANKETS) JAN. Cl - OEG 31 NOT APPLICABLE HAY OR STRAW MULCH SI GE THEE M NOXIOUS WEEDS AND AT LEAST SOUL OF ME RBER SHALL BE 10 INCHES W MORE W LENGTH. WEN SEEDING 2 T WIM NATW CHASMS, HAY MOM A NATINE GRAM IS A SUGGESTED 0 MULCHWG MATERIAL• IF AVNLABLE M. FERTILIZER REQUIREMENTS (ALL DISTURBED AREAS) UJ 1. STIES WILL BE FPTUZED ACCOFGNG TO LABORATORY SOIL ANALYSS 1 AND RECOWIENDATNXI. W 2. IF APPROKD BY ME CITY C FORT COWNS, IN ABSEN(£ OF A SqL ANALYSIS. A MINIMUM OF 4U POUNDS W AVNLA9LE INTERVIEW AND 4U a POUNDS CIF AVNUBtE PHOSPHORUS WLL BE APPLIED PER ACRE. a$ `alb Inlet CONSTRUCTION SEQUENCING $ � — Naalsal uA,m• so sueammx scrum Peas a - 4PD,3 M mRLtm M 'TA'e aw'. _� Gravel Filter r m (Approx. 3/4_ MAtM WI[i1CATlr6 m MI r9NOLm SpdKI1E SLAY IEOIQ 4lYTIM A 1[•A z06YL FA N'MOVµ 89 THE gtt Diameter) Wre Scresn Concrete (Approx. 1/2" Mean) Block O .0.G wood Sue A Wire Screen 'cravel Filter PLAN VIEW YW PN60T GIIWID MIND FROaIMI CO3iR0. SO L Rpg11NG PEbYERR BARROR AMXTONAL BARRIERS IEGUOUTIE METHODS SOL VAI OTHER RAINFALL EROSION CCWTR0. SRNCNRµ SEDWUNT TRAP/ BASIN INLET TIMES STRAW LAMORS FE SILT NCE BARRIERS SAND BAGS BARE SOL PREPMATM COMPNRROM9 TTR40NG ASPHALT/ CONCRETE PANNG OTHER 1EEETATK: PERMANENT SEED PLANTING MULCHING/ SEALANT T:MPORMY $EEO PUNTING Sao INST4 LAVON NETTNGS/ MATS/ BLANXM OTHER LL W O se W y LL sa y z �s O W 0 n H � I Y oversaw WATTLE "A WATTLE ':5 General Nate,: FBtered Runoff Wo,er City of Fort Collins, COIOTedO I. Inspect end repair filters Offer each UTILITY PLAN APPROVAL BALING MIRE ON 9farm event. Remove sediment when INSTALLATION Nnw ROK one half of the filter depth has been Wire Screen APPROVED: filled. Removed Sediment ,boll be de- ` city (it.) Dttr Dale (B) STAKES SHOULD BE DRIVEN ACKM TRW EACH OTHER AND w EACH SIDE OE WATTLE. posited in red tributary to a sedi- 2•X4 Wood SIUtl \` 4-6- OF STAKE PROTRUDING ABOVE THE WATTLE. SAILORS WIRE w NYLON RCPE ment baain orotherfiltering measure. Curb Inlet SHOULD BE TIED TO STAKES ACROSS WATTLE, STAKES SHOULD THEN SO DRIVEN IN UNTIL 2 Sediment and gravel Shall be immediately CHECKED BY: BALING WRE w NYLON ROPE IS SUFFICIENTLY DRUG 10 THE WAFFLE. removed from traveled way of roam. SECTION A -A fifer k Wastewater UtWry Date WHEN INSTAWNO RUNNING LENGTHS OF WATTLES, 10 PREIEM SHIF1WG, BUTT THE SECOND WATTLE NCHTLY AGAINST THE DRST. DO xor DiMi THE ENDS. STAKES SHOULD BE DRIVEN I ET ERO0 CND. ACRSM To.. AND w EACH SHE OE WATTLE LEANING 4'-B' OF CHECKED BY: STAKE PflOTRVGNG ABOVE THE WATTLE. BµNG WRE OR Nnw ROPE SHOULD BE TIED $IDrlpwatR DtlI1L] Date TO STAKES IN AN HOUR GLASS FORMATION IFRwT TO BACK DE WATTLE 'A ACROSS 10 FRONT OF WATTLE 'B', ACROSS 10 BACK AND BACK 10 FRONT Cr WATTLE -A'). STAKES CITY DF GREELEY SRWLD THE BE ORIKN IN UNTIL BATING 'HE ON NYLON ROPE IS SUFRCMTLY yNG 10 CHECKED BY: ME w4rnE. mawrm eT Puke t Recreation Date WATInRWa o M � CHECKED BY: RENEW DOES NOT CONSTITUTE 'AR OVAL' a PLANS Tie En&ear Date PERMITIEE KS IRESPO19BfE FW ACCURACY AND CDNPLETENESS OF PIANs I CHECKED BY: Date EC01 4 or 40 SKI SCALE Ml J. N/A HORIZONTAL' 1'.30' N. T. S. NO�E Union Place ' B E Y O N D E N G I N E E R I N G Final Drainage & Erosion Control Study - I. General Location and Description A. Location The Union Place site is located in the Northeast Quarter of the Northeast Quarter of Section 2, Township 7 North, Range 69 West of the 6 h Principal Meridian to the City of Fort Collins, Larimer County, Colorado. The site is located immediately south of Willox lane, west of Willox Crossing ' P.U.D. (McDonalds / gas station) and College Avenue (US 287), north of a trailer park, and east of a residential subdivision. The future Mason Street corridor runs north -south through the site near its eastern boundary. One of McDonald's detention ponds is currently located in the very southeast corner of the site. A significantly larger future regional detention pond will also be t located in the southeast comer of the site. Refer to Section IH.B below regarding the McDonald's pond and the future regional pond. There is an irrigation ditch running along the northern and western property boundaries. B. Description of Property t The Union Place site (referred herein as "the site", "this site) is approximately 10.3 acres in size that will be developed into residential and commercial lots with associated utilities and streets. The developer for the Union Place project wishes to create a sustainable, low -impact project. According to the Low Impact , Development Center's webpage "low Impact Development is a new, comprehensive land planning and engineering design approach with a goal of maintaining and enhancing the pre -development hydrologic regime of urban and developing watersheds." Examples of reducing and possibly eliminating stormwater runoff include a series of: ' • Bio-swales • Rain gardens ' • Tree wells • Permeable pavements and sidewalks ' • Flat and shallow detention ponds • Xeriscaping (which leads to a reduction in water supply) t This project proposes a comprehensive approach in planning, engineering, and landscaping to create an environmentally sensitive approach to land development. Except for Willox Lane and Mason Street, the site contains private streets in order to achieve these goals and not conflict with City standards and maintenance requirements. As part of the preliminary study for the project, the site was graded to surface drain almost all of the runoff to the inverted alley crowns (which could 1 N:\FC60277\Drainage\Wmd\FC80277_Dminag epcm FinaB.dce ' NOLTE Union Place ' BEYOND ENGINEERING Final Drainage &. Erosion Control Study be turned partially permeable with the use of porous pavements) or road -side swales while still providing curb and gutter and an "urban feel." As part of this final study, the LID techniques have been incorporated into the design. The following is a summary of the existing conditions: Ground Cover - The site doesn't currently contain any buildings but there are existing utilities to the site that once serviced a residence. The existing ground cover consists mostly of weeds, native grasses, and past agricultural crops. Grades - In general, the majority of the site slopes southeasterly at an approximately 0.6% slope. Soil Type - According to the NRCS Web Soil Survey, the majority of the site consists of Nunn clay loam, 0 to 1 percent slope (Soil Type Q. According to the Subgrade Investigation and Pavement Recommendations Union Place . West Willox Lane Fort Collins, Colorado by CTL Thompson Incorporated., "the results of infiltration tests indicate design infiltration rates ranging from 0.5 to 1.5 inches per hour with a design average infiltration rate of 1.0 inches per hour ... it appears the majority of the site would be suitable for stormwater detention or retention underneath pervious paving." According to the same study "ground water was measured at depths of about 5 to 6 V2 feet below existing grades." Irrigation - There is an irrigation ditch running along the northern and western property boundaries. There are no known wetlands within the site. Utilities - An existing sanitary sewer main runs south -north paralleling the west property boundary. It turns easterly about 115-120' south of Willox Lane ' centerline and parallels Willox lane through the site. Two City of Greeley waterlines traverse the northeast comer of the site. Detention Ponds and Storm Sewer - One of McDonald's detention ponds is currently located in the southeast corner/bumpout of the site. A stubout from the McDonald's site has been provided to the Union Place site to accept historic flows. ' H. Drainage Basins and Sub -Basins A. Major Basin Description According to City personnel, this site was removed from the floodplain by the Dry ' Creek Flood Control Project. The site is in the Dry Creek basin where the 2-year historic release rate has been specified as 0.2 cfs/acre. 2 1 N:kFCB02770minapNWordTCB0277_DminapRepott_ bml3.doe ' NOLTE Union Place ' B E Y O N D E N G I N E E R ING Final Drainage & Erosion Control Study ' B. Sub -Basin Description Historically, the runoff from this site directs flow southeasterly to a proposed flared end section and storm pipe designed by the Willox Crossing PUD (see below). The Willox Crossing PUD is elevated higher than this site which has created somewhat of a berm along Union Place's eastern property boundary. ' Runoff is collected in a very flat pan at the bottom of the "berm" on the berm's western side that directs runoff southerly where it is captured at a slight low point at the flared end section near the Willox Crossing PUD Pond #1. The flows from the emergency spillway for Pond #1 are directed onto the Union Crossing site. Refer to section lH.B below for more explanation on how Willox Crossing PUD affects this site. ' The information provided to Nolte Associates, Inc. by the City of Fort Collins from Ayres Associates shows that offsite runoff of approximately 19 cfs from the ' west represented by Basin 306 enters the trailer park south of the site and then flows northerly onto the site. However, after conducting a site visit, we believe that this offsite flow actually stays on the trailer park and does not redirect ' northerly. Ayres Associates also show offsite runoff from the north from Basins 405 and 305 with a combined flow of about 168 cfs. These offsite flows will not need to be detained, however the flows from the north will need to be passed ' through the site. This majority of the site proposes to direct runoff to a detention pond (comprising of three basins) located in the east and southeast corner of the site. As Mason Street is being required to be constructed and there is very little useable space between Mason Street and the eastern property boundary, this "unusable" space ' will be used for detention that will also integrate the existing Willox Crossing PUD detention Pond #1. The release rate of the proposed pond will not exceed that set by Willox Crossing.PUD or 0.2 cfs/acre, whichever is less. A smaller detention pond is proposed near the western property boundary. Detention will also be provided under some of the permeable pavement. III. Drainage Design Criteria A. Regulations The design criteria for this study are directly from the City of Fort Collins Storm Drainage Design Criteria and Construction Standards Manual and the Urban Storm Drainage Criteria Manuals. Volumes 2, and 3 (referred to herein as USDCM). Nolte Associates, Inc.'s understands that the City of Fort Collins is currently revising its Storm Drainage Design Criteria to follow that of Urban Drainage. Therefore, the USDCM has been used as a reference for runoff calculations with City of Fort Collins rainfall intensities. 3 N:\FCB0277TkainapkWord\FCB0277_DrainageReport_Final3.dce BEYOND ENGI NEGRI N G Union Place Final Drainage & Erosion Control Study B. Development Criteria Reference and Constraints This site has been included in the North College Drainage Improvements Design Alternative Analysis Report, by Ayres Associates, dated February 2006. The following is a summary of this study that affects this site (reference is provided in the Appendix): . • As part of this Study, regional Pond C from Alternative 2 is proposed in the southeast corner of the site. According to City personnel the site will be required to provide onsite detention for the proposed development. As part of the regional improvements, the pond will be deepened (with a proposed storm sewer) and enlarged if necessary. If the regional needs are greater than the development requirements, the City would purchase the difference. According to the study, Pond C would need a surface area of 2 acres and approximate depth of 5.5 feet, or 5.56 acre-feet. The estimated pond bottom elevation is 4976.80. • This site is located in SWMM model Basin 307. Runoff from north of Willox Lane represented by Basins 405 and 305 (total combined flow of ' approximately 168 cfs) will enter the site near Mason Street. Runoff from the west (approximate flow of 19 cfs) is represented by Basin 306 is assumed to enter the southwest corner of the site. (However, after ' conducting a site visit, the flows to the southwest corner of the site are believed to stay on the trailer parr and not be directed back onto the Union Place site). ' This site has been included in the Final Drainage Report and Erosion Control Study for Willox Crossing Final P. U.D. McDonalds/Amoco Site at Willox Lane ' and College Avenue, Fort Collins, Colorado by R & R Engineers -Surveyors, Inc., dated October 7, 1998 (referred to herein as McDonalds or Willox Crossing PUD). The following is a summary of this study and plan set that affects this site (reference is provided in the Appendix): • The McDonald's Study used an older version of rainfall intensities. ' • The McDonald's detention Pond#1 is located in McDonald's Basin F which accepts runoff from McDonald's Basin A (western portion of the ' McDonalds site). Basin A and Basin F are 0.856 and 0.331 acres, respectively. Basin A has 0.173, 0.639, and 0.044 acres of landscape, pavement, and rooftop, respectively. Basin F is landscape. ' • The Union Place site is located in McDonald's Basin OS-1. Total 100-year runoff to the flared end section (connects to a manhole that also discharges ' Detention Pond #1) is 4.56 cfs. • Detention Pond #1 was designed to discharge at 0.11 cfs. The emergency spillway for the pond was directed westerly toward the flared end section 4 N:\FCB0277ThaiB \Word\FCB0277_DrainWReport_Final3.doe NOLTE Union Place BEYOND ENGINEERING Final Drainage & Erosion Control Study in Basin OS-1 to provide a second chance to enter the storm system before causing nuisance flows to neighboring properties. In the event of a significant event, runoff would eventually pool and discharge to the trailer park. In order to better protect that facility, Willox Crossing PUD proposed to re -grade some of the pasture area and route the flows through the 18" RCP and flared end section located west of detention Pond #1. C. Hydrological Criteria In accordance with the Fort Collins policy, a minor and major storm for the Fort Collins area is identified as the 2-year and 100-year storms, respectively. A major storm for the Fort Collins area has a recurrence interval of 100 years has a peak intensity of 9.95 in/hr. These storms have been used as a basis for planning and system design. The peak flow rates for design points have been calculated based on the Rational Method as described in the USDCM with storm duration set equal to the time of concentration for each sub -basin. This method was used to analyze the developed runoff from the 2-year (minor) and the 100-year (major) storm events assuming Type C soils. The Rational Method is widely accepted for drainage design involving small drainage areas (less than 160 acres) and short time of concentrations. The Rational Method is ideal for storm sewer sizing and small detention pond sizing (for tributary areas no larger than 90 to 160 acres). Runoff coefficients were assumed based on impervious area and soil type and are given in Appendices. Figure PP-1 in the USDCMwas utilized to reduce the effective impervious area for basins with permeable pavement. Following the geotechnical engineer's recommendation, underdrains are assumed to not be needed. D. Hydraulic Criteria The developed site will convey runoff to the detention ponds in a safe and effective manner via curb and gutter, swales, concrete pans, and a small amount of storm sewer. Runoff will be also allowed to infiltrate with the use of permeable pavements and infiltration trenches located in several of the basins. Detention Ponds The majority of the runoff produced by the site will be conveyed to the proposed detention pond (Pond P) located in the southeast comer of the development. Additional storage is also provided in Basins C2, A3, and D under the porous pavement. A small detention pond is also located in Basin Cl. 5 N.\FCB027TDminap\WordTCB0277_DramapReport FinW3,doc NO437E Union Place BEYOND ENG IN BERING Final Drainage & Erosion Control Study Detention Ponds C 1 and P were sized utilizing the Rational Formula -Based Modified FAA Procedure (assuming the required pond volume is maximized at 120 minutes or less). Pond P will have a minimum of 1.0-feet of freeboard. The release rate for Pond P was set at 2.26 cfs so as not exceed the minimum of either: • 0.20 cfs per acre of onsite area runoff (0.20 x 11.3 = 2.26) (off -site runoff will be directed over the spillway). • 4.67 cfs (4.56 cfs plus 0.11 cfs) given in the' Willox Crossing PUD study as allowable release into the flared -end -section designed for Basin OS-1 and the Pond #1 release rate. Refer to Section N.B. below and Appendix B for detention pond calculations and summary. Inlets This site has been graded to minimize storm sewer and inlets. Instead, open channels (swales), curb -cuts, and sidewalk chases have been utilized as much as possible. However, where required (such as Willox Lane), street inlets are Type R curb inlets or Type 13 combination inlets. The 5' Type R inlets were analyzed assuming 12% clogging. The Combination Type 13 inlets were ' analyzed assuming 50% clogging on the grate and 10% clogging on the curb opening. Area inlets were analyzed assuming 50% clogging. The following assumptions were made in the inlet capacity analysis: • For storm Line SD-01, the 5' Type R inlet in West Willox Lane (SDI- E4) was sized for the 100-year runoff for Basin E4 (offsite runoff from the north is assumed to bypass the inlet). The grated manhole in Basin E3 (SDI-E3) was sized for the 2-year storm. ' • For storm Line SD-03, the Type C area inlet has capacity for the 100- year storm although the storm line was sized for the 2-year storm (see below). • For storm Line SD-04, the 5' Type R inlet in West Willox Lane (SDI- H) was sized for the 100-year runoff for basin H (offsite runoff from the north is assumed to bypass the inlet). • For storm Line SD-06, the 5' Type R inlet in West Willox Lane (SDI - GI) and the single Type 13 combination inlet in Basin G2 (SDI-G2) were sized for the 100-year runoff for Basin G 1 (offsite runoff from the north is assumed to bypass the inlet) and Basin G2, respectively. Refer to Appendix D for inlet analyses. 6 N:WCB02770mmageMordTCB0277_DmmageReport_Fina13.doc NOLTE Union Place BEYOND ENG IN EERING Final Drainage & Erosion Control Study Storm Sewer The following assumptions were made in the storm sewer analysis: • The starting tail water surfaces for lines SD-06 and SD-01 were set to the estimated future 100-year water surface elevation of 4981.30. These pipes were sized utilizing Bentley Systems' StormCAD for the 100-year storm for onsite runoff (offsite runoff from the north is considered to bypass the inlets). • Storm Line SD-02 between Basins PI and P2 was sized so that it could function as an equalization pipe now and in the future. • Storm Line SD-03 was sized as a culvert for the 2-year storm. Runoff in excess of the 2-year storm will overtop the alley and flow to the detention pond. • The starting tail water surface for line SD-04 was set to the estimated future 100-year water surface elevation of 4981.30. This pipe was sized as a culvert for the 100-year storm for onsite runoff (offsite runoff from the north is considered to bypass the inlet). • A small pipe (12" PVC) was placed over the. Greeley Waterline. Runoff in excess of the capacity of this pipe will flow via the existing concrete pan along the east side of the site. Refer to Appendix D for storm sewer analyses. Street Capacity Except for Mason Street and Willox Lane, streets within the site are private and will not be designed to have a crown. The following street sections are found in the development: • Green Leaf Street and Urban Prairie Street are cross -sloped to drain to curb and gutter with curb cuts that will allow the runoff to enter a depressed landscape strip or bio-swale between the street and detached sidewalk within the tree lawn. • The alleys (noted as private drives on the plans) west of Blue Sun Street will be cross -sloped southerly to a rollover curb that will convey the runoff easterly. • The alley east of Blue Sun Street that discharges to Urban Prairie Street will contain an inverted crown with roll-over curb on both the north and south edges. This alley will have a 4' wide pervious pavement strip down its centerline that will collect stormwater and then disperse it to the 30" gravel layer underneath the entire alley width. 7 N:\FCB0277Dmft ge\WordWCB0277_Dm iWReport_F=B.doc NOLTE Union Place ' BEYOND ENGINEERING Final Drainage & Erosion Control Study • The alley adjacent to Detention Pond P is cross -sloped to discharge to Detention Pond P. This alley will consist of permeable pavement that will collect stormwater and then disperse it to the 3' gravel layer underneath. Utilizing F1owMaster, all private street sections were analyzed as open ' channels to convey 133% of the 100-year runoff. Refer to Open Channels below for capacity of private street sections. ' Public street capacities for major flows will be analyzed using Manning's Equation for channel flow. Assuming an allowable 6" of crown overtopping per City of Fort Collins Storm Drainage Design Criteria and Construction Standards Manual, estimates of the capacity of Willox Lane and Mason Street to convey the offsite runoff from Basins 405 and 305 have been included Appendix C. Willox Lane was analyzed assuming flows from Basin 405 only ' (about 74 cfs based on area of Basin 405 to the total area of Basin 405 and 305). The structures on the south side of Willox Lane will need to be elevated to be out of the depth of flow within the street. This will require that the finished floor elevation of all buildings be elevated at least 14" above the adjacent sidewalk on Willox Lane. ' Omen Channels 'Streets within the site are private and will not be designed to have a crown. Instead, they are typically cross -sloped to drain to curb and gutter with curb ' cuts that will allow the runoff to enter a bio-swale between the street and detached sidewalk. A typical section includes 4:1 and 6:1 side slopes (starting ' at the bottom of the curb) and a 1.0' wide bottom for a total of a 5.5' wide swale at 0.75' depth between the sidewalk and street curb. However, the street is also allowed to convey the difference between the major and minor storm events and therefore the allowable open channel section includes the 2% street cross -slope. Manning's coefficients of 0.04 and 0.016 were utilized in the landscaped and paved areas, respectively, to analyze the capacity of the swales/streets. The open channels (swales and streets that direct runoff to swales) within the ' project have been sized to convey 133% of the 100-year runoff. The swales have been designed to be fairly flat (as low as 0.6% in the grass -lined areas) to slow the runoff and act as water quality features within the site. Refer to Appendix C for open channel capacities. n Other Conveyances Most sidewalk chases and curb cuts will be designed for the minor storm with overtopping of the curbs/sidewalks in larger storm events. 8 N:\FCB02770mmage\WordhFCB0277_DrmnageReport_Final3.doc l NOTE Union Place 1 BEYOND* ENG IN EERING Final Drainage & Erosion Control Study 1 E. Variance Request This site does not completely follow City of Fort Collins guidelines. Due to the flat nature of the site plus the desire to incorporate low impact design features we request the following: 1. To allow the detention ponds and roadside swales to have as low as 0.5% 1 longitudinal slopes without concrete pans to allow decreased runoff intensities, allow for water quality and low -impact features, and to allow the site to surface drain. 2. To allow the use of LID elements including: • Bio-swales • Rain gardens and infiltration trenches • Permeable pavements and sidewalks 1 • Flat and shallow detention ponds • Curb cuts and sidewalk chases to eliminate the need for inlets and ' storm sewer IV. Drainage Facility Design 1 A. General Concept ' The site will ultimately consist of ground covered by pavement (permeable and impervious), rooftop, and landscape. The porous/pervious pavements allow for a reduced basin runoff coefficient as described in USDCM based on the amount of ' impervious area runoff to pervious areas. Water quality volume has been added to the required detention pond calculations assuming an extended detention basin will be utilized for water quality treatment only for basins that have few or no LID incorporated into them (such as the public streets). Throughout the rest of the site, water quality has been provided in the 1 landscape features and the very flat proposed detention pond and has not been added to the required extended detention pond volume. This site would have normally required 0.23 acre feet for extended detention, but due to the onsite LID 1 components it is only providing 0.05 acre feet for extended detention. All referenced tables, charts, formulas, etc. are included in the Appendix. The ' area, time of concentration, and runoff of each proposed sub -basin is summarized in Appendix A. The project site was divided into several different developed sub - basins as explained further below: t 1 9 N.WCB0277NDwinWNWordNFCB0277_Dmin4g eport_Final3.doc 1 Union Place ' BEYOND ENGINEERING Final Drainage & Erosion Control Study Basin A Basin A consists of Basins Al, A2, and A3 located in the southwest corner of the site. Basin Al consists of condos and a greenway containing an infiltration trench. Runoff not infiltrated is directed to Basin A2 (which contains condos and streets) to the rollover curb in the alley where it is conveyed easterly to Basin A3. Basin A3 consists of the back of residential lots and alley. The curb in the alley ends near Design Point A3 where the combined flows from basins Al, A2, and A3 discharge directly to the proposed detention pond. The alley in Basin A3 consists of permeable pavement with additional underground storage. Basin B ' Basin B consists of Basins B 1, B2; and B3 located in the western and central part of the site. Basin B1 consists of several condos and surrounding alleys. Runoff is directed to the rollover curb in the alley where it is conveyed ' easterly to Basin B2. Basin B2 consists of condos, the front of residential lots, and Urban Prairie Street. Basin B3 also consists of the front of residential lots ' and Urban Prairie Street. Runoff is collected in the bio-swale along the southern perimeter of Urban Prairie Street and is directed to Design Point B3 where the combined flows from these three basins discharge directly to the t proposed detention pond via a larger swale that combines flows from Basins B and C. ' The parking strip on the south side of Urban Prairie Street will consist of permeable pavement. Rain gardens will be required for the front of the triplexes that front Urban Prairie Street. ' Basin C Basin C consists of Basins C1 through C4. Basin C1 contains the front of ' single-family residential homes and a community park near the western edge of the site that will contain an infiltration trench and a small detention pond. This pond is being utilized to provide water quality and reduce the runoff to ' the east and will detain as much runoff as the available volume will allow. The detained runoff will release via a small orifice into a sidewalk chase onto Blue Sun Street and to Basin C2. The detained runoff from Basin C 1 has been ' subtracted from the required volume of Pond P. Basin C2 consists of condos, streets, and the inverted crown alley in the central portion of the site. The inverted alley in Basin C2 will consist of a 4' wide pervious pavement strip ' will collect runoff and distribute it to the 30" gravel layer below. Runoff from Basins C 1 and C2 that is not infiltrated is. conveyed to a low point near Design ' Point C2 into a grassed area represented by Basin C3. The runoff will be combined with Basin C4 (which consists of condos that discharge runoff to a bio-swale in the tree lawn on the north side of Urban Prairie Street) and M conveyed via a concrete pan, sidewalk chase, and swale to the detention pond. 10 N:\FCB0277TkWnage\Wor&FCB0277_DrainageReport_Finalldoc ' N Union Place O BEYOND E N G I N E E R I N G __✓ Final Drainage & Erosion Control Stu(y�]- ' ' Basin D Basin D consists of the alley located along Detention Pond P as well as the back of some of the triplexes along Urban Prairie Street. The alley in Basin D tconsists of permeable pavement with additional underground storage. Basin E ' Basin E consists of E 1 through E4 located in the northern part of the site. Basin E1 contains several condos, single-family residential lots, and alley. Runoff is directed to the rollover curb in the alley where it is conveyed easterly to Basin E2. Basin E2 contains condos and commercial lots and Part of Green Leaf Street. Runoff is collected in the bio-swale containing infiltration trenches along the southern perimeter of Green Leaf Street where runoff is directed easterly to Design Point E2. Runoff that does not infiltrate will overtop the curb and cross via the street pan into Basin E3. Basin E3 consists of commercial lot and a small amount of a single-family lot. Combined runoff from Basins E1, E2, and E3 will be directed to Design Point E3 via bio-swales and enter an inlet and storm pipe that discharges to Detention Pond P. Basin E4 consists of the commercial lots and Willox Lane along the northern perimeter of the site. Runoff from Basin E4 is directed via curb and gutter to an inlet and storm sewer in Willox Lane where it is combined with the flows from Basins E1, E2, and E3. At a minimum, the parking strips on the north and south side of Green Leaf Street will consist of permeable pavement. Basin F Basin F consists of commercial lot and portions of Green Leaf Street. Runoff is directed to a sidewalk chase at Design Point F that discharges directly to Pond P. Basin G Basins GI and G2, located on the eastern side of the site but west of Mason Street, consist of commercial lot and portions of Green Leaf Street, West Willox Lane, and Mason Street. Runoff from Basin GI is directed to a 5' Type R inlet in the southwest curb return at the intersection of Willox Lane with Mason Street. Runoff from Basin G2 is also directed to a combination Type 13 inlet in Green Leaf Street just west of Mason Street. The combined runoff from Basins GI and G2 is directed to Detention Pond P. Basin H Basin H consists of the northeast portion of Mason Street and Willox Lane. Runoff is directed to a Type R inlet and discharged to Basin P3. 11 N:\FCB0277\Drmmge\Word\FCB0277_prainageReport_ykwl3.doc NOq=TE Union Place BEYOND END IN EERING Final Drainage & Erosion Control Study Basin J Basin J consists of the west and east sides of Mason Street represented by Basins JI and J2, respectively. Runoff is directed southerly and discharged via swales to Basins P1 and P2. When Mason Street is extended to the south in the future, inlets will need to be constructed near Design Points J1 and J2 or collected elsewhere on the future Mason Street. Basin P Basin P consists of onsite Detention Pond P that collects runoff from the majority of the site. Basin P consists of Basins P1, P2, and P3 that represent portions of the detention pond that are located west, east, and north of the Greeley Waterline, respectively. Basin P is mostly landscaped. Basin P has been over -excavated to the regional pond depth and therefore will consist of partial retention until the future regional detention pond outfall storm sewer is constructed. Refer to Section M.D above and Section N.B. below for details. Basin M Basin M consists of the McDonald's Basin A (western portion of the McDonalds site). Areas of pavement, rooftop, and landscape were taken directly from the Final Drainage Report and Erosion Control Study for Willox Crossing Final P. U.D. McDonalds/Amoco Site at Willox Lane and College Avenue and are given in Section HLB. above. Basin U Basin U consists of undetained runoff along the southern and western perimeter of the site. This area is all landscaped except for a small portion of sidewalk that connects to the sidewalk north of Westwood Drive. 12 N:\FCB0277\Dr ge\Word\FCB0277_DramageRep rrt-Final3.dor NCUBBBE Union Place BEYOND ENGINEERING Final Drainage & Erosion Control Study B. Specific Details The following is a basin summary table: Basin Area Cz Ctoo Q2 Qt00 k acres qfs cfs min Al 0.23 1 0.26 0.58 0.13 1.01 10 A2 0.30 1 0.68 0.80 0.58 2.39 5 A3 0.31 1 0.24 0.57 0.14 1.20 14 Bl 0.24 0.54 0.71 0.31 1.44 8 B2 0.58 0.40 0.63 0.49 2.70 11 B3 0.28 0.36 0.61 0.22 1.30 10 C1 0.49 0.25 0.57 0.25 2.06 11 C2 0.57 0.56 0.72 1 0.91 14.09 5 C3 0.07 0.06 0.51 0.01 0.28 10 C4 0.18 1 0.32 0.60 0.13 0.84 9 D 0.50 1 0.22 0.57 0.25 2.19 10 El 0.31 1 0.69 0.81 0.61 2.48 5 E2 0.77 1 0.36 0.61 0.79 4.66 5 E3 0.33 1 0.34 0.60 0.32 1.96 5 E4 1.21 1 0.49 0.68 1.17 5.67 13 F 0.20 1 0.26 0.58 0.15 1.13 5 Gl 0.41 1 0.51 0.69 1 0.44 12.08 11 G2 0.27 1 0.42 0.64 1 0.24 1 1.29 11 H 0.23 1 0.66 0.79 0.43 1.81 5 11 0.20 1 0.67 0.79 0.37 1.54 5 J2 0.26 0.60 0.75 0.45 1.94 5 Pi 1.53 0.06 0.51 0.12 3.52 30 P2 0.81 0.06 0.51 0.06 2.05 25 P3 0.19 0.08 0.52 0.04 0.83 8 M 0.86 0.59 1 0.74 1 1.17 1 5.09 9 U 0.36 0.06 0.51 0.01 0.36 Basin Area Q2 Q100 1. acres c s cfs min Al-A2 0.53 0.56 2.75 11 A]-A3 0.84 0.69 3.94 12 Bl-B2 0.82 0.77 3.98 11 CI-C2 1.05 0.90 4.93 12 1.13 0.91 5.20 12 1.30 0.99 5.74 13 2.40 1.90 10.62 13 MEI-E2 1.07 1.30 6.69 6 1.40 1.51 8.05 7 2.61 2.36 12.00 13 0.68 0.68 3.37 1 11 A-G2, Jl, P1 8.95 4.15 25.33 1 30 A-M 11.30 1 5.29 1 32.20 1 30 The following table is a summary of the detention pond volumes and release rates. 100 yem Roq Area of Storap 100-year Depth D, Top-0 � Notes Pond 8 Runoff Vohnoa Rate WSF1. Based on BeimFlev. .Vohmte Provided Outlet Pipe acre ji acre acre- s ft Jt t Vohanecawatedfrome�tigowNat Pond L73 11.30 4.40 2.26 4979.86 L10 4982.30 4978.76. Wades area n basin P3. Vohme calculated frombottom ofpond at Pond P - Regional #1 5.58 4976.8. Does not nlrude area a basin P3 Vohne cabAtted from bottom ofpond at Pond P - Regiond #2 5.77 4976.8. Does idcude area in basin P3. PondCl 1 0.07 1 0.49 1 0.07 0.20 14985.71 1 1.06 1 N/A N/A This site has provided detention pond volume in excess of that required. The following is a summary of assumptions: 13 N:1FCB0277\Drainage\Word\FCB0277_DramageReport_Final3.doc NO�E Union Place B E Y O N D E N G IN E E R ING Final Drainage & Erosion Control Study • The volume provided in Detention Pond C 1 has been subtracted from the overall volume required in Pond P. Pond C release rate is based on available volume. • Detention has been provided under porous pavement in Basins C2, A3, and D. The underlying gravel layer is 30" deep with 35% voids. The detention provided was subtracted from the overall volume required in Pond P. Refer to calculations in Appendix B. • The starting water surface for the detention pond was set at 4978.76 (not the regional depth of 4976.8) which is the invert of the existing 18" pipe that Pond P will discharge to. • Pond volumes were assumed to maximize at 120 minutes. • A storm pipe was constructed between Basins P1 and P2 to equalize the ponds. The orifice plate for Pond P was sized for the release rate of 2.26 cfs. The existing flared end section on the outfall pipe will be replaced with a headwall, orifice plate, and trash screen. • The existing McDonalds pond outlet will be plugged. ' • . Water quality volume for Basins Jl, J2, H, G1, and E4 has been added to the required detention pond volume. The remaining basins direct runoff to swales with minimal slope, infiltration trenches, rain gardens, and ' permeable pavement where water quality has been provided. Ultimately, the spillway for Pond P will be over the low point in Mason Street at ' its southern end of the site. When Willox Crossing PUD was designed, the emergency spillway for Pond #1 was constructed to direct flow westerly onto this ' site. Because the low point in the topography is southeasterly, this has created a difficulty in designing a well-defined emergency spillway other than Mason Street.. In the event that pond fills up beyond its capacity, the water will spill into ' Mason Street and back up into Willox Lane. V. Conclusions ' A. Compliance with Standards Storm drainage calculations have typically followed the guidelines provided by the City of Fort Collins Storm Drainage Design Criteria and Construction Standards Manual and/or the Urban Storm Drainage Criteria Manuals Volumes ' 2, and 3. B. Drainage Concept ' The drainage system has been designed to convey the runoff to the designated design points and the detention ponds in an effective manner as safe as possible. 14 N:\FCB02771Drainage\WorffCB0277IhamageRepod_Fuml3.dce Union Place NC�E ' BEYOND ENGINEERING Final Drainage 8c Erosion Control Study ' As proposed, the site has detention pond volume (4.40 acre-feet) in excess of that required (1.73 acre-ft). As shown on the detention pond calculations in Appendix B, the ponds have been graded to the regional depth. Assuming an ultimate water ' surface elevation of 4981.30 and an invert elevation of 4976.8, Pond P has a volume of 5.58 acre-feet (this does not include the contribution from Basin P3). If Basin P3 is included in the regional detention pond the available volume will be ' increased to 5.77 acre-feet. As mentioned above, the regional pond will require 5.56 acre-feet and therefore, this development has provided adequate volume for the future regional detention facility ' VI. An equalization pipe is required to connect the ponds on either side of Mason Street so that they are hydraulically connected. A flat 24" pipe was designed to . carry the flows from the west pond to the east pond. In the future when.this pond functions as a regional pond, this pipe will help equalize flows between the two ponds. It is not known where the future flows will come into the ponds or where the flows will exit the ponds. The pipe was designed flat to allow for options in the future and sized at 24" to allow for different scenarios in the future. The actual equalization pipe size needed in the future may be smaller or larger and will be based on timing and flows to each of the ponds. This will need to be designed by the city's consultant in the future with the design of the storm sewer into and out of the regional detention pond. C. Water Quality Water quality for an extended detention basin for basins not incorporating LID has been added to the required detention pond volumes. Due to the incorporation of low -impact -design elements and relatively flat ponds and swales, water quality volume was not added to the extended detention pond for basins incorporating LID. Although some volume has been added to the overall required pond volume, a water quality plate has not been proposed for this site due to approximately 2' of retention. Erosion and Sediment Control In addition to the permanent low -impact design Best Management Practices (BMP's), the following temporary and permanent BMP's will be installed and maintained to control on -site erosion and prevent sediment from traveling off -site during and/or after construction: Silt Fence — a woven synthetic fabric that filters runoff. The silt fence is a temporary barrier that is placed at the base of a disturbed area. • Vehicle Tracking Control — a stabilized stone pad located at points of ingress and egress on a construction site. The stone pad is designed to reduce the amount of mud transported onto public roads by construction traffic. 15 N:\FCB0277\Dramage\Word\FCB0277_DramageReport_Fuml3.doc ' Union Place Final Drainage & Erosion Control Study ' BEYOND ENGINEERING v ✓ • Straw Wattles — wattles act as a sediment filter in swales around inlets. They are a temporary BMP and require proper installation and maintenance to ensure their performance. ' • Riprap — Riprap will be used downstream of all storm sewer outfalls to control erosion of the receiving channels. ' • Sediment Basin — The detention pond will act as a temporary sediment basin . during construction. ' VII. References 1. Final Drainage Report and Erosion Control Study for Willox Crossing Final P.U.D. ' McDonalds/Amoco Site at Willox Lane ad college Avenue, Fort Collins, Colorado, R & R Engineers -Surveyors, Inc., October 7, 1998. 2. Natural Resources Conservation Service Web Soil Survey at websoilsurvey.nres.usda.gov/app 3. North College Drainage Improvements Design Alternative Analysis Report, Ayres Associates, February 2006 4. Suberade Investieation and Pavement Recommendations Union Place West Willox Lane Fort Collins, Colorado, CTL Thompson Incorporated., June 23, 2009. 5. Urban Storm Drainage Criteria Manual, Urban Drainage and Flood Control District, Wright Water Engineers, Inc., Denver, Colorado, June 2001. 16 N.\FCB02770mmage\Word\FC80277_IhamageAeport_Final3.dm 1 1 1 1 1 1 t Runoff Calculations I PROJECT NAME Union Place PROJECT NUMBER FCB0277 CALCULATED BY MLW & SME Rational Method Runoff Calculations %I (Percent Impervious) is a weighted average based on area type. Runoff C is based on %1, UDFCD Eqs RO-6 and RO-7. Cy based initial ground type and Table 601 /414_U(V*60 sec/min) t21y=11.80.1-C,)L'c]/S", S= in %, L=length (N. slope of overland Flow (400' max) check (for urban or developed areas only) = total length/l80+ 10 t'1V=C,S", Swatercourse slope in Nft, UDFCD Equation RO-4 (6)mint. - 5 min Areas Runoff Coefficient Time of Concentration Bldg. Paved Effective Pervious Open Initial Overland Flow Time (ti) ' Travel/Channelized Time of Flow (Q to Check for Intenisty Runoff, Q;=Ci*Ai*li Basin Total Composite a * /a[ A Design g +tt Final t a a /oI=90% %1=100% Imperv. Perv. Total Imperv. to Perv. Ratio %1=2% Initial Length g Sloe p ylz) Length g Sloe p Velocity 3> Check Total 5) to I [ Qz QI� 1.33* %J Point Ground C5(1) C,. 44 4? Length et6) z loo Qloo Basin acres acres acres acres acres acres Fig PP-1 acres C2 C100 Cz*A C100*A %/ Type ft % min ft % fps min min . u fi min min in/hr in/hr cfs cfs cfs urban Al 0.23 0.07 0.02 0.00 0.00 0.00 0.0 0% 0.14 0.26 0.58 0.06 0.13 37% 0.08 DPAI Open 0.16 43 1.5 9.7 53 0.9 15 1 1.4 0.6 10 u 96 11 10 2.21 7.72 0.13 1.01 AI A2 0.30 0.10 0.17 0.00 0.00 0.00 2.0 40% 0.03 0.68 0.80 0.20 0.24 86% 0.26 DPA2 0.90 12 3.1 0.9 205 0.6 20 1 1.5 2.2 3 u 217 11 5 2.85 9.95 1 0.58 2.39 A2 A3 0.31 0.04 0.00 0.10 0.05 0.16 2.0 40% 1, 0.11 0.24 0.57 0.08 0.18 33% 0.10 DPA3 Open 0.16 42 2.2 8.5 730 0.6 20 1.5 7.9 16 u 772 14 14 1.92 6.71 0.14 1.20 A3 B1 0.24 0.08 0.11 0.00 0.00 0.00 0.0 0% 1 0.05 0.54 0.71 0.13 0.17 75% 6.18 DPB1 Open 0.16 38 3.3 7.1 110 0.6 20 1.5 1.2 8 u 148 11 8 2.40 8.38 0.31 1.44 1.9 B1 B2 0.58 0.11 0.21 0.05 0.02 0.07 2.0 40% 0.19 0.40 0.63 0.23 0.36 59% 0.34 DPB Open 0.16 39 2.1 8.3 177 0.6 15 1.2 2.5 11 1 u 216 11 11 2.13 7.42 0.49 2.70 B2 B3 0.28 0.06 0.07 0.03 0.02 0.05 2.0 40% 0.10 0.36 0.61 0.10 0.17 53% 0.15 DPB Open 0.16 38 2.0 8.3 99 0.6 15 1.2 1.4 10 u 137 11 10 2.21 7.72 0.22 1.30 1.7 B3 C1 0.49 0.13 0.04 0.00 0.00 0.00 0.0 0% 0.31 0.25 0.57 0.12 0.28 34% 0.16 DPCI Open 0.16 64 2.1 10.7 115 0.6 15 1.2 1.6 12 u 179 11 11 2.13 7.42 0.25 2.06 C1 C2 0.57 0.23 0.20 0.04 0.02 0.06 2.0 40% 0.07 0.56 0.72 0.32 0.41 77% 0.44 DPG2 0.90 29 2.1 1.5 200 0.6 20 1.5 2.2- 4 u 229 11 5 2.85 9.95 0.91 4.09 C2 C3 0.07 0.00 0.00 0.00 0.00 0.00 0.0 0% 0.07 0.06 0.51 0.00 0.04 2% 0.00 DPC3 Open 0.16 58 0.5 16.0 0 0.5 20 1.4 0.0 16 u 58 10 10 2.21 7.72 0.01 0.28 C3 C4 0.18 0.06 0.02 0.00 0.00. 0.00 0.0 0% 0.09 0.32 0.60 0.06 0.10 47% 0.08 DPC4 Open 0.16 26 2A 6.8 173 0.6 15 1.2 15 9 u 199 11 9 2.30 8.03 0.13 0.84 1.1 C4 D 0.50 0.04 0.00 0.18 0.09 0.26 1 2.0 40% 0.19 0.22 0.57 0.11 0.28 30% 0.15 DPD Open 0.16 73 2.0 11.5 0 0.6 20 1.5 0.0 12 u 73 10 10 2.21 7.72 0.25 2.19 D E1 0.31 0.13 0.15 0.00 0.00 0.00 0.0 0% 0.03 0.69 0.81 0.21 0.25 87% 0.27 DPE1 0.90 33 2.1 1.6 121 0.5 20 1.4 1.4 3 u 154 11 5 2.85 9.95 0.61 2.48 3.3 El E2 0.77 0.08 0.23 0.17 0.09 0.26 2.0 40% 1 0:20 0.36 0.61 1 0.28 0.47 53% 0.41 DPE2 0.90 59 2.3 2.1 206 0.6 15 1.2 3.0 5 u 265 11 5 2.85 9.95 0.79 4.66 E2 E3 0.33 0.01 0.11 0.07 0.04 0.10 1.8 37% 1 0.09 .0.34 0.60 1 0.11 0.20 51% 0.17 DPE3 0.90 49 2.5 1.9. 116 0.6 20 1.6 1.2 3 u 165 11 5 2.85 9.95 0.32 1.96 E3 E4 1.21 0.27 1 0.59 0.00 0.04 0.04 0.0 10% 1 0.31 0.49 0.68 0.59 0.82 69% 0.84 1 DPE4 Open 0.16 36 3.7 6.6 532 0.5 20 1.4 6.3 13 u 568 13 13 1.98 6.92 1.17 5.67 7.5 E4 F 0.20 0.00 0.05 0.05 0.06 0.11 0.8 22% 0.04 0.26 0.58 0.05 0.11 37% 0.07 DPF 0.90 89 2.8 2.4 60 0.7 20 1.7 0.6 3 u 149 11 5 2.85 9.95 0.15 1.13 F G1 0.41 0.07 0.23 0.00 0.03 0.03 0.0 10% 0.08 0.51 0.69 0.21 0.28 72% 0.29 DPGI Open 0.16 67 2.5 10.2 164 0.5 20 1.4 1.9 12 u 231 11 11 2.13 7.42 0.44 2.08 2.8 Gl G2 0.27 0.05 0.11 0.01 0.03 0.03 0.2 13% 0.07 0.42 0.64 0.11 0.17 61% 0.17 DPG2 Open 0.16 84 3.1 10.7 18 0.6 20 1.5 0.2 11 u 102 11 11 2.13 7.42 0.24 1.29 G2 H 0:23 0.00 0.20 0.00 1 0.00 0.00 0.0 0% 0.04 0.66 0.79 0.15 0.18 85% 0.20 DPH 0.90 25 2.0 1.4 164 0.5 20 1.4 1.9 3 u 189 11 5 2.85 9.95 0.43 1.81 H JI 0.20 0.00 0.17 0.00 0.00 0.00 0.0 0% 0.03 0.67 0.79 0.13 0.15 86% 0.17 DPJI 0.90 25 2.0 1.4 226 0.5 20 1.4 2.7 4 u 251 11 5 2.85 9.95 0.37 1.54 11 J2 0.26 0.00 0.21 0.00 0.00 0.00 0.0 0% 0.05 0.60 0.75 0.16 0.20 81% 0.21 DPJ2 0.90 25 2.0 1.4 226 0.5 20 1.4 2.7 4 u 251 11 5 2.85 9.95 0.45 1.94 J2 PI 1.53 0.00 0.01 0.00 0.00 0.00 0.0 0% 1.52 0.06 0.51 0.09 0.78 3% 0.04 DPPI Open 0.16 200 0.5 30.1 30 30 1.30 4.52 0.12 3.52 P1 P2 0.81 0.00 0.00 0.00 0.00 0.00 0.0 0% 0.81 0.06 0.51 0.04 0.41 2% 0.02 DPP2 Open 0.16 140 0.5 24.8 25 25 1.43 4.98 0.06 2.05 P2 P3 0.19 0.00 0.01 0.00 0.00 0.00 0.0 0% 0.19 0.08 0.52 0.01 0.10 5% 0.01 DPP3 Open 0.16 22 2.1 6.2 98 0.5 15 1.1 1.5 8 u 120 11 8 2.40 8.38 0.04 0.83 P3 M 0.86 0.04 0.64 0.00 0.00 0.00 0.0 0% 0.17 0.59 0.74 0.51 0.63 80% 0.68 DPM Open 0.16 9 2.30 8.03 1.17 5.09 M U 0.36 0.00 0.00 0.00 0.00 0.00 0.0 0% 0.36 0.06 0.51 0.02 0.18 2% 0.01 DPU . 0.01 0.36 U Al-A2 0.53 0.26 0.37 65% 0.34 DPA2 Open 0.16 55 1 2.0 1 10.0 122 0.6 20 1.5 1.3 11 u 177 11 11 2.13 7.42 0.56 2.75 3.7 Al-A2 A 0.8 0.34 0.55 53% 0.45 DPA3 Open 0.16 55 2.0 10.0 -330 0.6 20 1.5 3.6 14 u 385 12 12 2.05 7.16 0.69 3.94 5.2 A 131-132 .2 0.36 0.54 64% 0.52 DPB Open 0.16 38 3.3 7.1 400 0.6 20 1.5 4.3 11 u 438 12 11 2.13 7.42 0.77 3.98 5.3 B1-B2 CI-C2 1.05 0.44 0.69 57% 0.60 DPC2 Open 0.16 64 2.1 10.7 332 0.6 20 1.5 3.6 14 u 396 12 12 2.05 7.16 0.90 4.93 6.6 Cl-C2 CI-C3 1.13 0.44 0.73 54% 0.60 CPC3 Open 0.16 64 2.1 10.7 381 0.6 20 1.5 4.1 15 u 445 12 12 2.05 7.16 0.91 5.20 CI-C3 C I.30 0.50 0.83 53% 0.69 DPC4 Open 0.16 64 2.1 10.7 389 0.6 20 1.5 4.2 15 u 453 13 13 1.98 6.92 0.99 5.74 C B, C 2.40 0.96 1.53 57% 1.36 DPB Open 0.16 64 2.1 10.7 428 0.6 20 1 1.5 4.6 15 u 492 13 13 L98 6.92 1.90 10.62 14.1 B, C E1-E2 1.07 0.49 0.72 63% 0.68 DPE2 0.90 33 2.1 1.6 419 0.6 20 1.5 4.7. 6 u 452 13 6 2.67 9.31 1.30 6.69 8.9 E1-E2 EI-E3 1.40 0.60 0.92 60% 0.84 DPE3 0.90 33 2.1 1.6 535 0.6 20 1.5 5.8 7 u 568 13 .7 2.52 8.80 1.51 8.05 10.7 E1-E3 E 2.61 1.19 1.73 65% 1.69 DPE3 13 1.98 6.92 2.36 12.00 E G 0.68 0.32 0.45 68% 0.46 DPG2. 11 2.13 7.42 0.68 3.37 G A-G2, Jl, Pl 8.95 3.19 5.60 49% 4.38 DPP 30 1.30 4.52 4.15 25.33 A-G2, J1, P1 A-M 11.30 4.07 1 7.12 49o/n 5.50 30 1.30 4.52 5.29 32.20 A-M FCB6277-Runoff Final3.xls, C, 10/13/2009 STRUCTURAL BEST MANAGEMENT PRACTICES Milm 70 N 60 rn a) c rn 0 50 m n E 40 c a) U m` 30 a a) 20 W 10; DRAINAGE CRITERIA MANUAL (V. 3) All With PP's Except Underdraipio RGP WOO 0000 0000 0000 RGP wMnderdrains CP w/ I filtration to to 00*10 All Other Infiltration is I PPs When to Possible, andrAllowed we 10 I 0.5 1 1.5 2 (Impervious Trib. Area)/(Porous Pavement Area) ' Notes: 1. Chart applies only to porous pavements described in Volume 3 of the USDCM, Structural MBPs chapter. Not to be used for other types of porous pavements. ' 2. Apply the "Effective Percent Imperviousness" to the total area that included the area of porous pavement and the tributary impervious area that can be made to flows uniformly onto PP. 3. Use no more than two units of impervious area for each unit of PP. All impervious areas exceeding ' this ratio shall be treated as 100% impervious in hydrologic calculations, including runoff volumes. 4. Whenever impervious areas cannot be made to run onto the pervious areas in a. uniform sheet -flow fashion, identify individual areas and what ratios apply to each and then composite them reating each as a separate area. ' Figure PP-1—Interim Recommended Effective Percent Imperviousness for Porous Pavements (Based on the Ratio of the Impervious Area Tributary to Porous Pavement)- ' S-34 2608-04 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) 2.0 RATIONAL METHOD For urban catchments that are not complex and are generally 160 acres or less in size, it is acceptable that the design storm runoff be analyzed by the Rational Method. This method was introduced in 1889 and is still being used in most engineering offices in the United States. Even though this method has frequently come under academic criticism for its simplicity, no other practical drainage design method has evolved to such a level of general acceptance by the practicing engineer. The Rational. Method properly understood and applied can produce satisfactory results for urban storm sewer and small on -site detention design. 2.1 Rational Formula The Rational Method is based on the Rational Formula: Q = CIA in which: Q = the maximum rate of runoff (cfs) (RO-1) C = a runoff coefficient that is the ratio between the runoff volume from an area and the average rate of rainfall depth over a given duration for that area I = average intensity of rainfall in inches per hour for a duration equal to the time of concentration, tc A = area (acres) Actually, Q has units of inches per hour per acre (in/hr/ac); however, since this rate of in/hr/ac differs from cubic feet per second (cfs) by less than one percent, the more common units of cfs are used. The time of concentration is typically defined as the time required for water to flow from the most remote point of the area to the point being investigated. The time of concentration should be based upon a flow length and ---- -' path thatresults in a time ofconcent-atio-- foron-ly - portionof thearea if that poti-n -of-the —catchme- --- ---- ---- ------ - t produces a higher rate of runoff. The general procedure for Rational Method calculations for a single catchment is as follows: 1. Delineate the catchment boundary. Measure its area. 2. Define the flow path from the upper -most portion of the catchment to the design point. This flow path should be divided into reaches of similar flow type (e.g., overland flow, shallow swale flow, gutter flow, etc.). The length and slope of each reach should be measured. 3. Determine the time of concentration, t,, for the catchment. Y, 2067-01 RO-3 Urban Drainage and Flood Control District RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) 4. Find the rainfall. intensity, !, for the design storm using the calculated r, and the rainfall intensity - duration -frequency curve. (See Section 4.0 of the RAINFALL chapter.) 5. Determine the runoff coefficient, C. 6. Calculate the peak flow rate from the watershed using Equation. RO-1. 2.2 Assumptions The basic assumptions that are often made when the Rational Method is applied are: 1. The computed maximum rate of runoff to the design point is a function of the average rainfall rate during the time of concentration to that point. 2. The depth of rainfall used is one that occurs from the start of the storm to the time of concentration, and the design rainfall depth during that time period is converted to the average rainfall intensity for that period. 3. The maximum runoff rate occurs when the entire area is contributing flow. However, this assumption has to be modified when a more intensely developed portion of the catchment with a shorter time of concentration produces a higher rate of maximum runoff than the entire catchment with a longer time of concentration. 2.3 Limitations The Rational Method is an adequate method for approximating the peak rate and total volume of runoff from a design rainstorm in a given catchment. The greatest drawback to the Rational Method is that it normally provides only one point on the. runoff hydrograph. When the areas become complex and where sub -catchments come together, the Rational Method will tend to overestimate the actual flow, which results in oversizing of drainage facilities. The Rational Method provides no direct information needed to route hydrographs through the drainage facilities. One reason the Rational Method is limited to small areas is that good design practice requires the routing of hydrographs for larger catchments to achieve an economic design. Another disadvantage of the Rational Method is that with typical design procedures one normally assumes that all of the design flow is collected at the design point and that there is no water running overland to the next design point. However, this is not the fault of the Rational Method but of the design procedure. The Rational Method must be modified, or another type of analysis must be used, when analyzing an existing system that is under -designed or when analyzing the effects of a major storm on a system designed for the minor storm. RO-4 2007-01 Urban Drainage and Flood Control District IDRAINAGE CRITERIA MANUAL (V. 1) 2.4 Time of Concentration RUNOFF One of the basic assumptions underlying the Rational Method is that runoff is a function of the average rainfall rate during the time required for water to flow from the most remote part of the drainage area 1 under consideration to the design point. However, in practice, the time of concentration can be an empirical value that results in reasonable and acceptable peak flow calculations. The time of ' concentration relationships recommended in this Manual are based in part on the'rainfall-runoff data collected in the Denver metropolitan area and are designed to work with the runoff coefficients also ' recommended in this Manual. As a result, these recommendations need to be used with a great deal of caution whenever working in areas that may differ significantly from the climate or topography found in the Denver region. For urban areas, the time of concentration, t, consists of an initial time or overland flow time, t;, plus the travel time, t„ in the storm sewer, paved gutter, roadside drainage ditch, or drainage channel. For non - urban areas, the time of concentration consists of an overland flow time, t,, plus the time of travel in a defined form, such as a swale, channel, or drainageway. The travel portion, t,, of the time of concentration can be estimated from the hydraulic properties of the storm sewer, gutter, swale, ditch, or drainageway. Initial time, on the other hand, will.vary with surface slope, depression storage, surface cover, antecedent rainfall, and infiltration capacity of the soil, as well as distance of surface flow. The time of concentration is represented by Equation RO-2 for both urban and non -urban areas: t' = ti + tI fP1 , lima t, = time of concentration (minutes) t, = initial or overland flow time (minutes) t, = travel time in the ditch, channel, gutter, storm sewer, etc. (minutes) ---The initial or overland flow time, q, may be calculated using equation RO-3: (RO-2) 0.395(1.1—CS) L tr - Soss (RO-3) in which: t; = initial or overland flow time (minutes) CS = runoff coefficient for 5-year frequency (from Table RO-5) 2007-01 RO-5 Urban Drainage and Flood Control District RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) L = length of overland flow (500 ft maximum for non -urban land uses, 300 ft maximum for urban land uses) S= average basin slope (ft/ft) Equation RO-3 is adequate for distances up to 500 feet. Note that, in some urban watersheds, the overland flow time may be very small because flows quickly channelize. 2.4.2 Overland Travel Time For catchments with overland and channelized flow, the time of concentration needs to be considered in combination with the overland travel time, t„ which is calculated using the hydraulic properties of the swale, ditch, or channel. For preliminary work, the overland travel time, t„ can be estimated with the help of Figure RO-1 or the following equation (Guo 1999): V = CVSW0.s (RO-4) in which: V = velocity (ft/sec) CV = conveyance coefficient (from Table RO-2) SW = watercourse slope (ft/ft) Table RO-2—Conveyance Coefficient, CV Type of Land Surface Conveyance Coefficient, CV Heavy meadow 2.5 Tillage/field 5 Short pasture and lawns 7 Nearly bare ground 10 Grassed waterway 15 Paved areas and shallow paved swales 20 The time of concentration, t,, is'then the sum of the initial flow time, t;, and the travel time, t„ as per Equation RO-2. 2.4.3 First Design Point Time of Concentration in Urban Catchments Using this procedure, the time of concentration at the first design point (i.e., initial flow time, t;) in an urbanized catchment should not exceed the time of concentration calculated using Equation RO-5. t` = 1L +10 (RO-5) in which: t� = maximum time of concentration at the first design point in an urban watershed (minutes) 2007-01 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF L = waterway length (ft) Equation RO-5 was developed using the rainfall -runoff data collected in the Denver region and, in essence, represents regional "calibration" of the Rational Method The first design point is the point where runoff first enters the storm sewer system. An example of ' definition of first design point is provided in Figure RO-2. Normally, Equation RO-5 will result in a lesser time of concentration at the first design point and will govern in an urbanized watershed. For subsequent design points, the time of concentration is calculated by accumulating the travel times in downstream drainageway reaches. ' 2.4.4 Minimum Time of Concentration Should the calculations result in a t, of less than 10 minutes, it is recommended that a minimum value of 10 minutes be used for non -urban watersheds. The minimum t, recommended for urbanized areas should not be less than 5 minutes and if calculations indicate a lesser value, use 5 minutes instead. 2.4.5 Common Errors in Calculating Time of Concentration ' A common mistake in urbanized areas is to assume travel velocities that are too slow. Another common - error is to not check the runoff peak resulting from only part of the catchment. Sometimes a lower portion ' of the catchment or a highly impervious area produces a larger peak than that computed for the whole catchment. This error is most often encountered when the catchment is long or the upper portion contains grassy parkland and the lower portion is developed urban land. 2.5 Intensity ' The rainfall intensity, I, is the average rainfall rate in inches per hour for the period of maximum rainfall of a given recurrence frequency having a duration equal to the time of concentration. After the design storm's recurrence frequency has been selected, a graph should be made showing 1 rainfall intensity versus time. The procedure for obtaining the local data and drawing such a graph'is explained and illustrated in Section 4 of the RAINFALL chapter of this Manual. The intensity for a design point is taken from the graph or through the use of Equation RA-3 using the calculated t,. 2.6 Watershed Imperviousness All parts of a watershed can be considered either pervious or impervious. The pervious part is that area where water can readily infiltrate into the ground. The impervious part is the area that does not readily ' allow water to infiltrate into the ground, such as areas that are paved or covered with buildings and sidewalks or compacted unvegetated soils. In urban hydrology, the percentage of pervious and ' impervious land is important. The percentage of impervious area increases when urbanization occurs ' 2007-01 RO-7 Urban Drainage and Flood Control District RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) and the rainfall -runoff relationships change significantly. The total amount of runoff volume normally increases, the time to the runoff peak rate decreases, and the peak runoff rates increase. Photograph RO-2=Urbanization (impervious area) increases runoff volumes, peak discharges, frequency of runoff, and receiving stream degradation. When analyzing a watershed for design purposes, the probable future percent of impervious area must be estimated. A complete tabulation of recommended values of the total percent of imperviousness is provided in Table RO-3 and Figures RO-3 through RO-5, the latter developed by the District after the evolution of residential growth patterns since 1990. 2.7 Runoff Coefficient The runoff coefficient, C, represents the integrated effects of infiltration, evaporation, retention, and interception, all of which affect the volume of runoff. The determination of C requires judgment and understanding on the part of the engineer. Based in part on the data collected by the District since 1969, an empirical set of relationships between C and the percentage imperviousness for the 2-year and smaller storms was developed and are expressed in Equations RO-6 and RO-7 for Type A and C/D Soil groups (Urbonas, Guo and Tucker 1990). For Type B soil group the impervious value is found by taking the arithmetic average of the values found using these two equations for Type A and Type C/D soil groups. For larger storms (i.e., 5-, 10, 25-, 50- and 100-year) correction factors listed in Table RO-4 are applied to the values calculated using these two equations. RO-8 2007-01 Urban Drainage and Flood Control District ' DRAINAGE CRITERIA MANUAL (V. 1) Table RO-3—Recommended Percentage Imperviousness Values 1 Land Use or Surface Characteristics Percentage Imperviousness Business: Commercial areas 95 Neighborhood areas 85 Residential: Single-family Multi -unit (detached) 60 Multi -unit (attached) 75 Half -acre lot or larger Apartments 80 Industrial: Light areas 80 Heavy areas 90 Parks, cemeteries 5 Playgrounds 10 Schools 50 Railroad yard areas 15 Undeveloped Areas: Historic flow analysis 2 Greenbelts, agricultural 2 -a------ysis------- ----- Off-site flow nal (when land use not defined) -----45 ------- Streets: Paved 100 Gravel (packed) 40 Drive and walks 90 Roofs 90 Lawns, sand y-soil-----------,---------.__.0-------- Lawns, clayey soil 0 See Figures RO-3 through RO-5 for percentage imperviousness. CA = KA + (1.31i' —1.44i z + 1.135i — 0.12) for CA >_ 0, otherwise CA = 0 ' CCD = KCD + (0.858i' — 0.786i z + 0.774i + 0.04) - ' CB — (CA + CCD 1 1/2 2007-01 Urban Drainage and Flood Control District RUNOFF (RO-6) (RO-7) RO-9 RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) in which: i = % imperviousness/100 expressed as a decimal (see Table RO-3) C,4 = Runoff coefficient for Natural Resources Conservation Service (NRCS) Type A soils CB = Runoff coefficient for NRCS Type B soils CcD = Runoff coefficient for NRCS Type C and D soils KA = Correction factor for Type A soils defined in Table RO-4 KcD = Correction factor for Type C and D soils defined in Table RO-4 Table RO-4—Correction Factors KA and KcD for Use with Equations 110-6 and RO-7 Storm Return Period NRCS Soil Type 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year C and D 0 -0.10i + 0.11 -0.18i + 0.21 -0.28i + 0.33 -0.33i + 0.40 -0.39i + 0.46 A 0 -0.08i + 0.09 -0.14i + 0.17 -0.19i + 0.24 -0.22i + 0.28 -0.25i + 0.32 The values for various catchment imperviousnesses and storm return periods are presented graphically in Figures RO-6 through RO-8, and are tabulated in Table RO-5. These coefficients were developed for the Denver region to work in conjunction with the time of concentration recommendations in Section 2.4. Use of these coefficients and this procedure outside of the semi -arid climate found in the Denver region may not be valid. The UD-Rational spreadsheet performs all the needed calculations to find the runoff coefficient given the soil type and imperviousness and the reader may want to take advantage of this macro -enabled Excel workbook that is available for download from the District's web site www.udfcd.org under "Download" —"Technical Downloads." See Examples 7.1 and 7.2 that illustrate the Rational method. The use of the Rational method in storm sewer design is illustrated in Example 6.13 of the STREETS/INLETS/STORM SEWERS chapter. RO-10 2007-01 Urban Drainage and Flood Control District ' DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF Table RO-5- Runoff Coefficients, C Percentage Imperviousness Type C and D NRCS Hydrologic Soil Groups 2- r 5- r 10- r 25- r 50- r 1 00r 0% 0.04 0.15 0.25 0.37 0.44 0.50 5% 0.08 0.18 0.28 0.39 0.46 0.52 10% 0.11 0.21 0.30 0.41 0.47• 0.53 15% 0.14 0.24 0.32 0.43 0.49 0.54 20% 0.17 0.26 0.34 0.44 0.50 0.55 25% 0.20 0.28 0.36 0.46 0.51 0.56 30% 0.22 0.30 0.38 0.47 0.52 0.57 35% 0.25 0.33 0.40 0.48 0.53 0.57 40% 0.28 0.35 0.42 0.50 0.54 0.58 45% 0.31 0.37 0.44 0.51 0.55 0.59 50% 0.34 0.40 0.46 0.53 0.57 0.60 55% 0.37 0.43 0.48 0.55 0.58 0.62 60% 0.41 0.46 0.51 0.57 0.60 1 0.63 65% 0.45 0.49 0.54 0.59 0.62 0.65 70% 0.49 0.53 0.57 0.62 0.65 0.68 75% 0.54 0.58 0.62 0.66 0.68 0.71 80% 0.60 0.63 0.66 0.70 0.72 0.74 85%. 0.66 0.68 0.71 0.75 0.77 0.79 90% 0.73 0.75 0.77 0.80 0.82 0.83 95% 0.80 0.82 0.84 0.87 0.88 1 0.89 100% 0.89 0.90 0.92 0.94 0.95 0.96 TYPE B NRCS HYDROLOGIC SOILS GROUP 0% 0.02 0.08 0.15 0.25 0.30 0.35 5% 0.04 0.10 0.19 0.28 0.33 0.38 10% 0.06 0.14 0.22 0.31 0.36 0.40 15% 0.08 0.17 0.25 0.33 0.38 0.42 20% 0.12 0.20 0.27 0.35 0.40 0.44 25% 0.15 0.22 0.30 0.37 0.41 0.46 30% 0.18 0.25 0.32 0.39 0.43 0.47 35% 0.20 0.27 0.34 0.41 0.44 0.48 40% 0.23 0.30 0.36 0.42 0.46 0.50 45% 0.26 0.32 0.38 0.44 0.48 0.51 50% 0.29 0.35 0.40 0.46 0.49 0.52 55% 0.33 0.38 0.43 0.48 0.51 0.54 60% 0.37 0.41 0.46 0.51 0.54 0.56 65% 0.41 0.45 0.49 .0.54 0.57 0.59 70% 0.45 0.49 0.53 0.58 0.60 0.62 75% 0.51 0.54 0.58 0.62 0.64 0.66 80% 0.57 0.59 0.63 0.66 0.68 0.70 85% 0.63 0.66 0.69 0.72 0.73 0.75 90% 0.71 0.73 0.75 1 0.78 0.80 0.81 95% 0.79 0.81 0.83 0.85 0.87 0.88 100% 0.89 0.90 0.92 0.94 0.95 0.96 2007-01 RO-11 Urban Drainage and Flood Control District RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) TABLE RO-5 (Continued) -Runoff Coefficients, C Percentage Imperviousness Type A NRCS Hydrologic Soils Group 2- r 5- r 10- r 25- r 50- r 1 00-r 0% 0.00 0.00 0.05 0.12 0.16 0.20 5% 0.00 0.02 0.10 0.16 0.20 0.24 10% 0.00 0.06 0.14 0.20 0.24 0.28 15% 0.02 0.10 0.17 0.23 0.27 0.30 20% 0.06 0.13 0.20 0.26 0.30 0.33 25% -0.09 1 0.16 0.23 0.29 1 0.32 0.35 30% 0.13 0.19 0.25 0.31 0.34 0.37 35% 0.16 0.22 0.28 0.33 0.36 0.39 40% 0.19 0.25 0.30 0.35 0.38 0A1 45% 0.22 0.27 0.33 0.37 0.40 0.43 50% 0.25 0.30 0.35 0.40 0.42 0.45 55% 0.29 0.33 1 0.38 0.42 0.45 0.47 60% 0.33 0.37 0.41 0.45 0.47 0.50 65% 0.37 0.41 0.45 0.49 0.51 0.53 70% 0.42 0.45 0.49 0.53 0.54 0.56 75% 0.47 0.50 0.54 0.57 0.59 0.61 80% 0.54 0.56 0.60 0.63 0.64 0.66 85% 0.61 0.63 0.66 0.69 0.70 0.72 90% 0.69 0.71 0.73 0.76 0.77 0.79 95% 0.78 0.80 0.82 0.84 0.85 0.86 100% 0.89 0.90 0.92 0.94 0.95 0.96 RO-12 2007-01 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF ' S0 ' 30 r~ 20 Z W U W d 10 ' Z W a CJ 5 ' U) W 3 ' O V 2 W H ' 1 5 MEN H FA ON 'oil 'I IN 11111110 �II�► 1 .2 § .5 1 2 3 5 10 20 VELOCITY IN FEET PER SECOND ' Figure RO-1—Estimate of Average Overland Flow Velocity for Use With the Rational Formula ' 2007-01 RO-13 Urban Drainage and Flood Control District JT Ir7 V. _T c Q Cl) 9 C O 7 own U � O U °f � c 0 3 o a U LL a N G � O u y C O M 0 U O c LL O G �► +' O 0 y ri � « m a U _ a R � w c C — '� o � U r 0 LL U 1 1 + ; I - ;.. + , , '-tit {•.. rl -10 0 0 O 0 O O 0 O O 0 0 0 0 0 0 0 0 0 0 0 0 T-: O G) co LO rt c7 N .- O (aL4lUl) AI!SLIOIuJ O N 0 f e City of Fort Collins Rainfall Intensity -Duration -Frequency Table for using the Rational Method (5 minutes - 30 minutes) Figure 3-1 a Duration (minutes) 2-year Intensity in/hr 10-year Intensity in/hr 100-year Intensity in/hr 5.00 2.85 4.87 9.95 6.00 2.67 4.56 9.31 7.00 2.52 4.31 8.80 8.00 2.40 4.10 8.38 9.00 2.30 3-93 8.03 10.00 2.21 3.78 7.72 11.00 2.13 3.63 7.42 12.00 2.05 3.50 7.16 13.00 1.98 3.39 6.92 14.00 1.92 3.29 6.71 15.00 1.87 3.19 6.52 16.00 1.81 3.08 6.30 17.00 1.75 2.99 6.10 18.00 1.70 2.90 5.92 19.00 1.65 2.82 5.75 20.00 1.61 2.74 5.60 21.00 1.56 2.67 5.46 22.00 1.53 2.61 5.32 23.00 1.49 2.55 5.20 24.00 1.46 2.49 5.09 25.00 • 1.43 2.44 4.98 26.00 1.40 2.39 4.87 27.00 1.37 2.34 4.78 28.00 1.34 2.29 4.69 ---29.00--- -- - 1.32------ -----.2.25 --- --- _- 4.60------- 30.00 1.30 2.21 4.52 . City of Fort Collins Rainfall Intensity -Duration -Frequency Table for using the Rational Method (31 minutes - 60 minutes) Figure 3-1b [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 - - -- 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 0.52 1.40 2.86 n APPENDIX B Detention Pond Analysis V o � y' o o � a o W O V O O � m S s Q � ¢ O y O v'1 V1 V'1 V1 e 0 M M M M X av h o00 0 C] M b N O y to y C N -% n M O O Q O 0 0 0 O n u N N 7 M 0 n 3 c O n 7 n O D\ M M 00 �1 a, N W O N Ls, Q O O N 0 of 0 M 0 N O Cy 3 O M b O N N „'i 7 O\ etl N b Q D N Mi O\ V N a - _ _ 5 a n Q V O m N N w C c W U y = O t .0 •C .a .0 3 w O O U U O C s F = o C C o 0 C v1 7 ll CI O O O U O O O CS V b 6. h O o 0 0 O 0 M M M E o o v a s w Q � s G w X = O E V o M N M N M N Q N C)N N N 00 m L m v¢o Detention Pond Calculations - POND P PROJECT NAME Union Place PROJECT NUMBER FCB0277 BE YON D E N G IN E E R ING Area (acres) C100*Area %I Comments A-M 11.30 7.12 49% TOTAL, Y = 11.30 7.12 49% Ave Cloo = 0.63 Qo , (cfs) = 2.26 0.20 cfs/acre Tc (min) = 30 Reauired Detention Pond Volume Rainfall Duration (T) Rainfall Intensity Q;� �C100*Area*I Inflow Volume Adjustment Factor Average Outflow Rate Outflow Volume Required Storage Volume I V (Q;,,*T*60) m= 0.5(1 + T�/T) Qac= m*Q.u, Va Qe *T *60 Vs V; Va min in/hr cs ft 3 cs ft 3 ft 3 5 9.95 70.89 21,267 1.00 2.26 678 20,589 10 7.72 55.00 33,001 1.00 2.26 1,356 31,645 15 6.52 46.45 41,807 1.00 2.26 2,034 39,773 20 5.60 39.90 47,877 1.00 2.26 2,712 45,165 25 4.98 35.48 53,220 1.00 2.26 3,390 49,830 30,,. 4.52 32.20 57,965 1.00 2.26 4,068 .53,89..7 35 4.08 29.07 61,043 0.93 2.10 4,407 56,636 40 3.74 26.65 63,950 0.88 1.98 4,746 59,203 45 3.46 24.65 66,558 0.83 1.88 5,085 61,472 50 3.23 23.01 69,037 0.80 1.81 5,425 63,612 55 3.03 21.59 71,238 0.77 1.75 5,764 65,475 60 2.86 20.38 73,354 0.75 1.70 6,103 67,252 70 2.59 18.45 77,501 .0.71 1.61 6,781 70,720 80 2.39 17.03 81,733 0.69 1.55 7,459 74,274 90 2.23 15.89 85,794 0.67 1.51 8,137 77,657 100 2.08 14.82 88,914 0.65 1.47 8,815 80,099 110 1.96 13.96 92,163 0.64 1.44 9,493 82,670 120 1.83 13.04 93,873 0.63 1.41 10,171 83.702 Max Volume,ft3= 83,702 Water Quality 28 1.92 acre ft Assume WQ needs to be provided in the extended detention basin for the basins given below. Other basins direct flow to grass -lined swales, porous pavements, infiltration trenches, flat bottom ponds or a combination and therefore WQ is provided in these features Basin Area %I*A %1 Total to Detention Pond requiring WQ in EDB acres J 1 0.20 0.17 86% J2 0.26 0.21 81% H 0.23 0.20 85% G1 0.41 0.29 72% E4 1.21 0.84 69% TOTAL 2.31 1.71 74% % I = Time=40 hours, from Figure SQ-2, WQCV = Net Required Storage = (WQCV/12)*Area* 1.2 = Less Storage provided in rock rubble section in pond = Required Storage = Total Required Detention Pond Volume 74% 0.29 watershed inches 2,964 ft 3 = 0.07 acre ft 1,436 ft3 = 0.03 acre ft 1,528 ft 3 = 0.04 acre-ft Total required Volume, without individual WQ and smaller detention = 85,230 ft' = 1.96 acre-ft Detention Provided in Pond C1 -2,868 ft 3 = -0.07 acre ft Detention Provided Under Porous Pavement in C2 -2,307 ft3 = -0.05 acre-ft Detention Provided Under Porous Pavement in A3 -1,768 ft 3 = -0.04 acre ft Detention Provided Under Porous Pavement in D -3,133 ft 3 = -0.07 acre-ft Total Required Volume = 75,154 ft 3 = 1.73 acre ft Detention Pond Volume and De Delta Volume = (d/3)(A I+A2+(A l *A2 rovided above elevation 4978. Elevation d Elevation Area Delta Volume Cumulative Volume ft ft ft z ft 3 ft' acre-ft 4YYn r Knttnm nt Kamnv�n/ Knit(/ 78.76 0 55,884 0 0, 0.00 79.00 P 0.24 66,238 14637 14,63.7 0.34 80.00 1.00 75,413 70776 85,413 1.96 4981.00 1.00 84,883 80101 165,514 3.80 4981.30 030 89,213 26112 191,626 4.40 4982.30 Tope of Berm Basin P1 I Basin P2 I Basin P3 Elevation Elevation Area- - ft 2 ft 3 ft a 4,978.76 )8,o47 17,254 584 4,979.00 45,969 18,564 1,705 4,980.00 50,640 21,681 3,092 4,981.00 55,346 25,332 4,205 4,981.30 56,866 27,062 5,285 4,982.30 i ne initial elevation 49/5. /b was based on the invert of the existing outlet pipe. This would have been bottom elevation for Pond P1 if temporary retention was not present W.S. Elevation, ft Elev81- Elev80 (V01R1qui11a-V0180)+Elev8o = Vo181 - V080 W.S. Elevation, ft = 4979.86 100-year Depth D, ft = 1.10 At elevation 4978.76 100-year Depth D, ft = 3.06 At elevation 4976.8 Top -of -Berm, ft = 4982.30 Freeboard ,ft = 2.44 I FCB0277_Runoff_Final3.xls, pond P 10/13/2009,4:08 PM Detention Pond Calculations - POND P PROJECT NAME Union Place PROJECT NUMBER FCB0277 BE Y O N D E N G IN E E R ING Orifice Orifice Flow Rate, Q (cfs) _ Co = Q = Qo,,, of pond, cfs = gravitational acceleration g, ft/sec a = diam, ft = Effective head on orifice Ho = D-1/2diam, ft = Area of orifice Ao, ft z= Area of orifice Ao, in a = diam, in= 0 Area of orifice A., ftz = Q 0.6 2.26 32.2 0.854 0.67 At elevation 4978.76 0.57 82.70 10.26 102 1 8 Co(2gHo)0" inch diameter opening Regional Detention Pond Volume and Depth (provided above elevation 4976.8) Delta Volume = (d/3)(A1+A2+(A1 *A2)0.5) Scenario #1 - Does not include basin P3 Basin P1 Basin P2 Bas Elevation d Elevation Area Delta Volume Cumulative Volume ft ft ft a ft, ft 3 acre ft 4976.8 0 0 0 0 0.00 4977.0 0.2 384 26 26 0.00 4978.0 1 47,876 17516 17,542 0.40 4979.0 1 64,533 55998 73,539 1.69 4980.0 1 72,321 68390 141,929 . 3.26 4981.0 1 80,678 76461 218,391 5.01 4981.3 0.3 83,928 24689 243,080 5.58 Scenario #2 - Does include basin P3 Elevation d Elevation Area Delta Volume Cumulative Volume ft ft ft2 acre ft 4976.8 0 0 0 01 0.00 4977.0 0.2 384 26 26 0.00 4978.0 1 47,876 17516 17,542 0.40 4979.0 1 66,238 56809 74,351 1.71 4980.0 1 75,413 70776 145,127 3.33 4981.0 1 84,883 t 80101 , 225,228 1 5.17 4981.3 0.3 89,213 1 ' 26 112 251,340 5.77 0 Scenario #2 - Does include basin P3 Elevation d Elevation Area Delta Volume Cumulative Volume ft ft ft2 acre ft 4976.8 0 0 0 01 0.00 4977.0 0.2 384 26 26 0.00 4978.0 1 47,876 17516 17,542 0.40 4979.0 1 66,238 56809 74,351 1.71 4980.0 1 75,413 70776 145,127 3.33 4981.0 1 84,883 t 80101 , 225,228 1 5.17 4981.3 0.3 89,213 1 ' 26 112 251,340 5.77 0 0 in P3 Basin Pl T Basin P2j Basin P3 Elevation Elevation Area ft ft 2 ft 2 ft 4,976.80 0 0 4,977.00 0 384 4,978.00 32,768 15,108 4,979.00 45,969 18,564 1,705 4,980.00 50,640 21,681 3,092 4,981.00 55,346 25,332 4,205 4,981.30 56,866 27,062 5,285 FCB0277_Runoff Final3.xls, pond P 10/13/2009,4:08 PM i' ..Ar Detention-Pon&Carouations EP N 3. O D CZ PROJECT NAME Uniona Plce --- PROJECT NUMBER FCB027i7i B E Y. O N D E N G I N E E R 1 N G CALCULATED BY MEW C1 Required Detention Pond Volume Area (a( 0.49 )TAL, - = 0.49 Ave Cloo = 0.51 ?out (cfs) t020 i�i!' To (min) = 11 *Area Comments .28 .28 0.42 cfs/acre Rainfall Rainfall Inflow Volume Adjustment Average Outflow Required Storage Durahon(T) Intensity *A*I Qi,� ZCIIoorea Factor Outflow Rate Volume Volume Vi (Qin*T*60) m= 0.5(1 + Tc/T) Qav= m*Qout Va Qav*T *60 VS V;-Vo I I. min in/hr jcfs ft 3 cfs ft 3 ft 3 5 9.95 217 830 1.00 0.20 61 769 10 7.72 2.15 1,289 1.00 0.20 122 1,167 15 6.52 1181 1,632 0.87 0.18 158 1,474 20 5.60 1156 1,869 0.77 0.16 189 1,681 25 4.98 1:39 2,078 0.72 0.15 219 1,859 30 4.52 1 26 2,263. 0.68 0.14 250 2,014 35 4.08 1.13 2,383 0:66 0.13 .280 2,103 40 3.74 1.,04 2,497 0.64 0.13 311 2,186 45 3.46 0.;96. 2,599 0.62. 0.13 341 - 2,258 50 3.23 0..90 2,696 0.61 0.12. 371 2,324 55 3.03 0.84 2,782 0.60 0.12 402 2,380 60 2.86 0.80 2,864 0.59 0.12 432 2,432 70 2.59 0.72 3,026 0.58 0.12 493 2',533 80 2.39 0.66 3,191 0.57 0.12 554 4637 90 2.23 0.62 3,350 0.56 0.11 615. 2',735 100 2.08 0.58 3,472 0.55 0.11 676 2796 110 1.96 0.55 3,599 0.55 0.1.1 737 21862 120 1.83 0.51 3,665 0.55 0.11 798 2,868 Max Volume, ft3 = 2,869 Max Volume, acre ft = 0.07 Detention Pond Volume and Depth Delta Volume = (d/3)(A1+A2+(A1 * a = depthib'etween elevations Al = Area of Previous Elevation, ft2 A2 = Area iof Current Rle.,ar;n„ frz Elevation d tion Area Delta Volume Cumulative Volume t f i ft 2 ft 3 ft ft 3 acre ft 4984.65 0 0 76,527 0 0 0.00 498;5;.00 0.35 ,578 184 184 0.00 4985,.71 0.71 2678 2,862 0.07 W.S. Elevation, ft = 4985.71 100-year Depth D, ft = 1.06 At outlet pipe Top -of -Berm, ft = 4985.71 Freeboard , ft = 0.00 Orifice Opening 1. Orifice Flow Rate; Q (cfs) = CoAo(2gHo)o.s Co = Q = Qout of = 0.6 p'tind, cfs 0.20 gravitational acceleration ft/sec 2 = 32.2 diam, ft °' .' ' 0 235`- Effective head on orifice Ho = D-1/2diam, ft = 0.94 Area of orifice! AO, ft2=.0.04 11 Area of orifice k, in 2 = 6.25 tam, in = 2.82 .i i! t Area of orifice Ao, ft2 = Q Co(2gHo)os B 2 7 inch diameter opening 8 FCB0277_Runoff_Finall.xls, pond 01 7/31/2009,7:38 AM ' STORAGE DRAINAGE CRITERIA MANUAL (V. 2) ' Design Example 6.1 shows calculations of allowable release rate and storage requirement using empirical equations. ' 3.2.3 Rational Formula -Based Modified FAA Procedure The Rational Formula -based Federal Aviation Administration (FAA) (1966) detention sizing method ' (sometimes referred to as the "FAA Procedure"), as modified by Guo (1999a), provides a reasonable estimate of storage volume requirements for on -site detention facilities. Again, this method provides sizing for one level of peak control only and not for multi -stage control facilities. The input required for this Rational Formula -based FAA volume calculation procedure includes A = the area of the catchment tributary to the storage facility (acres) C = the runoff coefficient QP = the allowable maximum release rate from the detention facility based on Table SO-1 (cfs) T, = the time of concentration for the tributary catchment (see the RUNOFF chapter) (minutes) P, = the 1-hour design rainfall depth (inches) at the site taken from the RAINFALL chapter for the ' relevant return frequency storms The calculations are best set up in a tabular (spreadsheet) form with each 5-minute increment in duration ' being entered in rows and the following variables being entered, or calculated, in each column: 1. Storm Duration Time, T (minutes), up to 180 minutes. 2. Rainfall Intensity, 1(inches per hour), calculated using Equation RA-3 from the RAINFALL chapter. ' 3. Inflow volume, V; (cubic feet), calculated as the cumulative volume at the given storm duration using the equation: V. —CIA 60T (SO-6) ' 4. Outflow adjustment factor m (Guo 1999a): m = 1 I 1 + T` 0.5 <_ m < 1 and T >_ T, (SO-7) 2 TJ 5. The calculated average outflow rate, Qav (cfs), over the duration T. ' Q.v = mQpo (SO-8) ' SO-10 0112007 Urban Drainage and Flood Control District 1 DRAINAGE CRITERIA MANUAL (V. 2) STORAGE 1 6. The calculated outflow volume, Vo, (cubic feet), during the given duration and the adjustment ' factor at that duration calculated using the equation: V. =.Q.v (60T) (SO-9) 7. The required storage volume, Vs (cubic feet), calculated using the equation: ' Vs = V,. — Vo (SO-10) The value of V, increases with time, reaches a maximum value, and then starts.to decrease. The ' maximum value of V, is the required storage volume for the detention facility. Sample calculations using ' this procedure are presented in Design Example 6.2. The modified FAA Worksheet of the UD-Detention Spreadsheet performs these calculations. 3.2.4 Simplified Full -Spectrum Detention Sizing (Excess Urban Runoff Flow Control) , With urbanization, the runoff volume increases. Percentage -wise, this increase is much more noticeable for the smaller storm events than for the very big ones, such as the 100-year storm. Wulliman and ' Urbonas (2006) suggested a concept they termed Full Spectrum Detention. This concept was studied using extensive modeling, including continuous simulations of a calibrated watershed. Based on this ' modeling the original set of equations was slightly modified to increase the EURV by 10%. The protocol that resulted and that is described below reduced runoff peak flows from urbanized areas to more closely approximate the runoff peaks along major drainageways before urbanization occurred. ' This concept captures a volume of runoff defined as the Excess Urban Runoff Volume" (EURV) and then releases it over approximately 72-hours. EURV is larger than the Water Quality Capture Volume (WQCV) ' defined in Volume 3 of this Manual and varies with the type of NRCS soil group upon which urbanization occurs. EURV includes within its volume the WQCV, which then makes it unnecessary to deal with it ' separately when the Full Spectrum Detention design is used. Full Spectrum Detention Equations SO-11, -12 and -13 may by used to find the EURV depths in watershed inches. They were developed using the hydrologic methods described in this Manual. , NRCS Soil Group A: EURV, =1.1 • (2.0491 • i — 0.1113) (SO-11) NRCS Soil Group B: EURV,, =1.1 • (1.2846 • i — 0.0461) (SO-12) ' NRCS Soil Group C/D: EURVco =1.1 • (1.1381 • i — 0.0339) (SO-13) ' in which, EURVK = Excess Urban Runoff Volume in watershed inches (K = A, B or CD), i = Imperviousness ratio (I/100) ' 01/2007 SO-11 ' Urban Drainage and Flood Control District u APPENDIX C Open Channel and Street Capacity Analysis i I 4 0 4 . Y is L 0 w O a O •-• M °� � U 0- N M V1 �O r T N M d d �o S 9 St� N N N N N N N N N N N N N N y N C wad � 0 0 0 0 0 0 0 0 0 0 0 0 0 0 aU U O II II II II II II II uo'a U 0mSr .` o000000004000 �O h ap T O h O N 0 C O A O P c pp C U C O m U y c � 7 C o0 � eyo U C � V O U o II N II II II O O .Q w Y U y C➢ e � Y UC •N �W+ G = m S m c w U t o n n u c = n O x Q, o li a al"Iololololololololololololol rdl QI �IOIOIOINIOIMIKIhI�D I�DI OI�IOI� c olV101b101m U V N d W d N N N N N U b U b b b b b N N Q\ N N N L Zvi O O �n V1 rv, O O �n O vi S 3 N N V lV lV N _ U U W 7 m 3vUC°u�FQ U H N 0 > 3 0 abi O c cn O L n 0 0 Z V O n L O c rz 'D w «O O + cd O M �D �D \O l- n 00 M O\ O\ 00 lr� lO b cM O Cl O O O O O O 0 0 0 O O O Cl UC] W b 'd c o c a �o id N cd .� 3 3 o 0 0 cn o 00 v 0 0 O M M N N q cd N �t y C y ❑ N N Vi L U c ^ p O vi o v, ^o a N N N a �00000ao 0000 0 0 0 0 C 0 0 0 0 3 �D % N 00 �o 00 -It kr) 01 N U U M Cl) M M ,-. ^ O Le)^-' 01 C1 Vl r L L O 0 6 6 6 Q Cl O O 0 a h r- N 01 Cl) M r- ^ \o ^ ^ '� Vl 00 M U M V'1 ^ M Ln O 00 [� N c Q Q m 7 U U U U W [Mil N W W M W U 0'a 01 W W U Q Q W U W W c 0 mw owu v d U w w w c7 Qn 0 c 0 U U m • L L a � U O o o `c° s w o w- 0 n b m cdll Y cn cn Y 3 3 c 3 0 0 0 C 0 r_o 0 � V) 3 3 0 U r"y o r_ w O w O N N L a��i a` c m rig 0v Y o 0 Q p c 0 ^� cn cn s s N p d y 3 d 3 adi d 3 0 0 o v adi uo co) cn 3 12' Alley Section with Rollover Curb with 3% Cross Slope ProiectRescription Friction Method Manning Formula Solve For Discharge Bentley Systems, Inca Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 8/3/2009 9:47:41 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666, Page 1 of. 1 12' Alley Section with Rollover Curb with 3% Cross Slope Pr ojectDescriptlon.'IN - Friction Method Manning Formula' Solve For Discharge Input Data �^ ., __.° v ; Channel Slope 0.66 % r7CGMple. Normal Depth 0.36 ft Section Definitions 0+00.00 0.36 0+12.00 0.00 0+13.42 0.40 Roughness Segment Definitions (0+00.00, 0.36) (0+13.42, 0.40) 0.016 (.KO loons Results Elevation Range 0.00 to 0.40 ft Flow Area 2.39 ft' Wetted Perimeter 13.33 ft Hydraulic Radius 0.18 ft Top Width 13.27 ft Normal Depth 0.36 ft Critical Depth 0.35 ft Critical Slope 0.00669 ft/ft Velocity 2.29 fUs Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 8/3/2009 9:48:04 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1.203-755-1666 . Page 1 of 2 12' Alley Section with Rollover Curb with '3%a Cross Slope Velocity Head 0.08 ft Specific Energy 0.44 ft Froude Number 0.95 Flow Type Subcritical Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 Upstream Depth Profile Description Profile Headloss Downstream Velocity UpstreamVelocity Normal Depth Critical. Depth Channel Slope Critical Slope 0.00 ft 0.00 ft Infinity ft/s Infinity ft/s 0.36 ft 0.35 ft 0.60 % 0.00669 ft/ft _ Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 8/312009 9:48:04 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 - Page 2 of 2 Friction Method Solve.For Cross Section for Section Al, Basins Al-A2 Manning Formula Normal Depth Channel Slope 60 % Normal Depth r Wil >`] pk _,?:Y�� y'� -`�° 7 ,. 25' 4 •.y��.b liy".^i ,yy�{{. qT^i':. nir.`ti 55 4�i.�*' ``�t" 1 0 0 a.�?g ,R3]xu--Y°.}l`te 0.45 0.40 0.35 0.30 a 0.25 rT 0.20 LO 0.15 0.10 0.05 0.00 -0.05 -0.10 -0.15 -0.20 -025 0+02 0+04 0+06 0+08 0+10 0+12 Station Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster 108.11.00.031 8/3/2009 8:24:46 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 u Cross Section for Section Al, Basins Al-A3 1 WE Friction Method Manning Formula Solve For Normal Depth Input Data- Channel Slope 0.60 Normal Depth 0.35 ft Discharge 5.20 Wis Cr if ect on Linage .. 0.65 0.6D e........_.....d._......._.. u..... ....... e..... _....... i.-............ .................. -. 0.55 ........a...... _........ ...._......-4............... >.............. ................ i..................... 0.50 _...... .............. a...... .........;........................ __..;.............. ............. 0.45 ........ ;.............. _........... ......._._.....c........._...—.......... .......... 0.4D ........_......__........._..._........_..._....;...............:.............. 0.35 ...._....._.._......... __........_...._....._.......:...............: .................. 0.30 q 0 0.25 ._................ .-_....._....:_. .... e-................................ >......... >...... — 0.20 ................ ......... ....... ....... .......... .................... ... ...._w. ............... ..... i w0.15 ._._................_....-...._._ ...... .._. 0.10 € i ............ ............. . . _.... _.... _..... _......... ...................... _..... 0.05 ......;............_.;...._..._..___._..........g........_.....;...._........: ............... 0.00 ....................... _.... ............... ;............... ;.,.................. 0.05 ..................................................................p...............i..................... -0.10 ........;.........._...:.._........._...._.........:.............. .a_ ............. ............. 0.15 -0.20 ................ >.......... .._....... __..>.............................. ........ .......... _ 0+00 0+02 0+04 0+06 0+03 0+10 0+12 Station R Bentey Systems, Inc:- Haestad Methods Solution Center Bentley FlowMaster. [08.11.00.03] 8/312009 8:38:03 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203.755-1666 Page 1 - of 1 u= 0.60 0.55 0.50 0.45 0.40 0.35 0.30 0 0.25 V 0.20 w 0.15 0.10 0.05 0.00 -0.05 -0.10 -0.15 -020 -0.25 0+00 0+05 0+10 0+15 Station Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 8/3/2009 8:44:26 AM 27 Slemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of . 1 16' Alley Section with Rollover Curb with 2% Cross Slope z: n Friction Method Manning Formula Solve For Discharge In ut Data �r��� 3.r•.,} .� � �` : ��F� �-x �R� � ; � � � _ ��, Channel Slope 0.50 % e,<Am ple Normal Depth 0.32 ft Section Definitions 0+00.00 0.32 0+16.00 0.00 0+17.42 0.40 l Roughness Segment Definitions (0+00.00, 0.32) (0+17.42, 0.40) 0.016 current nougnness vveigmea Pavlovskii's Method Method Open Channel Weighting Method Pavlovskii's Method Closed Channel Weighting Method Pavlovskii's Method ' Results ' Elevation Range Flow Area Wetted Perimeter tHydraulic Radius Top Width ' Normal Depth Critical Depth . Critical Slope ' Velocity ' 81312009 8:44:49 AM 0.00 to 0.40 ft 5.30 ft'/s 2.74 ft' 17.18 ft 0.16 ft 17.14 ft 0.32 7 ft 0.30 ft 0.00705 tuft 1.93 ft/s Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.031 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203.755-1666- Page 1 of 2 16' Alley Section with Rollover Curb with 2% Cross Slope Results h �, Velocity Head 0.06 ft Specific Energy 0.38 ft . Froude Number 0.85 Flow Type Subcritical GUF$glnput Data ° {_ a ; r BPVTi.-i� '�I..:1 `i'Y}ry'-+ m ' Y„ sL. l'•:. Sv Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 G,V ®utPut Data'A i1115 Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity Infinity f /s Upstream Velocity Infinity fUs Normal Depth 0.32 ft Critical Depth 0.30 ft Channel Slope 0.50 % Critical Slope 0.00705 ft/ft Bentley Systems, Inc. Haestad Methods'Solution Center . Bentley FlowMaster [08.11.00.03] 8/3/2009 8:44:49 AM . - 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755.1666 Page 2 of 2 Cross Section for Section B1, Basin B1 PkojectDescnpfion=.s - a Friction Method Manning Formula Solve For Normal Depth Channel Slope 0.60 % Normal Depth 0.21 ft Discharge 1.90 ft3/s 0.55 0.50 0.45 0.40 0.35 0.30 0 0.25 V 0.20 ru 5 0.1...... 0.10 0.05 0.00 -0.05 -0.10 0.15 -0.20 -0.25 L 0+00 0+05 0+10 0+15 Station Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 8/3/2009 8:45:53 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 Cross Section for Section El. Basin E1 +Y 'i"i`Yi 1'Wy°`"'g'ym"+�.._• Project Descrlptlon x .�~ft��. �1� `fib. RV k'=2ui'+� �.. & j}gk'iG MEN- Ma , Friction Method Manning Formula Solve For Normal Depth mm Channel Slope 0.50 % Normal Depth 0.29 ft Discharge 3.30 ft3/s _.-c: scar #T = aer a x r u .r-3- s S•.x •sr.€. GrossRSectionl`mage n'3A. 0.65 ................................:.._..................._......v................................ 0.60 - .........................................................._................................... 0.55 ....... _....... i.......... ............ .... ..... I......... ................ ......i................. ......:........ , 0.50 ............................._.:.........................--.._................................ 0.45 ...................................................... ................. ....... ....... ......... ................ 0.40 ..............._..........................................._..._..................................... 0.35 ................................................................................................ 0.30 _.....__.....„.....................:......._................ 0 0.25 ._-........... ...I. ................... _....i.......... ............ ....... .................. ......... .... 0.20 i ......................................_v............................ w0.15_.............. i........ ....... ...._..........i.........................:.............................. 0.10 i ..................---._......._.........._........... ...... 0.05 ........... :................. _............. ...... ... ... ........... .__.............. ............ 0.00 ............................................. 0.05_..._.........i........................._.... -0.10 ........._._........................__.._i...............................b.........:...................... -0.15 _.... ..i.._............................ :.............. ............... _a ................ -- ........ ... -0.20 -0.25 0+00 0+05 0+10 0+15 Station Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 8/3/2009 8:58:02 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 Cross Section for Section B2, Basins B1-B2 Descnptlon, Protect p Friction Method Manning Formula Solve For Normal Depth Input Data = 'g ' ' Channel Slope 0.60 % Normal Depth 0.59 ft Discharge 5.30 ft /s Goss Section lmage� 1.80 1.60 — ............... -i........... ......__:....... ........_ ..._... ........-........... 1.40- 1.20 .......... ....... ......... ...................... ..................... ...... .............. ............ c 1.00 o..........i............ ....... i....... _............. €..................... .............. ........ _............ 0.80 i .........................................................:.......... . LL' 0.60 _ 0.40 0.20 ........_._.-.........-_..._i----...._...._... ............ ............._........ 0.00 -0.20 0+00 0+10 0+20 0+30 0+40 0+50 Station Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.031 9/9/2009 8:05:28 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755.1666 Page 1 of 1 Cross Section for B3, Basin B3 Protect Friction Method Solve For Manning Formula Normal Depth IriptatData� _ Channel Slope Normal Depth Discharge 0.60 0.42 ft 1.70 ft3/s Cross Section,lmage... 1.60 1.40 1.20 1.00 c 0.80 a w 0.60 0.40 0.20 0.00 -0.20 0. Station Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster 108.11.00.03] 9/9/2009 8:07:12 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1.203-755.1666 . Page 1 of 1 Cross Section for C4, Basin C4 Friction Method Manning Formula. Solve For Normal Depth Input Data1,11NOWAM"Em ME - Channel Slope 0.66 Normal Depth 0.45 It Discharge 1.10 fN/s Station Bentley Systems, Inc. Heel Methods Solution Center . Bentley FlowMaster [08.11.00.03] 813/2009 10:48:00 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 - Page 1 of 1 Invereted Crown Friction Method Manning Formula Solve For Discharge 0.80 0.70 0.60 0.50 0.40 c 0 .V 0.30 n m w 0.20 0.10 0.00 -0.10 -0.20 0 Station 8 Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 8/3/200911:13:14 AM - 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 - . Page 1 of 1 ' Invereted Crown Alley ' P,r'b t Descnptlon,:- Friction Method Manning Formula Solve For Discharge Input•Data� �a-e'�i?>' 2��"�' y"d9 *.aYss"`* '#Fz^'���``' a�y_�m.� ,$y� a� > �� . Channel Slope 0.60 % eXGM alb ' Normal Depth 0.56 ft Section Definitions 0+00.00 0+01.42 0+07.50 0+13.85 0+15.00 Roughness Segment Definitions 0.56 0.17 0.00 0.17 0.56 (0+00.00, 0.56) (0+15.00, 0.56) 0.016 ' Options currem Kougnness vvelgmea Pavlovskii's Method Method Open Channel Weighting Method Pavlovskii's Method ' Closed Channel Weighting Method . Pavlovskii's Method ' Discharge 25.62 ft-/s Elevation Range 0.000 to 0.560 ft ' Flow Area 6.35 ft' I Wetted Perimeter 15.094 ft Hydraulic Radius 0.42 ft ' Top Width 14.973 ft Normal Depth 0.56 ft ' Critical Depth 0.58 ft ' Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 8/3/2009 11:13:31 AM 27 Siemens Company Drive Suite200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2 Invereted Crown Alley Critical Slope 0.00494 Wit Velocity 4.04 ft/s Velocity Head 0.25 ft Specific Energy 0.81 ft Froude Number 1.09 Flow Type Supercritical Downstream Depth 0.00 ft Length 0.000 ft Number Of Steps 0 Upstream Depth Profile Description Profile Headloss Downstream Velocity Upstream Velocity Normal Depth Critical Depth Channel Slope Critical Slope 0.00 ft 0.00 ft Infinity ft/s Infinity fUs 0.56 ft 0.58 ft 0.60 % 0.00494 ft/ft Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster 108.11.00.03] 8/3/2009 11:13:31 AM 27 Slemons Company Drive Suite200 W Watertown, CT 06796 USA +1-203-755-1666 - ' Page 2 of 2 Cross Section for C2, Basins CI-C2 Friction Method Manning Formula Solve For Normal Depth Channel Slope 0.60 % Normal Depth 0.30 ft Discharge 6.60 ft /s � '4 U tom. ? 0.61 0.71 0.61 0.51 0.41 c 0 0.31 a m w 021 0.11 0.01 -0.11 -0.21 Station Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 10/13/2009 4:25:41 PM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 Cross Section for Boa, Basins B,C Friction Method Manning Formula Solve For Normal Depth Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 10/13/2009 4:26:20 PM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 rCross Section for B4b, Basins B,C Projecescriptio" t+Dn ,v ' Friction Method Manning Formula Solve For Normal Depth .717 Input{Data h F Channel Slope 0.60 ' Normal Depth 0.96 ft Discharge 14.10 Wls "� ' 2.00 1.80 1.60 ' 1.40 C 120 0 1.00 w 0.80 0.60 0.40 020 0.00 -0.20 0+00 10/13/2009 4:26:41 PM 0+05 0+10 0+15 0+20 Station Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1. of 1 ' Cross Section for B4c, Basins B,C PrgjectDescnptlon ' Friction Method Manning Formula Solve For Normal Depth N i Iripit4Data q 4 f X51i -r1 1c pa i .. LL ty4 2 -$tit n Channel Slope 0.60 ' Normal Depth 0.86 ft Discharge 14.10 ft /s 1.31 1.21 ' 1.11 1.01 0.91 0.81 0.71 c ,0 0.61 $� 0.51 0.41 0.31 021 0.11 0.01 -0.11 ' 0.21 Station Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 10/1312009 4:27:00 PM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 Cross Section for. E2, Basin E1-E2 4- 0(,9wi ct ©escnption '§ _ Friction Method Manning Formula Solve For Normal Depth Input Data .i Channel Slope 0.60 % Normal Depth 0.56 ft Discharge 8.90 ft'/s Cross Section Image• _-= 0.90 0.80 0.70 0.60 0.50 c 0.40 0.30 w 0.20 0.10 0.00 -0.10 -020 0 Station Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 8/32009 12:51:48 PM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203.755-1666 Page 1 of 1 Cross Section for E3, Basins E7-E3 R cila scnptlon _- 4 Friction Method Manning Formula Solve For Normal Depth Input Data , `' zT Channel Slope 0.60 % Normal Depth 0.67 ft Discharge 10.70 ft'/s - Cross Section Image,m -,_ 1: 1. 1. 0. 0. 0. o a 0. m w 0. 0. 0. 0 0 -0 -0 30 20 10_ 30 30-.. 30 r0 30 i0 10 30 20 _ 10 Station p+25 0+30 Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster 108.11.00.03] 813/2009 1:24:08 PM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 Cross Section for E4, Basin E4 `i` r"":i rY v "i� "y a ProjectxDescnI pfion- g '.G,a r'F£1 R'n - ��rl .e F„s vM. ff.� Friction Method Manning Formula Solve For Normal Depth Input Data F� ."�'a r.i'e.'- +�� _.�_ "�'=..rig".....t-�'��.ia ��t�csc..� S� �.��•��..x df§s,.,�"*c.:� « a r'k _ ,,.. Channel Slope 0.46 Normal Depth 0.67 ft Discharge 7.50 ft3/s a nii`raaF"`—nv-`re"y'$t`i'" Cross Secfion Image,'F> : , 1.20 1.10 1.00 0.90 0.80 0.70 0 0.60 > 0.50 m w 0.40 0.30 020 0.10 0.00 -0.10 -0.20 10/1312009 4:37:10 PM 0+60 0+70 0+80 Station Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203.755-1666 Page 1 of 1 Cross Section for G1, Basin G1 bescnptlon Project p S Friction Method Manning Formula Solve For Normal Depth }'a i till Channel Slope 0.50 Normal Depth 0.38 ft Discharge 2.80 fP/s Cross'Section Image — r ._ M . $_<;• f 1.10 1.00 0.90 0.80 0.70 0.60 C 0.50 0.40 `L 0.30 020 0.10 0.00 -0.10 -0 20 Station 0+70 0+80 Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster 108.11.00.03] 10/13/2009 4:37:43 PM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1.203-755-1666 Page 1 of 1 Cross Section for Willox ultimate '�' � ' . Friction Method Manning Formula Solve For Normal Depth .*, 5 Channel Slope 0.50 % ' Normal Depth 0.99 ft d ✓fj%L . G R-n Ls—D/✓ 11a nn f43lc Discharge Cross,Sestiin Image; 1.10 1.00 0.90 0.80 ........................................... 0.70 x 0 0.50 0.40 w 0.30 020 0.10 0.00 -0.10 -0.20 0+20 0+40 0+60 0+80 Station Bentley Systems, Inc. Haestad Methods Solution Center . Bentley FlowMaster 108.11.00.03] 10113/2009 4:31:27 PM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 Worksheet for Willox ultimate 0 " '�a " — Zli-'xA Friction Method Manning Formula Solve For Normal Depth Channel Slope 0.50 % Discharge 114.00 ftl/s Section Definitions 0+00.00 0.81 0+06.00 0.69 0+15.50, 0.50 0+16.00 0.50 0+16.00 0.00 0+18.00 0.17 0+42.00 0.69 &L2 A-' 0+66.00 0.17 0+68.00 0.00 0+68.00 0.50 0+68.50 0.50 0+78.00 0.69 0+86.00 0.85 Roughness Segment Definitions (0+00.00, 0.81) (0+06.00, 0.69) 0.016 (0+06.00. 0.69) (0+15.50, 0.50) 0.040 (0+15.50, 0.50) (0+68.50, 0.50) 0.016 (0+68.50, 0.50) (0+78.00, 0.69) 0.040 (0+78.00, 0.69) (0+86.00, 0.85) 0.016 P"-�'�4 IWAX WON NO ON ETT L;urrem Kougnness vveigmea Pavlovskii's Method Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 10/13/2009 4:32;31 PM 27 Slemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2 Worksheet for Willox ultimate 1-2 KOptions v:'3 r "`. 3R _ 4 <%.;` ;:- W Open Channel Weighting Method Pavlovskii's Method Closed Channel Weighting Method Pavlovskii's Method �'` Normal Depth 0.99 It Elevation Range 0.000 to 0.850 It Flow Area 41.62 ft' Wetted Perimeter 87.351 ft Hydraulic Radius 0.48. ft Top Width 86.000 ft Normal Depth 0.99 ft Critical Depth 0.88 It Critical Slope 0.01123 ft/ft Velocity 2.74 ft/s VelocityHead' 0.12 ft Specific Energy 1.11 ft Froude Number 0.69 Flow Type Subcritical Downstream Depth 0.00 ft Length 0.000 ft Number Of Steps 0 Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 0.99 ft Critical Depth 0.88 ft Channel Slope 0.50 % Critical Slope 0.01123 ft/ft Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] ' 1011312009 4:32:31 PM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1.203-755-1666 Page 2 of 2 1.10 1.00 0.90 0.80 0.70 0.60 0.50 0.40 w 0.30 0.20 0.10 0.00 -0.10 -0.20 Oi �-- 'iVle l C4110J Th-thC ViCinl+ 2CL$ 2- ibnc1s 14,1,, e)ward P00d) 0 f-U s lopes 2 5 } Ireje. 00 0+20 0+40 0+60 Station 1 186,47 KO.9 � 1,4q CJS-5 copact�c.� IowS �er aCcs►n 405 = 168 cssS /1 . i inp�}-�iGw -fCJ e*1lefr t Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 6/8/2009 12:52:59 PM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203.755-1666 .Page 1 of 1 0+00.00 0.93 0+09.00 0.75 0+14.00 0.65 0+21.50 0.50 0+22.00 0.50 0+22.00 0.00 0+24.00 0.17 0+47.00 0.63 Grawyl 0+70.00 0.17 0+72.00 0.00 0+72.00 0.50 0+72.50 0.50 0+80.00 0.65 0+85.00 0.75 0+94.00 0.93 Roughness Segment Definitions (0+00.00, 0.93) (0+09.00, 0.75) 0.035 (0+09.00, 0.75) (0+14.00, 0.65) 0.016. (0+14.00, 0.65) (0+21.50, 0.50) 0.035 (0+21.50, 0.50) (0+72.50, 0.50) 0.016 (0+72.50, 0.50) (0+80.00, 0.65) 0.035 (0+80.00, 0.65) (0+85.00, 0.75) 0.016 Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.63] 6/81200912:53:17 PM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 .. Page 1 of 3 i Worksheet for Mason " a y�?Y 0 _'4.`e;.,.ib .:u . , i3 .,.,.'. T. _ i. i.�,�-+h3rt :�_ ♦ �'z %a>r- �. N 3`t5e- -. ii SlopeChannel 0.60 SlopeCdtical 11 Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03] 6/8/2009 12:53:17 PM 27 Siemons Company Drive Suite 200 W Watertown, CT,06795 USA +1-203.755.1666 Page 3 of 3 0 2 4 6 8 10 12 14 SLOPE OF GUTTER -Figure-4-2 REDUCTION FACTOR FOR ALLOWABLE GUTTER CAPACITY Apply reduction factor for applicable slope to the theoretical gutter capacity to obtain -allowable gutter capacity. (From: U.S. Dept. Of Commerce, Bureau of Public Roads, 1965) MAY 1984 4-4 DESIGN CRITERIA 1 .. 4.2.3 Major Storms The determination of the allowable street flow due to the major storm shall be based on the following criteria: • Theoretical capacity based on allowable depth and inundated area. ' • Reduced allowable flow due to velocity conditions. 4.2.3.1 Street Encroachment ' Table 4-2 sets forth the allowable.street inundation for the major storm runoff. Table 4-2 MAJOR STORM — STREET RUNOFF ENCROACHMENT Street Classification Maximum Encroachment Local (includes places, alleys, Residential dwellings, public, ' marginal access & collector) commercial, and industrial buildings shall not be inundated at the ground line unless buildings are flood proofed. The depth of water overthe crown shall not ' exceed 6 inches. Arterial and Major Arterial Residential dwellings, public, commercial and industrial buildings shall not be ' inundated atthe ground line unless buildings areflood proofed. Depth of water at the street crown shall not exceed 6 inches to allow operation of emergency ' vehicles. The depth of water overthe gutterflowline shall not exceed 18 inches. In some cases, the 18 inch depth overthe gutterflowline is more restrictive than the ' 6 inch depth over the street crown. For these conditions, the most restrictive of the two criteria shall govern. 4.2.3.2Theoritical Capacity Manning's equation shall be used to calculate the theoretical runoff -carrying capac- ity based on the allowable street inundation. The equation will be as follows: Q =1.486 Rm S'12 A n Where Q=Capacity, cfs n = Roughness Coefficient R=Hydraulic Radius, A/P S = Slope, feet/feet A=Area,—feet Appropriate "n" values can be found in Table 4-3. Any values not listed should be located in the Geological Survey Water Supply Paper, 1849. . Table 4-3 MANNING'S ROUGHNESS COEFFICIENTS FOR STREET SURFACES Surface Roughness Coefficient Gutter & Street...................................................................... 0.016 DryRubble ...................................... :...................................... 0.035 Mowed Kentucky Bluegrass ................................................. 0.035 Rough Stony Field.w/Weeds................................................. 0.040. Sidewalk & Driveway............................................................ 0.016 ' MAY 1984 4-5 DESIGN CRITERIA 1 APPENDIX D G Storm Sewer and Inlet Capacity Analysis O In T � y � t� y 10 0 T V d r- O T 00 C)o6 N r` W 0) O cY w Q > U) m C 0 0 0 0 0 0 Lri o Lri rn rn rn v v v (4) UOIIBA913 O LO T O O t T O + A 0 0 0 LO 0 I i (0 U) T r T co T 00 v (n E o O o O p U N r,� ! �o 1 �T i 1 N y ,ri a .. t 0) O ' w-cn o. N -ri _ o f0 + T ffJ N O t ! 7 U M ^ L K °°C U cmpC'v 1 Lo r co ; ,co+ cc Nc v \ o.. o o+ . N CL I C 41 p i r. O ,w Lr) (p 1, 1 °° co N a- 0 L w 0 ' °'- N� `, con. d t L C7 `' Lo IL r- 00'^— > Of V! •, n O ! 1 wL, (D rt ICT C fn NLU > ! C LL c c {j' o ! + co T N I � � I N tl I U Y 1 O U-) t O O O O to co O 00 L, I- O a) 0 ' (4) u01jen913 I • 3 N Solve For: Headwater Elevation Culvert Calculator Report SD-03 ' Culvert Summary Allowable HW Elevation ' Computed Headwater Elew Inlet Control HW Elev. Outlet Control HW Elev. 0.00 ft 4,981.34 ft 4,981.30 ft 41981.34 ft Headwater Depth/Height Discharge Tailwater Elevation Control Type 1.45 1.98 cfs 4,981.30 ft Outlet Control. ' Grades ' Upstream Invert Length 4,979.16 ft 34.00 ft Downstream Invert Constructed Slope 4,979.02 ft 0.41 % Hydraulic Profile Profile PressureProfile Slope Type N/A Flow Regime N/A Velocity Downstream 1.12 ft/s Depth, Downstream Normal Depth Critical Depth Critical Slope 2.28 ft 0.56 ft 0.53 ft 0.49 % ' Section Section Shape ' Section Material Section Size Number Sections Circular Concrete 18 inch 1 Mannings Coefficient Span Rise 0.013 1.50 ft 1.50 ft ' Outlet Control Properties Outlet Control HW Elev. Ke 4,981.34 ft 0.50 Upstream Velocity Head Entrance Loss 0.02 ft 0.01 ft Inlet Control Properties ' Inlet Control HW Elev. 4,981.30 ft Inlet Type Square edge w/headwall Flow Control Area Full Unsubmerged 1.8 ft' ' M C Y 2.00000 0.03980 0.67000 HDS 5 Scale Equation Form 1 1 Title: FCB0277 Project Engineer: Administrator n:\...\drainage\haestad\culvertmaster\ftnal.cvm Nolte and Associates CulvertMaster v3.2 [03.02.00.01] 08/04/09 01:46:48W&entley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 Culvert Calculator Report SD-04 Solve For: Headwater Elevation Culvert Summary Allowable HW Elevation 0.00 ft Headwater Depth/Height 1.42 Computed Headwater Elevi 4.981.33 R Discharge 1.81 cfs ' Inlet Control HW Elev. 4,981.30 It Tailwater Elevation 4,981.30 ft Outlet Control HW Elev. 4,981.33 ft Control Type Outlet Control ' Grades Upstream Invert 4,979.20 ft Downstream Invert 4,979.05 ft ' Length 32.00 ft Constructed Slope 0.47 % ' Hydraulic Profile Profile PressureProfile Depth, Downstream 2.25 ft Slope Type N/A Normal Depth 0.51 ft ' Flow Regime N/A Critical Depth 0.51 ft . Velocity Downstream 1.02 ft/s Critical Slope 0.49 % ' Section Section. Shape Circular Mannings Coefficient 0.013 Section Material Concrete Span 1.50 ft ' Section Size 18 inch Rise 1.50 ft Number Sections 1 Outlet Control Properties Outlet Control HW Elev. 4,981.33 ft Upstream Velocity Head 0.02 ft Ke 0.50 Entrance Loss 0.01 ft Inlet Control Properties ' Inlet Control HW Elev. 4,981.30 ft Flow Control Unsubmerged 9 Inlet Type Square edge w/headwall Area Full 1.8 ft2 — -- ---K -- ------0.00980 — -- HDS_5_Chart------- -- — —---- ---------- ..-- ---- ---- ---- ---—..-..._.._. M 2.00000 HDS 5 Scale 1 ' C 0.03980 Equation Forth 1 Y 0.67000 t Title: FCB0277 Project Engineer: Administrator n:\..-\drainage\haestad\culvertmaster\final.cvm Nolte and Associates CulvertMaster v3.2 [03.02.00.01] 08/04/09 01:47:44®Uentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 1 ' PROJECT NAME Union Place PROJECT NUMBER FCB0277 CALCULATED BY MLW & SME 1 1 1 Input Values are in blue Change for other types of grated inlets Change for other inlets Refer to Table ST-7 Change for other types of inlets DesQign Daiow d W N Co L Inlet Type h 0 Cw Co Lw Ao I weir di orifice d orifice di di d Local Depression in Inlet Type Inlet Id Basin Allowable Depth of Inlet (3" Length of Adjusted Inlet Type: Height of angle of Weir Orifice Figure ST Depth of YP Basin Depth of flow Outside Gutter Typical for # of Single -Unit Length of Inlets= Length = Grate, Curb, Curb .inclined Discharge Discharge Weir Orifice - EQl EQ2 5, di = controls, use max flow Flow Flow of Width e R) Type Inlets Clog Factor Type R N*L Co,�N. L, Depressed Curb, Opening throat Coeff. Coefficien Length Area d+(h/2)sin Outside of Depression Slotted t 0 Depression cfs in in - ft in in J1 fr in ft sf ft ft ft fi in in 5'Type R SDI-E4 E4 5.67 3.6 2.47 , 2.00 3.00 1 0.88 60.00 1 5.00 1 4.40 depressed curb 5.95 63.40 2.30 0.67 8.00 2.18 0.456 0.23 0.455 1 0.456 5.473 2.47 5'Type R SDI-G 1 Gl 2.08 3.6 0.04 2.00 3.00 1 0.88 60.00 5.00 4.40 depressed curb 5.95 63.40 2.30 0.67 8.00 2.18 0.234 0.03 0.253 0.253 3.038 0.04 5'Type R SDI-H H 1.81 3.72 1 0.00 2.00 1 3.00 1 0.88 60.00 5.00 4.40 depressed curb 5.95 65.40 2.30 0.67 8.00 2.18 0.213 0.02 0.249 0.2 in 2.990 0.00 ' EQ 1, ST-27: Q;=C Lwd' s or d = (Q;/(CwLw))0.667 EQ2, ST-28: Q CoAo(2gd)", d = (Qj/(CoAJ)2/(2g) 1 / 1 1 1 1 ` 1 u I FCB0277-Runoff Fina13.xIs, TYPE R 10/14/2009,9:31 AM PROJECT NAME Union Place BEYOND ENGINEERING PROJECT NUMBER FCB0277 CALCULATED BY MLW 'Grate = Neenah R-2553 Weir Pefirneter, L = 75.60 in Open Area, A = 158.40 in2 Allowable Capacity, c = 50% Weir Calculation: is QW = CLH C= 3.00 CL= 3.15 ft 6.30 ft 1.10 ft' Orifice Calculation: Q0 = CA(2gH)' C= , 0.67 Ac = 0.55 ft2 H ft H in, Qw-WLET CfS Qo-MET CfS Rules CfS Inlet 11D Total Q2 0.00 0.0 0.00 0.00 0.00 0.10 1.2 0.30 0.94 0.30 0.20 2.4 0.85 1.32 1 0.85 -0 :6 T" 0.30 3.6 1.55 1.62 1.55 0.40 4.8 2.39 1.87 1.87 0.50 6.0 3.34 2.09 2.09 0.60 7.2 4.39 2.29 2.29 0.70 8.4 5.53 2.47 2.47 0.80 9.6 6.76 2.64 2.64 0.90 10.8 8.07 2.81 .2.81 1.00-- 9..45-- 2.96 - ---------- ----------- - - N FCB0277-Runoff Final I.xls,.Neenah R-2553 8/4/2009,7:44 AM FK0jEU'j'jNAfVLL Union riace BE Y O N D E NO IN E E R INC PROJECT NUMBER FCB0277 CALCULATED BY MLW Grate = CDOT Type C Close Mesh Grate Weir Perimeter, L = 125.75 in 10.48 ft Open Area, A = 985.47 in2 6.84 ft2 Capacity, c = 50% Weir Calculation: Orifice Calculation: . .5 Qw = CLH1.5 Q0= CA(2gH)' C = 3.00 C � cL= 5.24 ft Ac = 0.67 3.42 ft2 H ft H in Qw-INLET CfS Qo-INLET CfS Rules CfS Inlet ID Total Q100 0.00 0.0 0.00 0.00 0.00 0.10 1.2 0.50 5.82 0.50 0.20 1 2.4 1.41 8.23 1.41 0.30 3.6 2.58 10.08 2.58 0.40 4.8 3.98 11.64 3.98 0:50 6.0 5.56 13.01 .5.56 0.60 7.2 7.31 14.25 7.31 0.70 8.4 9.21 15.39 9.21 -79 0.80 9.6 11.25 16.46 11.25. 0.90 10.8 13.42 17.45 13.42 FCB0277-Runoff Finallxls, Type C 8/4/2009,7:37 AM ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & (Based on Reaulated Criteria for Maximum Allowable Flow Depth an Project: Union Place Inlet ID: SDI-G2 TBACK SsncK Hy OURS d 8 TCRO W M T. TMA% W �- T. Street / Crown S, _ 5 4 . mum Allowable Width for Spread Behind Curb Slope Behind Curb (leave blank for no conveyance credit behind curb) ring's Roughness Behind Curb of Curb at Gutter Flow Line e from Curb Face to Street Crown Width Transverse Slope Longitudinal Slope - Enter 0 for sump condition ig's Roughness for Street Section Allowable Water Spread for Minor & Major Storm Allowable Depth at Gutter Flow Line for Minor & Major Storm Flow Depth at Street Crown (leave blank for no) Gutter Cross Slope (Eq. ST-8) . Water Depth without Gutter Depression (Eq. ST-2) Water Depth with a Gutter Depression Allowable Spread for Discharge outside the Gutter Section W IT - W) Gutter Flow to Design Flow Ratio by FHWA HEC-22 method (Eq. ST-7) Discharge outside the Gutter Section W, carded in Section Tx Discharge within the Gutter Section W (QT- Qx) Discharge Behind the Curb (e.g., sidewalk, driveways, & lawns) Maximum Flow Based On Allowable Water Spread Flow Velocity Within the Gutter Section V'd Product: Flow Velocity Times Gutter Flowine Depth tical Water Spread tical Spread for Discharge outside the Gutter Section W (T- W) Flow to Design Flow Ratio by FHWA HEC-22 method (Eq. ST-7) tical Discharge outside the Gutter Section W, carried in Section Tx TR Discharge within the Gutter Section W (Qd - Qx) Discharge Behind the Curb (e.g., sidewalk, driveways, & lawns) Total Discharge for Major & Minor Storm Flow Velocity Within the Gutter Section d Product Flow Velocity Times Gutter Flowline Depth Slope -Based Depth Safety Reduction Factor for Major & Minor (d > 6") Storm Max Flow Based on Allow. Gutter Depth (Safety Factor Applied) Resultant Flow Depth at Gutter Flowline (Safety Factor Applied) Resultant Flow Depth at Street Crown (Safety Factor Applied) STORM max. allowable STORM max. allowable TBACK = It Sa�cK = It vent. / ft. horiz nencK = HCURB = 6.00 inches TCROWR- 18.5 ft a = 1.52 inches W = 2.00 It Sx .` 0.0200 ft. vert / ft horiz So = 0.0000 ft. vert. / ft horiz rl mEEr = Minor Storm Major Storm T. =1 1 18.5 n 185fl- di = 6.00 6%0 inches X = yes Uin Cfn r„lainr SMrm Sw: y d: Tx: Eo: Qx: QW: ABACK Or: V V•d TTR = Txr E. Qxr : Qw' QBACK' Q= V= V•a R• Old: d: dCRavm 0.0833 0.0833 4.44 4.44 5.96 5.96 16.5 16.5 0.322 0.322 0.0 0.0 0.0 0.0 0.0 0.0 SUMP SUMP 0.0 0.0 0.0 i 0.0 AM..,.r 4fn RA.i�r, cm„r, 18.7 18.7 16.7 16.7 0.319 -0.319 0.0 0.0 0.0 0.0 0.0 0.0 0.0 03 0.0 0.0 0.0 0.0 0.0 0.0 SUMP SUMP SUMP SUMP 1/ft fiches uhes ds .IS :ts :fs ps ds ft ds Ifs :is ps :is nches riches Minor Stonn Major Storm II n Minimum of Q. or Q. ' Q.,. _ SUMP SUMP CIS OK -greater than flow given on sheet'Q-Peak' 1 LID -Inlet SDI-G2.xls, Q-Allow 8/4/20b% 7:32 AM INLET IN A SUMP OR SAG LOCATION ' ProjectUnion Place Inlet ID = SDI-G2 ,�--Lo (C)- I ' 7\N Wp H-Vert W ' l.o (G) . .. .. ., r11Nno MAJnR 'Type Local of Inlet Local Depression (additional to continuous gutter depression'a' from'O-Allovn Number of Unit Inlets (Grate or Curb Opening) Grate Information ' Length of a Unit Grate Width of a Unit Grata Area Opening Ratio for a Grate (typical values 0.15-0.90) Clogging Factor for a Single Grffie (typical value 0.60 - 0.70) ' Grate Weir Coefficient (typical value 3.00) Grate Orifice Coefficient (typical value 0.67) Curb Opening Information Length of a Unit Curb Opening t Height of Vertical Curb Opening in Inches Height of Curb Orifice Throat in Inches Angie of Throat (see USDCM Figure ST-5) Side Width for Depression Pan (typically the gutter width of 2 feet) ' Clogging Factor for a Single Curb Opening (typical value 0.10) Cum Opening Weir Coefficient (typical value 2.30-3.00) Cum Opening Orifice Coefficient (typical value 0.67) Resulting Gutter Flow Depth for Grits Inlet Capacity in a Sum ' Clogging Coefficient for Mulbple Units Gogging Factor for Multiple Units Grate as a Weir. The Controlling Factor Will Be: Flow Depth at Local Depression without Clogging (0.24 cis grate, 0 cis cum) ' Flow Depth (Cum Opening Only) without Clogging (0 cis grate, 0.24 cis cum) Flow Depth at Local Depression with Clogging (0.24 cis grate, 0 cfs cum) Flow Depth (Cum Opening Only) with Clogging (0 cis grate, 0.24 cfs cum) Grata as an Orifice ' Flow Depth at Local Depression without Clogging (0.24 cis grate, 0 cis cum) _ Flow Depth at Local Depression with Clogging (0.24 cis grate, 0 cis cam) Resulting Gutter Flow Depth Outside of Local Depression Type = BWieol = No = CDOT/Denver 13 Combination 3,00 3.00 1 1 inches I e G) = We = Anne = Cr (G) _ C. (G)= C. (G) _ Le (C) _ H,w,= Ke = Theta = We= Cr(C)= C„ (C) = C. (C) = MINOR MAJOR feet feet feet inches inches degree feet MINOR MAJOR 3.00 3.00 7.50 7.50 5.25 5.25 0.0 0.0 200 2.00 0.10 0.10 230 2.30 0.67 0.6711 MINOR Cost= 1.00 Clog = 0.50 Curb Opening as Weir dw = MAJOR 1.00 0.50 Curb Opening As Weir inches de.e.e = dam.= d� = inches inches inches MINOR MAJOR dy= de,= 0.58 1.75 inches inches 0,78 2.39 3.00 3.00 1.73 1.73 047 0.47 0.50 0.50 3.00 3.00 0.67 0.67 1.71 4.15 0.76 2.32 2.50 5.51 0.78 2.39 Resultin Gutter low Depth for Cum O enin Inlet Capacity in a Sum MINOR MAJOR Clogging Coefficient for Multiple Units Ccef = 1.00 1.00 Clogging Factor for Multiple Units Clog = 0.10 0.10 Lunt as a Weir, Grata as an Orifice - - MINOR MAJOR Flow Depth at Local Depression without Clogging (0.15 cis grate, 0.09 cis cum) dM = 0.42 1.26 inches -..._ Flow Depth at Local Depression with Clogging (0:11cis grate.-0:13cfswm)__--_q,o=_.-__.__._....0.55_.. --- .1.fi6 inches______ Curb as an Orifice, Grate as an Orifice MINOR MAJOR Flow Depth at Local Depression without Clogging (0.24 cis grate. 0 cis cum) del = 0.58 1.75 inches Flow Depth at Local Depression with Clogging (0.24 cis grate, 0 cis cam) d„ = 0.76 2.39 inches Resultina Gutter Flow DaoN Outside of Local Depression d�= 0.00 0.00 inches Inlet Length Inlet Interception Capacity (Design Discharge from Q-Peak) Rant Gutter Flow Depth (hued on sheet O-Allow geometry) Rant Street Flow Spread (based on sheet O-Allow geometry) Ifant Flow Depth at Street Crown L O, d T f UD-Inlet SDI-G2.xls, Inlet In Sump 8/4I2009, 7:32 AM IOTE: When specifying or ordering grates - ,lease refer to "CHOOSING THE PROPER INLET GRATE" on pages 108 and 109. R-2548 Catch Basin Frame, Vane Grate Heavy Duty Uses R-1728 frame. R-2549 Catch Basin Frame and Grate z�4 I •I k Heavy Duty Note 4-5/8" holes in wall for bolting to corru- gated pipe. Furnished only when specified. — — 20" /• Fits inside 24" corrugated metal pipe. 2 Uses R-1645 frame. R-2552 �Q Catch Basin Frame, Grate Heavy Duty 24 13/16 23 3/4' 1 /2" 11 r- 1 25/32' A I I& 1 6 7/8' 21 21132' � 28 1/8' Uses R-1714 frame. 33 15/32" R-2553 , t� Catch Basin Frame, Grate _ , �j•�,f �/'�... Heavy Duty 1g - 251/4' 24" 1 3/8' I I 3. 221/2' I I 341/4' N Uses R-1553 frame. 96 NEENAH FREE OPEN AREAS OF NEENAH GRATES WEIR WEIR WEIR WEIR SQ. PERIMETER SQ. PERIMETER SO. PERIMETER SQ. PERIMETER CATALOG GRATE FL LINEAL CATALOG GRATE FL LINEAL CATALOG GRATE FT. LINEAL CATALOG GRATE FT. LINEAL NUMBER TYPE OPEN FEET NUMBER TYPE OPEN FEET NUMBER TYPE OPEN FEET NUMBER TYPE OPEN FEET R-1792-AG G 02 2.7 R-2031 E 1.1 6.0 'R-2298 F 1.2 . 6.7 R-2453 K 0.8 62 R-1792-BG G 0.3 315 R-2040 D 0.9 6.0 R-2299 B 12 6.7 - R-2461-A . A 1.1 5.8 R-1792-CG G 0.5 4.3 R-2040 C 1.1 6.0 8-2299 F 1.2 6.7 R-2461-A B' 1.2 5.8 R-1792-DG G 0.7 4.8 R-2040 E 1.1 6.0 R-2300 G 1.2 6.8 R-2461-A C 1.1 5.6 R-1792-EG G 1.0 5.8 R-2040 F 0.7 6.0 R-2300 C 1.6 6.8 R-2464 D 1.0 6.0 R-1792-FG G 1.7 6.6 R-2050 D 0.9 6.0 R-2370 B 1.2 6.8 R-2466-A B 1.2 5.8 R-1792-GG G 2.0 7.4 R-2050 C 1.1 6.0 R-2370 F 1.3 6.8 R-2466-A E .1.1 5.8 R-1792-HG G 2.7 9.0 R-2050 E 1.1 6.0 R-2370 A 1.1 6.8 R-2467 C 1.1 5.9 R-1792-JG G 3.7 10.5 R-2050 F 0.7 6.0 R-2370 G - 1.2 6.8 R-2467 D 0.9 5.9 R-1792-KG G 4.8 12.1 R-2060 A 1.1 6.0 R-2371 G 1.2 6.7 R-2471 D 0.9 5.9 R-187B-AIG A or 0.5 4.6 R-2060 B 12 6.0 - R-2390 G 1.4 6.7 R-2471-B D 0.9 5.9 R-1878-A2G A orC 0.8 6.0 R-2060 C 1.1 - 6.0 R-2390 C 1.5 6.7 R-2474 A 1.1 5.7 R-1878-A3G A or C 1.0 6.7 R-2060 E 1.1 6.0 R-2392 C 1.4 6.7 R-2474 G 12 5.7 R-1878-A4G A or C 1.1 7.3 R-2070 D 0.9 6.0 R-2392 G 1.4 6.7- R-2475 A 1.1 5.8 R-1878-A513 A or 1.8 7.8 R-2070 B 12 6.0 R-2394 .G 12 6.8 R-2481 A 1.1 5.7 R-1878-A6G A orC 2.7 8.6 R-2070 E 1.1 6.0 R-2395-1 G 1.6 6.6 R-2494 G 0.8 5.1 R-1878-A7G A orC 2.1 92 R-2077 B 12 6.0 - R-2398 G 1.4 6.7 R-2496 G 0.6 4.7 R-1878-A8G A or 2.3 9.8 R-2077 C 1.1 6.0 R-2401 G 1.4 6.8 R-2498 G OA 4.1 R71878-A913 A orC 2.5 10.6 R-2077 D 1.0 6.0 R-2401 C 1.6 6.8 R-2498-A G 0.4 4.1 R-1878-A10G A or 3.0 12.3 R-2077 E 1.1 6.0' R-2401-A G 1.2 6.5 R-2498-B G 0.4 4.1 R-1878-BIG A 0.6 5.7 R-2077 F 0.6 6.0 R-2401-B E 0.9 6.2 R-2499 G 0.2 3.1 R-1878-132G A 0.9 fi.5 R-2080 D 1-.0 5.9 R-2402 G 0.7 6.5 R-2500 G 0.9 6.2 R-1878-13313 A 12 7.5 R-2080 C 12 5.9 R-2402 C 1.1 6.5 R-2501 G 1.1 6.8 R-187B-B4G A 2.1 8.5 R-2090 A 1.1 5.0' R-2404 G 1.1 6.7 R-2502 D 0.9 6.0 R-1878-135G A 2.5 9.6 R-2090 B 12 5.8 R-2405 A 1.0 . 6.5 R-2502 G 1.3 6.0 R-1878-B6G C 2.6 9.5 R-2090 C 1.2 5.8 R-2405 C 1.6 6.5 R-2504 G 1.3 6.0 R-1878-13713 A 2.6 10.5 R-2090 D to 5.8 R-2410 K 0.9 6.1 R-2504 D 0.9 6.0 R-1878-BBG A 3.7 12.6 R-2090 E 1.1 5.8 R-2411-A G 0.7 6.6 R-2510 C 1.3 5.8 R-1678-13913 C 3.3 11.6 R-2090 G 1.0 5.8 - R-2412-A G 1.0 62 R-2510-1 G 0.4 4.1 R-1878-BIDG C 4.9 13.5 R-2100 A 1.1 5.8 R-2412-A1 E 1.0 6.3 R-2510-2 G 1.6 72 R-1878-BlIG A 5.0 14.7 R-2100 C 1.1 5.8 R-2412-A2 G 0.7 6.5 R-2510-A C 1.1 5.8 R-1879-AIG A or 0.4 4.6 R-2100 E 1.1 5.8 R-2412-A3 C 1.1 6.3 R-2525-A E 02 3.1 R-1879-A213 A or C 0.B 6.0 R-2100 F 0.6 5.8 R-2412-A3 E 1.0 6.3 R-2525-C G 0.4 4.1 R-1879-A3G 'A or 12 6.7 R-2110 A 1.1 5.8 R-2412-A4 C 1.0 6.5 R-2525-D G 0.4 4.1 - R-1879-A4G A orC 1.4 7.3 R-2110 E 1.1 5.8 R-2412-A5 K . 0.8 6.3 R-2525-E E 0.6 4.7 R-1879-A5G A or 1.9 7.8 R-2112 A 1.1 5.8 R-2412-A6 G 1.1 6.3 R-2525-F G 0.8 6.4 R-1879-A6G A or 2.0 8.6 R-2112 � B 1.2 5.8 - R-2414 D 1.0 6.1 R-2525-G G 0.8 5.1 R-1879-A7G A orC 1.7 .9.2 R-2112 C 1.1 5.8- R-2418 G 9.0 6.2 R-2533 A 1.1 5.8 R-1879-ASG A orC 22 9.8 R-2112 E 1.1 5.8 R-2418-A K 1.0 6.3 R-2534 C 0.9 6.0 R-1879-A9G A or C 2.8 10.6 R-2112 F 0.6 6.8 R-2420-A A 1.0 6.4 R-2535 C 1.1 5.8 R-IB79-A10G A or C 3.7 12.3 R-2112 G 0.6 5.8 R-2420-B . G 1.1 5.9 R-2535-A C 1.1 5.8 R-1879-BlG A 0.6 5.7 R-2120 A 1.1 5.8 R-2421-A A 1.0 6.1 R-2540 D 1.1 5.9 R-1879-B2G C 0.9 - 6.5, R-2120 C 1.1 5.8 R-2422-A K 1.0 62 R-2540-A D 1.1 5.9 R-1879-B3G C 1.0 7.5 R-2120 F 0.6 5.8 R-2422-C G 1.0 -62 R-2545 K 0.4 4.7 R-1879-13413 A 1.4 8.5 R-2120 G 1.1 . 5.8 R-2423 G 1.0 62 R-2546 K 0.4 3.5 R-1879-B513 A 1.9 9.6 _ R-2250 G 3.0 9.9 R-2424-A__ R-1879-863 A 2.4 9.5 R-2251 G '2.9 9A R-2427 D 0.9 6.0 R-2549 D 0.9 6.0 R-1879-137G A 3.0 10.6 R-2255 c 1.4 8.4 R-2427-A G 1.0 62 R-2552 K 0.8 6.2 R-1879-BBG A 32 12.6 R-2255 G 1.9 8.4 R-2428 D 1.0 6.0 R-2552-A K 0.8 6.2 R-1879-B9G A 3.2 11.6 R-2270 G 1.9 8.4 R-2428 C 1.1. 6.0 R-2552-B K 0.8 6.2 R-1879-B10G C 4.2 13.5 R-2275 G 1.9 8.4 R-2428 F 0.6 5.0 R-2553 G 1.1 6.3 - R-2290 K 1.2 7.6 R-2429 D 1.0 5.9 R-2554 G 1.1 6.3 R-2014 C 1.1 6.0 R-2290-A K 1.2 7.6 R-2429 E 1.3 5.9 R-2555 G 1.1 6.3 R-2014 E 1.3 6.0 R-2290-B K 1.0 7.5 R-2429 G 1.2 5.9 R-2556 G 1.5 - 6.7 R-2015 D 0.9 6.0 R-2293 G 1.6 72 R-2435 G 0.9 5.8 R-2556-A F 1.4 6.8 R-2015 C 1.1 6.0 R-2296 B 1.2 6.7 R-2437 D 1.0 5.9 R-2557 G 2.0 8.4 R-2015 G 12 6.0 R-2296 F 12 6.7 R-2437 E 1.3 5.9 R-2558 G 2.0 8.4 R-2030 D 1.1 6.0 R-2297 B 12 6.7 R-2437-8 G 0.9 5.8 R-2559 F 1.4 6.8 R-2030 C. 1.1 6.0 R-2297 F 1.2 6.7 R-2438 D 1.0 5.9 R-2560-A Beehive 0.3 3.1 8-2031 D 1.1 6.0 R-2298 . .B 12 6.7 R-2438 E 1.3 5.9 R-2560-B Beehive 02 4.1 • NOTE: On catalog #'s R-4990-AA thru R-4999=1-9, SQ:Fr. OPEN and WEIR PERIMETER are per lineal foot. Type K indicates "Special" grate style and is not among standard types illustrated. Type M indicates roll -type or mountable curb. NEENAH J�tft STREET/INLETS/STORM SEWERS DRAINAGE CRITERIA MANUAL (V. 1) J 3.0 INLETS 3.1 Inlet Functions. Tvoes and Aonronriate Annlications Stormwater inlets are a vital component of the urban stormwater collection and conveyance system. Inlets collect excess stormwater from the street, transition the flow into storm sewers, and can provide maintenance. access to the storm sewer system. They can be made of cast-iron, steel, concrete, and/or pre -cast concrete and are installed on the edge of the street adjacent to the street gutter or in the bottom of a swale. Roadway geometrical features often dictate the location of pavement drainage inlets. In general, inlets are placed at all low points (sumps or sags) in the gutter grade, median breaks, intersections, and crosswalks. The spacing of inlets placed between those required by geometric controls is governed by the design flow spread (i.e., allowable encroachment). In other words, the drainage inlets are spaced so ' that the spread under the design (minor) storm conditions will not exceed the allowable flow spread (Akan and Houghtalen 2002). ' There are four major types of inlets: grate, curb opening, combination, and slotted. Figure ST-4 depicts the four major types of inlets along with some associated geometric variables. Table ST-5 provides information on the appropriate application of the different inlet types along with advantages and disadvantages of each. Table ST-5—Applicable Settings for Various Inlet Types .Inlet Type Applicable Setting Advantages Disadvantages Grate Sumps and continuous grades Perform well over wide Can become clogged (should be made bicycle safe) range of grades Lose some capacity with increasing grade Curb -opening Sumps and continuous grades Do not clog easily Lose capacity with (but not steep grades) Bicycle safe increasing grade Combination Sumps and continuous grades High capacity More expensive than (should be made bicycle safe) Do not clog easily grate or curb -opening --------- --------- ---------- - -------------- ------ -acting alone ---- Slotted Locations where sheet flow must Intercept flow over wide Susceptible to clogging be intercepted. section - 3.2 Design Considerations Stormwater inlet design takes two forms: inlet placement location and inlet hydraulic capacity. As previously mentioned, inlets must be placed in sumps to prevent ponding of excess stormwater. On streets with continuous grades, inlets are required periodically to keep the gutter flow from exceeding the ' encroachment limitations. In both cases, the size and type of inlets need to be designed based upon their hydraulic capacity. ST-16 Rev. 06/2002 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) STREETS/INLETS/STORM SEWERS Inlets placed on continuous grades rarely intercept all of the gutter flow during the minor (design) storm. ' The effectiveness of the inlet is expressed as an efficiency, E, which is defined as: E = Qi IQ (ST-15) in which: E = inlet efficiency ' Q, = intercepted flow rate (cfs) Q = total gutter flow rate (cfs) , Bypass (or carryover) flow is not intercepted by the inlet. By definition, Qb = Q - Qi (ST-16) in which: Qb = bypass (or carryover) flow rate (cfs) ' The ability of an inlet to intercept flow (i.e., hydraulic capacity) on a continuous grade generally increases . with increasing gutter flow, but the capture efficiency decreases. In other words, even though more ' stormwater is captured, a smaller percentage of the gutter flow is captured. In general, the inlet capacity depends upon: • The inlet type and geometry. ' The flow rate (depth and spread of water). ' The cross (transverse) slope. • The longitudinal slope. ' The hydraulic capacity of an inlet varies with the type of inlet. For grate inlets, the capacity is largely dependent on the amount of water flowing over the grate, the grate configuration and spacing, and the ' velocity of flow. For curb opening inlets, the capacity is largely dependent on the length of the opening, the flow velocity, street and gutter cross slope, and the flow depth at the curb.. Local gutter depression ' along the curb opening helps boost the capacity. On the other hand, top slab supports can decrease the capacity. Combination inlets do not intercept much more than their grates alone if they are placed side by side and are of nearly equal lengths but are much less likely to clog. Slotted inlets function in a manner ' similar to curb opening inlets (FHWA 1996). Inlets in sumps operate as weirs for shallow pond depths, but eventually will operate as orifices as the ' depth increases. A transition region exists between weir flow and orifice flow, much like a culvert. Grate Rev.06/2002 ST-17 Urban Drainage and Flood Control District ' STREET/INLETS/STORM SEWERS DRAINAGE CRITERIA MANUAL (V. 1) ' inlets and slotted inlets tend to clog with debris, so calculations should take that into account. Curb opening inlets tend to be more dependable for this reason. 3.3 Hydraulic Evaluation The hydraulic capacity of an inlet is dependent on the type of inlet (grate, curb opening, combination, or ' slotted) and the location (on a continuous grade or in a sump). The methodology for determination of hydraulic capacity of the various inlet types is described in the following sections: (a) grate inlets on a ' continuous grade (Section 3.3.1), (b) curb opening inlets on a continuous grade (Section 3.3.2), (c) combination inlets on a continuous grade (Section 3.3.3), (d) slotted inlets on a continuous grade (Section 3.3.4), and (e) inlets located in sumps (Section 3.3.5). ' 3.3.1 Grate Inlets (On a Continuous Grade) The capture efficiency of a grate inlet is highly dependent on the width and length of the grate and the ' velocity of gutter flow. If the gutter velocity is low and the spread of water does not exceed the grate width, all of the flow will be captured by the grate inlet. This is not normally the case during the minor ' (design) storm. The spread of water often exceeds the grate width and the flow velocity can be high. Thus, some water gets by the inlet. Water going over the grate may be capable of "splashing over" the grate, and usually little of the water outside the grate width is captured. ' In order to determine the efficiency of a grate inlet, gutter flow is divided into two parts: frontal flow and side flow. Frontal flow is defined as that portion of the flow within the width of the grate. The portion of ' the flow outside the grate width is called side flow. By using Equation ST-1, the frontal.flow can be evaluated and is expressed as: Qw - Q[1- (1- (WIT)f"' _ (ST-17) ' in which: Qw = frontal discharge (flow within width Wj (cfs) '- Q = total gutter flow (cfs) found using Equation ST-1- --- - _— _— - ---------- - - - W =width of grate (ft) T= total spread of water in the gutter. (ft) It should be noted that the grate width is generally equal to the depressed section in a composite gutter section. Now by definition: QS -Q-Qw in which: (ST-18) ST-18 Rev. 06/2002 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) STREETS/INLETS/STORM SEWERS Q$ = side discharge (i.e., flow outside the depressed gutter or grate) (cfs) The ratio of the frontal flow intercepted by the inlet to total frontal flow, Rr, is expressed as: R f = Q„,; IQ„, =1.0 — 0.09(V — V.) for V >! Vo, otherwise Rf = 1. 0 (ST-19) 1 In which: Qw; = frontal flow intercepted by the inlet (cfs) V = velocity of flow in the gutter (ft/sec) Vo = splash -over velocity (ft/sec) The splash -over velocity is defined as the minimum velocity causing some water to shoot over the grate. This velocity is a function of the grate length and type. The splash -over velocity can be determined using the empirical formula (Guo 1999): Vo =a+# — re2 +7/1e3 (ST ZO) in which: Va = splash -over velocity (ft/sec) Le = effective unit length of grate inlet (ft) a, �3, y, = constants from Table ST-6 Table ST-6—Splash Velocity Constants for Various Types of Inlet Grates Type of Grate a R y Bar P-1-7/8 2.22 4.03 0.65 0.06 Bar P-1-1/8 1.76 3.12 0.45 0.03 Vane Grate 0.30 4.85 1.31 0.15 45-Degree Bar 0.99 2.64 0.36 0.03 Bar P-1-7/8-4 0.74 2.44 0.27. 0.02 30-Degree Bar 0.51 2.34 0.20 0.01 Reticuline 0.28 2.28 0.18 0.01 Rev. 06/2002 STA 9 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) STREETS/INLETS/STORM SEWERS Qs = side discharge (i.e., flow outside the depressed gutter or grate) (cfs) The ratio of the frontal flow intercepted by the inlet to total frontal flow, Rr, is expressed as: R f = Qw; I Qw =1.0 — 0.09(V — V.) for V >! Vo, otherwise Rf = 1.0 (ST-19) in which: Qw = frontal flow intercepted by the inlet (cfs) V =velocity of flow in the gutter (ft/sec) Vo = splash -over velocity (ft/sec) The splash -over velocity is defined as the minimum velocity causing some water to shoot over the grate. This velocity is a function of the grate length and type. The splash -over velocity can be determined using the empirical formula (Guo 1999): Vo = a + PLe — YL 2 + 17Le3 (ST-20) In which: Vo = splash -over velocity (ft/sec) Le = effective unit length of grate inlet (ft) a, P, y, r/ = constants from Table ST-6 Table ST-6—Splash Velocity Constants for Various Types of Inlet Grates Type of Grate a R 7 11 Bar P-1-7/8 2.22 4.03 0.65 0.06 Bar P-1-1/8 1.76 3.12 0.45 0.03 Vane Grate 0.30 4.85 1.31 0.15 45-Degree Bar 0.99 2.64 0.36 0.03 Bar P-1-7/8-4 0.74 2.44 0.27. 0.02 30-Degree Bar 0.51 2.34 0.20 0.01 Reticuline 0.28 2.28 0.18 0.01 Rev. 06/2002 ST-19 Urban Drainage and Flood Control District STREET/INLETS/STORM SEWERS DRAINAGE CRITERIA MANUAL (V. 1) The ratio of the side flow intercepted by the inlet to total side flow, R5, is expressed as: RS = 1 �(ST-21) 1+ 0.15V 's Sz f-3 9ii^liif 1 V = velocity of flow in the gutter (ft/sec) L = length of grate (ft) The capture efficiency, E, of the grate inlet may now be determined using: E = Rf (QJQ)+ RS (Qs IQ) (ST-22) Example 6.9 shows grate inlet capacity calculations. 3.3.2 Curb-Openinq Inlets (On a Continuous Grade) The capture efficiency of a curb -opening inlet is dependent on the length of the opening, the depth of flow at the curb, street cross slope and the longitudinal gutter slope (see Photograph ST-3). If the curb opening is long, the flow rate is low, and the longitudinal gutter slope is small,, all of the flow will be captured by the inlet. This is not normally the case during the minor (design) storm. In fact, it is generally uneconomical to install a curb opening long enough to capture all of the flow. Thus, some water gets by the inlet, and the inlet efficiency needs to be determined. Photograph ST-3—Gutterlstreet slope is a major design factor for both street and inlet capacity. ST-20 Rev. 06/2002 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) STREETS/INLETS/STORM SEWERS The hydraulics of curb opening inlets are less complicated than grate inlets. The efficiency, E, of a curb - opening inlet is calculated as: E = 1 — [1— (L/LT )]" for L < LT, otherwise E = 1.0 in which: L = installed (or designed) curb -opening length (ft) LT= curb -opening length required to capture 100% of gutter flow (ft) and, for a curb -opening inlet that is not depressed, 0.6 LT = 0.6 L 0.425 0.3 1 nSs in which: Q = gutter flow (cfs) SL = longitudinal street slope (ft/ft) S,r = steel cross slope (ft/ft) n = Manning's roughness coefficient For a depressed curb -opening inlet, 0.6 LT = 0.6 Q0.42SL0.3 r 1 1 (ST-25) \nSe J The equivalent cross slope, Se, can be determined from Se = Sx + a Eo (ST-26) ' (ST-23) (ST-24) in which a = gutter depression and W = depressed gutter section as shown in Figure ST-1 b. The ratio of the flow in the depressed section to total gutter flow, Eo, can be calculated from Equation ST-7. See Examples 6.8 and 6.9 for curb -opening inlet calculations. 3.3.3 Combination Inlets (On a Continuous Grade) Combination inlets take advantage of the debris removal capabilities of a curb -opening inlet and the capture efficiency of a.grate inlet. If the grate and the curb opening are side -by -side and of approximately equal length, the interception capacity is found by assuming the grate acts alone. If all or part of the curb - opening inlet lies upstream from the grate (a desirable configuration), the inlet capacity is enhanced by Rev. 06/2002 ST-21 Urban Drainage and Flood Control District 1 ' STREET/INLETS/STORM SEWERS DRAINAGE CRITERIA MANUAL (V. 1) ' the upstream curb -opening capacity: The appropriate equations have already been presented, but Example 6.10 illustrates the procedure. ' 3.3.4 Slotted Inlets (On a Continuous Grade) Slotted inlets can generally be used to intercept sheet flow that is crossing the pavement in an ' undesirable location. Unlike grate inlets, they have the advantage of intercepting flow over a wide section. They do not interfere with traffic operations and can be used on both curbed and uncurbed sections. Like grate inlets, they are susceptible to clogging. Slotted inlets function like a side -flow weir, much like curb -opening inlets. The FHWA (1996) suggests the hydraulic capacity of slotted inlets closely corresponds to curb_opening inlets if the slot openings ' exceed 1.75 inches. Therefore, the equations developed for curb -opening inlets (Equations ST-23 through ST-26) are appropriate for slotted inlets. ' 3.3.5 Inlets Located in Sumps All of the stormwater excess that enters a sump (i.e., a depression or low point in grade) must pass through an inlet to enter the stormwater conveyance system. If the stormwater is laden with debris, the inlet is susceptible to clogging. The ponding of water is a nuisance and could be hazardous. Therefore, the capacity of inlets in sumps must account for this clogging potential. Grate inlets acting alone are not ' recommended for this reason. Curb -opening inlets are more appropriate, as are combination inlets. Photograph ST-4 shows a curb opening inlet in a sump condition. Photograph ST-4—Inlets that are located in street sags and sumped can be highly efficient. As previously mentioned, inlets in sumps function like weirs for shallow depths, but as the depth of ' stormwater increases, they begin to function like an orifice. Orifice and weir, flows have been exhaustively ST-22 Rev. 06/2002 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) STREETS/INLETS/STORM SEWERS studied. Equations are readily available to compute requisite flow rates. However, the transition from ' weir flow to orifice flow takes place over a relatively small range of depth that is not well defined. The FHWA provides guidance on the transition region based on significant testing. The hydraulic capacity of grate, curb -opening, and slotted inlets operating as weirs is expressed as: Qr = CwLw d 1.5 (ST727) in which: Qi = inlet capacity (cfs) ' C, = weir discharge coefficient L„, = weir length (ft) ' d = flow depth (ft) Values for C„. and L,,, are presented in Table ST-7 for various inlet types. Note that the expressions given for curb -opening inlets without depression should be used for depressed curb -opening inlets if L > 12 feet. The hydraulic capacity of grate, curb -opening, and slotted inlets operating as orifices is expressed as: Qj = Co Ao (2gd)os (ST-28) in which: Q; = inlet capacity (cfs) 1 Ca = orifice discharge coefficient ' A,= orifice area (ft) d = characteristic depth (ft) as defined in Table ST-7 ' g = 32.2 ft/seC2 Values for Co and Ao are presented in Table ST-7 for different types of inlets. Combination inlets are commonly used in sumps.. The hydraulic capacity of combination inlets in sumps depends on the type of flow and the relative lengths of the curb opening and grate. For weir flow, the ' capacity of a combination inlet (grate length equal to the curb opening length) is equal to the capacity of the grate portion only. This is because the curb opening does not add any length to the weir equation (Equation ST-27). If the curb opening is longer than the grate, the capacity of the additional curb' length ' should be added to the grate capacity. For orifice flow, the capacity of the curb opening should be added to the capacity of the grate. ' Rev.06/2002 ST-23 ' Urban Drainage and Flood Control District STREET/INLETS/STORM SEWERS DRAINAGE CRITERIA MANUAL (V. 1) Table ST-7—Sag Inlet Discharge Variables and Coefficients (Modified From Akan and Houghtalen 2002) Inlet Type Cw Lw, Weir Equation Definitions of Terms Valid For Grate Inlet 3.00 L + 2W d < 1.79(Ao/Lw) L = Length of grate W = Width of grate d = Depth of water over grate Ao= Clear opening area Curb Opening 3.00 L d < h L = Length of curb opening Inlet h = Height of curb opening d = d; - (h/2) d; = Depth of water at'curb opening Depressed Curb 2.30 L + 1.8W d < (h + a) W = Lateral width of depression Opening Inlet3 a = Depth of curb depression . Slotted Inlets 2.48 L d < 0.2 ft L = Length of slot d = Depth at curb The weir length should be reduced where clogging is expected. 2 Ratio of clear opening area to total area is 0.8 for P-1-7/8-4 and reticuline grates, 0.9 for P-1-7/8 and 0.6 for P-1-1/8 grates. Curved vane and tilt bar grates are not recommended at sag locations. 3 If L > 12 ft, use the expressions for curb opening inlets without depression. C. A6' Orifice Equation , Definition of Terms Valid for Grate Inlet 0.67 Clear d> 1.79(Ao/L,) d = Depth of water over grate opening areas Curb Opening 0.67 (h)(L) d; > 1.4h d = d; - (h12) Inlet (depressed d; = Depth of water at curb opening or undepressed, horizontal orifice h = Height of curb opening throats) Slotted Inlet 0.80 (L)(W) d> 0.40 ft L = Length of slot W = Width of slot d = Depth of water over slot The orifice area should be reduced where clogging is expected. 5 The ratio of clear opening area to total area is 0.8 for P-1-7/8-4 and reticuline grates, 0.9 for P-1-7/8 and 0.6 for P-1-1/8 grates. Curved vane and tilt bar grates are not recommended at sag locations. 6 See Figure ST-5 for other types of throats. 3.3.6 Inlet Cloaoinci Inlets are subject to'clogging effects (see Photographs ST-5 and ST-6). Selection of a clogging factor reflects the condition of debris and trash on the street. During a storm event, street inlets are usually ST-24 Rev. 06/2002 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) STREETS/INLETS/STORM SEWERS loaded with debris by the first -flush runoff volume. As a common practice for street drainage, 50% clogging is considered for the design of a single grate inlet and 10% clogging is considered for a single curb -opening inlet. Often, it takes multiple units to collect the stormwater on the street. Since the amount of debris is largely associated with the first -flush volume in a storm event, the clogging factor applied to a multiple -unit street inlet should be decreased with respect to the length of the inlet. Linearly applying a single -unit clogging factor to a multiple -unit inlet leads to an excessive increase in length. For instance, a six -unit inlet under a 50% clogging factor will function as a three -unit inlet. In fact, continuously applying a 50% reduction to the discharge on the street will always leave 50% of the residual flow on the street. This means that the inlet will never reach a 100% capture and leads to unnecessarily long inlets. Photograph ST-5—Clogging is an important consideration when designing inlets. Photograph ST-6—Field inlets frequently need maintenance. Rev. 06/2002 ST-25 Urban Drainage and Flood Control District ' STREET/INLETS/STORM SEWERS DRAINAGE CRITERIA MANUAL (V. 1) ' With the concept of first -flush volume, the decay of clogging factor to curb opening length is described as (Guo 2000a): ' 1 2 3 N-1 Co -N i_1 = KCo C = IV (Co + eCo + e Co + e Co + ..... + e Co) = N e N . (ST-29) _1 ' in which: ' C = multiple -unit clogging factor for an inlet with multiple units Co = single -unit clogging factor ' e = decay ratio less than unity, 0.5 for grate inlet, 0.25 for curb -opening inlet N = number of units ' K = clogging coefficient from Table ST-8 Table ST-B—Clogging Coefficients to Convert Clogging Factor From Single to Multiple Units' N= 1 2 3 4 5 6 7 8 >8 Grate Inlet (K) 1 1.5 1.75 1.88 1.94 1.97 1.98 1.99 2 Curb Opening (K) 1 1.25 1.31 1.33 1.33 1.33 1.33 1.33 1.33 ' This table is generated by Equation ST-29 with e = 0.5 and e = 0.25. When N becomes large, Equation ST-29 converges to: C= C° N(1— e) (ST-30) For instance, when e = 0.5 and Ca = 50%, C = 1.0/Nfor a large number of units, N. In other words, only the first unit out of N units will be clogged. Equation ST-30 complies with the recommended clogging ._..factor_fora.single-unit.inlet_and_decays.on_the_clogging_effect_for_a_multiple_unit ' The interception of an inlet on a grade is proportional to the inlet length, and in a sump is proportional to the inlet opening area. Therefore, a clogging factor shall be applied to the length of the inlet on a grade as:. Le = (1— C)L (ST-31) in which Le = effective (unclogged) length. Similarly, a clogging factor shall be applied to the opening area of an inlet in a sump as: . ' ST-26 Rev. 06/2002 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) STREETS/INLETS/STORM SEWERS Ae =(1—QA in which: Ae = effective opening area A = opening area 3.4 Inlet Location and Spacing on Continuous Grades (ST-32) 3.4.1 Introduction Locating (or positioning) stormwater inlets rarely requires design computations. They are simply required in certain locations based upon street design considerations, topography (sumps), and local ordinances. The one exception is the location and spacing of inlets on continuous grades. On a long, continuous grade, stormwater flow increases as it moves down the gutter and picks up more drainage area. As the flow increases, so does the spread. Since the spread (encroachment) is not allowed to exceed some specified maximum, inlets must be strategically placed to remove some of the stormwater from the street. Locating these inlets.requires design computations by the engineer. 3.4.2 Design Considerations The primary design consideration for the location and spacing of inlets on continuous grades is the spread limitation. This was addressed in Section 2.2. Table ST-2 lists pavement encroachment standards for minor storms in the Denver metropolitan area. Proper design of stormwater collection and conveyance systems makes optimum use of the conveyance capabilities of street gutters. In other words, an inlet is not needed until the spread reaches its allowable limit during the design (minor) storm. To place an inlet prior to that point on the street is not economically efficient. To place an inlet after that point would violate the encroachment standards. Therefore, the primary design objective is. to position inlets along a continuous grade at the locations where the allowable spread is about to be exceeded for the design storm. 3.4.3 Design Procedure Based on the encroachment standard and street geometry, the allowable street hydraulic capacity can be determined using Equation ST-11 or Equation ST-12. This flow rate is then equated to some hydrologic technique (equation) that contains drainage area. In this way, the inlet is positioned on the street so that it will service the requisite drainage area. The process of locating the inlet is accomplished by trial -and - error. If the inlet is moved downstream (or down gutter), the drainage area increases. If the inlet is moved upstream, the drainage area decreases. The hydrologic technique most often used in urban drainage design is the Rational method. The Rational method was discussed in the RUNOFF chapter. The Rational equation, repeated here for convenience, Rev. 06/2002 ST-27 Urban Drainage and Flood Control District ' STREET/INLETS/STORM SEWERS DRAINAGE CRITERIA MANUAL (V. 1) ' is: Q = CIA (ST-33) ' in which: ' Q = peak discharge (cfs) C = runoff coefficient described in the RUNOFF chapter ' / = design storm rainfall intensity (in/hr) described in the RAINFALL chapter A = drainage area (acres) As previously mentioned, the peak discharge is found using the allowable spread and street geometry. The runoff coefficient is dependent on the land use as discussed in the RUNOFF chapter. The rainfall ' intensity is discussed in the RAINFALL chapter. The drainage area is the unknown variable to be solved. Once the first inlet is positioned along a continuous grade, an inlet type and size can be specified. The ' first inlet's hydraulic capacity is then assessed. Generally, the inlet will not capture all of the gutter. flow. In fact, it is uneconomical to size an inlet (on continuous grades) large enough to capture all of the gutter flow. Instead, some carryover flow is expected. This practice reduces the amount of new flow that can ' be picked up at the next inlet. However, each inlet should be positioned at the location where the allowable spread is about to reach its allowable limit. ' The gutter discharge for inlets, other than the first inlet, consists of the carryover from the upstream inlet plus the stormwater runoff generated from the intervening local drainage area. The carryover flow from ' the upstream inlet is added to the peak flow rate obtained from the Rational method for the intervening local drainage area. The resulting peak flow is approximate since the carryover flow peak and the local runoff peak do not necessarily coincide. . t ST-28 Rev. 06/2002 Urban Drainage and Flood'Control District DRAINAGE CRITERIA MANUAL (V. 1) STREETS/INLETS/STORM SEWERS CUR! O►ENINO INLET COMBINATION INLET BLOTTED DRAIN INLET Figure ST-4—Perspective Views of Grate and Curb -Opening Inlets Rev. 06/2002 ST-29 Urban Drainage and Flood Control District STREET/INLETS/STORM SEWERS DRAINAGE CRITERIA MANUAL (V. 1) hl. 11 11 ' ST-30 Rev. 0612002 Urban Drainage and Flood Control District P n APPENDIX E Erosion Control 1 I 1 1 PROJECT NAME Union Place PROJECT NUMBER FCB0277 CALCULATED BY MLW 1 SD-01 1 Diameter (D) _ Q= yl = 1 Ye Yn = 1 Yc /D F=Q/D" = 1 Da=(D+yn)/2 (if supercritical) or Da = D (if not supercritical) _ 1 �s = a Minimum riprap size = Type L 1 d50 2ft 11.82 cfs 1.24 ft 1.24 ft 1.39 ft 0.62 BEYOND EN G IN EE B INC Not Supercritical 2.09 Use Figure MD-23 2ft 4.18 Figure MD-21 9 in 1/(2tan0) = . 6.7 Figure MD-23 Use V = 1 5.5 fps At=QN= 2.148 L = [1/(2tan0)1*(Ac/yi D) _ -2 ft 1 Lmin = 3*D = 6 ft L_.-= 10*D = 20 ft Use L = Use W = depth of riprap = 2*d5o 6ft 8 ft (based on flared -end -section 18 in width +11 each side of FES) FCB0277_Runoff Finall.xls, Riprap-SDO1 8/4/2009,11:43 AM Culvert Calculator Report Riprap Solve For. Headwater Elevation Culvert Summary Allowable HW Elevation Computed Headwater Elev: Inlet Control HW Elev. Outlet Control HW Elev. 0.00 ft 4,980.16 ft 4,980.06 ft 4,980.16 ft Headwater Depth/Height Discharge Tailwater Elevation Control Type 0.99 11.82 cis 0.00 ft Outlet Control Grades Upstream Invert Length 4,978.17 ft 65.00 ft Downstream Invert Constructed Slope 4,977.91 ft 0.40 % Hydraulic Profile Profile Slope Type Flow Regime Velocity Downstream M2 Mild Subcdtical 5.80 ft/s Depth, Downstream Normal Depth Critical Depth Critical Slope 1.24 ft 1.39 ft 1.24 ft 0.55 % Section . Section Shape Section Material Section Size Number Sections Circular Concrete 24 inch 1 Mannings Coefficient Span Rise 0.013 2.00 ft 2.00 ft . Outlet Control Properties Outlet Control HW Elev. Ke 4,980.16 ft 0.50 Upstream Velocity Head Entrance Loss 0.41 ft 0.21 ft Inlet Control Properties Inlet Control HW Elev. 4,980.06 ft Inlet Type Square edge w/headwall --K--.-_—.__0.00980-----HDS_5_Chart------_.--._-_-- Flow Control Area Full Unsubmerged 3.1 ft M C Y 2.00000 0.03980 0.67000 HDS 5 Scale Equation Form 1 1 Title: FCB0277 Project Engineer. Administrator n:\...\drainage\haestad\culvertmaster\final.cvm Nolte and Associates CulvertMaster v3.2 [03.02.00.01] 08/04/09 11:39:30OMentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 DRAINAGE CRITERIA MANUAL (V. 1) MAJOR DRAINAGE Table MD-7—Classification and Gradation of Ordinary Riprap % Smaller Than Given Intermediate Rock Riprap Designation Size by Weight Dimensions (inches) dso.(inches)* Type VL 70-100 12 50-70 9 35-50 6 6** 2-10 2 Type L 70-100 15 50-70 12 35-50 9 9** 2-10 3 Type M 70-100 21 50-70 18 35-50 12 12** 2-10 4 Type H 70-100 30 50-70 24 35-50 18 18 2-10 6 Type VH 70-100 42 50-70 33 35-50 24 24 2-10 9 * d5o = mean particle size (intermediate dimension) by weight. ** Mix VL, L and M nprap with 35% topsoil (by volume) and bury it with 4 to 6 inches of topsoil, all vibration compacted, and revegetate. Basic requirements for nprap stone are as follows: Rock shall be hard, durable, angular in shape, and free from cracks, overburden, shale, and organic matter. Neither breadth nor thickness of a single stone should be less than one-third its length, and rounded stone should be avoided. '0 The rock should sustain a loss or not more tnan 4u ro aver ouu revolutions in an aui asiUl i «bL t�u� Angeles machine—ASTM C-535-69) and should sustain a loss of not more than 10% after 12 cycles ' of freezing and thawing (AASHTO test 103 for ledge rock procedure A). Rock having a minimum specific gravity of 2.65 is preferred; however, in no case should rock have a specific gravity less than 2.50. ' 4.4.1.2 Grouted Boulders Table MD-8 provides the classification and size requirements for boulders. When grouted boulders are used, they provide a relatively impervious channel lining which is less subject to vandalism than ordinary riprap. Grouted boulders require less routine maintenance by reducing silt and trash accumulation and ' Rev.04/2008 MD-61 Urban Drainage and Flood Control District 1 ' DRAINAGE CRITERIA MANUAL (V. 1) 7.0 PROTECTION DOWNSTREAM OF PIPE OUTLETS MAJOR DRAINAGE This section is intended to address the use of riprap for erosion protection downstream of conduit and ' culvert outlets that are in -line with major drainageway channels. Inadequate protection at conduit and culvert outlets has long been a major problem. The designer should refer to Section 4.4 for additional ' information on major drainage applications utilizing riprap. In addition, the criteria and guidance in Section 4.4 may be useful in design of erosion protection for conduit outlets. The reader is referred to Section 7.0 of the HYDRAULIC STRUCTURES chapter of this Manual for information on rundowns, and ' to Section 3.0 of the HYDRAULIC STRUCTURES chapter for additional discussion on culvert outfall protection. ' Scour resulting from highly turbulent, rapidly decelerating flow is a common problem at conduit outlets. The riprap protection design protocol is suggested for conduit and culvert outlet Froude numbers up to 2.5 (i.e., Froude parameters Q/doZ s or Q/WH' S up to 14 ft° 5/sec) where the channel and conduit slopes are parallel with the channel gradient and the conduit outlet invert is flush with the riprap channel protection. Here, Q is the discharge in cfs, do is the diameter of a circular conduit in feet and W and H are the width and height, respectively, of a rectangular conduit in feet. 7.1 Configuration of Riprap Protection 1 Figure MD-25 illustrates typical riprap protection of culverts and major drainageway conduit outlets. The additional thickness of the riprap just downstream from the outlet is to assure protection from flow ' conditions that might precipitate rock movement in this region. 7.2 Required Rock Size The required rock size may be selected from Figure MD-21 for circular conduits and from Figure MD-22 for rectangular conduits. Figure MD-21 is valid for Q/DMZ 5 of 6 or less and Figure MD-22 is valid for ' Q/W111.5 of 8.0 or less. The parameters in these two figures are: or_Q1WH0 in-which_Q_is_the_design discharge_in cfs, DJs_the_diameter o_f_a circular conduit__._ ' in feet, and Wand Hare the width and height of a rectangular conduit in feet.. 2. YID, or Y/H in which Y, is the tailwater depth in feet, D, is the diameter of a circular conduit in feet, ' and His the height of a rectangular conduit in feet. In cases where Y, is unknown or a hydraulic jump is suspected downstream of the outlet, use YID, = Y,/H = 0.40 when using Figures MD-21 and MD-22. tRev.04/2008 MD-103 Urban Drainage and Flood Control District ' MAJOR DRAINAGE DRAINAGE CRITERIA MANUAL (V. 1) 3. The riprap size requirements in Figures MD-21 and MD-22 are based on the non -dimensional parametric Equations MD-18 and MD-19 (Steven, Simons, and Lewis 1971 and Smith 1975). Circular culvert: (Do\/Dc\ts = MD-18) 1fI 0.023 ( CD 5 / Rectangular culvert: C H)(H) =0.014 (MD719) CWH1.5 The rock size requirements were determined assuming that the flow in the culvert barrel is not supercritical. It is possible to use Equations MD-18 and MD-19 when the -flow in the culvert is supercritical (and less than full) if the value of D, or His modified for use in Figures MD-21 and MD-22. Whenever the flow is supercritical in the culvert, substitute D° for D, and H. for H, in which D° is defined as: D =(D�+Yj .2 in which the maximum value of D. shall not exceed D, and H _ (H+Y°� in which the maximum value of K. shall not exceed H, and: D° = parameter. to use in place of D in, Figure MD-21 when flow is supercritical D, = diameter of circular culvert (ft) H° = parameter to use in place of H in Figure MD-22 when flow is supercritical H = height of rectangular culvert (ft) Y° = normal depth of supercritical flow in the culvert (MD-20) (MD-21) ' MD-104 04/2008 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) MAJOR DRAINAGE 7.3 Extent of Protection The length of the riprap protection downstream from the outlet depends on the degree of protection , desired. If it is necessary to prevent all erosion, the riprap must be continued until the velocity has been reduced to an acceptable value. For purposes of outlet protection during major floods, the acceptable velocity is set at 5.5 ft/sec for very erosive soils and at 7.7 ft/sec for erosion resistant soils. The rate at which the velocity of a jet from a conduit outlet decreases is not well known. For the procedure recommended here, it is assumed to be related to the angle of lateral expansion, e, of the jet. The velocity is related to the expansion factor, (1/(2tan6)), which can be determined directly using Figure MD-23 or Figure MD-24, assuming that the expanding jet has a rectangular shape: where: and: where: Lp _(2tan B)(Y,I —W) Lp = length of protection (ft) 1. W = width of the conduit in (ft) (use diameter for circular conduits) Y, = tailwater depth (ft) 0 = the expansion angle of the culvert flow Q = design discharge (cfs) (MD-22) . 0 (MD-23) .V = the allowable non -eroding velocity in the downstream channel (fUsec) ' A, = required area of flow at allowable velocity (f:2) In certain circumstances, Equation MD-22 may yield unreasonable results. Therefore, in no case should Lp be less than 3H or 3D, nor does L,, need to be greater than 10H or 10D whenever the Froude parameter, Q/WH' S or Q/D2 5, is less than 8.0 or 6.0, respectively. Whenever the Froude parameter is ' greater than these maximums, increase the maximum Lp required by%D, or % Hfor circular or rectangular culverts, respectively, for each whole number by which the Froude parameter is greater than ' 8.0 or 6.0, respectively. ' Rev.04/2008 MD-105 Urban Drainage and Flood Control District ' MAJOR DRAINAGE DRAINAGE CRITERIA MANUAL (V. 1) ' 7.4 Multiple Conduit Installations The procedures outlined in Sections 7.1, 7.2, and 7.3 can be used to design outlet erosion protection for ' multi -barrel culvert installations by hypothetically replacing the multiple barrels with a single hydraulically equivalent rectangular conduit. The dimensions of the equivalent conduit may be established as follows: 1. Distribute the total discharge, Q, among the individual conduits. Where all the conduits are hydraulically similar and identically situated, the flow can be assumed to be equally distributed; [' otherwise, the flow through each barrel must be computed. 2. Compute the Froude parameter QIDC12.5 (circular conduit) or QJW;H;' 5 (rectangular conduit), where ' the subscript i indicates the discharge and dimensions associated with an individual conduit. 3. If the installation includes dissimilar conduits, select the conduit with the largest value of the Froude parameter to determine the dimensions of the equivalent conduit. 4. Make the height of the equivalent conduit, Hey, equal to the height, or diameter, of the selected ' individual conduit. 5. The width of the equivalent conduit, WeQ, is determined by equating the Froude parameter from ' the selected individual conduit with the Froude parameter associated with the equivalent conduit, Q/WH t.s , eq ' MD-1.06 04/2008 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) El 2( MAJOR DRAINAGE - MMMMMMIWAMM MEN FAIMPAAFE MEn E 0 Si No �a� � 0 [lop-090 MWE�O®® 00 .2 A Y /D .6 O t Use Do instead of D whenever flow is supercritical in the barrel. **Use Type L for a distance of 3D downstream. Figure MD-21—Riprap Erosion Protection at Circular Conduit Outlet Valid for Q/D2"5 <_ 6.0 Rev. 0412008 Urban Drainage and Flood Control District MD-107 DRAINAGE CRITERIA MANUAL (V. 1) A = Expansion Angle MAJOR DRAINAGE iii IFAAAREA wo 0 .1 2 .3 A .0 .o r o TAILWATER DEPTH/ CONDUIT HEIGHT, Yt/D Figure MD-23—Expansion Factor for Circular Conduits Rev. 04/2008 MD-109 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) MAJOR DRAINAGE Extend riprap to height of culvert or normal flow depth, whichever is lower �• Ina 00 We • •r flatter ]Downstream channel • _• thickness on channel banks PLAN v2 PROFILE of L1.5*d50 L/2 Flow so nular bedding NOTES: 1. Headwall with wingwalls or flared end section required at all culvert outlets. 2. Cutoff wall required at end of wingwall aprons and end section. Minimum depth of cutoff wall = 2*d50 or 3-feet, whichever is deeper. 3. Provide joint fasteners for flared end sections. Figure MD-25—Culvert and Pipe Outlet Erosion Protection Rev. 04/2008 Urban Drainage and Flood Control District MD-111 APPENDIX F References & Previous Studies 0 a HIMI N .0 O R P O .R R 7 -.E .D SUBGRADE INVESTIGATION AND PAVEMENT RECOMMENDATIONS UNION PLACE WEST WILLOX LANE FORT COLLINS, COLORADO Prepared For: -- -------------Merten-Design-Studio---- 55 South 32Id Avenue Boulder, Colorado 80305 Attention: Mr. Robert Ross Project No. FC04911-120 June 23, 2009 351 Linden Street I Suite 140 1 Fort Collins, Colorado 80524 Telephone:970-206-9455 Fax:970-206-9441 TABLE OF CONTENTS SCOPE 1 SUMMARY OF CONCLUSIONS 1 SITE CONDITIONS 2 PROPOSED CONSTRUCTION 2 PREVIOUS AND OTHER INVESTIGATIONS 2 INVESTIGATION 3 SUBSURFACE CONDITIONS 4 PAVEMENT SELECTION 5 PERVIOUS PAVEMENT RECOMMENDATIONS 7 CONVENTIONAL PAVEMENT RECOMMENDATIONS 9 SUBGRADE AND PAVEMENT MATERIALS AND CONSTRUCTION 10 WATER-SOLUBLE SULFATES 10 MAINTENANCE 12 SURFACE DRAINAGE FOR CONVENTIONAL PAVEMENTS 12 LIMITATIONS 12 FIGURE 1 - LOCATIONS OF EXPLORATORY BORINGS FIGURES 2 THROUGH 4 - SUMMARY LOGS OF EXPLORATORY BORINGS FIGURES 5 THROUGH 8 - SINGLE RING INFILTROMETER TESTS FIGURE 9- ESTIMATED DEPTH TO GROUND WATER APPENDIX A - RESULTS OF LABORATORY TESTING APPENDIX B - SAMPLE SITE GRADING SPECIFICATIONS APPENDIX C - PAVEMENT CONSTRUCTION RECOMMENDATIONS APPENDIX D - MAINTENANCE PROGRAM 0 SCOPE This report presents the results of our subgrade investigation and pavement recommendations for the proposed Union Place development located on West Willox Lane in Fort Collins, Colorado. The purpose of the investigation was to evaluate the subsurface conditions and pavement support. characteristics for the design of the private roadways, alleys and parking areas within the development. This report was prepared from data developed during field exploration, previous investigations by others, laboratory testing, engineering analysis, and experience with similar conditions. The report includes a description of subsurface conditions found in our exploratory borings and recommendations for the design of the proposed paved areas. If the project grading, pavement locations/elevations or proposed construction changes, we should be requested to review our recommendations presented in this report to determine if they apply to the new proposed construction. Our opinions are summarized in the following paragraphs. Additional descriptions of the subsurface conditions, results of our field and laboratory investigations and our opinions, conclusions and recommendations are includedin the subsequent sections of this report. SUMMARY OF CONCLUSIONS 1. Soils encountered in our borings consisted of up to 14 feet of sandy clay ' over 0 to 5 feet of clayey sand over sandy gravel with cobbles. Bedrock was encountered in the majority of the borings at depths of about 191/2 to 251/2 feet below the ground surface. 2. Ground water was measured at depths of about 5 to 61/2 feet below existing grades. Existing groundwater levels may affect pavement construction at the site. t3. Swell tests indicate the site will not require mitigation for expansive soils; however, stabilization may be necessary for areas with soft or yielding tsubgrade soils. 4. The results of infiltration tests indicate design infiltration rates ranging from 0.5 to 1.5 inches per hour with a design average infiltration rate of 1.0 inches per hour. Based on these results, it appears the majority of the site would be suitable for stormwater detention or. retention MERTEN DESIGN STUDIO PRIVATE ROADWAYS AT UNION PLACE - :1 CTL I T PROJECT NO. FC04911-120 underneath pervious paving provided the maximum seasonal ground water would be a minimum of three feet below the bottom of the storage reservoir. 5. Our subsurface investigation indicates the soils are generally considered to exhibit fair to poor subgrade support characteristics. Pervious and conventional pavement recommendations are presented in the body of this report. SITE CONDITIONS The Union Place Development is located south of West Willox Lane, west of the intersection of West Willox Lane and North College Avenue in Fort Collins, Colorado. The vacant 9.57±-acre lot tract is relatively flat, sloping gradually to the east. Irrigation ditches are located along the north and east boundaries of the site. The north, south, and west sides of the property are bordered by single-family residences and a trailer park. A fast food restaurant is located directly east of the site. At the time of our investigation, ground cover consisted of natural grasses, weeds, and several trees. PROPOSED CONSTRUCTION We understand private roadways, alleys and parking lots are planned for the development. Pervious pavement or infiltration galleries are planned for some of the paved areas. We understand that one to two feet of fill is planned over the site to realize final grades. In addition to paved areas, we understand that single-family homes, multi- family homes, and mixed -use buildings up to three stories are planned for the site. PREVIOUS AND OTHER INVESTIGATIONS We reviewed a Preliminary Geotechnical Engineering report prepared by Terracon for this site (Project No. 20055188, dated November 3, 2005). For their investigation, Terracon drilled three borings to depths of 12 to 25 feet. Their borings encountered approximately six inches of topsoil over medium stiff, sandy clay and loose to medium dense, silty sand with gravel. Siltstone/claystone bedrock was encountered at depths of 20 and 23 feet below existing grades. Ground water was encountered at MERTEN DESIGN STUDIO PRIVATE ROADWAYS AT UNION PLACE 2 CTL I TPROJECT NO. FC04911.120 - I ' depths of 6.5 to 7 feet below existing grades. Swell -consolidation tests performed on two overburden samples revealed low to moderate expansive potential. Terracon ' anticipated a composite pavement section consisting of 4 to 51/2 inches of asphaltic concrete over 6 to 9 inches of aggregate base course for local residential and/or minor ' collector roadways at the site. ' Our subsurface investigation encountered similar subsurface conditions as those. reported by Terracon. However, we did encounter a fairly continuous soft or very loose soil layer at approximately 4 feet below existing grades in some of the borings. 1 In addition to this subgrade investigation and pavement design report, we have ' prepared a separate report providing foundation recommendations and geotechnical design criteria for the structures within the development (CTL I T Project No. FC04911- 120, dated June 17,.2009). We are also preparing two additional reports for the construction of Mason Street on the east side of the site and improvements to West Willox Lane along the northern portion of the site. INVESTIGATION Subsurface conditions at the site were investigated by drilling borings in areas to ' include planned single-family and multi -family residences, mixed -use 'buildings, and paved areas. Borings were drilled using 4-inch diameter, continuous -flight augers and 6- inch diameter hollow -stem augers on a truck -mounted drill rig. The approximate locations of the borings and proposed structures are shown on Figure 1. In areas of ' —planned-single-family-and-multi-family-residences;l5 borings -were -drilled -to -depths-of----------- ---- approximately 20 to 35 feet. In areas of the proposed mixed -use buildings, three borings ' were drilled to depths of about 35 feet. Three borings were drilled to depths of about 10 feet in areas planned for paving. Our field representative observed drilling, logged the soils. and bedrock found in the borings and obtained samples. Summary logs of the ' borings, including results of field penetration resistance tests, are presented on Figures 2 through 4. ' MERTEN DESIGN STUDIO PRIVATE ROADWAYS AT UNION PLACE .3 CTL :i T PROJECT NO. FC04911-120 1 Samples obtained during drilling were returned to our laboratory and visually examined by the geologist and geotechnical engineer for this project. Laboratory testing included moisture content, dry density, swell -consolidation, unconfined compressive strength, Atterberg limits, standard Proctor, and water-soluble sulfate tests. Results of laboratory tests are presented in Appendix A and summarized on Table A4. On May 18, 2009, we performed four single -ring infiltrometer tests to measure the infiltration rate of the subgrade soils for the design of stormwater detention or retention underneath pervious pavement or for infiltration galleries. Approximate infiltrometer test locations are shown on Figure 1. The results of the single -ring infiltrometer tests are presented on Figures .5 through 8. A factor of safety of 2 was applied to field infiltration tests to determine a design infiltration rate. Design infiltration rates for the sandy clay subgrade soil ranged from 0.5 to 1.5 inches per hour with an average initial design infiltration rate of 1.0 inches per hour for the site. Infiltration rates can decrease over time from sedimentation and other factors not clearly understood. SUBSURFACE CONDITIONS Soils encountered in our borings consisted of 2 to 14 feet of soft to stiff, sandy 'clay over 0 to 5 feet of very loose to loose, clayey sand over medium dense to very dense sandy gravel with cobbles. A soft or very loose soil layer was encountered approximately 4 feet below existing grades in some of the borings. This layer appears to be somewhat continuous across the site and with an average thickness of about 3.5 feet. Some of the borings caved in the sandy gravel. Very hard sandy claystone and clayey sandstone bedrock were found in the majority of the borings at depths of about 19.5 to 25.5 feet below the ground surface. Swell tests of the overburden materials and our experience in, this area indicate the subgrade soil has a low to medium expansion potential. Bedrock underlying this site is moderately to highly expansive; however, there is sufficient separation from the bedrock that we judge it will not affect the proposed pavements. Additional descriptions of the. subsurface conditions are presented on our boring logs and in our laboratory testing. MERTEN DESIGN STUDIO PRIVATE ROADWAYS AT UNION PLACE 4 CTL I T PROJECT NO. FC04911-120 Ground water was encountered at depths. between about 5 to 61/2 feet below . existing grades. Groundwater levels will vary seasonally and may change as development of the site progresses. We anticipate temporary dewatering may be required for installation of utilities and some foundation construction. Figure 9 presents ' the approximate depth to ground water at this site. The subgrade for all pavements should be located at least 3 feet above maximum seasonal ground water. PAVEMENT SELECTION ' It is our understanding that a pervious pavement system is preferred at this site. Other types of pervious pavement, including but not limited to porous asphalt and ' pervious brick pavers, may be considered for the roadways, parking areas and alleys. The concepts of storm water control and pollution abatement are similar for most ' pervious pavement alternatives. We have also included recommendations for conventional hot mix asphalt (HMA) and aggregate base course (ABC) composite pavement and portland cement concrete (PCC) pavement. Factors that may affect the ' selection of pavement alternatives include initial cost, aesthetics, long-term performance, ' maintenance, stabilization limitations, and land -use. Based on the measured infiltration rates, we believe the subgrade soils exhibit ' infiltration qualities that. are acceptable for stormwater infiltration through pervious pavement. American Concrete Institute (ACI) generally recommends a minimum infiltration rate of 0.5 in/hr for the subgrade soils below a pervious concrete system, which should be sufficient for other types of pervious pavements. Pervious concrete and porous asphalt pavements are products that are constructed on -site and the chance of placement of below -standard materials is much higher. than manufactured materials, such as brick pavers. Methods for testing and determining the quality of pervious concrete and porous asphalt in the field are limited Mand are under development, therefore in our opinion, the likelihood of below -standard pervious pavement and porous asphalt placement is significant, and the owners must understand the risks of using these products. Pervious brick pavers, on the other hand, are manufactured with much stricter quality control and below -standard materials have a MERTEN DESIGN STUDIO PRIVATE ROADWAYS AT UNION PLACE 5 CTL I T PROJECT NO. FC04911-120 lower chance of being delivered to the site. Some pervious concrete and asphalt pavements in the Front Range area have not performed well due to either, poor installation, improper materials, poor maintenance or other factors not clearly understood. The long-term performance of pervious concrete pavement has not been established in the freeze -thaw climates of the Front Range area of Colorado and should be used with caution until further studies and case histories are published. It is critical that wheeled traffic not be allowed on the subgrade during excavation and construction for pervious pavements. Subgrade soils cannot be reworked for stabilizing in the event soft or yielding soils are present. Most pervious pavements require frequent vacuuming and sweeping to remove sediment that accumulates over time. Lack of proper maintenance can cause the pervious pavements to plug, seal and deteriorate. For the anticipated traffic conditions at the site, conventional HMA and PCC pavements, on the other hand, have historically performed well under climatic conditions in the Front Range area. Methods for testing and quality control are well established. Our experience indicates conventional rigid PCC pavements generally perform better than asphalt pavements in areas where trucks stop and maneuver. In areas such as entrances, loading and unloading zones, and trash collection areas, we recommend conventional PCC pavement be used. PCC pavement appears to perform better in these areas because the concrete better distributes wheel loads over a larger area resulting in lower subgrade stresses. Long-term maintenance of PCC pavement is typically less than asphaltic concrete pavements. Infiltration galleries can be constructed underneath conventional pavement with limitations; however, the method of conveyance to the infiltration galleries can be more complex than for pervious pavements. Ground water was encountered in the borings at depths ranging from.5 feet to 61/2 feet below the surface. The bottom of the storage reservoir for pervious pavements and pavement subgrade for conventional pavements should be located at least 3 feet above the maximum seasonal groundwater levels to maintain water quality and pavement stability. MERTEN DESIGN STUDIO PRIVATE ROADWAYS AT UNION PLACE 6 CTL I T PROJECT NO. FC04911-120 ' We envision that a member of the design team that ultimately configures the roadways, alleys and parking lots will select the locations for which the different ' pavement sections will be used. PERVIOUS PAVEMENT RECOMMENDATIONS It is our understanding that the parking lots, private roadways, and alleys will be subjected primarily to automobile traffic with some delivery and trash truck traffic. Therefore, we believe traffic conditions for the parking lot and access drive will be similar to a local residential roadway. Design traffic numbers for the development were not available when this report was prepared. For our calculations, we estimated an EDLA ' value of 5 with a calculated equivalent single axle load (ESAL) of 36,500 for a 20-year pavement design. Laboratory tests on selected samples indicated the sandy clays that ' will be the parking lot subgrade generally classify as AASHTO category A-6 with group indices ranging from 11 to 15. For our design, we estimated a conservative R-value of 5 ' for the subgrade soils. If engineered fill is needed, we have assumed it will be soils with, similar, or better, characteristics. Our design is based on the AASHTO 1993 "Guide for Design of Pavement Structures", the American Concrete Institute (ACI) Report No. ACI .522R-06 for pervious concrete, and our experience and estimations. The pavement recommendations for pervious concrete pavement are summarized in Table A below. We should be contacted to reevaluate our recommendations when design traffic numbers for the development, additional. studies,. research data, and case histories for pervious concrete pavement become available. - TABLE -A- ----------- - --- -_-------- _ _-- PERVIOUS CONCRETE PAVEMENT MINIMUM THICKNESSES Parking Areas, Private Roadways, Alleys MERTEN DESIGN STUDIO PRIVATE ROADWAYS AT UNION PLACE CTL LT PROJECT NO. FC04911. 120 8" PCP + 12" SRA 7:. Although some structural strength is provided to the pervious concrete pavement ' by the SRA layer, the main function of the SRA layer is to provide a reservoir for storm water runoff from precipitation that falls on the paved surface. Therefore, our ' recommendation of a 12-inch thick layer of gap -graded aggregate is a minimum. The actual thickness of the gravel/reservoir layer should be determined by the civil engineer ' for the project based on hydraulic characteristic of the site and the design storm event. The gravel layer should consist of either' single -sized coarse aggregate or grading between 3/4 inch and 3/8 inch meeting the requirements of ASTM D 448 and C 33. The , aggregate must be clean and free of fines. A geotextile fabric such as Mirafi 50OX or equivalent may be placed at the base of the gravel layer to separate it from the ' subgrade. This will help to reduce the co -mingling and silting of the gravel reservoir, thereby helping to preserve the reservoir permeability. We recommend the permeability ' and moisture characteristic of the subgrade soil below the pervious concrete be monitored. The surface of the subgrade below the pervious pavement gravel reservoir should be kept as flat as possible to allow for increased retention time for the underlying ' soils to absorb water. The surface of the subgrade may need to be benched to achieve a. relatively flat surface. Trenches may need to be constructed in the subgrade in order ' to retain runoff infiltration and reduce the chance of ponding at lower sections of the parking lot. Subgrade preparation for the areas constructed with pervious concrete , should be performed in a manner that will minimize the disturbance of the natural sandy clay soils. Wheel ruts and other imperfections should be raked and recompacted before ' placement of aggregate materials. Otherwise, moisture treatment and compaction of the subgrade soils below the parking lot should not be performed. Although some equipment traffic will be necessary during the grading operation, this traffic should be ' keep to a minimum. The properties of the fill placed to raise site grades in pervious pavement areas should be carefully considered to ensure water is capable of infiltrating ' the soils. The elevation of the subgrade of the storage reservoir should be kept at least 3 feet above maximum seasonal ground water. ' We anticipate that during site development activities and preparation of ' subgrade for pervious pavements, some areas of yielding soils will be encountered. If MERTEN DESIGN STUDIO , PRIVATE ROADWAYS AT UNION PLACE $ CTL I T PROJECT NO. FC04911-120 14 soft or very loose yielding soils are encountered during site. development or construction, we should be consulted to assist the project team with stabilization alternatives. Stabilization alternatives would likely include subexcavation and replacement, geosynthetics, chemical stabilization and/or crowding with large, angular aggregate. However, subgrade stabilization should not excessively compromise infiltration capabilities of the soil. CONVENTIONAL PAVEMENT RECOMMENDATIONS We have considered conventional flexible asphaltic concrete and rigid portland cement concrete pavements as alternatives to pervious pavements. Our designs are based on the AASHTO 1993 "Guide for Design of Pavement Structures" and our experience. We have based our recommendations on the same traffic and subsurface conditions as the pervious pavement recommendations describe in the preceding section of this report. The conventional pavement sections are summarized in Table B below. We should be consulted to reevaluate our recommendations in the event ■ infiltration galleries are planned underneath conventional pavements. ' TABLE B CONVENTIONAL PAVEMENT MINIMUM THICKNESSES --------- --- - Parking Areas -Private Roadways, Alleys 5" HMA.+ 8" ABC - - - _— 6" PCC — Our conventional concrete pavement recommendation is based on the concrete panels having doweled. transverse joints and non -tied shoulders or non -doweled transverse joints and longitudinal joints and/or tied shoulders. Soft or very loose subgrade soils that may yield during pavement construction ' were encountered in some of the borings at the site. The subgrade must be stable prior to placement of paving materials. Methods for stabilizing- subgrade soils for conventional ' MERTEN DESIGN STUDIO PRIVATE ROADWAYS AT UNION PLACE - 9 CTL I T PROJECT NO. FC04911-120 pavements include soil replacement (as described for pervious pavements), geogrid or geotextile reinforcement, and chemical stabilization with lime or fly ash. Typical treatment of soft or very loose subgrade soils in this area consists of mixing a minimum of 12% fly ash in the upper one foot of the existing subgrade soil. A mix design can refine the recommended amount of fly ash or determine the appropriate amount of lime. However, lime application may have liability issues associated with lime dust and contamination with the neighboring population. Our scope of work did not include design of a soil/fly ash mixture. We should be consulted in the event soft or yielding subgrade soils are encountered during construction. SUBGRADE AND PAVEMENT MATERIALS AND CONSTRUCTION The design of a pavement system is as much a function of the quality of the paving materials and construction as the support characteristics of the subgrade. The construction materials are assumed to possess sufficient quality as reflected by the strength coefficients used in the flexible pavement design calculations. Materials and construction requirements of Larimer County Urban Areas Street Standards (LCUASS) should be followed. Material properties and construction criteria for the pavement alternatives are provided below. These criteria were developed from analysis of the field and laboratory data, our experience and LCUASS requirements. Criteria for subgrade preparation, paving materials and construction for conventional pavements are presented in Appendix C. If the materials cannot meet these recommendations, our pavement recommendations should be reevaluated based upon available materials. Materials planned for construction should be submitted and the applicable laboratory tests performed to verify compliance with the specifications. WATER-SOLUBLE SULFATES Concrete that comes into contact with soils can be subject to sulfate attack. We measured water-soluble sulfate concentrations in four samples from this site. Concentrations were measured between 0.1 and 0.51 percent, with one sample having a sulfate concentration greater than 0.2 percent and three samples with concentrations less than 0.2 percent. Water-soluble sulfate concentrations between 0.2 and 2 percent MERTEN DESIGN STUDIO PRIVATE ROADWAYS AT UNION PLACE 10 CTL I T PROJECT NO. FC04911-120 ' indicate Class 2 sulfate exposure, according to the American Concrete Institute (ACI). For sites with Class 2 sulfate exposure, ACI recommends using a cement meeting the ' requirements for Type V (sulfate resistant) cement or the equivalent, with a maximum water-to-cementitious material ratio of 0.45 and air entrainment of 5 to 7 percent. As an talternative, ACI allows the use of cement that conforms to ASTM C 150 Type II requirements, if it meets the Type V performance requirements (ASTM C 1012) of ACI ' 201, or ACI allows a blend of any type of portland cement and fly ash that meets the performance requirements (ASTM C 1012) of ACI 201. In Colorado, Type 11 cement with ' 20 percent Class F fly ash usually meets these performance requirements. The fly ash content can be reduced to 15 percent for placement in cold weather months, provided a water-to-cementitious material ratio of 0.45 or less is maintained. ACI also indicates ' concrete with Class 2 sulfate exposure should have a minimum compressive strength of 4500 psi. Concrete should be air entrained. ' Sulfate attack problems are comparatively rare in this area when quality concrete ' is used. Considering the range of test results, we believe risk of sulfate attack is lower than indicated by the few laboratory tests performed. The risk is also lowered to some ' extent by damp -proofing the surfaces of concrete in contact with the soil. ACI indicates sulfate resistance for Class 1 exposure can be achieved by using Type II cement, a maximum water-to-cementitious material ratio of 0.50, and a minimum compressive ' strength of 4000 psi. We believe this approach should be used as a minimum at this project. The more stringent measures outlined in the previous paragraph will better control risk of sulfate attack and are more in alignment with written industry standards. Surface flatwork exposed to the soils, such as pavements, sidewalks, and driveways and --patios,—is- usual ly- constructed -with -a-mix-that-exhibits--moderate -resistance-to- sulfate ------- ---- ' attack. We have rarely seen instances of sulfate attack on surface flatwork. Our threshold limit of water-soluble sulfates in soils for single application of fly ash or lime for subgrade stabilization is 0.5 percent. Colorado Department of Transportation threshold limit of water-soluble sulfates in soils for single application of fly ash or lime for stabilization is 0.2 percent. Additional tests for sulfates are recommended after the subgrade has been, cut or filled to rough grade. Based on our test results,. we believe double application of fly ash or lime is recommended where MERTEN DESIGN STUDIO - PRIVATE ROADWAYS AT UNION PLACE t 1 CTL I T PROJECT NO. FC04911-120 3 1 chemical stabilization of the subgrade is selected. Recommendations for fly ash or lime ' application are provided in Appendix C. MAINTENANCE ' We recommend a preventive maintenance program be developed and followed for all pavement systems to assure the design life can be realized. Choosing to defer maintenance usually results in accelerated deterioration leading to higher future ' maintenance costs. Special maintenance will be necessary for the pervious concrete pavement to help maintain drainage. Recommended maintenance programs for ' pervious pavements and conventional pavements are outlined in Appendix D. SURFACE DRAINAGE FOR CONVENTIONAL PAVEMENTS t The primary cause of premature deterioration of conventional pavement is infiltration of water into the pavement system. This increase in moisture content usually ' results in the softening of base course and subgrade and eventual failure of the pavement. We recommend that the pavement surface and surrounding ground surface be sloped to cause surface water to run off rapidly and away from conventional ' pavements. Backs of curbs and gutters should be backfilled with compacted fill and sloped to prevent ponding adjacent to backs of curbs and to paving. The final grading of ' the subgrade should be carefully controlled so the pavement design cross-section can be maintained. Low spots in the subgrade that can trap water should be eliminated. ' Seals should be provided within the curb and pavement and in all joints to reduce the possibility of water infiltration. ' LIMITATIONS Our borings were spaced to obtain a reasonably accurate indication of pavement conditions for the proposed construction. The borings are representative of conditions ' encountered only at the exact boring locations. Variations in the subsurface conditions not indicated by our borings are always possible. A representative of our firm should ' observe subgrade preparation, subgrade stabilization, and pavement construction. MERTEN DESIGN STUDIO PRIVATE ROADWAYS AT UNION PLACE 12 CTL I TPROJECT NO. FC04911-120 The pavement section and construction recommendations included in this report are based upon our field observations, laboratory testing, estimated traffic levels, AASHTO design methods, ACI guidelines and our experience. Routine maintenance, such as sealing, repair of cracks, and power washing or vacuuming are necessary to achieve the long-term life of pavement systems. If the design recommendations and construction guidelines cannot be .followed, or anticipated traffic loads change significantly, we should be contacted to review our recommendations. We believe this investigation was conducted with that level of skill and care ' ordinarily used by geotechnical engineers practicing in this area at this time. No warranty, express or implied, is made. If we can be of further service in discussing the ' contents of this report or in the analysis of the influence of subsoil conditions on design of the pavements, please call the undersigned. h\S.ktof PBOFESP, Oyu CTL THOMPSON,Dols AIPG `,; cer. ti�ya ••�"c 00 ' Thomas nFinle.......•••'' �' S Senior Geologist 9''s 6 QS VdoH*�o Pp0 L!c •R ' Reviewed O� tis 'o C 3 �a EriccD. B 'cot, PE obin Dornfest;: •, Project Ma �ONAI Geotechnical Department Manager MERTEN DESIGN STUDIO PRIVATE ROADWAYS AT UNION PLACE - 13 CTL I- T PROJECT NO. FC04911-120 L t s !'- feat >p 1 4 �*%; w4"wwe'P � ai tiy� .lam �1�♦ a �- • I r. J RL U, `- L 7 low 3010 w•A Jac: r 4 �•1 ; ((••� .r IRS .9 .3 i` .�I �� ♦ !w ..♦ 1.64�� a, :a { 44 IC If 44 now, bME; 1111 it st a ,, - y T �l At Jr. Sf y11 'I RAI it LAP y AS 1 1 + AM r �' Apful r•v..j� YCI� i i. room ALI act l 17. r•I+4u —aa_� _ i� . +�1+•♦ �.- , r� . �►�+ w�asear���.. ti-� P9 1 C, ''.��.�A It MAI _ r..... ter,: � , • ;�� Vol ANEW ;I it Olt -��Ifa�+! r •. i �.wGAw _ I Y• �1. } • r,p: a hv. 4It i 1 n t t Asa Cn C O .0 o� T� ` v0 LLt i No Text Hydrologic Soil Group—Larimer County Area, Colorado Union Place Hydrologic Soil Group 'i .•..+ LL1. $.." Sys vl v ' i> R.i fa#Hi �$ i ,jjydrologlc'Sod Group —Summary by�MaprUntt Larimer County Area,;Coloredo 'xMapiunit Map Rating " Acres lh AOI 'R s Perent,of'AQI,> i symbol„r unitlname g 22 Caruso clay loam, 0 to 1 C 6.0 17.0% percent slope 73 . Nunn clay loam, 0 to 1 C 29.3 83.0% percent slope Totals for Area of Interest 35.3 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when•the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. t The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly ' wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. ' Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow. infiltration rate (high runoff potential) when - — ------—thoroughlywet-These consist -chiefly of clays-that-have-a-high-shrink=swell— — - -- — -- potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. ' If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options ' Aggregation Method: All Components ' USDA Natural Resources Web Soil Survey 2.1 3/10/2009 i Conservation Service National Cooperative Soil Survey Page 3 of 4 No Text WAR. R&R ENGINEERS - SURVEYORS, INC. October 7, 1998..: Mr. Basil Y.:Hamdan Civil. Engineer II: . City of Fort Collins Storm *Water Utility 235 Mathews Street Fort Collins,. CO 80522 RE: Request for Variance Detention_ Requirements Dear _Mr. Harridan: . _ Dueto the considerations presented in the accompanying drainage report R&R:Engineers- Surveyors, Inc. is requesting a waiver from the detention requirements as set forth in the "Storm Drainage Design Criteria and Construction Standards.. as they apply to the Wii.lox Crossing Final P.U.D. Physical constraints to the property do not allow adequate volumes or practicable constraints to release rates to provide maintainable facilities. In particular, being requited to compensate for off -site improvement flows and on -site areas discharging without being detained would result in negative release rates A situation which is ... obviously .not attainable. We have maximized. storage volumes in the two proposed on site. . ponds and providedrelease orifices.2 inches in diameter., which are the.minimum size-we`feel racticable for reliable op eration peratlon and maintenance.. Both ponds also: -offer some permanent water qualitycontrols perahe Cities request: It is our contention. that the variance we are asking for,. inconjunction with the storm drain. utility improvements we —are tnetigating beyond eur on -site requirements,`will not constitute a hazard or. detract in any way from the operations -and maintenance of adjoining facilities.. pQ ��pt1 Tp�p Sincerely, o 3W 5 . . oel D. Tompkins; P.E.. . Project Engineer cc: .McD6nalds Corporation 10 I14VERNESS DRIVE EAST, #229 ENGLEw,OOD, CO 80112 PH 303.792.284E FX 30-3.790.0754. INTRODUCTION Willox Crossing Final P.U.D. is a joint McDonald's / Amaco ' facility proposed in north Fort,Collins. More specifically it is located at the south-west corner of _College Avenue and Willox Lane. It is a portion of Section 2, Township 7 ' North, Range 69 West of the 6tn Principal Meridian, Larimer County, Colorado. ' Willox Crossing has a platted acreage of 1.8950 acres, but is significantly larger as a drainage basin due to off site flows onto or through said property. The site is generally flat with native grass and weeds for ground cover. Several large trees also exist on the site and every effort has been made to preserve them. The slope of the site is generally eastward to an existing drainage swale along College Avenue. This ditch drains north to south passing through several CMP culverts. Observations have shown these drainage facilities to be in an advanced state of disrepair and probably significantly impede flows. The subject site is located in the 100-year floodplain as delineated in both the Flood Insurance Rate Map Number 080102 0004 C (dated March 18, 1996) and the Dry Creek Drainageway Planning map provided by the City of Fort ' Collins. However; it is not shown to be within the Floodway on either of those exhibits. The City of Fort Collins has been presented with and granted approval of a variance request to construct within the floodplain. ' Soils on this site and the surrounding area are classified as being Hydrologic Soil Group "B." These types of soils are characterized as moderately fine to moderately coarse in nature with moderate infiltration rates when thoroughly. ' wetted. ° To the west of this site is a large open field, roughly acres, with a single trailer home on it. The field, at time of observation, was covered with short, cut grasses is believed to be regularly cultivated with hay crops. . Bordering Willox Crossing to the south is a car wash and self storage facility which drains south through on -site 11. and drainage facilities. North and east property lines are, as indicated above, bordered by Willox Lane and College Avenue,. respectively. 2 There is, however, a large upstream contributing basin to , the north bordered, roughly, by the Weld Canal, College Avenue, and Willox Lane. In the natural condition these areas would have drained south-east across the 'subject site. ' With the existing construction of Willox Lane that flow is intercepted and diverted to the swale on the west side of College Avenue. Inlets at Willox Court and the Willox / ' College Intersection are in place to carry runoff to the swale. However, those facilities are woefully undersized and it is expected that Willox Lane is over -topped by any ' significant event; including the 2-year storm. It is the intent of this report to show general compliance , with the City of Fort Collins Stormwater Utility "Storm Drainage Design Criteria and Construction Standards." Due to hardships unavoidable at this location not all of those Criteria can be met; justification and requests for , variance, where applicable, are included herein. it HISTORIC DRAINAGE For developed comparison the site, less 0.116 acres, is treated as a single historic basin of 1.779 acres. Storm runoff from that site is calculated at 0.29 CFS and 0.62 CFS for the 10= and 100-year events, respectively. The 0.116 acres broken out will not have any impervious cover in the developed condition, does not contribute to excess runoff, and is not routed through detention facilities. Please refer to the Appendices of this report for all calculations. Overall drainage patterns were reported in the "Present Drainage Patterns and Flow Volumes" report submitted to the City of Fort Collins in 1996. Therein the offsite flows generated north of Willox Lane as mentioned above are quantified.. That report is included in its entirety. in an Appendix of this report. MAJOR BASIN DESCRIPTION There exists a hydrologic study.for the "Dry Creek Drainage Way," prepared by Gingery Associates, Inc. and dated December of 1997 for the City of Fort Collins,'Larimer County, and Colorado Water Conservation Board. The subject site and surrounding area fall within the Dry Creek Basin. As stated above the site is inundated during the 100-year and 500-year storm events to elevations of 4982.0 and 4982.5, respectively. ' 4 DESIGN CRITERIA The criteria used for this study was the City of Fort Collins Stormwater Utility "Storm Drainage Design Criteria and Construction Standards," hereinafter referred to as the criteria. Peak runoff rates were determined using the widely utilized Rational Method of the form: Q = CIA where, Q =.peak storm runoff in cubic feet per second (cfs) C = rainfall coefficient - ratio of runoff to rainfall I = rainfall intensity in inches per hour A = drainage area.in acres The 2-year, 10-year (initial), and 100-year (major) storm event rainfall intensities were determined by look -up. Runoff coefficients were taken from or composites of those tabulated in the criteria. Times of concentrations were determined using the overland and shallow concentrated flow methods as described therein. Calculations for the above referenced characteristics can be found in the appropriate appendices at the back of this report. DRAINAGE SYSTEM DESIGN For design purposes Willox Crossing P.U.D. has been divided into six onsite and three offsite basins. Each basin and resulting drainage considerations is discussed in detail below. Please refer to the enclosed drainage maps for illustration of the boundaries indicated. BASIN "A" The 0.856 acres of this basin is roughly one-half of the total developed area. Runoff will flow overland through landscape and parking areas before collecting in Detention Pond #1 in the south-west corner of the facility. Developed storm discharge rates from this basin have been calculated at 2.99 CFS and 5.98 CFS for the 10- and 100-year events. G J IBASIN "B" ' In combination with Basin "A" this 0.814 acres accounts for almost all of the remaining on -site impervious cover resulting from the proposed ' development. Runoff will be routed.overland through landscaping and parking before collecting in Detention Pond #2 in the north-east corner of the facility. Runoff rates have been calculated at 2.55 CFS and 5.18 CFS for the 10- and 100-year events. BASIN %%C" This is 0.028 acres of landscaping and sidewalk adjacent to the Willox Lane improvements which will flow offsite without entering a detention facility. Developed runoff is minimal at 0.06 CFS and 0.1.4 CFS. Please refer to the detention facilities discussion. below. BASIN %%D" A small portion of the exit drive (0.051 acres) drains to College Avenue. The resulting storm discharges 0.22 CFS and 0.36 CFS will immediately enter ' the swale.in the west .ROW of the street. BASIN "E" This two part basin totaling 0.080 acres is'•a thin band of landscaping which contains no impervious cover. and does not contribute to excess runoff. However, the 0.06 and 0.07 CFS of runoff will have to be directed toward.the car wash / self storage facility south of our site. It will be necessary for McDonald's Corporation to obtain a drainage, easement from the owners thereof. BASIN "F" Detention Pond #1 is;. itself; 0.33I--acres of" -land -- ------------- which will be.replanted with native grasses and will not contribute to excessive runoff from the site. ' Obviously, the 0.08 CFS and 0.17 CFS of runoff generated therein will contribute. to the.operating parameter of that pond. 6 BASIN "OS-1" Consisting of 11.015 acres of pasture land and landscaping this area will not contribute to excess runoff in the developed condition. Historically, this site collected off -site near the south end of Detention Pond #1 where it sat until dissipated through infiltration and evaporation. Contours and site visits indicate that in the event of a significant event that runoff would eventually pool and discharge to the trailer park south thereof. At some point a small v- shaped swale was installed in an effort to drain ponded water north and east to the College Avenue swale. At less than 0.1% slope that swale would not provide significant routing capacity to prevent discharge to the trailer park in a larger return period event. However,.in order to better protect that facility and eliminate the aesthetically unappealing puddles we are proposing to re -grade some of the pasture area (see construction sheet C-lC) and route those flows to College Avenue through an 18" RCP. Total runoff collected at the F.E.S. intake to that pipe has been calculated at 2.12.CFS for the 10-year event and 4.56 CFS for the 100-year event. BASIN "OS-2" In the ultimate developed condition this basin could consist of as much as 1400 LF of Willox Lane. Estimated herein at 1.303 acres the resulting 4.06 and 8.25 CFS of runoff therefrom will be intercepted by a 5' Type R Inlet at station 3+00 of that road. BASIN "OS-3" Consists of the 0.330 acres of College Avenue which will be improved to the ultimate condition with construction of the McDonald's site. Runoff of 1.57 and 2.38 CFS will enter the ROW swale immediately south of our property 7 DETENTION ' The Fort Collins' Drainage Criteria establishes a release rate for the 100-year developed site at the historic 2-year level. That historic rate is 0.17 CFS which,.when ' compensating for the bypass of BASIN's "Cl' and "D" results in a negative (-) .33 CFS discharge. Obviously this is not attainable. Therefore, the approach taken herein is to . equip the ponds with orifices 2 inches in diameter, which is the minimum practical in our opinion, and determine discharges based on maximum attainable water surface volumes and resulting elevations. The resulting discharge rates are 0.11 CFS for Pond #1 and 0.16 CFS for Pond #2. Compensating for the bypass of the two above referenced basins total site discharge will be 0.77 CFS, or 0.15 CFS above the historic release. A request for variance from the detention requirements as set forth in the "Storm Drainage Design Criteria and Construction Standards" accompanies this report. POND #1 Total 100-year inflow to this pond is 3.67 CFS which is throttled to 0.11 CFS at discharge. This is accomplished with 8232 cubic feet of storage volume between elevations of 79.50 and 80.51. The 2948 cubic feet between 78.76 and 79.50 is used as water quality ' volume. The emergency spillway for this pond has been located such that any overflow will be directed toward the F.E.S. inlet collecting drainage from Basin OS-1; thus,. having a second chance to enter the storm drain system before causing any nuisance flows to neighboring properties. ' POND #2 The 5.18 CFS of developed flow to this facility is released at a rate of 0.16 CFS through a 2" diameter orifice. at. elevation 79.75.\ Total detention — 5205 cubic feet though maximum required volume is 4868 cubic feet at an elevation of 81.61. The 1247 cubic ' feet between the bottom of the pond at 78.64 and the orifice at 79.75 is used as water quality volume. 0 UTILITY IMPROVEMENTS It is not economically viable to install drainage facilities at this location which would.be able to handle all off -site flows. Grade restraints of existing structures maximizes pipe sizes to 24 inches in diameter at grades as shallow as 0.25%. At the cities request we are proposing to install two such pipes, one stubbing out at the proposed 5' Type R Inlet at Station 3+00 in Willox Lane. The second pipe will stub out at the west.end of proposed improvements thereon. Pipe capacity will total approximately 22 CFS which is less than the 107year total flow at the Willox Lane and College Avenue intersection. Capacity approaches the 2-year event and will provide for all nuisance flows. The proposed inlet in College Avenue (5' Type R) has been installed at the request of Stormwater Utilities for those same nuisance flows and no capacity data is provided herein. WATER QUALITY IMPROVEMENTS Using the UDFCD Water Quality Capture volume graph for the entire 1.90 acre site at a commercial impervious rate of 95% results in a required storage of 0.475 inches of runoff (3,276 cubic feet). Actual storage provided in ponds #1 and #2 is 4,195 cubic feet; providing 919 cubic feet of excess. CONCLUSIONS This report demonstrates the maximum level of service that can be provided for stormwater mitigation at the'Willox Crossing P.U.D. Though detention facilities do not function within the standard parameters it.is our assertion that the runoff patterns delineated herein do not contribute adversely to the already problematic situation. In fact, the inclusion of up -sized piping in Willox Lane and College Avenue provides additional storm drain capacity serving to reduce flooding conditions already present. Therefore, the improvements as outlined herein will not contribute adversely to the safety or welfare of the general public nor impede the operation of adjacent public facilities. M N. COLLEGE AVE �- — •------- i ! i i oS-2 I I 4. 06 S. 25 i I, (-_------_ I� 1:> clf5choryes I I I i I I✓ j ❑S-1 11. 015AC 12 .56 I I I I I j I 1 I j ' I I j I I I i ' I i L— —---............... =•---- WILLOX CROSSING FINAL P.U.D. '�FTSITE DRAINAGE BASINS Datei 8-24-98 Checked b j JT Job No. 1 MC620 Drawn By, RBT Q 0 y 150' 300' SCALES 1' =.150' R & R Englneers=Surveyors, Inc. #10 Inverness Drive East, Suite 229 Englewood, Colorado 80112 (303)792-2846 �, 2 �iiyia�eeee-eS'ruueyosce, ,9icc. #10 Inverness Drive East, Suite 229 Englewood, CO 80112 UUU I L - • • .- Date 1+/6 198 By an-r Chk ' Subject F1zr,PrsrLr> iES,,•;ua lasrn, Co/Iw/Ic_TEK1� IGS:_ _.:. :. _ ... _,: R>AS1.N._ ARFA A -A .. Ib /mil Nb"rAP ? nRIVF AVAL I: RUUI° ?/•IV <:D l:O/lt% To-r Qi _ .. .... _._ ...... 0. 1 73.. O. G3rj._ ... v...oy A ss6 .. L- a. 7 1 5....._.. :._:.O •.`t 6__;_._.:...•...: U .:,i.3'_3_:. _ _-.......... - ...__ ....-:. _.!-._v.. S l'.i ...:.._.._ _..._..... _.. 0-017 p o. 0I t j-_._ O. 037 . IF. 0-050 os-.l lf.ol5...'..._:.. - - 1/.olS�.... ..._ 05 Z O.Z7.5...._._.'. ..... — /,OZa'' oS-3 � O o37 � _ - O • Z93' o . 330 ..:....... ?O _ACRE.--_aM.. 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Date 4 /6 //gg By JnT Chk #10 Inverness Drive East, Suite 229 Englewood, CO 80112 Subject 1 9 - — — -- 1 i sheet of ' Sheetl ' DETENTION POND 1 100-YEAR RETURN PERIOD CALCULATIONS ' Basin area = 1.187 acres Release Rate = 0.11 cfs Volume Duration Intensity Inflow Inflow Release Detention min sec in/hr CxA cfs CF CF CF . 5 300 7.20 0.87 6.26 1879.2 33 1846.2 ' 10 600 7.20 0.87 6.26 3758.4 66 3692.4 15 900 5.97 0.87 5.19 4674.5 99 4575.E 20 1200 5.20 0.87 4.52 5428.8 132 5296.8 25 1500 4.60 0.87 4.00 6003.0 165 5838.0 30 1800 4.16 0.87 3.62 6514.6 198 6316.6 35 2100 3.80 0.87 .3.31 6942.6 231 6711.6 40 2400 3.50 0.87 3.05. 7308.0 264 7044.0 45 2700 3.23 0.87 2.81 7587.3 297 7290.3 50 3000 3.01 0.87 2.62 7856.1. 330 7526.1 55 3300 2.79 0.87 2.43 8010.1 363 7647.1 60 3600 2.59 0.87 2.25 8111.9 396 7715.9 65 3900 2.43 0.87 2.11 8245.0 429 7816.0 70 4200 2.30. 0.87 2.00 8404.2 462 7942.2 ' 75 4500 2.17. 0.87 1.89 8495.6 495 8000.6 80 4800 2.06 0.87 1.79 .8602.6 528 8074.6 85 5100 1.95 0.87 1.70 8652.2 561 8091.2 90 5400 1.86 0.87 1.62 8738.3 594 8144.3 95 5700 1.77 0.87 1.54 8777.4 627• 8150.4 100 6000 1.70 0.87 1.48 8874.0 660 8214.0 ' 105 6300 1.62 0.87 1.41 8879.2 693 8186.2 110 6600 1.56 0.87 .1.36 8957.5 726 8231.5 115 6900 1.49 0.87 1.30 8944.5 759 8185.5. 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Q y V • � ' l 03. cr in Im 1 �� a{r'or Q �Ca0.moo,- � LrCa oa 3 � t � c� . 0: CLa L CX MEm { ao.3J aQQ NF�o m ao�Q Fr wy a.•K� r r V ... n F-, 4 '.. s _ } �' 0 _. Lou :. Q n cy- O .. o Co- � Q — U Q ¢ o l r. Z�u'•t� Q�QIi �uj 2 ♦ :aiJ _ - .. _ - - .. Zcu o � f QLO r (n } zooLO (30 CD rn�r.� �F na o �: o Q 11 Ln i - 1741 .. .. o W o] o- W 03 7- 0 0 NORTH COLLEGE DRAINAGE IMPROVEMENTS DESIGN ALTERNATIVE ANALYSIS REPORT Prepared for City of Fort Collins Utilities 700 Wood Street Fort Collins, Colorado 80522 5 ASSOCrIATES P.O. Box 270460 Fort Collins, Colorado 80527 (970) 223-5556, FAX (970) 223-5578 Ayres Project No. 32-0950.01 N-COLMMOC February 2006 7.2 Alternative 2 — Design Assumptions Alternative 2 provides a 100-year storm drainage design for the east side of College Avenue. Alternative 2 includes two regional detention ponds (B & C) and a regional water quality . pond (A). The proposed storm sewer alignment follows future street segments shown in the City's Transportation Master Plan (2004). The following assumptions provide a basis for the design: • Pond C will require 5.6 ac-ft of storage, with a surface area of 2 acres and an approximate depth of 5.5 ft. • Pond B will require 21.7 ac-ft of storage, with a surface area of 6 acres and an. approximate depth of 6 ft. • Pond A (water quality) will require 8.7 ac-ft of storage, with a surface area of 4 acres and an approximate depth of 4.5 ft, based on a 40-hour drain time. • Any undeveloped or redeveloping land north of the Anheuser-Busch water line will not need to provide detention once their corresponding regional detention ponds (B or C) are built and the connecting storm sewer system is in place.. These properties will not need to provide water quality once the water quality pond A is built and the connecting storm sewer is in place. • Any new or re -developing land south of the Anheuser-Busch water line will need to provide on -site detention but not water quality once Pond A and the connecting storm sewer system is built. • Table 7.2 which follows details the location and type of inlets required for the Alternative 2 storm sewer design. n c 7.3 Ayres Associates i 95 140 Qe�h 939 285 315 107 ' 50 903 007 960 902 962 904 964 905 p( 501 490 965 405 102 966 502 504 505 968 970.. 302 404 C5 eke) LS 1 1 1 1 1 1 POND RATING CURVE Description: Pond C (Alternative 2) PondlnverC = Due to the high groundwater levels in the area the bottom of the pond will be at 49T7.00. A 1.92ft high by 4ft wide concrete channel will start at the invert out of the pond.. The channel will extend through the pond to the pond inlet. At the storm sewer into the pond the channel will be a 0.2ft high by 4ft wide channel. " The outflow corresponds to the given storm event SURFACE DELTA CUM. CUM. ELEV. AREA DEPTH AREA VOLUME VOLUME VOLUME ft. s .ft. ft. Acres Acre-feet Acre-feet Cf 18"OUTLET PIPE" cis STORM EVENT 4975.08 0 0.00 0.000 0.037 0.000 0 - - 4977.0 2500 1.92 0.057 0.558 0.037 1600 4977.27 17593 2.19 0.188 8.03 2-year 4978.0 58399 2.92 1.341 1.387 0.595 25928 4978.45 60209 3.37 1.219 9.61 10- ear 4979.0 62421 3.92 1.433 1.480 1.982 86327 4980.0 66542 4.92 1.528 1.576 3.462 150797 4980.25 67598 5.17 3.856 11.60 50- ar 4981.0 70765 5.92 1.625 1.674 5.038 219440 4981.31 72105 6.23 5.557 12.48 100- ear 4983.00 4982.00 4981.00 4980.00 c 4979.00 4978.00 4977.00 ' ' x ' t' W _ _ E 4976.00 _ _ --- - ---4975.00 4974.00 '0.0 1.0 Pond C -Stage Volume Curve 2.0 3.0 4.0 5.0 Volume, ac-ft � 11 -IRN S It .. �� fit 1 1 t'. � ) s 'fir5 x �14 Z 0 J W p NH N j0 Z W QW m J WZ W U O z .Qz CL g a Z ti Orn a. v a� O ' Detention Pond(s): The proposed detention ponds need. to be hydraulically connected, which means they ' need to operate as one pond. This generally requires a large pipe or box culvert connecting the ponds. Otherwise the volume for the two smaller ponds cannot be counted in the total volume. In addition, because the ponds will need to be hydraulically ' connected, the maximum ponding depth is being controlled by Pond N which is to an elevation of 4981.00. Ayres has regraded the pond areas using a 4:1 side slope'and a maximum depth of 4976.8 to see if the required volume of 5.6 ac-ft can be achieved. The ' grading is attached as a PDF. If the ponds can be hydraulically connected then the required volume can be achieved. ' Off -Site Drainage: On page 4, 1" bullet of the drainage report it states that: "The site is located in SWMM model Basin 406. Basin 406 includes some area to the west but east of Maplewood ' Drive. Runoff from the north of Willox Lane represented by Basin 405 does not enter the site. Runoff from properties further west also does not enter the site." ' These basins refer to the original Dry Creek Master Plan that was completed by URS in March 2002. This model was used as a starting point for the North College Drainage ' Improvements Design (NCDID). For the NCDID the existing conditions model was revised and the existing basins were re -delineated. The proposed development encompasses Basin 307. Basin 306 (3.8acres) is located to the west of the project site ' and currently drains to a swale located along the south edge of the proposed - development/Basin 307. During a 100-year event approximately 19cfs will travel onto the proposed development. Basins 405 (10.1 acres) and 305 (12.8 acres) are located just north of the proposed development. During the minor and major storm events these basins drain to an undersized storm sewer system at the northeast comer of Basin 406. When the existing storm sewer reaches capacity, the storm water overflows ' (approximately 168cfs) to the south and through Basin 406. Basin 308 is the current McDonalds development. While Union Place does not need to provide detention for these off -site basins it does need to provide capacity for the off -site flows to pass through ' the development. The storm water from these offsite basins need to be accounted for in the proposed development storm drainage calculations. Ayres has provided exhibits which show the off -site drainage basins from the NCDID report. 1 1 1 1 POND RATING CURVE Description: Combined Union Place Pond Pondl Pond Nt Pond N2 TOTAL SURFACE DELTA CUM. GUM. ELEV. AREA AREA AREA AREA DEPTH AREA VOLUME VOLUME VOLUME ft. sa.ft. sa.ft. soft. sq.ft. ft. Acres Acre-feet Acre-feet Cf No Text 0 mom QI SPIN MINIMUM ow' P. �W! *••-tw Line Y.. I' 1 ®�. � � ®� •- �® III; IIII�`i i "' ,II I �NEI --- _ ' __ �''.. � der ,, � � , ►STORMITIPE �► . y I i , LIMIT DEPTH OF ROW UNIT DEPTH OF FLOW IT zx - 34 2Z_� a14 zx SIDEWALK x LAWN \'4 SEE DETAIL p g 2 THIS SOEWAIK ASPHALT/ WRB & SHEET ASPHALT/ CONCRETE CDR. AND SEE DETAIL CONCRETE PAVEMENT GUTTER PAVEMENT GUTTER 1 THIS SHEET SECTION Al SECTION C4 N.T.S. N.T.S. OMIT DEPTH LIMIT DEPW ROW OF ROW LOF 2% 3x� 3x 2x 2� 3 LAWN LAWN ASPHALT/ CURB & ASPHALT/ CURB & CONCRETE PAVEMENT GUTTER CONCRETE PAVEMENT GUTTER SECTION 131 SECTION E1 LIMIT DEPTH a Row 3tl zx 3! zs' ro EOP (TYPICAL) zx z.s' aW 1 2R Fx SIDEWALK -_ a.s,T 6_V 4.5' �/ C5' SEE DETAIL SIDEWALK SIDEWALK I THIS ASPHALT/ CONCRETE CURB AND SEE DETAIL ASPHALT SHEET PAVEMENT GUTTER 1 MIS CONCRETE PAYLMENT CURB & SHEET GUTTER SECTION B2 N.T.S. LIMIT DEPTH OF ROW 34• 2% 2x 4.5' SIDEWALK SIDEWALK SEE DETAIL CURB AND ASPHALT/ CONCRETE 1 THIIS GUTTER PAVEMENT SHEET SECTION B3 N.T.S. OMIT DEPTH OF ROW tz.r 2x III 2x MIN. M'a 2% 2% WRS & GUTTER ASPHALT/ CONCRETE PAVEMENT SECTION C2 N.T.S. SECTION E2 N.T.S. 16' TO EUP (TYPICAL) 7 .5' 5' 2"'zx 4.5' 1.0' SIDEWALK ASPHALT/ CONCRETE PAKMENT DURO a WITTER SECTION E3 N.T.S. 52- 2% z-4x SO' vOEWALK ASPHALT/ CONCRETE PAVEMENT WRB & GUTTER SECTION E4 & G1 N T5. --�- T r REFER TO OPEN b MANNR/STRF£T •^ CAPACITY TABLE $ Pa THIS SHEET SECTION 64a, 64b, 134c 4.5' SIDEWALK CURB WITH CURB CUT\ ALLOWABLE DEPTH OF FLOW = 0. DETAIL 1 zys' 2.75' DETAIL 2 ADMNrHANaR I<m CAPerm Temp Abxabk Cekak6d 01pen Chlml/Skml SeclkO SeNkO BOOKS) 1339QIa D0001' a Cm Skip OeMOof Noka 171 FII IT ATOY Sx xffi Rb0 Cub AI AI-A3 3.7 am Ob 3% 0.31 AI-A3 51 am Oh 3% 035 IW AVYSec400.A6Robler Cleb BI BE 1.9 0.32 9.6 255 0.21 EI EI 33 039 OS 14% 119 B2 BI-B2 5.3 1 Ok 216k Sk (&land 0.59 INbuaP SO BT B3 1.7 1 0.6 4:1 k6Pak a42 Ca C4 1.1 0.5 0.6E 53:1 ad "I 0.45 1SMNpm4Cmw Aky C2 CLC2 6.6 030 A. Pool Clk 0. E 0.6 TipkMRJ SWx165eclko bulxvm UAm Plabk Bda KC 14.1 1.19 0.6 5.81 &% 31a9ee00 Va in Skma NN lkkdoa PaOd Bob BC 14.1 1.94 ok 41 0.9E Oevl�Sxak Eft & C 143 0.95 &6 14.4:1 aed STI 086 SWels Sectiw SolW SMe of(bew Q SHIM 8.9 0.59 0.6 2%m&mL45:1 •d IIOBHPow my 6:1 ma" 036 klodelc adeaua Smk Sealko SOIW Side oflTnm 2%MStm51o:1 and 6 RHO 10.7 O.R 0.6 0.6E ,§ 5:l ksvgk S SMeofWaoK FA R 7.5 6"oer 0.4E 2% Mw Suxa SideofWbxla¢ a GI 19 6"0,arccmm 0.5 24 0.43 W z 02 Q l- J w a. W z� O_ z_ Z a Z:) o z W CIE 2 O W w a 2 W 6 w � 5 g o u w g§ m np $a City of Fort Collins, Colorado UTILTTY PLAN APPROVAL APPROVED: Day hEpm - DINt CHECKED BY: rare. k eeeMeela Dt01V Date CHECKED BY: BMrmntw Utility Satz N1eeT ruuL DR02 CHECKED BY: Pub It P maaaa Date 5 rc 40 RaT SCALE CHECKED BY: TeOia 8apveer DwaI .mr1a� 1"-+'+ XpaIKWTN: 1"-n CHECKED BY: -�� FL,B"u ,( I - �� l� �I E4 ' , Zf nw Waita sit OE1J1 a4N Et IRRIGATION I I I DITCH II I 00D� o DRIVE 4954 T 1 � � 1/ II 1 INFILTRATION TRENCH SEE SHEET GR04 FOR -_ DETAILED INFORMATION `..� DETENTION POND CI L DETENTION PONI C OUTLET AN( SIDEWALK CHASI m c poll. so 16��fl v 1,� via, I`\ ra J ICI IslasIT m 1 A)REFER TO NOTE 6 FOR REQUIRED 02J o2e RAIN GARDEN DIMENSIONS INFILTRATION TRENCHSEE EA3 II DETAILED NFORMATION ' AL Y O.J1 0.N F • • Al amwe L. usa -- BIMu Am G2 CIO Q2 CIO pppA Cls cfs Al 0.23 0.26 0.58 0.13 1.01 A2 0.30 DAB 0.60 0.58 2.39 A3 1 0.31 10.24 1 0.57 1 0.14 1.20 BIT 0.24 0.54 0.71 0.31 1.44 B2 0.58 0.40 0.63 0.49 2.70 Ill 0.28 0.$6 0.61 0.22 1.30 CI (149 0.25 0.57 0.25 1 2.06 C2 0.57 0.56 0.72 0.91 4.09 C3 0.07 O)IN 0.51 0.01 0.28 C4 OAR 0.$2 0.60 CM 0.94 D 0.50 0.22 0.57 0.25 2.19 El 0.31 0.69 0.81 0.61 2AS E2 077 0.$6 0.61 0.79 4.66 11 Basin Area C2 CIO Q2 QIN RLFS cfs Cfs E3 0.33 0.34 0.60 0.32 1.96 BSI 1.21 0.49 0.68 1.17 5.67 F 0.20 0.26 0.58 0.15 1.13 Gl 0.41 0.51 0.69 0.44 2.08 G2 0.27 0.42 0.M 0.24 1.29 IT 013 0.66 0.79 0.43 1.81 11 0.20 0.67 0.79 0.37 1.54 J2 0.26 0.60 0.75 0.45 1 1.94 Pi 1.53 0.06 0.51 0.12 1 3.52 P2 0.81 0.06 0.51 0.06 2.05 P3 0.19 0.08 0.52 0.04 0.83 M 0.86 0.59 0.74LI] 5.09 II 0.36 0.06 0.51 0.01 0.36 RMImed Simw 10D-Iv, Sbaw A1ea Of VOA R&I Rue 100le DeAD, TolrOf Nub POvI VolumeR"nff PINKItki WSEL Ba tlae BcaniPlv. otain Poe rc.7 awe , ft ft POOdP 1.73 ILIO LAO 226 4999.86 1.10 4992.30 vol.lewtnkloi Borne gwGBu 49R.76. Nc - u®ob®P3. VOM 4911. Dosmt iamlNmmofpmdrt Pod P-Re�dgll 338 vicudemuba®P3 5.77 Volans sbukWd Itt LLfbotl®ofpovdel Pond P-Re�1e182 4976.8. Dos mubam P3. 0.0] 0.49 0.07 07A 4985.71 1.06 WAU`a A Po dC1 NOTES TYPE ( INLE' 1. SEE SHEET CVOs 4: CW02 FOR STANDARD EROSION AND MOMENT CONTROL CONSTRUCTION PUN NOTES 2. REFER TO SHEETS GRM-GRO3 FOR CURB CUT AND SIDEWAU( CHASE LOCATIONS. 3. SEE SHEET DR02 FOR SWALE SECTIONS. 4. STERNA SEVER AND INLET SIZES FOR REFERENCE ONLY. REFER TO SHEETS Soon AND SON FOR STORM SEWER AND INLET SIZES. 5. REFER TO SHEET EMT FOR ERDSION CONTROL. 6. ME ROOFTOP OF EACH TMPIEX FACING URBAN PRAIRIE STREET (LOCATED IN BASINS 92 AND 03) SHALL DRAIN TO A RAIN GARDRN(S) MAT IS AT LEAST 66 SQUARE FEET, W1M A MAXIMUWA GERM OF 6'. 7. RIPRAP DOWNSTREAM OF ALL STgiM SEWER 41ALL BE A MINIMUM SIZE OF TYPE L (a- MEAN PARTICLE SIZE BY WT]GHT) FOR A MINIMUM OF 6' FROM ME END OF FLARED END SECTION UN1E_6S OMER'WSE UBEIED. WRAP MPRAP AROUND FLARED END SECTION ACCORDING TO ME RIPRAP DETAIL ON SIIEET DT04. 46" m FUTURE SPILLWAY INTO INTO MASON STREET ON BOTH SIDES OF THE ROAD �``MODDIND TYPE R INLET ii l; 1 all or -� bg TYPE R INLET a 4 C2 0 P3 a P. a19 nON o w CROSSVALLOING CROSSING PUD (McDONALDS) IN M 1p am Ww L� Wa 3 !POND P OUTLET / TO EXISTING 180 / STORM PIPE CURB CHANNEL AND PERMANENT PUMP MAY BE REQUIRED AS PER w THE DEVELOPMENT AGREEMENT IF Z POND DOES NOT INFILTRATE. S,EE Q SHEET DT04 FOR DETAILS. - J j a ' EXISTING STORM SEWER a W PER WILLOX CROSSING PLUD �Ij--- Q Q PLUG EXISTING Z Q McDOALDS PONDOUTLETD r T T EXISTING McDONALDS tl�DETENTION POND TO II I P2 I BE RE -GRADED AS 1 �I I I I PART OF POND P �I Sd W e� LEGEND S BASIN DESIGNATION o a LL m XXX XXX 2 - YEAR RUNCEF COEFFICIENT PROPOSED STORM DRAIN PIPE BASIN AREA (ac.) ISO - YEAR RUNOFF COEFFICIENT v R PROPOSED STORM DRAIN INLET i F M Nsff 0 BASIN BOUNDARY - -5124 - EXISTING 1' CONTOUR .. .. FUTURE SPILLWAY--5130-- EXISTING 5' Clj1TOUR Li ® -st24i PROPOSED 1' GNTOIR DESIGN PONT -sm.- PROPOSED 5' TQUR City of Fort Collins, Colorado PROPOSED ROW DIRECTION C EXISTING STORII MANHOLE UTUHY PLAN APPROVAL 1 EXISTING STOR� DRAIN INLET APPROVED: Al 1 } PROPOSED SWALE CROSS SECTION ` LLL���JJJ EXISTING STORM DRAIN PIPE CRY D�40 s EXISTING STORM DRAIN FES CHECKED BY: PERMEABLE PAVERS PAIa 4 BNNlenlu DQUL7 DN1.e CHECKED BY: 91wmNab U00 Date xLr NNN P/E PERMEABLE PAVELE}IT h DDR01 mw .moo Mn a am2.Y CHECKED BY: Pub a �� 24 TO 6' ROCK RUBBLE rz 6 40 (SEE STREET DTI FOR ETAILS) NNNagWN mums�0ALE''." CHECKED BY: nAme 8RO65Q � Iroamvr r=w TYPE L MPRAP NEWWW NOT Downuum •.wIW Jnfw OF PIx6 (SITE SIIEET DTI FOR DETAES) PEANI RESPONSIBLE FOR A RAGA AND CHECKED BY: 'Wa NUMMER FC902" ar General Noted: SF SILT FENCE 1. me maximum tributary area Is limited to 0.25 acres per IN feet or fence. Z. Inspect and sRemo" storm evet Wa merit When steel or Filter Fabric one half of the height of the fence has Prod! Poet been filled. Removed eedmmt MEW be deposited In so tributary to a eedlmmt baste a, other filtering Bo..l"Illad Trmcn FEE F test 4AJOY SMhely ON SIMME, WATTLES SHICULD We to et3d MMWM� ANDLE AT THE LED OF THE Wood Post ME wo-mc�, SECTION VIEW ® VEHICLE TRACKING CONTROL 1n• �i■ S I BALLOX CROSSING POD _(MCDONALDS) GREED OOF EELWATER U EA W LINE EASEMENT CONTRACTOR TO i Ip INLET PROTECTION — GRAVEL LEGEND j€ I OPROPOSED INLET FILTER y EEO OSTRAW WATTLE 7 g6 C SILT fFNCE Ea aEE MEHICLE TRACKING CONTROLEl E E SO¢ --4sBl-- EXISTING 1' CONTOUR P36 -- Avact,— EXISTING 5' CONTOUR S€; R —WBR— PROPOSED 1' CIXITWR e E —4Bet— PROPOSED 5' CONTOUR 4 bal So Bissell PROPOSED STORM PIPE O PROPOSED STORM DRAIN MANHI Q EXISTING STORM PIPE Xal 2: EXISTING STORM MANHOLE W EXISTING STORM DRAIN INLET 0 M WE ' EXISTING STORM DRAIN FEE l L=hl m Rn NOTES S CgIIRCI CMiRV(.1NRI 1101ES 1. 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Realm. -ea .mimml anon De SEE- (B) s ^AKs 91fu➢ BE MI ADMISS ROW EACH Amµ AM M F 1 TE OF EATS E, Pont" im n ores Iabutarr to a deal- z'x4• woM stay n\�TW 11SH B11 M MK G RnDI RGE mall Dasio w other liltring m NET WE III Arthers "Aml ME M ME WATE N CE OIIMII x IINn 3. Sediment and gravel Mall be teed otelY CUM Inlet RAIRG WE G Nw1 ROPE IS aunoDlnY removes from Endorsed Woy a/ .mall. SISCTION A -A G RUNNING LINGTHS Car MS 10 9tlinHE, EU M "I's FIRST W 01 b.EE9AP ME Ex05 SIANES s1MD E ROW FEEME DRIVEN I FEE µD G LEAO1 9LE OF YMTIIE tEANNC 4'-f V WATTLE MI STAVE aRo1wOM AHOWTILY AGUES! nIC ME WEATTLE B NK OR xnM RCPE 9_w_AD E RD TO STAKES IH µ M(I,R 0.ASl EMNATLG (rFOPT TO BACK 6 NANM A 9IlG TEE DT' E (AmfY ED IR(MIT OF wATRE 9•. AERDSS ro BACK AM BAWInwMMT OF nY STAI 9pllm ME EE LRWII IN FIDE DILHG NES DID e ME WHERE Mcµ s � EYEEtm WF NEW MAW Iruaor amM MOM mlMa MAJOHAAf1ER BMRMI SEAMT IIMfM1TMMOM CONTROL Qagi nW/ BA9I SILT MERs another? �R� ALT/ 0.Y1gE2 PAWIC al �a=HT FTANMG INSTALLATION % MA3/ Nu2R OBp IT g N1E'MM W E ROM WMBBIE PER APAMACY NO F MANS City of Fort Collin, Colorado UTRITY PLAN APPROVAL APPROVED: City ED Dane CHECKED BY: eater R 1MIeReb Duty Di CHECKED BY: Stcrow"ir Buoy Date CHECKED BY: P.Tiv A Rem tm Dite CHECKED BY: h bve CHECKED BY: MLA EC01 O /0 s SCUtLE WRM'AL 1'•N/A M9ZM IAL' I �sH