Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
2236 Coy Avenue - Drainage Study (2)
10/15/2008 City of Bakersfield Engineering Department 1501 Truxtun Ave. Bakersfield, CA. 93301 Drainage Calculations for 2236 Coy Ave. Total Area = 12.380 ac. Area 1 = 2.11 ac., Paved Area = 0.829 ac., Gravel = 1.281 ac. L = 210 , Hi.Pt. = 374.00, CB = 371.00 , Elev. Diff. = 3.00 TC = 8 min., therefore use 10 min., I10 = 1.80 /hr. C = ((0.829/2.11) * 0.90) + ((1.281/2.11) * 0.15) = 0.44 Q = (0.44)(1.80)(2.11 ac.) = 1.67 cfs 18 pipe -Q = ( 0.00061 /0.012 )( 18 8/3 )(0.005 1/2 ) = 8.007 cfs 8.007 cfs > 1.67 cfs therefore 18 pipe size & slope okay. 1.67 cfs < 9.546 cfs /2 therefore 3 x 3 Grate Inlet okay. Area 4 = 2.81 ac. L = 300 , Hi.Pt. = 373.30, CB = 370.50 , Elev. Diff. = 2.80 TC = 10.5 min., therefore use 10 min., I10 = 1.80 /hr. C = 0.15 per C.O.B. Letter dated 9/25/2008 Q = (0.15)(1.80)(2.81 ac.) = 0.759 cfs Areas 1 & 4 = 2.11 + 2.81 = 4.91 ac. C = ((0.829/4.91) * 0.90) + ((4.091/4.91) * 0.15) = 0.28 Q = (0.28)(1.80)(4.91 ac.) = 2.475 cfs 8.007 cfs > 2.475 cfs therefore 18 pipe size & slope okay. 0.759 0.759 cfs < 9.546 cfs /2 therefore 3 x 3 Grate Inlet okay. Area 5 = 2.15 ac. L = 305 , Hi.Pt. = 373.00, CB = 370.00 , Elev. Diff. = 3.00 TC = 9.5 min., therefore use 10 min., I10 = 1.80 /hr. C = 0.15 per C.O.B. Letter dated 9/25/2008 Q = (0.15)(1.80)(2.15 ac.) = 0.580 cfs Areas 1 thru 5 = 2.11 + 2.39 + 2.55 + 2.81 + 2.15 = 12.01 ac. C = ((0.829/12.01) * 0.90) + ((6.241/12.01) * 0.15) = 0.14 1. 2003 20th Street Bakersfield, CA. 93301 (661) 326-1543 (661) 326-0421 Fax hendengg@earthlink.net Q = (0.14)(1.80)(12.01 ac.) = 3.027 cfs 8.007 cfs > 3.027 cfs therefore 18 pipe size & slope okay. 0.580 cfs < 9.546 cfs /2 therefore 3 x 3 Grate Inlet okay. Area 2 = 2.39 ac. L = 265 , Hi.Pt. = 373.00, CB = 370.00 , Elev. Diff. = 3.00 TC = 9.5 min., therefore use 10 min., I10 = 1.80 /hr. C = 0.15 per C.O.B. Letter dated 9/25/2008 Q = (0.15)(1.80)(2.39 ac.) = 0.645 cfs 18 pipe -Q = ( 0.00061 /0.012 )( 18 8/3 )(0.005 1/2 ) = 8.007 cfs 8.007 cfs > 0.645 cfs therefore 18 pipe size & slope okay. 0.645 cfs < 9.546 cfs /2 therefore 3 x 3 Grate Inlet okay. Area 3 = 2.55 ac. L = 290 , Hi.Pt. = 373.00, CB = 370.00 , Elev. Diff. = 3.00 TC = 9.5 min., therefore use 10 min., I10 = 1.80 /hr. C = 0.15 per C.O.B. Letter dated 9/25/2008 Q = (0.15)(1.80)(2.55 ac.) = 0.689 cfs Areas 2 & 3 = 2.39 + 2.55 = 4.94 ac. Q = (0.15)(1.80)(4.94 ac.) = 1.334 cfs Areas 1, 2, 3, 4, & 5 = 4.94 + 7.07 = 12.01 ac. Q = (0.15)(1.80)(12.01 ac.) = 3.243 cfs 8.007 cfs > 3.243 cfs therefore 18 pipe size & slope okay. 0.1.334 cfs < 9.546 cfs /2 therefore 3 x 3 Grate Inlet okay. Area 6 = 0.91 ac. L = 290 , Hi.Pt. = 373.00, CB = 370.00 , Elev. Diff. = 3.00 TC = 9.5 min., therefore use 10 min., I10 = 1.80 /hr. C = 0.15 per C.O.B. Letter dated 9/25/2008 Q = (0.15)(1.80)(0.91 ac.) = 0.246 cfs Areas 1, 2, 3, 4, 5, & 6 = 4.94 + 7.07 + 0.91 = 12.92 ac. C = ((0.829/12.92) * 0.90) + ((12.091/12.92) * 0.15) = 0.20 Q = (0.20)(1.80)(12.92 ac.) = 4.651 cfs 2. 8.007 cfs > 4.651 cfs therefore 18 pipe size & slope okay. 0.246 cfs < 9.546 cfs /2 therefore 3 x 3 Grate Inlet okay. Sump: V = 0.15(0.20)(12.38 ac.) = 0.371 ac. ft. or 16,178 cu.ft. V = 1/6(Bottom Area + 4 * Mid Area + H.W. Area) Depth V = 1/6((1267.0 ) + (4 * 3101.8 ) + (5446.6 )) (7.5 ) V = 22,317 cu.ft. or 0.512 ac.ft. 22,317 > 16,178 therefore sump size okay. Hydraulic Grade Line: Sump Bottom Elevation = 361.00 Sump Inlet to CB #6: Pipe Len. = 30 Sump -18 Pipe Inlet -Soffit Elev. = 361.50 + 1.50 = 363.00 18 Pipe @0.50% -4.651 cfs. Exit Loss -k = 1.0, V = 4.651/((0.75 )2 * 3.1416) = 2.632 fps. HL = ( 1.0 * (2.632)2 ) /64.4 = 0.108 Pipe Loss ( Sump to CB #4) -S = ( (Q * N) /(0.00061 * D8/3) )2 S = ( (4.651 * 0.012 )/(0.00061 * (18)8/3) )2 = 0.00169 HL = 0..00169 * 30 = 0..0507 Grade Line elev. = 363.00 + 0.108 + 0.051 = 363.159 Catch Basin #6 -HL = kv2/2g, 2g = 64.4 ft./sec., V = Q/A Outlet Loss -D = 5 , d = 1.5 , (d/D)2 = 0.09 therefore k = 0.15 V = 4.651 /((.75 )2 * 3.1416) = 2.632 fps. HL = ( 0.15 * (2.632)2 ) /64.4 = 0.0161 Grade Line elev. = 363.159 + 0.016 = 363.175 3. This document was created with Win2PDF available at http://www.daneprairie.com. The unregistered version of Win2PDF is for evaluation or non-commercial use only.