HomeMy WebLinkAbout05 - Design Report - Flanders Creek Subdivision - Stormwaterr^c^=/ ^/o^ ^5/0^5nnn[]nnflu[JuuuuuuuDESIGN REPORTSTORM WATERMANAGEMENTFLANDERS CREEKSUBDIVISIONPrepared for:DENNIS BALIANPrepared by:C & H Engineering and Surveying, Inc.205 EdelweissBozeman,MT 59718(406)587-1115Project Number: 05189June, 2005IIH(,^'I.%xN^.%>?%>yi .^$^-SSQJNo67t'Stl-.^^".</^;!^NS!^'^i^y
Engineering and Surveying Inc.205 Edelweiss Drive • Bozeman, Montana 59718www.chenginears.com • info@chengineers.com'-:-.r'-r:>::l•••':'" : •:uUL:--:^". . .; '...-- —;-"~^/:\''l •;'1 \'..^LETTER OF TRANSMITTALDATE:July 25, 2006TO:City ofBozeman EngineeringAttn: Sue Stodola20 E. Olive St.Bozeman,MT.59715FROM:Jan JupkaRE:Flanders Creek Subdivision - Gutter Capacity on Sherwood Ave. (05189)OTY. DESCRIPTION1letter requesting a deviation from City Standard Gutter Capacity1Set of Calculations and C.O.B. Curb capacity drawingPURPOSE:•As You RequestedFor Your Information/RecordsFor Your Review & ApprovalFor Design RevisionsFor Your Signature/retumOther: (See Remarks)U.S. MailFederal Express• Hand DeliveredFor Pick UpREMARKS:Copies to:
nJuly 24, 2006City ofBozeman Engineering Dept.Attn: Sue Stodola, P.E.20 E. Olive StreetP.O. Box 1230Bozeman, MT 59771-1230RE: Flanders Creek Subdivision, Stonn Water Design Report Deviation (05189)Dear Sue,This letter is concerning the storm revisions letter dated 6/22/06 and the conversation Brian, yourselfand I had regarding the calculations. It was determined that the gutter capacity was inadequate for thecalculated flowrate. Therefore it was required to find a way to slow the flowrate or request adeviation. Since we could not find a practical solution for slowing the flowrate, we would like torequest a deviation from the city standard of a maximum gutter flow area of 1 .24 ftA2, a wettedperimeter of 9.23 ft at a depth of .15 ft from the top of the curb.Inlet #6 at a total flowrate of3.59cfs flows with an area of 1.46ftA2just .22ftA2 more than the citystandard and at a depth of .127ft from the top of curb which is only .023ft deeper than city standards.Inlet #7 at a total flowrate of 3.13cfs flows with an area of 1.32ftA2, just .08ftA2 more than citystandard and at a depth of .142ft from the top of the curb, just .008ft higher than city standards.The maximum flowrate for Sherwood Avenue is 2.88cfs, the flowrate for the two inlets in questionare 3.13cfs and 3.59cfs. We hope to show that although these are over the city standard they are notat an excess that would be hazardous to fa-affic and therefore should be allowed a deviation in this onecase. Calculations of how these figures were arrived at are included. Please review this material foryour approval and contact us if any additional information is needed.Sincerely,Jan Jupka, E.I.Enc.G:\c&h\05\05189\0f5ce\05189 Stodola stomi deviation072406.wpd
Calculation for deviation reguest for gutter capacity on Sherwood Ave.From the city standard drawing included in the after the calculations, max gutter capacity is 1.24ftA2 and 9.23ft (wetted perimeter) at a distance of. 15 feet from the top of curb. By using thisdrawing in auto-cad and adjusting the water level distance from top of curb we find:@. 1375ft: A=1.3585ftA2, P=9.6654ft@.125ft: A=1.4810ftA2, P=10.0975ft@.l 125ft; A=1.6081ftA2, P=10.5324ftBy then inserting A and P into the standard gutter flow rate equation:Q=Q=(1.486/n)AR2/3Sl/2n= 0.013 for ConcreteA=?ft2p=?ftR=A/P = ? ftR2/3 = ? ftS = 0.0060 ft/ftSl/2 = 0.07746 ft/ft@.l 375ft Q=:Q = (1.486/0.013)(1.3585)(0.2703)(0.07746)= 3.252 cfs@.125ftQ=:Q=(1.486/0.013)(1.4810)(0.2781)(0.07746)= 3.647cf8@.l 125ft Q=:Q=(1.486/0.013)(1.6081)(0.2857)(0.07746)= 4.067cf8Assuming a linear relationship between the distance from the top of curb to the water surface andthe area(for the purpose of narrowing parameters):Ra=Q*dd=distance from top of curb to water surfaceA=areaRa=d*AQ=flowrateLooking for A and P with a Q of3.59cfs which is closest to 3.647cfs, therefore using .125ft.@.125ft,Ra=4559Using .4559, when d=Ra/Qd=(.4559/3.59)=12699
From auto-cad at a distance of.l27ftwegetanA=1.4613 andaP=10.0311, by then pluggingthem back into the original Flowrate equation Q=3.582Fromauto-cad atdistanceof .1267ft we get an A= 1.4643 andP=10.0415, then by plugging backinto original Flowrate equation Q=3.592, therefore:@ Q=3.59cfsA=1.46ftA2P=10.0415ftd=. 127ftNow looking for A and P with a Q of3.13cfs which is in between 3.252cfs and 2.88, thereforeusing. 1375ft and. 15ft.@.15ft,@.1375ft,Ra=.432Ra=.447Using .44, when d=Ra/Qd=(.44/3.13)=141From auto-cad at a distance of. 141ft we get an A=l .3263 and a P=9.5472, by then plugging themback into the original Flowrate equation Q=3.15From auto-cad at distance of .1417ft we get an A=l.3198 and P=9.5230, then by plugging backinto original Flowrate equation Q=3.130, therefore:@Q==3.13cfsA=1.32ftA2P=9.52ftd-142ft
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s. s.nEngineering and Surveying Inc.205 Edelweiss Drive * Bozeman, Montana 59718Phone (406) 587-1115 • Fax (406) 587-9768www.chengineers.com • info@chengineers.comLETTER OF TRANSMITTAL'n,l..i.n.o;tIJUL 15 2005DATE:TO:FROM:RE:July 15,2005CityofBozemanEngineering DepartmentAttn: Serri 'Sfr'Justin Weiser, E.I.Flanders Creek Subdivision (04770)OTY. DESCRIPTION1Stonnwater Master PlanPURPOSE:•As You RequestedFor Your Infomiation/RecordsFor Your ApprovalFor Design RevisionsFor Your Signature/retumOther: (See Remarks)U.S. MailFederal Express• Hand DeliveredFor Pick UpREMARKS:Copies to:
tSheatIof IIjn i/u/»® S/28/05§5sy)u?CQ^s^la^sa^tl§sSJ4=J-^^-^_-§01^1s^S»-ARBA3-5pnoy poofnuoffoyROha/fT^-.^^0:^^ijN1•«os0iDRADWjEIStJB-ARfl^^-ltt)<!>-.•^0^5?u6^'ts-Slec*ag!3-:?-)'=•»KlaDRADfiAGE.SUB-AFtEAsAayl/S•BQ.§9c^QL»gi$Si^^ec3'sPRA(NA(5EtREAH0^-S3s<^>'~s?!*^n'(^?SUB-A^-s^-.ce'=(;,•s>su>c&°sm>08-*-s.^;^^0<-<"\^la;?a\MAINAGE SUDARIA2-3fi•ayiLviii.y .-.•ayii^^ij.i.^i.jat?tflzai<\£bd?1u.<^IgQC2sI I«^3•>VT,icQlI IEDRAINAGESUB-AREA2-39-ir^fc^ajlI Ict:°DRAINAGE^0S3^0^:iSUB-AREA3-4^|DKAlN4Ub|S)0?- ^[^2II I I II I II IQ;%^!J0a.s^3y^EC\Q-Q<"Q,Jqs-\anua^noziii)/,s.\:>.HWyieyy y6a6,10-CO.IOO,1.0.6:0.l0N]wfsKi.a.swh-.^\n-^---~<DRAINAGE PLANSCALE: 1"a200'^?iScale In Feet0200200Braw-w Bah: S/Z7/OSR0 60Scale In Meters60sD1L,^04770
TEngineering and Surveying Inc.205 Edelweiss Drive • Bozeman, Montana 59718wwvAchenginseps.com * info@chengineers.com^fp^r-nnnf?^;:; ••— .-.....,. ., ,.. ..... .........;^ ;UL.^::..;:....,,;,^j:'; ;:;J^ rM!;LETTER OF TRANSMITTALDATE:June 22, 2006TO:City ofBozeman EngineeringAttn: Sue Stodola20 E. Olive St.Bozeman,MT.59715FROM: Jon JupkaRE:Flanders Creek Subdivisions - (05189)OTY. DESCRIPTION1letter addressing changes to stonn sewer1Set of revised calculations from the design reportPURPOSE:^As You RequestedFor Your Information/RecordsFor Your Review & ApprovalFor Design RevisionsFor Your Signature/retumOther: (See Remarks)U.S. MailFederal Express • Hand DeliveredFor Pick UpREMARKS:Copies to:
nnJune 22, 2006City of Bozemaii Engmeeriiig Dept.Attn: Sue Stodola, P.E.20 E. OUve StreetP.O. Box 1230Bozeman,MT 59771-1230RE: Flaiiders Creek Subdivision, Storm Water Design Report Revisions (05 189)Dear Sue,Please fmd the enclosed revisions for the stoim water design report for the above referenced project.These revisions are m response to a letter from you dated February 8, 2006. A brief narrative of therevisions mid additional uitonTiation requested are as foUows:1. Upon further review of the drainage calculations, inconsistencies were fomid m thecalculations for the overlaiid flow distaiice and time of concentration. By correctmg therunoff coefficient "C" and the overland flow distance, the gutter capacity was found to bebelow the maxunum aUowed. Therefore additional outlets are not needed. Calculations aremcluded to show this.2. ^a.^^(^b.The 24" PVC from Catch Basm #9 to Detention Pond #3 was instaUed as a 24"diameter pipe, which is larger thaii the previously approved size, but more thanadequate to handle the storm water load.The 15" PVC from Catch Basiti #10 to Detention Pond #3 is now consistent at a0.5% slope on both the design report and the plaiis, with calculations mcluded.^c.^y^\%?<^^'v^ 4.^^°y^5'^y.^?-Calculations are mcluded for the 15" PVC pipe i-unruiig from Catch Basm #10 toDetention Pond #3 at a 6.01% slope which matches the plans.Detention Pond #1 is now labeled as 2000cfon plan Sheet Cl.O to match the design report.The wen- that was mstalled m the outlet control structure was 18" H x 1.95" W. The con-ectweir for this outlet control structure is 18"H x 1.29"W. The plan sheet is now correctlylabeled to match the design report. The weir dimensions wiU be corrected to the sizemdicated.The calculations for Detention Pond #2 which is now a Retention Pond are included. SheetC 1.0 is still labeled Retention Pond.The weir for Detention Pond #3 was mstaUed at 18" H x 9.77" W. In the design report, theheight dimension was caUed out as 12", not 18". The correct width for an 18" weu- is 5.31".
0^6.^ 7.f^This is now con-ectly labeled m the plans, with the calculations attached. A new weir wffl beordered and iiistaUed in the outlet structure.Sheets Cl.O, C4.10 aiid C4.il are now labeled witha 30" sewer instead of 36" sewer. Thestonn easement was adjusted to accormnodate the 30" stonn sewer line.On sheet Cl.O the legend now includes proposed Storm Sewer Mam aiid proposed StonnSewer Maiihole. The drawmg is also to scale.8. On sheet C4.11 it is now clearly labeled as a 60" diameter Stonn Sewer Manhole.Tills suimnarizes the extent of the modifications from the previous plaii aiid design report subixdttal.If any other chaiiges occur, we wffl notify you hninediately. Please review this material for yourapproval aiid contact us if any additional mfomaation is needed.Sincerely,.t.Jon Jupka, E.I.Enc.G:\c&h\05\05189\0ffice\05189 Stodola storm revisions 061906. wpd
n0Storm Sewer revisions:The following calculations are included for the revisions to the outlet pipe from Pond #3 toBaxter Ditch.The time of concentration for sub-area #3-1 is calculated below:?/^^-^-35-; -.f../(^^7^1 /'^^-T^)A/k^i ^-2^^--6'^^Time of Concentration^^ <-3Overland flow(20i0 ft @ 1 .0%, C=0.30) = 23.27 min-^^. ^ ^ -^' /Gutter flow(580 ft @ 1.10% avg. slope on Cottonwood Road)V= (1.486/n)R2/3Sl/2 (n-0.013, A=1.24 ft, P-9.23, R2/3=0.2623, Sl/2=0.1049)V=3.14ft/sT= 580 ft/3.14 ft/s/60s/min = 3.1 minGutter flow(260 ft @ 0.60% avg. slope on Sherwood Way)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.0775)V= 2.32 ft/sT= 260 ft/2.32 ft/s/60s/min = 1.9 minTotal Time of Concentration = 28.27 minutes(0.471 hours) i-~^-"~ C ^ 2For a 25-year ston-n event 1^ = 0.78X-64 = 0.78(0.47)-64 == 1.26 in/hr /- s^ C / ^-/ ^Qz5 Medium Density Lots =-CIA = 0.30(1.26 in/hr)(3.4023 acres) = 1.28 cfs /,SC? c^ ( '. S>oc ^-Q25r/w=CIA =0.70(1.26 in/hr)(l.6478 acres) =1.45 cfs /!'^ V/.'?/)Q25 Total-(1.28+1.45)-/ir^ ''1'- ; ?.-7 .^"-.The time of concentration for sub-area #3-2 is calculated below:2.74 cfsQ?, ".'.^Total flow rate entering catch basin #6/^//^c CTf T^T^^-^y--'-^ (c-/;' <^').\: 22.68min. ^/^-/-^ ^-/Time of ConcentrationOverland flow(1^0 ft @ 1.0%, C=0.30)Gutter flow(585 ft @ 0.85% avg. slope on Flanders Creek Avenue)V= (1.486/n)R2/3S'/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.0922)V= 2.76 ft/sT= 585 ft/2.76 ft/s/60s/min == 3.5 minGutter flow(245 ft @ 0.60% avg. slope on Sherwood Way)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.0775)V= 2.32 ft/sT- 245 ft/2.32 ft/s/60s/min = 1.8minTotal Time of Concentration = 27.98 minutes (0.466 hours) <- zc/-3 )For a 25-year storm event ^ = 0.78X-64 = 0.78(0..466)-64 = 1.27 in/hr // 3 ^)Qz5 Medium Density Lots = CIA = 0.30(1.27 in/hr)(3.2849 acres) = 1.25 cfs I •?^Qzs r/w = CIA = 0.70(1.27 in/hr)(1.2770 acres) = 1.13 cfs / 2LfQzs Total =(1.25+1.13)2.38 cfs = Total flow rate entering catch basin #7-^!^/ ^-."'"-< . i^. .' -' ;- ^•^Te-^-^-.'•."-<•;The time of concentration for sub-area #3-3 is calculated below:Time of ConcentrationOverland Flow (140 ft @ 1.0%, C=0.60) = 9.7 min.Gutter Flow (143.5 ft @ 0.75% avg. slope on Twin Lakes Drive)
nV= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P-9.23, R2/3=0.2623, Sl/2=0.08660)V= 2.60 ft/sT= 143.5 ft / 2.60 ft/s / 60 s/min = 0.92 min.Total Time of Concentration = 10.62 minutes (0.177 hours)For a 25-year stonn event 135 = 0.78X-64 = 0.78(0.177)-64 = 2.36 in/hrQz5 High Density Lots = CIA = 0.60(2.36 in/hr)(0.8744 acres) = 1.24 cfsQz5 r/w = CIA = 0.70(2.36 in/hr)(0.20 acres) = 0.33 cfsQz5 Total = (1.24+0.33) = 1.57 cfs = Total flow rate entering catch basin #8Time of ConcentrationOverland Flow (140 ft @ 1.0%, C=0.60) = 9.7 min.Gutter Flow (218.42 ft @ 0.75% avg. slope on Twin Lakes Drive)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.08660)V= 2.60 ft/sT= 218.42 ft / 2.60 ft/s / 60 s/min = 1.40 min.Total Time of Concentration = 11.1 minutes (0.185 hours)For a 25-year storm event ^5 = 0.78X-64 = 0.78(0.185)-64 = 2.30 in/hrQz5 High Density Lots = CIA = 0.60(2.30 in/hr)(1.1937 acres) = 1.65 cfsQz5 r/w = CIA = 0.70(2.30 in/hr)(0.30 acres) = 0.48 cfsQz5 Total = (1.65 + 0.48) = 2.13 cfs = Total flow rate entering catch basin #9The capacity of the curb and gutter, at a 0.75% slope, with a depth of water 0.15' below the top ofcurb is calculated as follows:Q=(1.486/n)AR2/3Sl/2n= 0.013 for ConcreteA= 1.24 ft2P = 9.23 ftR = A/P = 1.24/9.23 = 0.1343 ftR2/3 = 0.2623 ftS = 0.0075 ft/ftSl/2 = 0.08660 ft/ftQ = (1.486/0.013)(1.24)(0.2623)(0.08660)= 3.21 cfs.1.57 cfs < 2.13 cfs ^ 3.21 cfs =* Gutter capacity is adequateQzs Total for Storm Sewer #3 = (3.58+3.13+1.57+2.13) =10.41 cfsThe time of concentration for sub-area #3-4 is calculated below:Time of ConcentrationOverland flow(140 ft @ 1 .0%, C=0.60) = 9.7 min.Gutter flow(340 ft @ 0.75% avg. slope on Twin Lakes Drive)(n=0.013, A=1.24 ft, P=9.23, Rz/3=0.2623, Sl/2=0.08660)V=(1.486/n)R2/3Sl/2V= 2.60 ft/sT= 340 ft/3.67 ft/s/60s/min = 2.2 minGutter flow(260 ft @ 0.87% avg. slope on A Street)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.0933)V= 2.78 ft/s
T= 260 ft/2.78 ft/s/60s/min = 1.6 minGutter flow(350 ft @ 1.5% avg. slope on Parkview Avenue)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.1225)V= 3.67 ft/sT= 350 ft/3.28 ft/s/60s/min = 1.6 minTotal Time of Concentration =15.1 minutes (0.25 hours)For a 25-year storm event 1^ = 0.78X-64 = 0.78(0.25)-64 = 1.89 in/hrQz5 High Density Lots = CIA = 0.60(1.89 in/hr)(2.008 acres) = 2.27 cfsQzs r/w = CIA = 0.70(1.89 in/hr)(1.5327 acres) = 2.03 cfsQz5 Total = (2.27+2.03) = 4.30 cfs = Flow rate entering catch basin #10Time of Concentration (Oak Street)Gutter flow(600 ft @ 0.5% avg. slope on Oak Street)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.07071)V= 2.63 ft/sT= 600 ft/2.63 ft/s/60s/min = 4.72 minTotal Time of Concentration = 4.72 minutes (0.079 hours)For a 25-year storm event ^5 = 0.78X-64 = 0.78(0.079)-64 - 3.95 in/hrQz5 r/w = CIA = 0.70(3.95 in/hr)(0.8276 acres) = 2.29 cfsQz5 Total == 2.29 cfs = Flow rate entering catch basin #10Q25 Total for Storm Sewer #4 = 4.30 cfs + 2.29 cfs = 6.59 cfsThe capacity of the curb and gutter, at a 1.5% slope for Parkview Avenue, with a depth of water0.15' below the top of curb is calculated as follows:Q=(1.486/n)AR2/3Sl/2n = 0.013 for ConcreteA= 1.24 ft2P = 9.23 ftR= A/P = 1.24/9.23 = 0.1343 ftR2/3 = 0.2623 ftS=0.015ft/ftSl/2=0.1225ft/ftQ = (1.486/0.013)(1.24)(0.2623)(0.1225) = 4.55 cfs.4.31 cfs < 4.55 cfs => Gutter capacity on Parkview Avenue is adequateThe capacity of the curb and gutter, at a 0.5% slope for Oak Street, with a depth of water 0.15'below the top of curb is calculated as follows:Q-(1.486/n)AR2/3Sl/2n = 0.013 for ConcreteA= 1.24 ft2P = 9.23 ftR = A/P = 1.24/9.23 = 0.1343 ftR2/3 = 0.2623 ftS=0.015ft/ftSl/2= 0.0707 Ift/ft
Q = (1.486/0.013)(1.24)(0.2623)(0.07071)= 2.63 cfs.2.29 cfs ^ 2.63 cfs =>• Gutter capacity on Oak Street is adequateThe time of concentration for sub-area #3-5 is calculated below:Time of ConcentrationGutter flow(615 ft @ 1.1% avg. slope on Cottonwood Road)V= (1.486/n)R2/3Sl/z (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.1049)V-3.14ft/sT= 615 ft/3.14 ft/s/60s/mm = 3.3 minTotal Time of Concentration =3.3 minutes (0.06 hours)For a 25-year storm event ^ = 0.78X-64 = 0.78(0.06)-64 = 4.721 in/hrQ25 r/w = CIA = 0.70(4.721 in/hr)(0.9936 acres) = 3.28 cfsQ25 Total for Stonn Sewer #5 = 3.28 cfs = Flow rate entering catch basin #11The capacity of the curb and gutter, at a 1.1% average slope for Cottonwood Road, with a depthof water 0.15' below the top of curb is calculated as follows:Q=(1.486/n)AR2/3Sl/2n= 0.013 for ConcreteA= 1.24 ft2P = 9.23 ftR = A/P = 1.24/9.23 = 0.1343 ftR2/3 = 0.2623 ftS=0.011ft/ftSl/2= 0.10488 ft/ftQ = (1.486/0.013)(1.24)(0.2623)(0.10488)= 3.89 cfs.3.28 cfs ^ 3.89 cfs =>• Gutter capacity on Cottonwood Road is adequate24" PVC from Catch Basin #9 to Detention Pond #3This pipe carries the storm water from drainage sub-areas 3-1 & 3-2 & 3-3. As previouslycalculated we should anticipate a flowrate of (3.58 +3.13+ 1.57 + 2.13) = 10.41 cfs from a 25-year storm event. Calculations are enclosed in the Appendix for a 24" PVC pipe at 1.85% slope.The 24-inch pipe will flow at a depth of 1.18 feet with a velocity of 5.42 ft/sec.15" PVC from Catch Basin #10 to Detention Pond #3This pipe carries the storm water from drainage sub-area 3-4. As previously calculated weshould anticipate a flowrate of 6.59 cfs from a 25-year storm event. Calculations are enclosed inthe Appendix for a 15" PVC pipe at 0.5% slope. The 15-inch pipe will flow at a depth of 1.02feet with a velocity of 6.13 ft/sec.15" PVC from Catch Basin #11 to Detention Pond #3This pipe carries the storm water from drainage sub-area 3-5. As previously calculated weshould anticipate a flowrate of 3.28 cfs from a 25-year storm event. Calculations are enclosed inthe Appendix for a 15" PVC pipe at 6.01% slope. The 15-inch pipe will flow at a depth of 0.39feet with a velocity of 10.18 ft/sec.
Detention Poud #3The total area served by Detention Pond #2 is 20.593 acres with a weighted C-factor of 0.524after development. The storage basin can have a release rate equal to the pre-development flow.The calculations for the pre-development time of concentration and flows are included in theAppendix. The pre-development flow (acceptable release rate) is 2.71 cfs.Calculations are also enclosed in the Appendix for sizing the detention pond by varying the stormduration and holding the release rate at 2.71 cfs. The required storage for Detention Pond #3 is15,175 cubic feet. The weir must also be sized to insure the discharge never exceeds theallowable release rate. The weir in the discharge structure for Detention Pond #3 will be 5.32inches in width. These calculations are included with the calculations for sizing the pond.The discharge pipe from Pond #3 to Baxter Ditch will be designed to handle a flow rate of 20.29cfs. The discharge pipe will be 30" RCP at a slope of 0.22%. Calculations are attached for thissection of pipe.Detention Pond #1The total area served by Detention Pond #1 is 3.62 acres with a weighted C-factor of 0.483 afterdevelopment. The storage basin can have a release rate equal to the pre-development flow. Thecalculations for the pre-development time of concentration and flows are included in theAppendix. The pre-development flow (acceptable release rate) is 0.658 cfs.Calculations are also enclosed in the Appendix for sizing the detention pond by varying the stormduration and holding the release rate at 0.658 cfs. The required storage for Detention Pond #1 is2,000 cubic feet. The weir must also be sized to insure the discharge never exceeds the allowablerelease rate. The weir in the discharge stmcture for Detention Pond #1 will be 1.29 inches inwidth. These calculations are included with the calculations for sizing the pond.
nrRetention Pond Calculationsv=?C=0.42A=645,559.2 ftA2V=C(.068)AV=l 8,437 ftA3At 1.5 feet deep the pond's area will be 12,291 ftA2, or 176' by 70'. The actual pond will have anarea of 12406.9 ftA2 a depth of 1.5' and a volume of 18,610 ftA3.Weir Calculations for Detention pond #3Allowable flow rate Q (cfs)= 2.712Head above weir notch (ft)= 1.50Weir Coefficient= 3.33Weir equation = Q=(C)(L)(H)A(3/2)Required length (ft)= .44298Required length (in)= 5.3158Weir Calculations for Detention pond #1Allowable flow rate Q (cfs)= 0.658Head above weir notch (ft)= 1.50Weir Coefficient= 3.33Weir equation = Q=(C)(L)(H)A(3/2)Required length (ft)= 0.1 076Required length (in)= 1.2907
y ^^C \^^ C^-^^i ^S^^T^ [^T^Tja^ tPo^^ ^^tmp#72Manning P-ipe CalculatorGiven input Data:Shape ........................... CircularSolving for ..................... Depth of FlowD-i ameter ........................ 24.0000 -i nFlowrate ........................ 5.4200 cfsSlope ........................... 0.0185 ft/ftManm ng's n ..................... 0. 0130Computed Results:Depth ........................... 6.81811nArea ............................ 3.1416 ft2Wetted Area ..................... 0.7348 ft2Wetted Perimeter ................ 26.9827 -inPerimeter ....................... 75.3982 -inVelocity ........................ 7.3762 fpsHydraul1c Radius ................ 3.9214 1nPercent Full .................... 28.4087 %Full flow Flowrate .............. 30.7698 cfsFull f1ow veloc-i ty .............. 9.7943 f psCritical informat-ioncritical depth .................. 9.8581 -incnt-ical slope .................. 0.0046 ft/ftCritical velocity ............... 4.4583 fpscr-it-ical area ................... 1.2157 ft2Cr-it-ical perimeter .............. 33.3922 inCnt-ical hydraul-ic radius ....... 5.2426 •inCritical top width .............. 23.6146 inSpecific energy ................. 1.4137 ftMinimum energy .................. 1.2323 ftFroude number ................... 2.0375Flow condition .................. Supercr-ificalPage 1
15' PO^ ^^^ C^'^^^^0 To Q£7^^iTa^ ^^ -^^'-"-)tmp#73Manning P-ipe CalculatorGiven Input Data:Shape ........................... d rcularSolv1ng for ..................... Depth of FlowD-i ameter ........................ 15.0000 i nFlowrate ........................ 6.5900 cfsSlope ........................... 0.0050 ft/ftManm ng's n ..................... 0. 0090Computed Results:Depth ........................... 12.2781 -i nArea ............................ 1.2272 ft2Wetted Area ..................... 1.0752 ft2Wetted Per-imeter ................ 33.9225 inPerimeter ....................... 47.1239 inVeloc1ty ........................ 6.1290 f psHydraulic Radius ................ 4.5643 InPercent Full .................... 81.8541%Full flow Flowrate .............. 6.5979 cfsFull flow velocity .............. 5.3764 fpsCritical informationcr-i t-i cal depth .................. 13.0382 1ncr-it-ical slope .................. 0.0037 ft/ftCnt-ica] velocity ............... 5.5355 fpsCr-i t-i cal area ./................. 1.1905 ft2Cr-it-ical perimeter .............. 34.6384 InCnt-ical hydraul-ic rad-ius ....... 4.9491 incn tical top w1dth .............. 15.0000 -i nSpecific energy ................. 1.5865 ftMimmum energy .................. 1.6298 ftFroude number ................... 1.2081Flow condition .................. Supercn'ficalPage 1
^t> pix 4'^^ ^A'T^r< c^^^(I TO l~<s..^^^Manning P-ipe CalculatorGiven Input Data:Shape ........................... d rcularsolving for ..................... Depth of FlowDiameter ........................ 15.0000 inFlowrate ........................ 3.2800 cfsSlope ........................... 0.0601 ft/ftManm ng's n ..................... 0. 0130Computed Results:Depth ........................... 4.6325 inArea ............................ 1.2272 ft2wetted Area ..................... 0.3223 ft2wetted Pen meter ................ 17. 6770 -i nPerimeter ....................... 47.1239 inveloc-i ty ....;................... 10^1757 fpsHydraulic Radius ................ 2.6258 inPercent Full .................... 30.8830%Full flow Flowrate .............. 15.8364 cfsFull flow velocity .............. 12.9046 fpsCritical informationcritical depth .................. 8.7873 incn t1cal s1ope .................. 0.0061 ft/ftcr-itical velocity ............... 4.3869 fpscnt-ical area ./................. 0.7477 ft2critical perimeter .............. 26.1365 1nCritical hydraulic radius ....... 4.1194 incr-i tical top w1dth .............. 15.0000 -i nSpec-ific energy ................. 1.9952 ftMinimum energy .................. 1.0984 ftFroude number ................... 3.3959Flow condition .................. Supercr-itical
A P PICES A-35sft-B:KIIftI'Is:s-^ff's'^^-;;^APPENDIX 19.AManning's Roughness Coefficient,a n(design use)channel materialnbplastic (PVC and ABS)clean, uncoated cast ironclean, coated cast irondirty, tuberculated cast ironriveted steellock-bar and welded steel pipegalvanized ironbrass and glasswood stavesmall diameterlarge diameterconcrete.average value usedtypical commercial, ball and spigotrubber gasketed end connections- full (pressurized and wet)- partially fullwith rough jointsdry mix, rough formswet mix, steel formsvery smooth, finished-vitrified sewercommon-clay drainage tileasbestosplaned timber (flume)canvasunplaned timber (flume)brickrubble masonrysmooth earthfirm gravelcorrugated metal pipe (CMP)natural channels, good conditionrip rapnatural channels with stones and weedsvery poor natural channels0.0090.013-0.0150.012-0.0140.015-0.0350.015-0.0170.012-0.0130.015-0.0170.009-0.0130.011-0.0120.012-0.0130.0130.0100.00850.016-0.0170.015-0.0160.012-0.0140.011-0.0120.013-0.0150.012-0.0140.0110.012 (0.010-0.014)0.0120.013 (0.011-0.015)0.0160.0170.0180.0230.024 (see App. 17.F)0.0250.0350.0350.060 ."•Compiled from various sources.;>Values outside these ranges have been observed, but these values are typical.pOFESSIONAL PUBLICATIONS,INC.•.sI;f11:-
nnnn1nnn.-J[J[j[Iu[] ^uuuuSTORM WATER MANAGEMENTSummarySTORM WATER mn-offfrom Flanders Creek Subdivision will be directed to several stormwater detention areas located through out the site. Sheet Dl, enclosed in the Appendix, highlightsthe individual drainage areas that drain to each storm water pond. The subdivision was dividedinto three separate watersheds, that will be directed to their own detention pond. Drainage area #1will drain to a point at the southern boundary of the central park, near the intersection of ParkviewAvenue and Glenwood Drive. Drainage area #2 will drain to a pond on the norther boundary ofthe central park, near the intersection of Annie Street and Parkview Avenue. Drainage area #3will drain to two detention ponds located at the north property line, by the intersection ofCottonwood Road and Oak Street. All proposed ponds will have an outlet pipe to Baxter Ditch toensure that the ponds drain during storm water events.Inlets will be placed to intercept the stonn water mnoffat intervals to ensure that the curb capacityis not exceeded, and to rout the stomi water to the desired storm water detention area. The stonnwater runoffrate was calculated with the rational fonnula as shown. A mnoff coefficient (C) of0.35 was used for the lots Zoned R3, and 0.60 was used for the larger R4 and R-0 lots asrecommended by the City ofBozeman Design Standards, and a composite C value was used for theright of way due to the higher percentage of impervious area.COMPOSITE RUNOFF COEFFICIENTThe mnoff coefficient for the R/W Area at 60 ft. wide:C^ = [(0.90x43 ft)+(0.20xl7 ft)]/60 ft = 0.70tw.^- G(;, - [(j),c)0/30')fCo.20^20'I]/^/ ^^^2
*'«>•>..^^</ /y^'7/^0X7£l";'•'*'11]ill! H^-S:P0 9.^Q't.. ^ :iDRAINAGE AREA #1 (Now includes Durston Road).-...AC 1,^1^Drainage Area #1 consi^gfa total of 157,770 ft2, with 61,360 ft2 of that being right of way,l'^c 61,660 ft2 of Park and 34,750 ft2 of high density lots. Drainage area #1 will be divided into twosubareas, one for each catch basin that will be utilized. The time of concentration for each sub-area needs to be calculated to determine the intensity of stonn that will contribute to each catchbasin.The time of concentration for sub-area #1-1 is calculated below:Time of Concentration^ . ^1,, Overland flow(340 ft @ 1.0%, C=0.60) = 15.17min.. ^=0.2623, Sl/2=0.0837)Gutter flow(270 ft @ 0.70% avg. slope on Glenwood Drive)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=V=2.51ft/sT= 270 ft/2.51 ft/s/60s/min = 1.8 minTotal Time of Concentration = 16.97 minutes(0.28 hours)For a 25-year storm event 135 = 0.78X--64 = 0.78(0.28)-64 = 1.76 in/hrQz5 Lots = CIA = 0.60(1.76 in/hr)(p J^7 acres) = 0.84 cfs _ ^.74 c^sQz5 r/w = CIA = 0.70(1.76 in/hr)(l-^9^ acres) = J-4^cfs (includes Durston Road)Q25 Park = CIA = 0.30(1.76 in/hr)(1.4155 acres) = 0.75 cfsQz5 Total = (0.84+>^7+0.75) = &3«5'cfs = Total flow rate entering catch basin #13'5S -,. . -i.i .-^. ,,.''"'" :•?/" - ^|.^A-i,. f'Tl'1--.- y'." -;I.Capacity of curb and gutter at 0.68%)Average slope (Parkview Ave. & Durston Road)^^.;/f^f^^^ Cf^0^5%o^. df^^ It <^0^Q=(1.486/n)AR2/3Sl/2n= 0.013 for ConcreteA= 1.24 ft2P = 9.23 ftR = A/P = 1.24/9.23 = 0.1343 ftR2/3 = 0.2623 ftS = 0.0068 ft/ft 0,00 75/<S1/2 = 0.08246 ft/ft o.og^oQ = (1.486/0.013)(1.24)(0.2623)(0.08246),«.-- \:'./ii. 0'0%(*Gty^^i'i^-p^^i^JD.^°% x 3^5:i'7 p,^. x /g'i.^ =_30^,0,/,Df% x 75.$'r' -^S7'2^.z8'/, 7/7' < <?D.'Z^' ^ 0''77% >< 20^'?3 +304,^0+?<?<)-1'^"^(TTT^.^o.^7.^ "I.7= 3.07 cfs.^ 3, 22. epsTotal flow in gutter along Parkview Ave. and Durston RoadQ =.1.47'cfs"1.7'^f.74--1^7 cfs< 3.07cf8Gutter capacity is adequate&/cThe time of concentration for sub-area #1-2 is calculated below:Time of ConcentrationGutter flow(250 ft @ 0.70% avg. slope on Glenwood Drive)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.0837)V=2.51ft/sT= 250 ft/2.51 ft/s/60s/min = 1.66 minTotal Time of Concentration = 1.66 minutes (0.03 hours)For a 25-year storm event 135 = 0.78X-64 = 0.78(0.03)-64 = 7.36 in/hr
0Qz5 r/w = CIA = 0.70(7.36in/hr)(0.2136 acres) =1.10 cfsQz5 Total = 1.15 cfs = Total flow rate entering catch basin #2Qz5 Total for Storm Sewer #1 = (2.27+1.10) = 3.37 cfsA'tf^',+\"Drainage Area #1t^^,^ ^?15" PVC from Catch Basin #1 to Catch Basin #2This pipe carries the storm water from drainage sub-area #1-1 and,l-lA.JAs previouslycalculated we should anticipate a flowrate of-S^cfs from a 25-year storm event. Calculationsarq enclosed for a 15" PVC pipe at 0.50% slo^e. The 15-inch pipe will flow at a depth of( 0.64)feet with a velocity of 3.76 ftYsec.15" PVC from Catch Basin #2 to Detention Pond #1— 3'13-— ^This pipe carries the storm water from drainage sub-areas-^1 & 1-2. As previously calculatedwe should anticipate a flowrate of(2-3^+ 1.10) = 3-4^cfs from a 25-year storm event.Calculations are enclosed in the Appendix for a 15" PVC pipe at 0.50% slope. The 15-inch pipewill flow at a depth of^82^feet with a velocity of 4. 1 Q ft/sec. ' ' ; ^/3,.,^'. ^^ •Detention Pond #1 ^ ppThe total area served by Detention Pond #1 is 3.62 acres with a weighted C-factor of 0.483 afterdevelopment. The storage basin can have a release rate equal to the pre-development flow. Thecalculations for the pre-development time of concentration and flows are included in theAppendix. The pre-development flow (acceptable release rate) is 0.658 cfs. °^Calculations are also enclosed in the Appendix^ for sizing the detention pond by varying the stormduration and holding the release rate at 0.658 cfs. The required storage for Detention Pond #1 istl 2,000 cubic feet. The weir must also be sized to insure the discharge never exceeds the allowablerelease rate. The weir in the discharge stmcture for Detention Pond #1 will be 1.2^ inches inwidth. These calculations are included with the calculations for sizing the pond.
T^/^ ^/' r^ ^A/ ^?0tmp#45Manning Pipe calculatorGiven Input Data:Shape ........................... CircularSolving for ..................... Depth of FlowD-i ameter ........................ 15.0000 1 n,.Fl owrate ........................ ^r3fr5^C"fsSlope ........................... 0.0050 ft/ftManning's n ..................... 0.0130,-'Computed Results:Depth ........................... <7.6950 j n^Area ............................ T.2272 ft 2Wetted Area ..................... 0.6339 ft2wetted Pen meter ................ 23. 9519 inPerimeter ....................... 47.1239 1 nVelocity ........................ ^7624 fpsHydraul1c Radius ................ -?78T10 i hPercent Full .................... 51.2998 %Full flow Flowrate .............. 4.5678 cfsFull flow velocity .............. 3.7221 f psCritical informationCr-i tical depth .................. 7.4134 1ncr-it-ical slope .................. 0.0057 ft/ftCritical velocity ............... 3.9449 fpscn't-ical area ................... 0.6046 ft2Critical perimeter .............. 23.3888 inCritical hydraulic radius ....... 3.7222 inCritical top width .............. 14.9990 -inSpec-if-ic energy ................. 0.8612 ftM-in-imum energy .................. 0.9267 ftFroude number ................... 0.9315Flow condit-ion .................. Subcntical3.33|i .n\^'f0^^Page 1
-J^/^/ ^ 7^ ?^^^ /^^^0tmp#46Manning P-ipe CalculatorGiven input Data:Shape ........................... circularSolving for ..................... Depth of FlowD1ameter ........................ 15.0000 itLFl owrate ........................ 3-490e-fcfsSlope ........................... 0.0050 ft/ftManning's n ..................... 0.0130Computed Results:Depth ........................... ,9.8191 -i nArea ............................ T.2272 ft2Wetted Area ..................... 0.8513 ft2Wetted Perimeter ................ 28.2775 inPerimeter ....................... 47.1239 inVelocity ....;................... ,4.0998 fpsHydraul -i c Rad-i us ................ 4:3350 1nPercent Full .................... 65.4608 %Full flow Flowrate .............. 4.5678 cfsFul1 f1ow vel oc1ty .............. 3.7221 f psCritical Informationcn" t1cal depth .................. 9.0905 1nCritical slope .................. 0.0062 ft/ftCnt-ical velocity ............... 4.4786 f psCr-i t1cal area ................... 0.7793 ft2Critical perimeter .............. 26.7429 -inCnt-ical hydraulic radius ....... 4.1960 -incn t1cal top w-i dth .............. 15.0000 1nSpecific energy ................. 1.0759 ftMin-imum energy .................. 1.1363 ftFroude number ................... 0.8796Flow condition .................. subcntical4^3l.^. /^G^i) -^;(1-*-0-^0^^'fPage 1
/t/<?A/^y/^rnDRAINAGE CALCULATIONSWatershed #10Pre-Developed ConditionsFlow Length = 580.00Slope (%)= 1.55C coeficient = 0.20Cf = 1.00Tc = (1.87*(1.1-C*Cf)(L)(1/2))/(s)(1/3)Tc (min)= 35.02307Storm Return Interval =I (in/hr) for 10 year storm l=0.64t(-°65)100.90813RATIONAL METHOD FOR CALCULATING FLOW RATERational Method = Q = C*1*AC coeficient =Cf =I (in/hr),2iArea (ft')0.201.000.91157770.00 = Area (AC)3.6219Total Runoff For 10yr Storm (ft3/s) = 0.657829
/l/^ ''S-^Y/^fnnDetention Pond #1Flanders Creek SubdivisionPark C =Area (Ft2) =Area (ac) =Total Area (ac) =Weighted C =Release Rate (cfs):Tc Method10 YearStormlength(min)10152021222324253035456075800.20 R3 Zone C61660.00 Area (Ft2) =1.42 Area (ac) =3.620.483 °1<-0.6580.35 R-OZoneC= 0.60 Right of Way C= 0.700.00 Area (Ft2) = 34750.00 Area (Ft2) = 61360.000.00 Area(ac)= 0.80 Area (ac) = 1.41 ^StormIntensity(In/Hr)TotalQ(ft3/s)Total RunoffVolume(ft3)ReleaseVolume(ft3)2.051.581.311.271.231.191.161.131.000.910.770.640.550.533.5852.7542.2852.2132.1472.0862.0291.9761.7551.5881.3491.1190.9680.9282150.892478.852741.442788.662834.442878.882922.082964.133159.453334.593641.194026.914354.024453.49394.70592.05789.39828.86868.33907.80947.27986.741184.091381.441776.142368.182960.233157.58RequiredStorage(ft3)1756.191886.811952.051959.791966.101971.071974.811977.391975.351953.151865.051658.721393.791295.91OUTLET CONTROL STRUCTURE SIZINGAllowable Flow Rate Q (cfs) =Head above Weir Notch (ft) =Weir Coefficient =Length of Weir (ft) =Weir Equation = Q = (C)*(L)*(H)(3/2>Required Length (ft)Required Length (in)0.10753051.29040.6581.503.33?
nnnnnn[1[][][Iu[]uuuuuuu<nr$^^i.d 13/27/^^vrDRAINAGE AREA #1Drainage Area^l consists of a total of 129,670 ft2, with 33,260 ft2 of that being right of way,61,660 ft2 ofParl^and 34,750 ft of high density lots. Drainage area #1 will be divided into twosubareas, one for e^ch catch basin that will be utilized. The time of concentration for each sub-area needs to be calculated to determine the intensity of storm that will contribute to each catchbasin.The time ofconcentration\for sub-area #1-1 is calculated below:Time of ConcentrationOverland flow(340 ft (@ 1 .0%, C=0.60) = 15.17min.Gutter flow(270 ft @ O.\0% avg. slope on Glenwood Drive)V= (1.486/n)R2/3S\2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.0837)V=2.51ft/sT= 270 ft/2.51 ft/s/60^min = 1.8 minTotal Time of Concentration =\16.97 minutes(0.28 hours)For a 25-year storm event 125 = 0.\SX-64 = 0.78(0.28)-64 = 1.76 in/hrQz5 Lots = CIA = 0.60(1.76 in/hr)((\7977 acres) = 0.84 cfsQ25 r/w = CIA = 0.70(1.76 in/hr)(0.5499 acres) = 0.68 cfsQz5 Park = CIA = 0.30(1.76 in/hr)(1.41^5 acres) = 0.75 cfsQz5 Total = (0.84+0.68+0.75) = 2.27 cfs\: Total flow rate entering catch basin #1The time of concentration for sub-area #1-2 is calculated below:Time of ConcentrationGutter flow(250 ft @ 0.70% avg. slope on Glen^ood Drive)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 f^ P=9.23, R2/3=0.2623, Sl/2=0.0837)V=2.51ft/sT= 250 ft/2.51 ft/s/60s/min = 1.66 minTotal Time of Concentration = 1.66 minutes (0.03 hou^)For a 25-year storm event 135 = 0.78X-64 = 0.78(0.03)-64 =\7.36 in/hrQz5 r/w = CIA = 0.70(7.36in^)(0.2136 acres) = 1.10 cfsQ25 Total = 1.15 cfs = Total flow rate entering catch basin #2Qz5 Total for Storm Sewer #1 = (2.27+1.10) = 3.37 cfs
nnnnnnnD[ID[I[J[Juuuuuun0DRAINAGE AREA #2Drainage Area #2 consists of a total of 645,550 ft2, with 163,150 ft2 of that being right of way,213,815 ft2 of park land, 178,080 ft2 low density lots and 83,725 ft2 of high density lots. Drainagearea #2 will be divided into four subareas, three for each area that contributes to a catch basin thatwill be utilized, plus the portion of the park that will drain into the detention pond. The time ofconcentration for each sub-area needs to be calculated to determine the intensity of storm that willcontribute to the catch basin.The time of concentration for sub-area #2-1 is calculated below:Time of ConcentrationOverland flow(340 ft @ 0.75%, C=0.60) = 16.7min.Gutter flow(280 ft @ 1.35% avg. slope on Glenwood Drive)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.1072)V= 3.22 ft/sT= 280 ft/3.22 ft/s/60s/min = 1.45 minGutter flow(865 ft @ 1.1 % avg. slope on Cottonwood Road)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.1049)V=3.14ft/sT= 865 ft/3.1 4 ft/s/60s/min = 4.6 minTotal Time of Concentration = 22.93 minutes (0.42 hours)For a 25-year storm event 135 = 0.78X-64 = 0.78(0.42)-64 = 1.36 in/hrQzs Low Density Lots = CIA = 0.35(1.36 in/hr)(2.1714 acres) = 1.03 cfsQz5 High Density = CIA = 0.60(1.36 in/hr)(1.4155 acres) = 1.16 cfsQz5 r/w = CIA = 0.70(1.36 in/hr)(1.7563 acres) = 1.67 cfsQ25 Total = (1.03+1.16+1.67) = 3.86 cfs = Total flow rate entering catch basin #3The capacity of the curb and gutter, at a 1.1% slope, with a depth of water 0.15' below top of curbis calculated as follows:Q=(1.486/n)AR2/3Sl/2n= 0.013 for ConcreteA= 1.24 ft2
n'1n0\1nnnnnn[][IuuuuuuuuP = 9.23 ftR = A/P = 1.24/9.23 = 0.1343 ftR2/3 = 0.2623 ftS = 0.0060 ft/ftSl/2=0.1000ft/ftQ = (1.486/0.013)(1.24)(0.2623)(0.1049)= 3.90 cfs.3.86 cfs < 3.90 cfs =» Gutter capacity is adequateThe time of concentration for sub-area #2-2 is calculated below:Time of ConcentrationOverland flow(l 10 ft @ 0.75%, C=0.35) = 15.4min.Gutter flow(800 ft @ 1.10% avg. slope on Twin Lakes Avenue)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.1049)V=3.14ft/sT= 800 ft/3.14 ft/s/60s/min = 4.25 minTotal Time of Concentration = 19.65 minutes(0.32 hours)For a 25-year stonn event 125 = 0.78X-64 = 0.78(0.32)-64 = 1.61 in/hrQz5 Low Density Lots = CIA = 0.35(1.61 in/hr)(1.9164 acres) = 1.08 cfsQ25 r/w = CIA = 0.70(1.61 in/hr)(1.1546 acres) = 1.30 cfsQz5 Total = (1.08+1.30) = 2.38 cfs = Total flow rate entering catch basin #4The time of concentration for sub-area #2-3 is calculated below:Time of ConcentrationGutter flow(800 ft @ 1.10% avg. slope on Twin Lakes Avenue)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.1049)V=3.14ft/sT= 800 ft/3.1 4 ft/s/60s/min = 4.25 minTotal Time of Concentration = 4.25 minutes(0.07 hours)For a 25-year storm event 125 = 0.78X-64 = 0.78(0.07)-64 = 4.25 in/hrQz5 r/w = CIA = 0.70(4.25in/hr)(0.8241 acres) = 2.45 cfsQz5 Total = 2.45 cfs = Total flow rate entering catch basin #5Q;5 Total for Storm Sewer #2 = (3.86+2.38+2.45) =8.69 cfs
nnnnnInnnnuuuuuuuuuDRAINAGE AREA #3Drainage Area #3 consists of a total of 897,020 ft2, with 253,215 ft2 of that being right of way,52,431 ft2 ofponds/openspace, 291,290 ft2 of medium density lots and 300,084 ft2 of high densitylots. Drainage area #3 will be divided into five subareas, one for each catch basin that will beutilized. The time of concentration for each sub-area needs to be calculated to determine theintensity of storm that will contribute to the catch basin.The time of concentration for sub-area #3-1 is calculated below:Time of ConcentrationOverland How(140 ft @ 1 .0%, C=0.50) = 15.8 min.Gutter flow(580 ft @ 1.10% avg. slope on Cottonwood Road)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.1049)V=3.14ft/sT=580ft/3.14ft/s/60s/min = 3.1minGutter flow(260 ft @ 0.60% avg. slope on Sherwood Way)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.0775)V= 2.32 ft/sT= 260 ft/2.32 ft/s/60s/min = 1.9 minTotal Time of Concentration = 20.8 minutes(0.35 hours)For a 25-year storm event 125 = 0.78X-64 = 0.78(0.35)-64 = 1.53 in/hrQz5 Medium Density Lots = CIA = 0.35(1.53 in/hr)(3.4023 acres) = 1.82 cfsQz5 r/w =C1A= 0.70(1.53 in/hr)(1.6478 acres) = 1.76 cfsQ25 Total = (1.82+1.76) = 3.58 cfs = Total flow rate entering catch basin #6The time of concentration for sub-area #3-2 is calculated below:Time of ConcentrationOverland flow(135 ft @ 1 .0%, C=0.35) = 15.5 min.Gutter flow(585 ft @ 0.85% avg. slope on Parkview Avenue)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.0922)V= 2.76 ft/sT= 585 ft/2.76 ft/s/60s/min - 3.5 min
nnnnnnfn/'[J[Ju[JuuuuuGutter flow(245 ft @ 0.60% avg. slope on Sherwood Way)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.0775)V= 2.32 ft/sT= 245 ft/2.32 ft/s/60s/min = 1.8 minTotal Time of Concentration = 20.8 minutes (0.35 hours)For a 25-year stonn event 125 = 0.78X-64 = 0.78(0.35)-64 = 1.53 in/hrQ25 Medium Density Lots = CIA = 0.35(1.53 in/hr)(3.2849 acres) = 1.76 cfsQ25 r/w = CIA = 0.70(1.53 in/hr)(1.2770 acres) = 1.37 cfsQz5 Total = (1.76+1.37) = 3.13 cfs = Total flow rate entering catch basin #7The time of concentration for sub-area #3-3 is calculated below:Time of ConcentrationOverland Flow (140 ft @ 1.0%, C=0.60) = 9.7 min.Gutter Flow (143.5 ft @ 0.75% avg. slope on Twin Lakes Drive)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.08660)V= 2.60 ft/sT= 143.5 ft / 2.60 ft/s / 60 s/min = 0.92 min.Total Time of Concentration = 10.62 minutes (0.177 hours)For a 25-year storm event 125 = 0.78X-64 = 0.78(0.177)-64 = 2.36 iiVhrQ25 High Density Lots = CIA = 0.60(2.36 in/hr)(0.8744 acres) = 1.24 cfsQz5 r/w = CIA = 0.70(2.36 in/hr)(0.20 acres) = 0.33 cfsQz5 Total = (1.24+0.33) = 1.57 cfs = Total flow rate entering catch basin #8Time of ConcentrationOverland Flow (140 ft @ 1.0%, C=0.60) = 9.7 min.Gutter Flow (218.42 ft @ 0.75% avg. slope on Twin Lakes Drive)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.08660)V= 2.60 ft/sT= 218.42 ft / 2.60 ft/s / 60 s/min = 1.40 min.Total Time of Concentration =11.1 minutes (0.185 hours)For a 25-year storm event 125 = 0.78X-64 = 0.78(0.185)-64 = 2.30 in/hr
nnnnnnfl[Inn\Q25 High Density Lots = CIA = 0.60(2.30 in/hr)(1.1937 acres) = 1.65 cfsQz5 r/w = CIA = 0.70(2.30 in/hr)(0.30 acres) = 0.48 cfsQz5 Total = (1.65 + 0.48) = 2.13 cfs = Total flow rate entering catch basin #9The capacity of the curb and gutter, at a 0.75% slope, with a depth of water 0.15' below the top ofcurb is calculated as follows:Q=(1.486/n)AR2/3Sl/2n= 0.013 for ConcreteA= 1.24 ft2P = 9.23 ftR=A/P= 1.24/9.23 =0.1343 ftR2/3 = 0.2623 ftS = 0.0075 ft/ftSl/2 = 0.08660 ft/ftQ = (1.486/0.013)(1.24)(0.2623)(0.08660)= 3.21 cfs.1.57 cfs ^ 2.13 cfs ^ 3.21 cfs => Gutter capacity is adequateQzs Total for Storm Sewer #3 = (3.58+3.13+1.57+2.13) =10.41 cfsuuuuuuuThe time of concentration for sub-area #3-4 is calculated below:Time of ConcentrationOverland flow(140 ft @ 1 .0%, C=0.60) = 9.7 min.Gutter flow(340 ft @ 0.75% avg. slope on Twin Lakes Drive)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.08660)V= 2.60 ft/sT= 340 ft/3.67 ft/s/60s/min = 2.2 minGutter flow(260 ft @ 0.87% avg. slope on A Street)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.0933)V= 2.78 ft/sT= 260 ft/2.78 ft/s/60s/min = 1.6 minGutter flow(350 ft @ 1.5% avg. slope on Parkview Avenue)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.1225)V= 3.67 ft/s
nnnnnn[In[InnIIuuuuuuuuT= 350 ft/3.28 ft/s/60s/min = 1.6 minTotal Time of Concentration =15.1 minutes (0.25 hours)For a 25-year stonn event 135 = 0.78X-64 = 0.78(0.25)-64 = 1.89 in/hrQz5 High Density Lots = CIA = 0.60(1.89 in/hr)(2.008 acres) == 2.28 cfsQ25 r/w = CIA = 0.70(1.89 in/hr)(1.5327 acres) = 2.03 cfsQz5 Total = (2.28+2.03) = 4.31 cfs = Flow rate entering catch basin #10Time of Concentration (Oak Street)Gutter flow(600 ft @ 0.5% avg. slope on Oak Street)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.07071)V= 2.63 ft/sT= 600 ft/2.63 ft/s/60s/min = 4.72 minTotal Time of Concentration = 4.72 minutes (0.079 hours)For a 25-year stonn event ^5 = 0.78X-64 = 0.78(0.079)-64 = 3.95 in/hrQz5 r/w = CIA = 0.70(3.95 in/hr)(0.8276 acres) = 2.29 cfsQz5 Total = 2.29 cfs = Flow rate entering catch basin #10Qz5 Total for Stomi Sewer #4 = 4.31 cfs + 2.29 cfs = 6.6 cfsThe capacity of the curb and gutter, at a 1.5% slope for Parkview Avenue, with a depth of water0.15' below the top of curb is calculated as follows:Q=(1.486/n)AR2/3Sl/2n= 0.013 for ConcreteA= 1.24 ft2P = 9.23 ftR = A/P = 1.24/9.23 = 0.1343 ftR2/3 = 0.2623 ftS=0.015ft/ftSl/2=0.1225ft/ftQ = (1.486/0.013)(1.24)(0.2623)(0.1225)= 4.55 cfs.4.31 cfs ^ 4.55 cfs =>• Gutter capacity on Parkview Avenue is adequateThe capacity of the curb and gutter, at a 0.5% slope for Oak Street, with a depth of water 0.15'
nnnnnnnn[jDI]u[Juuuuuubelow the top of curb is calculated as follows:Q=(1.486/n)AR2/3Sl/2n= 0.013 for ConcreteA= 1.24 ft2P = 9.23 ftR = A/P = 1.24/9.23 = 0.1343 ftR2/3 = 0.2623 ftS=0.015ft/ftSl/2 = 0.07071 ft/ftQ = (1.486/0.013)(1.24)(0.2623)(0.07071)= 2.63 cfs.2.29 cfs < 2.63 cfs =>• Gutter capacity on Oak Street is adequateThe time of concentration for sub-area #3-5 is calculated below:Time of ConcentrationGutter flow(615 ft @ 1.1% avg. slope on Cottonwood Road)V= (1.486/n)R2/3Sl/2 (n=0.013, A=1.24 ft, P=9.23, R2/3=0.2623, Sl/2=0.1049)V=3.14ft/sT= 615 ft/3.14 ft/s/60s/min = 3.3 minTotal Time of Concentration = 3.3 minutes (0.06 hours)For a 25-year storm event 125 = 0.78X-64 = 0.78(0.06)-64 = 4.721 iiVhrQ25 r/w = CIA = 0.70(4.721 in/hr)(0.9936 acres) = 3.28 cfsQ25 Total for Storm Sewer #5 = 3.28 cfs = Flow rate entering catch basin #11The capacity of the curb and gutter, at a 1.1% average slope for Cottonwood Road, with a depth ofwater 0.15' below the top of curb is calculated as follows:Q=(1.486/n)AR2/3Sl/2n= 0.013 for ConcreteA= 1.24 ft2P = 9.23 ftR = A/P = 1.24/9.23 = 0.1343 ftR2/3 = 0.2623 ftS=0.011ft/ft
nnnnnnrjuuuuuuuuSl/2= 0.10488 ft/ftQ = (1.486/0.013)(1.24)(0.2623)(0.10488)= 3.89 cfs.3.28 cfs < 3.89 cfs => Gutter capacity on Cottonwood Road is adequateDrainage Area #1^^c^A ^l^fo^15" PVC from C^tch Basin #1 to Catch Basin #2This pipe carries th^storm water from drainage sub-area #1-1. As previously calculated weshould anticipate a flo\yrate of 2.27 cfs from a 25-year stonn event. Calculations are enclosed inthe Appendix for a 15" ^VC pipe at 0.50% slope. The 15-inch pipe will flow at a depth of0.62 feet with a velocity of\3.72 ft/sec.15" PVC from Catch Basin #? to Detention Poud #1This pipe carries the storm water\from drainage sub-areas 1-1 & 1-2. As previously calculatedwe should anticipate a flowrate of (^.27 + 1.10) = 3.37 cfs from a 25-year storm event.Calculations are enclosed in the Appendix for a 15" PVC pipe at 0.50% slope. The 15-inch pipewill flow at a depth of 0.80 feet with aVelocity of 4.07 ft/sec.Detention Pond #1The total area served by Detention Pond #1 i^ 2.213 acres with a weighted C-factor of 0.435 afterdevelopment. The storage basin can have a release rate equal to the pre-development flow. Thecalculations for the pre-development time of concentration and flows are included in theAppendix. The pre-development flow (acceptable\-elease rate) is 0.541 cfs.Calculations are also enclosed in the Appendix for sizipg the detention pond by varying the stormduration and holding the release rate at 0.541 cfs. The inquired storage for Detention Pond #1 is1,390 cubic feet. The weir must also be sized to insure th^ discharge never exceeds the allowablerelease rate. The weir in the discharge stmcture for Detention Pond #1 will be 1.95 inches inwidth. These calculations are included with the calculations f^r sizing the pond.
nnnnnnDrainage Area #2n0r[Ifl[I[Jur i[Juuu15" PVC from Catch Basin #3 to Catch Basin #4This pipe carries the storm water from drainage sub-area 2-1. As previously calculated we shouldanticipate a flowrate of 3.86 cfs from a 25-year storm event. Calculations are enclosed in theAppendix for a 15" PVC pipe at 0.50% slope. The 15-inch pipe will flow at a depth of 0.88 feetwith a velocity of 4.17 ft/sec.15" PVC from Catch Basin #4 to Catch Basin #5This pipe carries the storm water from drainage sub-areas 2-1 & 2-2. As previously calculatedwe should anticipate a flowrate of (3.86 + 2.38) = 6.24 cfs from a 25-year storm event.Calculations are enclosed in the Appendix for a 15" PVC pipe at 1.0% slope. The 15-inch pipewill flow at a depth of 0.99 feet with a velocity of 6.00 ft/sec.18" PVC from Catch Basin #5 to Detention Pond #2This pipe carries the storm water from drainage sub-areas 2-1 & 2-2 & 2-3. As previouslycalculated we should anticipate a flowrate of (3.86 +2.38+2.45) = 8.69 cfs from a 25-year stormevent. Calculations are enclosed in the Appendix fora 18" PVC pipe at 0.75% slope. The 18-inch pipe will flow at a depth of 1.173 feet with a velocity of 5.86 ft/sec.Detention Pond #2The total area served by Detention Pond #2 is 14.820 acres with a weighted C-factor of 0.420after development. The storage basin can have a release rate equal to the pre-development flow.The calculations for the pre-development time of concentration and flows are included in theAppendix. The pre-development flow (acceptable release rate) is 1.984 cfs.Calculations are also enclosed in the Appendix for sizing the detention pond by varying the stonnduration and holding the release rate at 1.984 cfs. The required storage for Detention Pond #2 is7,700 cubic feet. The weir must also be sized to insure the discharge never exceeds the allowablerelease rate. The weir in the discharge structure for Detention Pond #2 will be 7.15 inches inwidth. These calculations are included with the calculations for sizing the pond.
nnnI,nnRr1.nnDrainage Area #30IIIIuu[Juuuu15" PVC from Catch Basin #6 to Storm MH #1This pipe carries the storm water fi-om drainage sub-area 3-1. As previously calculated we shouldanticipate a flowrate of 3.58 cfs from a 25-year storm event. Calculations are enclosed in theAppendix for a 15" PVC pipe at 0.50% slope. The 15-inch pipe will flow at a depth of 0.83 feetwith a velocity of 4.12 ft/sec.15" PVC from Catch Basin #7 to Storm MH #1This pipe carries the storm water from drainage sub-area 3-2. As previously calculated we shouldanticipate a flowrate of 3.13 cfs from a 25-year storm event. Calculations are enclosed in theAppendix for a 15" PVC pipe at 0.50% slope. The 15-inch pipe will flow at a depth of 0.76 feetwith a velocity of4.Gl ft/sec.18" PVC from Storm MH #1 to Catch Basin #8 to Storm MH #2 to Catch Basin #9These pipes cany the storm water from drainage sub-areas 3-1 & 3-2 & part of 3-3. Aspreviously calculated we should anticipate a flowrate of (3.58 + 3.13 + 1.57) = 8.28 cfs from a25-year storm event. Calculations are enclosed in the Appendix for a 18" PVC pipe at 0.60%slope. The 18-inch pipe will flow at a depth of 1.26 feet with a velocity of 5.24 ft/sec.24" PVC from Catch Basin #9 to Detention Pond #3This pipe carries the storm water from drainage sub-areas 3-1 & 3-2 & 3-3. As previouslycalculated we should anticipate a flowrate of (3.58 +3.13+ 1.57 + 2.13) = 10.41 cfs from a 25-year storm event. Calculations are enclosed in the Appendix for a 24" PVC pipe at 0.50% slope.The 24-inch pipe will flow at a depth of 1.18 feet with a velocity of 5.42 ft/sec.15" PVC from Catch Basin #10 to Detention Pond #3This pipe carries the storm water from drainage sub-area 3-4. As previously calculated we shouldanticipate a flowrate of 6.60 cfs from a 25-year storm event. Calculations are enclosed in theAppendix for a 15" PVC pipe at 1.0% slope. The 15-inch pipe will flow at a depth of 1.05 feetwith a velocity of 5.99 ft/sec.
nnn[,nnnn/^^0Ii15" PVC from Catch Basin #11 to Detention Pond #3This pipe carries the stonn water from drainage sub-area 3-5. As previously calculated we shouldanticipate a flowrate of 3.28 cfs from a 25-year storm event. Calculations are enclosed in theAppendix for a 15" PVC pipe at 0.50% slope. The 15-inch pipe will flow at a depth of 0.78 feetwith a velocity of 4.05 ft/sec.Detention Pond #3The total area served by Detention Pond #2 is 20.593 acres with a weighted C-factor of 0.524after development. The storage basin can have a release rate equal to the pre-development flow.The calculations for the pre-development time of concentration and flows are included in theAppendix. The pre-development flow (acceptable release rate) is 2.71 cfs.Calculations are also enclosed in the Appendix for sizing the detention pond by varying the stormduration and holding the release rate at 2.71 cfs. The required storage for Detention Pond #3 is15,175 cubic feet. The weir must also be sized to insure the discharge never exceeds theallowable release rate. The weir in the discharge stmcture for Detention Pond #3 will be 9.77inches in width. These calculations are included with the calculations for sizing the pond.uuuuuuuu
nnnnnnn[]an0APPENDIX[Iuuuuuuu
r1« • 1r~)[ }"!^i1\):N4=J4^^0t^-'I-s,YrWAINABB\pvoy poorrvuoffoySUfr-AREAM^fl-00&fl>—agosfl^lIDRAIN^GEIStlB-ARElAL 2fl^9^G&'s•secg•^A\3-c^^DRAWAGE,o SUB^B(EAN61s•y0•gs?^3ecJE.00SB"-Iee:^?(EA2-2m•A•yu^8G£SK,atf§aiyu&n.y sffSjvj^Aii.i.f^,PQ}£\•*.>^)<^DRAINAGESUB-AREA2-30J.I I I3I I I<:C)0\4iIsI I II I I9s§)it^DRAINAGE!u830^%^ KDKA1MUKI- M^I I I 1111 I I ISUB-AREA3-4ceC/3*^7gm•^0I\Q?i@3ai01^\a.snuan.v^not'ns/^v^^isa 'a&aotO.CO.100,10,£O.LON]\>j3'TY2-\'^\--n-i^DRAINAGE PLANjSCALE: 1-=200')]:J;J^2006011[Scale In Feet0 2000 60Scale In MetersShaet I of II3{5^El Ssiy>ES-11Isu§^s•^llliSlli0\mB S/II/Bi®tWasg^KsIs^0os1^o8Drswmg Sah: (/27/05, 3:\05\05189\DRAINAGE.dwQ, 6/28/20054:33:46 PM, 1:0.989943#047701D1
y,.r y^^fnnnnn(Iu[JuuuuuunHme of Concentrstion!n orde^o use the Rainfs'! htgnsity Duration Curve, the time of concentrstion must beKnown. This can be determined either by me 'oiiowing &suat'on or the "Ovsriand Time o\Flow Curves' from the Urban Storm Drainage Criteria Manuai, induded in this report (SssFigure 3-2). ' . . ' . •To = 1.87(^-1 -CCf) D''-./2s'•/^Where Tc = Time of Concentration, minutesS = Siope'of Basin, %C = Rational Msthod Runotf Coeffideni.D = Length of Basin, feetCf = Frequency AdjustmenS FactorTime of concentration calculations should reflect channel and-storm sev/ervei&cities as weiias ovsriand flow times..1200rm i ] _rT.i \n i\ \ /; \j\ i\ '\i \ i.. \ /: \ \it• i i i iiii u'HTu^ \/u\ i 1/1 !/!' r yjI ! ;^QTJ3IT7" l/ I /I • D y j I ZL\",01 j i i ^M.H.i/1 / i/i/n/' i n1000~LATI^i^_uj7^r_/ i/1 i/ r i /RS?!T?177?%4-^/ .LJ/!im—m^./1/i i/i h .r rpnyn^'11 I I I |1o|/ j i J 7^DT/ '\/\ i \ 'S/ I I i i!i 1(ZOj L^j.l n~~^TT~i j"\ i/IAi/l'^ F/rT^^TI 1.1 ! i I&00I! JMi J I/ ^J/J I MJ \-/'\ F^rTTTT M ! '!I..1 I i j].j jjLl_^LZr7^n7-M "I l/'i i i-IJ i! )jL",l~J3100'=}J1- I J ! i l]^ ! N/!/JZLJZl_L/LU_i1-.I! i 1 .1.11 -I^J/M.AJZ.LI/ !/i7l I 1.1 II i^t I M s0ii n 11 j lllllTr-lT^ /. i/1 i/f 1 i ii i. f-^i u1Iu-ru?22QIi i n i i j./i i/n/y \irr\ /ii i t i i/^jj.^u ^50°.n-n—TTT7TT7 n / i/!l7ri i .1 l-T^H-R^J r').i i- u i I. J L11U3U s/' 1/i i i .1 \ '}A \J ' J 1') i J/lLCZiZlA'TTH^^ I i I I IA ! ^it i.i i 1 j/y •i/_y_j7I7^'i ^i i i L-^/I i/^.!LLZ400;i ) i I'}// /iy) ^/' j/j /i i/i I j, .jcp'i-^TM. i ^1 ! ^J l .M I LA/i/i^Z£Z7T/ i ! i^^]^1 U^lUi1 i !^i J 1/^^FA^JZ£LZJ_±1ZJ^~^1UU^LUJ5.0/ tr\\f\/^A A A ^Ag ! j i I \ .N~^t~7Ql~\AA^±ZLZQKJ^n-lI ^ i i i i. I//'/^7t7F7^—FrH^TT^rC:F>^^5 L1±JJ^1-^££Z:I^THTT^^^5 ^rrTT^VM^TATZIZ^ZLMl-t^l-iS^—-^ zoo'nZL^^^Z^~Ty^n^T!:^^^ '. '-N=[[A-lj'L^S:^~^r7.^^^.~u^}. j Ll;:;pr!!^7^^yW\ -7X^'Zr;!^T J^ ^" i "! _! ^^< I '' '-i^1-^^T^^^Z^Ti L^-rT I )J^@nus0u>-0KQ?-J>0Oi'^^^ Ti'EZKFTR' T^:'^L_n:"^ r i i JzoG.^^/'^^^^'\ .u[_<'TT] r icst^nu.^-/:.! III I i !0~IM[OFCONCENTRATIONTc)14 -/FIGURS 2IiI
rr'-iII'r'f]i00II.ir;iIrbIIKl.JKlI;1IIIru^,..y.,'-'3-.'6 Coefficient of RunorfThe coefficient of runoff represents the psrcsntags of totalrainfall that will run off a site during a storm.Tne; coefficient of runoff is affected by the shape of thebasin, g-round slope, antecedent precipitation, ground conditions[froz'en or unfrozen, satu.ratsd or unsatura-csd) , and type of soil(ssepage rate). The coefficiant of runoff variss wi-&h time duringa storm since surface storage and adsorptio.n decreases as theduration and to.tal amount o.f rainfall increases. The. design stonriwill oft^n b° preced'e.d by a longer term, less intense storm that.reduces available surface storag-e and the potential adsorptionrats.For simplieity, the design coeff-icients listed in Table 1shall be utilized f&r analysis. The coefficients, assume someantecedent precipitation, but not a inajor storm. Steep slopss tendto raduc£ the time available for percolation and the amount ofavailable surface storage'. As such, runoff coeffici&nts shown varywith ths slops of the water shed. For basins with a variation inslope, separate cosfficients will bs used.3.7 Adju.sfcmeat for ZafrsTjesfc StorssThe preceding variablas are based on the recurring storm, thatis, a 5-year stona. For ston&s with higher intensities., -anadjustment of the runoff coefficient is required because of thelessening amount of infiltration, depres-sion rersn-tion and otherlosses that have a proportionally sroallor "rfect on s-Lorm runoff.15 -I•1I1IIIIIIBBI1t?I
r-1nn;.-•-•SSj=;'.:,sss&^' ;:^''s-RATIONAL METHOD FREQUENCY ADJUSTMENT FACTORSsa-.sei:i•s.::-'•"••_£„IIJiI£tf•-7-.^r^y-^ 11-a;SuStorm Return Periodfyears_'i2 to 1011 to 2526" to 50.51 to 100Frequency Factor--cf-1.001..101.20•1.25Note:' The product of C times Cp shall not exceed 1.00.3.8 SWKM MethodThe S''WMM prograia shall be used for any drainage plan and willbe required for major.subdivisions and planned unit developmentscontaining 10 acres or more or having a time of concentr'ation ofone hour or greater. .Development of the st.ors drainage r"u-noff datausing the SWMM-3 computer model requires the services of aprofessional engineer trained in the use of this computer inodel.Only those individuals knowledgeable in storm drainage compu'fcsrmodeling shall be retained to evaluate the data req~uired herein.The S"wMI4 analysis will utilize SWMM-3 Micro computer modsl oracceptable updates. The analysis will follow the prescribedmethodology.., contained in the computer model. This section provideslimits on variabl&s to be used in the model.The "Runoff Module" of S'vR'M-3 s'hall bs used for all areas inGreat Falls larger'than 10 acres. This module is used to determinepipe • sizes based on design storm rainfall hydrographs, soilconditions, land use and topography. The program also determinesthe total runoff produced by a storm for detention basin design.17 -J•a.^
nnnnnf]n[][]Duuuuuuuuunn0";>-Ikw>-i--3>•co?=1aQ^ ta^ >3&de^.s:'-=) ;s^^Nps3K !L^>^snP3! &3B0^0s^\J'Ni.gl» ssl^^-^ Q" ^11C^t>Ill^ s^; ^s ^^s§§^ 0','i
nnnf;r;nn0n[I[IuuuuuuuuDRAINAGE CALCULATIONSWatershed #1-1^ (^7/0^tFlow Length =Slope (%) =C coeficient =Cf =Tc = (1.87*(1.1 -C*Cf)(L)(1/2))/(s)(1/3)Tc(min)= 15.17Storm Return Interval =I (in/'hr) for 25 year storm i-0.78t(-°-64)3401.0.60; 1.10251.8'S0398
./'r^t-6.rnnnn[][In[Inv0^ ^ i/s--ftfr'./nc5./"'f^•n^-n.K^7D^^/^ ^.^ .-Iuuuuuuuutmp#2Manning Pipe CalculatorG-iven input Data:Shape .......... ....\............ C-i rcularSol v-i ng for ........ .\... ........ Depth of FlowD-iameter ........... ..\ .......... 15.0000 InFlowrate ............. \ ......... 2.2700 cfsSlope .............. ...\........ 0.0050 ft/ftManm ng' s n ......... ....\....... 0. 0130^€^c^d \^/o^computed Results:Depth ..................... \.. .. 7.4731 inArea ...................... ..\... 1.2272 ft2Wetted Area ........... .......\.. 0.6108 ft2Wetted Pen meter .......... ....\. 23.5082 InPerimeter ................. .....\ 47.1239 inVeloc-i ty ....;............... ...\ 3.7165 fpsHydraut-ic Rad-ius ................ \3.7414 -inPercent Full .................... \49.8209 %Fu11 flow Flowrate .............. 4^.5678 cfsFull flow veloc-ity .............. 3^221 fpsCritical Informationcn t1cat depth .................. 7.22^Critical slope .................. 0.005^Critical velocity ............... 3.8813Critical area ................... 0.5849Cn't-ical perimeter .............. 23.0101Critical hydraulic rad-ius ....... 3.6601 in'Critical top w-idth .............. 14.9898 in'Specific energy ................. 0.8374 ftMinimum energy .................. 0.9030 ftFroude number ................... 0.9373Flow condition .................. Subcn'ticalinft/ftpst2Page 1
> fKq.^64/l L^t^tAnnnn--Mf^f"}<;^-^ D^4-€^n<n po^d i^^-Y[I[In[Iu[Juuuuuutmp#3^^1^J [Z^/o5Manning Pipe CalculatorGiven Input Data:Shape .......\................... c-i rcularSolving for ..\.................. Depth of FlowDiameter ......\................. 15.0000 inFlowrate .......\................ 3.3700 cfsSlope ...........\............... 0.0050 ft/ftMann-i ng's n ......\.............. 0. 0130Computed Results:Depth ............ ...\... ........ 9.5826 1nArea ................ .\...... .... 1.2272 ft2Wetted Area ...........\......... 0.8277 ft2wetted Perimeter .......\........ 27.7827 InPerimeter ...............\. ...... 47.1239 inVelocity .............. ...\...... 4.0715 fpsHydraul -i c Rad1us ...... ....\..... 4.2901 i npercent Full ........... ....\.... 63.8841%Ful 1 f1 OW Fl owrate ...... ...\.... 4. 5678 cfsFull f1 ow vel oc-i ty ........ ..\--- 3 • 7221 f psCnticat Informationcritical depth .................\ 8.9180 Incritical slope ..................\ 0.0062 ft/ftCritical velocity ............... \4.4266 fpsCritical area ................... \).7613 ft2Critical perimeter .............. 2^.3979 inCritical hydraulic radius ....... 4\1529 inCritical top w-idth .............. 15\0000-inSpecific energy ................. 1.0^36 ftM-immum energy .................. 1.11^7 ftFroude number ................... 0.884'iFlow condition .................. subcr-i'ficalPage 1
n•-1nnDRAINAGE CALCULATIONSWatershed #11,.^^ l-il-i-'/^I:II11uuuuuuuPre-Developed ConditionsFlow Length = 580.00Slope (%)= 1.55;Ccoeficient= 0.20Cf = 1.00Tc = (1.87*(1.1-C*Cf)(L)(1/2))/(s)(1/3)Tc (min)= 35.02307Storm Return Inten/al =I (in/hr) for 10 year storm l=0.64t(-°'65>100.9<)813RATIONAL METHOD FOR CALCULATING FLOW RA1Rational Method = Q = C*i*AC coeficient;Cf =I (in/hr) =2)Area (ftz)0.201.000.91129670.00 = Area (AC)t3,2.976^Total Runoff For 10yr Storm (ff/s) = 0.540665
n0yDetention Pond #1Flanders Creek SubdivisionPark C =Area (Ft2) =Area (ac) =Total Area (ac):Weighted C =Release Rate (cfs)To Method<$^^<^^c[;z/^/<?r10 YearStormlength(min)1015202530354045506065707580\0.2061^0.001.^2.980.4350.541R3 Zone CArea (Ft2) =Area (ac) =0.350.000.00R-0 Zone CArea (Ft2) =Area (ac) =StormIntensity(In/Hr)TotalJ.'(ft3/s)'Total RunoffVolume(ft3)ReleaseVolume(ft3)2.051.581.311.131.000.910.830.770.720.640.610.580.550.532.6592.0431.6941.4661.3021.1781.0801.0000.9340.8300.7880.7500.7180.688\\ 1595.191838.41?033.16t98.32^&23^3.172473..062591 :^92700.452801.89N2986.513071.363152.073229.113302.88324.40486.60648.80; 811.00973.201135.401297.601459.791621.991946.392108.592270.79,2432.99<595.190.60 Right of Way C= 0.7034750.00 Area (Ft2) = 33260.000.80 Area (ac) = 0.76RequiredStorage(ft3)1270.791351.821384.361387.321369.971337.671293.791240.651179.901040.12962.77881.28796.12707.69OUTLET CONTROL STRUCTURE SIZINGAllowable Flow Rate Q (cfs) =Head above Weir Notch (ft) =Weir Coefficient =Length of Weir (ft) =Weir Equation = Q = (C)*(L)*(H)(3/2)Required Length (ft);Required Length (in):0.16236171.94830.5411.003.331.00uuu
nnnrri[][I1Ili0DRAINAGE CALCULATIONSWatershed #2-1Flow Length =Slope (%) =C coeficient =Cf =340.000.750.60i.10Tc = (1.87*(1.1-C*Cf)(L)(1/2))/(s)(1/3)Tc(min)- 16.70Storm Return Interval =I (in/hr) for 25 year storm !=0.78{('°'64)25n1.768464[juuuuuuuu
nnnDRAINAGE CALCULATIONSWatershed #2-2n[:r'[j0[J[JuuuuuuuFlow LengthSlope (%) =C coeficientCf =110.000.750.351.10Tc = (1.87*(1.1 -C*Cf)(L)(1/2))/(s)(1/3)Tc(min)= 15.43Storm Return Interval =(in/hr) for 25 year storm l=0.78t<-°64)251.859849
nnnnnnnn[Ic^^-&c3.^^ 1"•-i,,r?/•f?7.-j^4/•-^•n^n 0&^?H n '7r f /ntmp#5.txtManmng Pipe calculatorGiven Input Data:Shape ........................... CircularSolv-i ng for ..................... Depth of FlowDt ameter ........................ 15.0000 -i nFlowrate ........................ 3.8600 cfsSlope ........................... 0.0050 ft/ftManm ng's n ..................... 0. 0130Computed Results:Depth ........................... 10.5753 I nArea ............................ 1.2272 ft2wetted Area ..................... 0.9247 ft2Wetted Per-i meter ................ 29.8994 inPer-imeter ....................... 47.1239 InVelocity ........................ 4.1743 f psHydraulic Radius ................ 4.4536 inPercent Full .................... 70.5019 %Full flow Flowrate .............. 4.5678 cfsFull flow velocity .............. 3.7221 fpsCritical Informationcritical depth .................. 9.6103 1ncn t1cal s1ope .................. 0.0064 ft/ftCritical velocity ............... 4.6316fp5Critical area ................... 0.8334 ft2Critical perimeter .............. 27.7825 inCritical hydraulic radius ....... 4.3197 1ncn t-i cal top w1dth .............. 15. 0000 i nSpeci f-i c energy ................. 1.1434 ftM-immum energy .................. 1.2013 ftFroude number ......... . . ........ 0.8639Flow condition .................. SubcnticaluuuuuuuuPage 1
,^'•c./•^•n^.o^o(v\^^/nprnnn[III0IIuuuuuuur".-/" . ' •c/An^i.Ljff^f-yi.^^^-ntmp#6.txtManning Pipe calculatorGiven Input Data:Shape ........................... C-ircularSot ving for ..................... Depth of FlowD-iameter ........................ 15.0000 inFlowrate ........................ 6.2400 cfsSlope ........................... 0.0100 ft/ftManm ng's n ..................... 0. 0130Computed Results:Depth ........................... 11.8590 inArea ............................ 1.2272 ft2wetted Area ..................... 1.0406 ft2Wetted perimeter ................ 32.8649 InPerimeter ....................... 47.1239 -inVeloc-i ty ........................ 5.9965 f psHydraulic Radius ................ 4.5595 inPercent Full .................... 79.0598 %Fu11 flow Flowrate .............. 6.4598 cfsFull flow velocity .............. 5.2639 fpsCn'tical informationCritical depth .................. 12.6299 inCn't-ical slope .................. 0.0075 ft/ftcritical velocity ............... 5.4358 fpscr-itical area ..'................. 1.1480 ft2Cr-itical perimeter .............. 33.8217 -inCr-itical hydraulic radius ....... 4.8876 InCr-i ticat top w-i dth .............. 15. 0000 1nSpecific energy ................. 1.5311 ftMinimum energy" .................. 1.5787 ftFroude number ................... 1.1908Flow condition .................. supercriticalPage 1
^ 1!;t^A-te-nnnnn<->ba^//'.tl:[Irrn[I[]uuuuuuu7r~</ ^ f. . fP^f^^^n f^s^^i ^Z/tmp#7.txtManning Pipe calculatorGiven Input Data:Shape ........................... C~i rcularsot v1ng for ..................... Depth of FlowDiameter ........................ 18.0000 1nFlowrate ........................ 8.6900 cfsSlope ........................... 0.0075 ft/ftManm" ng's n ..................... 0. 0130Computed Results:Depth ........................... 14.0782 1 nArea ............................ 1.7671 ft2wetted Area ..................... 1.4828 ft2Wetted Perimeter ................ 39.0656 inPenmeter ....................... 56.5487 Inveloc-i ty ........................ 5.8604 fpsHydraul-ic Radius ................ 5.4659 1nPercent Full .................... 78.2121 %Full flow Flowrate .............. 9.0970 cfsFul 1 f~\ ow vel oct ty .............. 5.1479 f psCritical informationcritical depth .................. 14.1016-incritical slope .................. 0.0067 ft/ftCritical velocity ............... 5.7123 fpscritical area ..'................. 1.5213 ft2Cnt-ical perimeter .............. 38.4776 inCritical hydraulic radius ....... 5.6933 incr-i t1cal top width .............. 18.0000 1nSpecific energy ................. 1-6850 ftM-immum energy .................. 1.7627 ftFroude number ................... 1.0655Flow condition .................. Supercnti'calPage 1
nnnDRAINAGE CALCULATIONSWatershed #2nfinfIIuuuuuuuuPre-Developed ConditionsFlow Length = 1250.00Slope (%)= ^,': 1.20,C coeficient= , 0.20Cf = ,: 1.00iTo = (1.87*(1.1-C*Cf)(L)(1/2))/(s)(1/3)Tc (min)= 55.9945Storm Return Interval =! (in/hr) for 10 year storm l=0.64t('°'65)100.669397RATIONAL METHOD FOR CALCULATING FLOW RATERational Method = Q = C*i*AC coeficient:Cf =(in/hr) =.2,Area (ftz)0.201.000.67645550.00 = Area (AC)14.8197Total Runoff For 10yr Storm (ft3/s) = 1.984057
nnnDetention Pond #2Flanders Creek SubdivisionPark C =• Area (Ft2) =Area (ac) =• Total Area (ac) =Weighted C =Release Rate (cfs)=Tc Method10 YearStormiength(min)f15202530313233343536373875800.20 R3 Zone C =220595.00 Area (Ft2) =5.06 Area (ac) =14.820.4201.9840.35 R-0 Zone C178080.00 Area (Ft2) =4.09 Area (ac) =StormIntensity(In/Hr)TotalQ(ft3/s)Total RunoffVolume(ft3)ReleaseVolume(ft3)1.581.311.131.000.980.960.940.930.910.890.880.860.550.539.8008.1287.0316.2456.1145.9895.8705.7575.6505.5475.4495.3563.4433.3018819.839754.1310546.4711241.4011371.1611498.2211622.7311744.8011864.57.11982.1312097.5912211.0315491.7215845.631785.652380.872976.083571.303690.353809.393928.434047.484166.524285.564404.614523.658928.259523.470.60 Right of Way C= 0.7083725.00 Area (Ft2) = 163150.001.92 Area (ac) = 3.75RequiredStorage(ft3)7034,187373.267570.387670.107680.817688.837694.297697.337698.057696.577692.987687.386563.466322.16OUTLET CONTROL STRUCTURE SIZINGAllowable Flow Rate Q (cfs)Head above Weir Notch (ft)Weir Coefficient =Length of Weir (ft) =Weir Equation = Q = (C)*(L)*(H)(3/2>Required Length (ft) = 0.5958128Required Length (in) = 7.14981.9841.003.331.00uuu
nnr\[,nn[IIInDRAINAGE CALCULATIONSWatershed #3-1Flow LengthSlope (%) =C coeficient:Cf =140.001.000.351.10Tc = (1.87*(1.1-C*Cf)(L)(1/2))/(s)(1/3)Tc(min)= 15.82Storm Return Interval =I (in/hr) for 25 year storm :=0.78t(-°64)251.830695[IDuuuuuuu
nr^nnr-1i[InDRAINAGE CALCULATIONSWatershed #3-2Flow LengthSlope (%) =C coeficient:Cf =135.001.000.35.1.10Tc = (1.87*(1.1-C*Cf)(L)o/2))/(s)(1/3)Tc(min)= 15.54Storm Return Interval =I (in/hr) for 25 year storm l=0.78t('°'64)251.852124[j[I[Iuuuuuu
nDRAINAGE CALCULATIONSWatershed #3-3nnf!11D[]uuuuuuuuuFlow LengthSlope (%) =C coeficient:Cf =140.001.000.601.10Tc = (1.87*(1.1-C*Cf)(L)(1/2))/(s)(1/3)Tc (min)= 9.74Storm Return Interval =I (in/hr) for 25 year storm :=0.78t(-064)252.497825
nnflnn[]I.[inDRAINAGE CALCULATIONSWatershed #3-4Flow LengthSlope (%) =C coeficient •-Cf =140.001.000.601.10Tc = (1.87*(1.1-C*Cf)(L)(1/2))/(s)(1/3)Tc (min)= 9.74Storm Return Interval =! (in/hr) for 25 year storm !=0.78t('°'64)252.497825uuuuuuuu
^•U. Ku^fA ^6 A ^Av-^ M^-J-\^inr1nnnn[1[I11rtmp#8.txtManning P-ipe calculatorGiven input Data:Shape ........................... d rcularSot v-i ng for ..................... Depth of Fl owDiameter ........................ 15.0000 inFlowrate ........................ 3.5800 cfsSlope ........................... 0.0050 ft/ftManning's n ..................... 0.0130Computed Results:Depth ........................... 9.9988 i nArea ............................ 1.2272 ft2Wetted Area ..................... 0.8690 ft2wetted perimeter ................ 28.6570 inPerimeter ....................... 47.1239 1nVel oc-i ty ................... 4.1197 f psHydraulic Radius ................ 4.3666 inPercent Full .................... 66.6588 %Full flow Flowrate .............. 4.5678 cfsFul1 f1ow vel oc-i ty .............. 3.7221 f pscritical informationCnt-icat depth .................. 9.2185 -inCritical slope .................. 0.0063 ft/ftcr-it-ical veloc-ity ............... 4.5167 f pscn" t-i cat area ................... 0.7926 ft2Cnt-ical per-imeter .............. 26.9990-inCritical hydraul-ic radius ....... 4.2274 1nCr-i t-i cal top width .............. 15. 0000 -i nSpecific energy ................. 1-0925 ftM-in-imum energy .................. 1.1523 ftFroude number ................... 0.8757Flow condition .................. subcntlcaluuuuuuuuPage 1
I-,yrc><f'>t-"^-.\.M^/H i.<.jr^rfAMH.1-•n-';n[inni[1n1.1I)[][Juuuuutmp#9.txtManning P-ipe calculatorGiven Input Data:Shape ........................... d rcularSolv1ng for ..................... Depth of FlowDiameter ........................ 15.0000 inFt owrate ........................ 3.1300 cfsSlope ........................... 0.0050 ft/ftManm ng's n ..................... 0. 0130Computed Results:Depth ........................... 9.1174 i nArea ............................ 1.2272 ft2wetted Area ..................... 0.7808 ft2Wetted Pen meter ................ 26.8224 -inPer-i meter ....................... 47.1239 1 nVelocity ....;................... 4.0089 f psHydraut-ic Radius ................ 4.1916 inPercent Full .................... 60.7828 %Full flow Flowrate .............. 4.5678 cfsFu11 f1ow vel oc1ty .............. 3.7221 f psCritical Informationcr-i t1cat depth .................. 8.5667 Incn t1cal st ope .................. 0.0061 ft/ftCritical velocity ............... 4.3190fp5Cn t1 cal area ./................. 0.7247 ft2Critical perimeter .............. 25.6954 -inCritical hydraulic rad-ius ....... 4.0614 inCri t1 cal top w-i dth .............. 15.0000 inSpec-i f1c energy ................. 1.0084 ftMinimum energy' .................. 1.0708 ftFroude number ................... 0.8956Flow condlt-ion .................. SubcnticalPage 1
^/ffr'^1 f'f^ '"/ TO i^-./'c^ a»j-/^ fy /y j"76»^>*7 /%^^.<f/nTT» c'»/^c<f <T<.^-/^)^'1vn-1fif]nn[1nimp#yC/<yManning Pipe CalculatorGiven Input Data:Shape ........................... d rcularSolving for ..................... Depth of FlowDiameter ........................ 18.0000 inFlowrate ........................ 8.2800 cfsSlope ........................... 0.0060 ft/ftManning's n ..................... 0.0130Computed Results:Depth ........................... 15.0569 inArea ............................ 1.7671 ft2Wetted Area ..................... 1.5788 ft2wetted perimeter ................ 41.5627 inPerimeter ....................... 56.5487 -inVeloclty ....;................... 5.2444 f psHydraulic Radius ................ 5.4701 inPercent Full .................... 83.6494 %Ful 1 f1 OW Fl owrate .............. 8.1366 cfsFull flow velocity .............. 4.6044 fpsCnt-ical informationcr-i t1cal depth .................. 13.7158 -i nCr-i tical slope .................. 0.0066 ft/ftCn't-ical velocity ............... 5.6210 fpsCritical area ................... 1.4730 ft2Critical perimeter .............. 37.7059 inCritical hydraulic radius ....... 5.6256 1ncn t1cal top w-i dth .............. 18.0000 -i nSpecif-i c energy ................. 1.6364 ftMln-imum energy .................. 1.7145 ftFroude number ................... 0.9409Flow condition .................. Subcnt-icaluuuuuuuuPage 1
-i-^/^r^^ i/e.Te.^7;^^ ^0^<i •UJ>t. 'Ch^^ fr^^ j2y// , ,^ fc. /^/ /';^12^7/05tmp#53Manning Pipe CalculatorGiven input Data:Shape ........................... C-i rcularSolving for ..................... Depth of FlowDiameter ........................ 18.0000 inFlowrate ........................ 10.4100 cfsSlope ........................... 0.0185 ft/ftMann-i ng's n ..................... 0. 0130Computed Results:Depth ........................... 11.4010 inArea ............................ 1.7671 ft2wetted Area ..................... 1.1801 ft2Wetted Perimeter ................ 33.1351 inPerimeter ....................... 56.5487 in8.8213 fpsHydraulic Radius ................ 5.1285 inPercent Full .................... 63.3387 %Full flow Flowrate .............. 14.2874 cfsFull flow velocity .............. 8.0850 fpsCritical informationcr-itical depth .................. 15.6587 inCritical slope .................. 0.0072 ft/ftCritical velocity ............... 6.0667 fpsCritical area ..'................. 1.7159 ft2Critical perimeter .............. 41.5918 inCritical hydraulic radius ....... 5.9409 -inCr1 t-i cal top w-i dth .............. 18.0000 1nSpecific energy ................. 2.1600 ftM-immum energy .................. 1.9573 ftFroude number ................... 1.7582Flow condition .................. SupercriticalPage 1
(^^Tc^h /J^JT/^7TO^e7^^^/^ ^^d fyS'<^^<^d•/sn[Innnfl0Guuuuuuuutmp#32Manning Pipe calculatorGiven input Data:Shape ........................... d rcularSolving for ..................... Depth of FlowDiameter ........................ 24.0000 1 nFlowrate ........................ 10.4100 cfsSlope ........................... 0.0050 ft/ftManm ng's n ..................... 0. 0130Computed Results:Depth ........................... 14.1055 inArea ............................ 3.1416 ft2Wetted Area ..................... 1.9199 ft2wetted Pen meter ................ 41.9321 inPerimeter ....................... 75.3982 inVeloc-i ty .^ ..;................... 5.4221 fpsHydraul-ic Radius ................ 6.5932 inPercent Full .................... 58.7730%Ful 1 f1 OW Fl owrate .............. 15.9965 cfsFull f1ow veloc-i ty .............. 5.0918 f psCr-it-ical InformationCr1t1cal depth .................. 13.9069 1nCritical slope .................. 0.0052 ft/ftCritical velocity ............... 5.5120fp5Critical area ................... 1.8886 ft2Critical perimeter .............. 41.5129 -inCritical hydraul-ic radius ....... 6.5512 inCritical top width .............. 24.0000 -inSpec-if-ic energy ................. 1.6314 ftMinimum energy .................. 1.7384 ftFroude number ................... 0.9764Flow condition .................. Subcr-iticalPage 1
.C^^ ^^^ ^/^ ^ />e/^//^ ^J ^Jnr-nnn[]nI]Du[Juuuuuutmp#X /2.Manning P-ipe calculatorGiven input Data:Shape ........................... d rcularSolving for ..................... Depth of FlowDiameter ........................ 15.0000 -inFlowrate ........................ 6.6000 cfsSlope ........................... 0.0100 ft/ftManning's n ..................... 0.0130Computed Results:Depth ........................... 12.6099 1 nArea ............................ 1.2272 ft2Wetted Area ..................... 1.1012 ft2Wetted Perimeter ................ 34.8055 inPerimeter ....................... 47.1239 -inVeloc-i ty ........................ 5.9934 f psHydraulic Rad-ius ................ 4.5560 inPercent Full .................... 84.0661 %Full flow Flowrate .............. 6.4598 cfsFul1 f1ow vel ocity .............. 5.2639 f psCr-it-ical informationCn t1cal depth .................. 13.0498 -i ncritical slope .................. 0.0076 ft/ftCnt-ical velocity ............... 5.5383 fpscritical area ..'................. 1.1917 ft2Critical perimeter .............. 34.6615 inCritical hydraul-ic rad-ius ....... 4.9508 inCn tical top width .............. 15.0000 1nSpecific energy ................. 1.5818 ftMim mum energy .................. 1.6312 ftFroude number ................... 1.1773Flow condition .................. Supercn't-icalPage 1
nc^-k'A~ &-^;^•J- <^?-'/?'~t^. A-^-Tfn-iff-r't;.-IIflpnnnnflDGGuuuuuuu//!r.•^-ST- '-^tmp#13.txtManning Pipe calculatorGiven input Data:Shape ........................... d rcularSot v1ng for ..................... Depth of Ft owDiameter ........................ 15.0000 1 nFlowrate ........................ 3.2800 cfsSlope ........................... 0.0050 ft/ft ^Manm ng's n ..................... 0. 0130Computed Results:Depth ........................... 9.4071 i nArea ............................ 1.2272 ft2Wetted Area ..................... 0.8101 ft2wetted Perimeter ................ 27.4186 inPer-i meter ....................... 47.1239 i nVelocity ........................ 4.0489 f ps ^Hydraulic Radius ................ 4.2545 inPercent Full .................... 62.7143 %Full flow Flowrate .............. 4.5678 cfsFull f1ow veloclty .............. 3.7221 f psCritical Informationcritical depth .................. 8.7873 incn t1cal st ope .................. 0.0061 ft/ftCritical velocity ............... 4.3869fp5cr-i t-i cal area ................... 0.7477 ft2Critical perimeter .............. 26.1365 inCritical hydraulic radius ....... 4.1194 InCritical top width .............. 15.0000inSpecific energy ................. 1.0367 ftMimmum energy .................. 1.0984 ftFroude number ................... 0.8888Flow condition .................. Subcnti'calPage 1
nnnniflnfuuuuuuunnDRAINAGE CALCULATIONSWatershed #3Pre-Developed ConditionsFlow Length = 1285.00Slope (%)= 3 1.16Ccoeficient= 0.20Cf = 1.00Tc = (1.87*(1.1-C*Cf)(L)(1/2))/(s)(1/3)Tc(min)= 57.41821Storm Return Interval =(in/hr) for 10 year storm !=0.64t('°'65)^100.658561RATIONAL METHOD FOR CALCULATING FLOW RATERational Method = Q = C*1*AC coeficientCf =(in/hr) =.2,Area (ftz)0.201.000.66897020.00 = Area (AC) ••t3/^\ -20.5927Total Runoff For 10yr Storm (ff/s) = 2.712305
JnnDetention Pond #3Flanders Creek SubdivisionPark C =Area (Ft2) =Area (ac) =Total Area (ac) =Weighted C =Release Rate (cfs)=Tc Method10 YearStormlength(min)152025303540455055606570901200.2052431.001.2020.590.5242.712R3 Zone CArea (Ft2) =Area (ac) =0.35291290.006.69R-0 Zone C =Area (Ft2) =Area (ac) =StormIntensity(In/Hr)TotalQ(ft3/s)Total Run offVolume(ft3)ReleaseVolume(ft3)1.581.311.131.000.910.830.770.720.680.640.610.580.490.4116.99414.09512.19210.8309.7978.9838.3217.7707.3036.9026.5526.2445.3034.39815294.2516914.4018288.3819493.4520574.0621558.4322465.7323309.65^24100.3424845.5825551.4726222.8928633.9431667.202441.073254.774068.464882.155695.846509.537323.228136.918950.619764.3010577.9911391.6814646.4519528.600.60300084.006.89Right of Way CArea (Ft2) =Area (ac) =0.70253215.005.81RequiredStorage(ft3)12853.1713659.6414219.9214611.3014878.2215048.9015142.5115172.7^15149.7315081.2814973,4814831.2113987.4912138.SOOUTLET CONTROL STRUCTURE SIZINGAllowable Flow Rate Q (cfs) =Head above Weir Notch (ft) =Weir Coefficient =Length of Weir (ft) =,(3/2)Weir Equation = Q = (C)*(L)*(H)Required Length (ft) = 0.814506Required Length (in) = 9.77412.7121.003.331.00uuu