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Home My WebLink AboutDrainage ReportThe-Barracks Subdivision -Phase 2 College Station, Texas Engineer: HARLE ENGINEERING COMPANY TBPE Firm Registration No. 4538 P.O. Box 11587 College Station, TX 77842 3002 Texas Avenue South College Station, Texas 77845 (979) ~93-7191 ...... -· ... . ·--~ APPENDIXE Storm Sewer Pipe Design Summary Revised May 2009 The Barracks Subdivision -Phase 2 Storm Sewer Pipe Summary (10-yr Storm) Pipe No. Channel 1 110 Pipe Size (In) 36 Length Slope (ft) (%) 67.62 0.25 96.00 0.25 Contributing Drainage Areas All Areas 120, 121, 122, 131, 140A, 1408, 140C, 141,142, 143, 144,145 Contributing Area (Acres) 10.458 Contributing Pipes All Pipes c 0.69 Tc (min) 12.46 110 (In/hr) 7.850 Q10 (cfs) 56.65 v (fps) 5.57 Travel Time (sec) (min) 12 0.20 i---8_._25_8_--t P120,P121 ,P122,P123,P131,P14 i---0_.6_9 ____ 1_2_.1_4--1_7_.9_4_3--11--45_.2_6_1 __ 5_.0_7·---t--1_9-t·--0._32 __ 1 O,P141A,P142,P143,P144,P145 1---1_2_0_-1-_3_6_1--2-0_.3_5-1_o._2_5--1120.131 ,140A,1408,140C,141,141---1-·-19-5---1 P123,P131,P140,P141A,P142, 0.69 12.10 7.956 39.50 7.60 3 0.04 f------·----1----1-----+-----+----lf------I 2, 143, 144, 145 P143,P144,P145 ----.-------------------------· ~~--=-24-'----t-~14~5~.3~8'--l--o~.5~1'-11----1_2~1 ,~12_2 ____ 11-_1~.0~5~3'----1------'-P~1=22=------1-~o~.6~9'--·l-~1~0=.2=5--1-8~.5~4~5-11_~6~.2~1_1--_4=·=82=----•--3~0'---t---=o~.5~o_1 ~ 24 80.00 0.69 122 0.966 -0.69 10 8.635 5.76 5.26 15 0.25 ,____12_3 _____ 35 __ 11--_7_7 ·-14__,,_0 __ ·2_0_ 131, 140A, 1408, 140C, 141 , 142, 14 1--6-·-78-7---t P131,P140,P141 A,P142,P143, P144,P145 0.69 11.93 8.004 37.48 7.96 10 0.16 3,144,145 131 36 31.00 0.20 131, 140C,141 , 142, 143, 144, 145 6.046 P140,P141A,P142,P143,P144, 0.69 8.025 33.48 7.24 4 0.07 P145 1------1---~1---1-----1-----------11------t------------+-----1----1---~-----lf-------11---1----1 140 1418 141A 36 289.50 0.43 140C,141,142,143,144,145 5.358 P141A,P142,P143,P144,P145 0.69 11.08 8.269 30.57 6.16 47 0.78 18 18 40.00 1_0_.8_0_. _____ 14_o_c ______ 1--_o_.6_2_0 __ 1--------------1--o_.6_9_..__1_0._1_1_ -1_8_.5_9_5--1r---3_.6_8_11 __ 4_._62 __ 1--~9 --1--0._14_-1 31 .00 0.80 140C 0.620 P141A 0.69 10 8.635 3.69 4.62 7 0.11 30 96.50 0.46 142,143,144,145 4.084 P143,P144,P145 0.69 10.83 8.352 23.53 6.36 15 0.25 30 125.50 0.40 143,144,145 3.098 P144,P145 0.69 10.46 8.474 18.11 5.72 22 0.37 24 42.00 0.82 144, 145 1.946 P145 0.69 10.36 8.510 11.43 6.69 6 0.10 ----t------·1------------1------1-------------1----1----t----1-----1-----+----+--·-~ 18 109.50 0.70 145 0.839 -0.69 10 8.635 5.00 5.14 21 0.36 Channel 2 256.51 0.30 210,220,320,330 2.200 P210,P220,P230,P310,P320,P330 0.69 11.36 11.037 16.75 4.23 61 210 2-24 24.00 0.30 210.220,320,330 2.200 P220,P230,P310,P320,P330 0.69 11.26 8.212 12.47 3.95 6 0.10 1-----1----t----i----~-----------t-------11----~---~---1-----1----1----1----1------1·----t---- 220 2-24 42.00 0.30 220,320,330 1.441 P230,P310,P320,P330 0.69 11.06 8.275 8.23 3.55 12 0.20 -----· ----------~-----·t-----1 ---~-'--~-----1----l·---~---·-ll----1------1----11----1 • 230 24 119.50 o:~ _____ 32_oc_,3_3_0 ___ -1 ___ 0_.1_1_5_-1--___ P_3_1_0'""",P_3_20""',P_3_3_o ____ o'-.6_9_-1-__ 1_0_.5_1 -1-8.457 4.52 3.63 33 o.55 _2_4_ lli:19 0.65 320,330 0.775 P320,P330 0.69 10.12 8.592 4.59 4.83 23 0.39 18 5.50 1.30 320,330 0.775 P330 0.69 10.11 8.597 4.60 6.33 1 0.01 --------~----l>-----+----··-18 29.50 0.85 330 0.617 -0.69 10 8.635 3.68 4.62 6 0.11 The Barracks Subdivision -Phase 2 Storm Sewer Pipe Summary (100-yr Storm) Pipe Pipe Length Slope Contributing Contributing Size Area Contributing Pipes c Tc 1100 Q100 v Travel Time No. Drainage Areas (In) (ft) ("!.) (Acres) (min) (In/hr) (cfs) (fps) (sec) (min) Channel 1 67.62 0.25 All Areas 10.458 All Pipes 0.69 12.46 10.600 76.49 6.16 11 0.18 110 36 96.00 0.25 5.35 18 120, 121 , 122, 131, 140A, 1409, 8.258 P120,P121 ,P122,P123,P131,P14 0.69 12.06 10.754 61 .27 0.30 140C,141,142, 143,144, 145 O,P141A,P142,P143,P144,P145 120 36 20.35 0.25 7.195 P123,P131,P140,P141A,P142, 0.69 12.02 10.770 53.47 7.89 3 0.04 120, 131 , 140A, 140B,140C, 141, 14 ----- 2, 143, 144, 145 P143,P144,P145 ·---- 24 145.38 0.51 121 ,122 1.063 P122 0.69 10.23 11 .530 8.46 5.20 28 0.47 24 80.00 0.69 122 0.966 -0.69 10 11 .639 7.76 5.70 14 0.23 ·- 123 36 77.74 0.20 6.787 P131 ,P140,P141A,P 142,P143, 0.69 11 .86 10.832 50.73 8.33 9 0.16 131 , 140A,140B, 140C, 141, 142, 14 - 3,144,145 P144,P145 - 131 36 31.00 0.20 131, 140C, 141 ,142, 143, 144, 145 6.046 P140,P141A,P142,P143,P144, 0.69 11.79 10.859 45.30 7.60 4 0.07 ------~-- P145 ~-- 140 36 289.50 0.43 140C, 141, 142, 143,144, 145 5.358 P141A,P142,P143,P144,P145 0.69 11.03 11.175 41.32 6.32 46 0.76 -.. 1418 18 40.00 0.80 140C 0.620 -0.69 10.10 11.594 4.96 5.39 7 0.12 141A 18 31 .00 0.80 140C 0.620 P141A 0.69 10 11.639 4.98 5.39 6 0.10 --- 30 96.50 0.46 142.143,144,145 4.084 P143,P144,P145 0.69 10.78 11.285 31 .80 6.36 15 0.25 30 125.50 0.40 143, 144, 145 3.098 P144,P145 0.69 10.43 11.440 24.45 6.02 21 0.35 -·-- 24 42.00 0.82 144,145 1.946 P145 0.69 10.33 11.484 15.42 7.16 6 0.10 18 109.50 0.70 145 0.839 -0.69 10 11.639 6.74 5.48 20 0.33 - Channel 2 256.51 0.30 210,220,320,330 2.200 P21 O,P220,P230,P31 O,P320,P330 0.69 11 .25 11.084 16.83 4.23 61 ---- 210 2-24 24.00 0.30 210,220,320,330 2.200 P220,P230,P31 O,P320,P330 0.69 11 .15 11.124 16.89 4.23 6 0.09 220 2-24 42.00 0.30 220,320,330 1.441 P230,P310,P320,P330 0.69 10.97 11 .202 11.14 3.84 11 0.18 230 24 119.50 0.30 320,330 0.775 P310,P320,P330 0.69 10.46 11 .426 6.11 3.93 30 0.51 24 113.19 0.65 320,330 0.775 P320,P330 0.69 10.10 11 .591 6.20 5.25 22 0.36 -· ------ 18 5.50 1.30 320,330 0.775 P330 0.69 10.09 11 .597 6.20 6.84 1 0.01 18 29.50 0.85 330 0.617 -0.69 10 11 .639 4.96 5.51 5 0.09 The Barracks Subdivision (July 8, 2009) Stonn Sewer Pipe Design Analysis (10 yr Stonn) Pipe Pipe Size Length Slope Surcharved No. Q10 V1D HGl1D Cini cn1 1%1 ... "'" Slope Oownstre8"1 Top Pipe HGl1D Slnlc1uN Elev. Fl Elev. Slnlc1uN Channel 1 67.152 0.25 5e.85 5.02 Dti•1.38 302.20 303.59 110 1·38 118.00 0.25 •5.28 U1 o.•0% Chonnol 1 302.83 305.83 JB 110 120 1·38 20.20 0.25 39.5 5.59 0.31% JB 110 308.50 303.00 308.05 ~ -·iol<,121"'-" 24 145.38 0.51 627 JB 110 308.50 303.49 1121 ~122:""" 24 80.00 0.69 5.78 1121 309.54 304.33 1122 123 1-38 77.llO 0.20 37"8 5.31 0.27% 1120 30823 30322 306.U Iii) -131 1-38 31.00 0.20 33.<8 •. 7' 025% 1130 308.16 303.51 306.39 1131 ,_ 140 1·38 289.50 0.43 30.57 4.33 0.19% 1131 308.18 303.73 306.50 1141 -1416 18 •o.oo 0.80 3.88 2.78 0.2•11 1141 310.20 308.06 307.14 JB 145 --141A 18 31.00 0.80 3.89 2.79 0.27% JB 145 310.65 306.48 307.23 1140 '5"1-·142#'; 30 94.00 0.46 23.53 1141 310.20 305.07 ~ ';!'._·_;143~., 30 125.50 0.40 18.11 JB 311.33 305.61 1143 o.82 ---·-;'..fl;-1.~:;;..~ 24 42.00 __jj.:!L ----1143 310.82 306.59 -114' -~ 18 109.50 0.70 5.00 1144 310.79 307.43 JB ·-Channel 2 25e.50 0.30 12.47 3.80 Dn•0.96' 302.37 30323 -- 210 2·24 24.00 0.30 1---1!£_ ~ 0.15% -Channel 2 303.34 305.34 -~ -220 2·2• 42.00 0.30 ~ _.UL 0.08% 1210 307.55 303.46 305.39 l220 _EQ_ 24 119.50 0.30 4.52 1.92 0.08% l220 307.55 303.84 305.42 JB 305 I~ ---~~310~i",; 2• 113.19 0.65 ~-307.20 304.05 JB 310 ------*tlio.~":~ 18 5.50 1.30 ~ ---JB 310 308.98 30529 ,._..__ 1320 ,~,330 -18 29.50 o.85 308.48 1320 309.03 305.48 ,___ Notes: 1. Losses for 1s· pipe are computed IS for 1 15.6" pipe (25% reduction in area) and losses for a 24" pipe are computed as for a 20.6" pipe (25% reduction in area). 2. Channel 1 is concrete-lined with 6' BW. 1.5:1 SS. 2.5' D, 0.25% slope & 67.6 LF long. 2. Channel 2 is concrete-lined with 2.5' BW. 1.5:1 SS. 2.0' D. 0.30% slope & 256.5 LF long. Ups tr.am Upstn:am Strvctu,. Top Pipe HGl1D Minor Loss -HGUD Elev. Fl Etev. Slnlmn. Coeff. LoH Elev. 302.37 303.78 308.50 302.87 308.01 JB 110 0.25 0.04 308.05 308.23 303.05 308.11 1120 0.50 0.02 -305.14 309.54 30423 1121 308.82 304.75 1122 308.18 303.38 308.35 1130 0.50 0.04 308.39 -308.18 303.57 308.'7 1131 0.50 0.03 308.50 310.20 304.97 307.05 1141 0.50 0.09 307.14 310.85 308.38 30723 JB 145 0.50 0.00 30723 310.57 308.73 307.31 1140 1.25 0.15 307"7 311.33 305.50 JB 310.82 306.09 1143 -310.70 306.93 1144 ·- 312.49 308.20 JB 303.14 304.00 307.55 303.41 305.38 1210 025 0.02 -305.39 307.55 303.59 305.42 1220 0.50 0.00 . 305.42 307.20 304.00 305.51 JB 305 12 5 0.07 305.58 308.98 304.79 JB 310 309.03 305.38 ~ -------- 1330 ,._..__ ,_______ The Barracks Subdivision (July 8, 2009) Stonn Sewer Pipe Design Analysis (100 yr Stonn) Plpo Pipe SIH Length Slopo No. (In) {fl) (%) Sun:hafll•d Q100 VtOO HGL100 ch fpl Slooo Oownanam Top Plpo HGLtOO Structure E .. Y. FL e .. v. Structure Chann8' 1 67.62 0.25 78.49 5.49 On•1.65' 302.20 303.85 110 1-36 96.00 0.25 61.27 8.87 0.72% Ch1nne11 302.41 305.41 JB 110 120 1-36 20.20 0.25 53.47 7.57 0.54% JB 110 308.50 302.75 306,17 1120 '"312.ti;;> 24 145.38 0.51 8.46 JB 110 308.50 303.49 1121 ~i"if22""0' 24 80.00 0.69 7.76 1121 309.54 304,33 1122 123 1·36 77.90 0.20 50.73 7.18 0.53% 1120 308.23 302,90 306.32 1130 131 1-36 31.00 0.20 45.3 6.41 0.46% 1130 308.16 303.16 306.82 1131 140 1·36 289.50 0.43 ~ _lli_ 0.34% 1131 308.18 303.32 307.01 1141 1418 18 40,00 0.80 4.96 3.74 0.45% 1141 31020 306,06 308.16 JB 145 141A 18 31.00 0,80 4.98 3.76 0.50% JB 145 310.65 306,48 308.33 1140 ~ t42·"1)! 30 94,00 -~ 31.8 1141 310.20 305.07 JB ·,",:,1'43 i1!> 30 125.50 0.40 24.45 JB 311 .33 305.61 1143 --~.Q ... ~: 24 42.00 0.82 -15.42 1143 310.82 306.59 --1144 ~HS';;>_ 18 109.50 0,70 6.74 1144 310.79 307.43 JB ~ 256.50 0.30 16.89 4.12 On•1.02' 302.37 303.39 ---2.!.Q.._ ~~-24.00 0.30 16.89 3.59 0.26% Channef 2 303.34 305.34 1210 ---220 2·24 42.00 0.30 ~ .--lE__ 0.13% 1210 307.55 -~ 305"3 ~ --230 24 119.50 0,30 6.11 2.59 0.14% 1220 307.55 303,64 305,48 JB 305 -·----..-~·3·10 '1!1! 24 113.19 0.65 6,2 JB 305 307.20 304.05 JB 310 ------- >i"320~f 18 5,50 1.30 -----6.20 JB 310 308.98 305.29 1320 ·"J,.,,..;330tf';l' 18 29.50 0.85 3oe.46 --1320 309.03 305.46 Notes: 1. Losses for 18" pipe are computed as for a 15.6" pipe (25% reduction in area) and losses for a 24" pipe are computed as for a 20.6" pipe (25% reduction in area). 2. Channel 1 is concrete~ined with 6' BW. 1.5:1 SS. 2.5' D. 0.25% slope & 67.6 LF long. 2. Channel 2 is conaete~ined with 2.5' BW, 1.5:1 SS. 2.0' D. 0.30% slope & 256.5 LF long. Upanam Up-mSltvcturo Top Plpo HGL100 Minor LOH Minor HGLtOO Etev. FL ei.v. Structure Coofl. Losa ei.v. 302.37 304.02 308.50 302.85 308,10 JB 110 0.25 0.07 308.17 308.23 302.8 306.28 1120 0.50 0.04 306.32 309.54 304.23 1121 ·- 308.82 304.75 1122 308.18 303.06 306.74 1130 0.50 0.08 306.82 308.16 303.22 308.96 1131 0.50 0.05 307.01 310.20 304.56 308.00 1141 0.50 0.16 308.16 310.65 306.38 308.34 JB 145 0.50 0.00 308.33 -~~ 306.73 308.49 1140 1.25 0.27 308.76 311.33 305.50 JB ·-310.82 308.09 1143 310.79 308.93 1144 ------312.49 308.20 JB -303. 14 304.16 307.55 303.41 305.40 1210 0.25 0.03 305.43 - ....1QUL 303.59 305.49 1220 0.50 -0.01 305.48 307.20 304.00 305.64 JB 305 1.25 0.13 305.77 --308.98 304.79 JB 310 --309.03 305.36 -~-. 1330 GENERAL Emergency Outfall: Spillway Length: Side slopes: Spillway Elev.: Top of Berm Elev.: Cross slope: Manning 's n: CONCLUSION Addendum No. 2 to Drainage Report The Barracks Subdivision -Phase 2 August, 2009 This addendum is issued to address proposed changes to the existing detention pond at the Barracks Subdivision The detention pond was constructed larger than the original design in order to provide additional fill for the streets and building lots in Phase I. However, the pond side slopes are steeper than the original design and the surface material is hard clay which has not become vegetated. As part of Phase 2, it is proposed to place fill material in the pond to reduce the steepness of the side slopes and improve soil characteristics so that vegetation can be established. The proposed side slopes of the pond will now be 3.5H: IV. The proposed grading modifications are shown on Sheet 6 of the construction drawings. The proposed grading will also eliminate the permanent pool of water in the pond. The volume of the pond will be greater than the original design since the original design had the pond side slopes at 4H: IV. An as-built certificaction of the pond will be provided once the modifications are complete. The emergency spillway for the pond will be modified to conform to its original design. The dimensions of the spillway are as follows. JOO ft. 8H: IV (approximate) 312.4ft 313.4ft 0.50% 0.025 (short grass) The detention pond in The Barracks Subdivision as currently proposed to be modified will function as originally designed. Page I of I Addendum to Drainage Report for The Barracks Subdivision Phase 2 College Station, Texas July, 2009 Engineer: HARLE ENGINEERING COMPANY TBPE Firm Registration No. 4538 P.O. Box 11587 College Station, TX 77842 3002 Texas Avenue South College Station, Texas 77845 (979) 693-7191 Developer: Greens Prairie Investors, Ltd . 4490 Castlegate Drive College Station , Texas 77845 (979) 690-7250 ... GENERAL Emergency Outfall: Spillway Length: Side slopes: Spillway Elev.: Top of Berm Elev.: Cross slope: Manning's n: Addendum to Drainage Report The Barracks Subdivision Phase 2 July, 2009 This addendum is issued to address proposed changes to the existing detention pond at the Barracks Subdivision The detention pond was constructed larger than the original design in order to provide additional fill for the streets and building lots in Phase I. However, the pond side slopes are steeper than the original design and the surface material is hard clay which has not become vegetated. As part of Phase 2, it is proposed to place fill material in the pond to reduce the steepness of the side slopes and improve soil characteristics so that vegetation can be established. The proposed grading modifications are shown on Sheet 6 of the construction drawings. The contours of this plan were used to determine storage volumes for input into HEC-HMS. The information in this addendum is provided to demonstrate that the pond functions as intended with these modifications. An as-built drawing of the pond will be provided once the modifications are complete. The as-built volume of the pond will be input into the HEC-HMS model. The emergency spillway for the pond will be modified to conform to its original design. The dimensions of the spillway are as follows. 100 ft. 8H: 1 V (approximate) 312.4ft 313.4ft 0.50% 0.025 (short grass) HEC-HMS Analysis Summary CONCLUSION Condition 2 yr 10 yr cfs cfs Pre-Dev. 55.3 114.4 .P?st-Dev: 52.9 110.0 _0..!:.l.Sm~L desi_g.!!) _____ .... ,_, _ Post-Dev. 51. l 103.4 ro osed Pond WSEL (as built) 309.6 310.7 144.8 180.5 I 210.2 1 137.4 166.~+--~4 ·~--·---i 137.4 161.5 182.3 I II 311.0 ! 311.6 312.2 312.8 I I Emergency Spillway Elev.= 312. 4 ft Top of Berm Elevation = 313. 4 ft Available Freeboard = 0.6 ft. The detention pond in The Barracks Subdivision as currently proposed to be modified will function as originally designed and the project will be in complicance with the B/CS Unified Desgin Guidelines. Page 1 of I ENGINEER The Barracks Subdivision, Phase 2 Drainage Report -Executive Summary HARLE ENGINEERING COMPANY P.O. Box 11587 College Station, Texas 77842 Phone/Fax: .(979) 693-7191 OWNER/DEVELOPER Greens Prairie Investors, LLC 4490 Castlegate Drive College Station, Texas 77845 Phone: (979) 690-7250 GENERAL DESCRIPTION AND LOCATION Location: Description: •Area: • Proposed Land Use: • #of Lots: • Existing Land Use : • Land Description: Adjoining Land Use : Primary Drainage Facility: Flood Hazard Information: FEMAFIRM: Floodplain: The Barracks Subdivision, Phase 2, is located on the north side of Rock Prairie Road West near its intersection with FM 2154 and is adjacent to Phase 1 of the Subdivision. 5.012 acres R3-Townhouse Residential 50 lots Vacant -previously used for an aquaculture facility Relatively flat ground that slopes toward the north west. The site is bounded on the north and east by undeveloped property, on the west by the Williamsgate Subdivision and on the south by Phase 1. Bee Creek tributary # 48041C0182 C No portion of this Phase lies within the floodplain of Bee Creek or its tributaries. HYDROLOGIC CHARACTERISTICS A portion of this site was previously used as an aquaculture facility and had numerous ponds on the site. These ponds were removed in Phase 1 and now the storm sewer pipes from Phase 1 discharge into ditches which carry the runoff to the northwest corner of the site. The runoff then enters an existing drainage on the adjacent tract which flows to a tributary of Bee Creek. This existing drainage was modified with the Phase 1 construction to provide additional depth for the storm sewer system and detention pond outfall pipes. GENERALSTORMWATERPLAN The drainage plan for this development will involve the installation of extensions of existing pipes and additional storm sewer pipes and inlets, which, along with the existing storm sewer systems, will collect and transmit the runoff into the existing drainage which flows across the adjacent tracts and eventually into Bee Creek. The detention pond for this proposed development was constructed with Phase 1 of this Subdivision and is located such that the storm sewer system discharge does not go through the pond. The detention pond analysis is provided in the Phase l Drainage Report. Page 1 of3 COORDINATION & STORMWATERPERMITTING The project will require that a Notice of Intent be submitted to the Texas Commission for Environmental Quality. No other permits are anticipated for this project. DRAINAGE DESIGN General Information: Street Design: Tc Methodology: Tc Minimum Design Storm Event: Pipe Materials: Manning's n Value: Runoff Coefficients: Design Constraints: Design Software: Stormwater runoff from Phase 1 & 2 of the subdivision will be collected by three storm sewer drainage systems within the development, a portion of which were constructed with Phase 1 of the Subdivision. Two of the three storm sewer systems converge near the intersection of Sergeant Drive and Lieutenant A venue. The two remaining storm sewer pipe systems discharge into a concrete channel at the northwest comer of the project and the runoff then enters the adjacent property in the modified drainage channel as designed in Phase 1. Standard cross-section (3% cross-slope, 27' B-B residential) with laydown curb & gutter on residential streets Standard cross-ection (3% cross-slope, 38 ' B-B minor-collector) with standard 6" curb & gutter on the minor collector street Asphalt pavement Standard recessed curb inlets (length varies) TR55 10 minutes 10-year -residential & collector street & storm sewer RCP, profile gasket or Corrugated HDPE w/smooth interior 0.013 0.69 for developed townhome lots Max. water depth in curb = 4.0 in. or 0.33 ft. -Residential Street Max. water depth in curb= 4.5 in . or 0.38 ft. -Minor Collector Street Min. flow velocity = 2.5 fps Max. flow velocity = 15 fps 100-yr storm runoff maintained within the ROW ( 4 inches above curb) Excel spreadsheets, DODSON HydraCalc Hydraulics This software was used to computes pipe capacity, tlowrate and velocity through each pipe, and determine hydraulic grade line elevations at each inlet or junction box. All of this information is shown in the summary tables in Appendix E. The College Station requirement for a 25% reduction in cross-sectional area of pipes less than 27" diameter is achieved by using internal pipe diameters that are less than the standard diameter. The 24" diameter pipe areas were reduced by 25% and a 20 .6" diameter pipe used in the analysis and the 18' diameter pipe areas were reduced by 25% and a 15 .6" diameter pipe was in the analysis. Page 2 of3 Design Results Applicable Exhibits: DETENTION DESIGN General: CONCLUSION CERTIFICATION The data presented in the Appendices indicates the gutter depth, inlet sizing and pipe sizes are in accordance with the requirements of the design guidelines. Exhibit A -Drainage Area Map Appendix A -Technical Design Summary Appendix B -Drainage Area Calculations Appendix C -Depth of Flow in Gutter Appendix D -Inlet Design Summary Appendix E -Pipe Design Summary The detention pond for The Barracks Subdivision was designed and constructed with Phase 1 of the Subdivision. No additional detention facilities are proposed with the development of Phase 2 this project. Based on the concurrence with the previous design assumptions and calculations used in Phase 1 and the design calculations prepared for the Phase 2 design, the drainage system in Phase 2 of the The Barracks Subdivision will function within the requirements and restrictions of the College Station Drainage Policy and Design Standards. I, Joseph P. Schultz, Licensed Professional Engineer No. 65889, State of Texas, certify that this report for the drainage design for The Barracks Subdivision, Phase2, was prepared by me in accordance with the provisions of the Unified Stormwater Design Guidelines. Page 3 of3 EXHIBIT A Drainage Area Map "'"' ... ., ... ,.,,. e I.XS THE BARRACKS SUBDIVISION PHASE 2 COLLEGE STATION, TEXAS 120 SCALE IN FEET '141A IUTI.-~-.:----------------------------,, ·-~ DETENTION POND HARLE ENGINEERING COMPANY nus .a.&D CW PltOnlSIONAL JDIGIND&I r1D1 DGJl'DAnoJrf NO. '6ae ._ DUS 4'fl!llW 801ml COU-. llr4110ll, DUS T7N6 171.181.7111 DRAINAGE AREA MAP EXHIBIT A APPENDIX A Technical Design Summary SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Start (Page 2.1) ' Engineering and Design Professionals Information ..•. Engineering Firm Name and Address: Jurisdiction City: Bryan \-\. Gtle. G"s·' .... -e.,,.;~ :i c..,h.fG.h/ p,o . e~~ 11581 V College Station Coll.!)~ )<\-o-\.',~1 7-.J.. 7784z.. Date ~ubmi~I: 'l P...fc Z..oti Lead Engineer's Name and Contact lnfo.(phone, e-mail, fax): Other: J-useo~' SckJtz 613~71'1{ )c c_Sc kv..l+z 84 e_ V<." n i.-... "c.-f Suppoi'ting Engineering I Consulting'"l=irm(s): Other contacts: L; .,,,; l Oc v-<I~~) U-d . ~ ·r..+-L n ° L fr.q,:M <"J .hr Pl--.c(( 1~0.04-e .. :\-,'," ('l,J) 7t.1-774 ~ ~. . ~ Developed Owner I Applicant Information , .•. ' Developer I Applicant Name and Address: Phone and e-mail: ~re.~.S Dn~r ;<. -:fnvfS·tir.s', L+J . b 1u -7 2-JO 1.J.J c \j 6tt>.pk.'ll.f /@_ VC.-c~, .... i'\ef Property Owner(s) if not Developer I Applicant (&address): Phone and e-mail: I ~ ';t '" ·~· ... ·Project Identification ,. -.·1,; .. :: ., • . ' "'I ,,, Development Name: {k 61-rnuk f ] .... bJ :11:r: •. ,. -fk&u z.. Is subject property a site project, a single-phase subdivision, or part of a multi-phase subdivision? Vh. J+; -0 \,..,,E' I If multi-phase, subject property is phase L of "l_ Legal description of subject property (phase) or Project Area: (see Section II , Paragraph B-3a) ero-N-h rt.l (Jurn.Jl Le&f"'-t A-7 ).ei1'2... C\Crr S C>f ~ I If subject property (phase) is second or later phase of a project, describe general status of all earlier phases. For most recent earlier phase Include submittal and review dates. QhoJt 1. ~'fl .. ~J ~ " 0fV'~""I Z.o~<l ~V.bW\.' 14J ' f cl\ C U.1VV\.-\-~ -h /" Ph ,1e 1 r f v.r>-.Y>t-t..r Zoo~ w e S ( "' General Location of Project Area, or subject property (phase): e_1)c_-tc Q 1 I ((l1 {i f' (2...1)(,J w~t+--lv-eJit-"F FM zrs-1- In City Limits? Bryan : acres. College Station: 5'. Cl I Z.. acres. STORMWATER DESIGN GUIDELINES Effective February 2007 Extraterritorial Jurisdiction (acreage): Bryan: College Station: Acreage Outside ET J: Page 3 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Continued (page 2.2) ~ Project Identification (continued) ·".&'l ,f. Roadways abutting or within Project Area or Abutting tracts, platted land, or built subject property: developments: J IA l:, d :v.'f ,~ ._, ~ rO k _f G e Y\. "-./ c \ Po1lc vvf.·1 w :1 l:a~r31-1-e Named Regulatory Watercourse(s) & Watershed(s): Tributary Basin(s): Nol'°' At 6c-c~ C re.:: le '',;:,j~}f · .Plat lnformatio,n~For Project 9r Subjec.t P.roperty ·(or Phase)· ' " .. '5 ~ -~" &' ~· """' Preliminary Plat File#: B ~ foo 15'1 Final Plat File#: Date: Name: \he G~n c-'t ~ Status and Vol/Pg: Pe>v--Jt"' 5 If two plats, second name: File#: Status: Date: "',,,... . . ;~ ,. :,'"'-~~ .. , .. ,... Z9ning tnformati9ri For Project or ~ubject Property for Phase) .;,_;o;; Zoning Type: ~-) Existing or Proposed? Case Code: . Case Date Status: Zoning Type: Existing or Proposed? Case Code: Case Date Status: . Stormwater Management Pianning For Project or Subject Property (or Phase) Planning Conference(s) & Date(s): Participants: (J~;(fyc f p,,./"'S -f .( .. ,..,. .. , W\<:.,... LDC~ J OC' 5<' h-Hz / l}Ja U on 14 .... t-Ln f( c_~J, [~ff Preliminary Report Required? N o Submittal Date Review Date Review Comments Addressed? Yes --No --In Writing? When? Compliance With Preliminary Drainage Report. Briefly describe (or attach documentation explaining) any deviation(s) from provisions of Preliminary Drainage Report, if any. ?J/ A-I STORMWATER DESIGN GUIDELINES Effective February 2007 Page 4 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration l Continued (page 2.3) t "• . .. . ·< Coorpination For Project or Subject Property (or ~ha~e) ~ ·'" "''· " t' :"' ' . . Note: For any Coordination of stormwater matters indicated below, attach documentation describing and substantiating any agreements, understandings, contracts, or approvals. Coordination Deot. Contact: Date: Subiect: With Other - Departments of Jurisdiction City (Bryan or College Station) Coordination With Summarize need(s) & actions taken (include contacts & dates): Non-jurisdiction City Needed? V Yes __ No __ Coordination with Summarize need(s) & actions taken (include contacts & dates): Brazos County Needed? v Yes No ---- Coordination with Summarize need(s) & actions taken (include contacts & dates): TxDOT Needed~ Yes __ No __ Coordination with Summarize need(s) & actions taken (include contacts & dates): TAMUS Needed? Yes No v ---- ,.,_ ~,fc',. ;~),, ..f . ~ ,•.~· , • , :-.. '<. ~z . ,,. ~; ~' <t ;· .,\~~ ·';-:"4>~ """ '""'.F"" -~·;;;· : \~ ,~,P~rmits For'Project~or .~c~bj_e"!=t Property (or Ph~s~). .' :_,,;;· '· '. ~--·.,.::.·~:~·~~;, ~-" As to stormwater management, are permits required for the proposed work from any of the entities listed below? If so, summarize status of efforts toward that obiective in soaces below. Entity Permitted or Status of Actions (include dates) Approved? US Army Crops of Engineers No v Yes --- US Environmental Protection Agency No /Yes_ Texas Commission on G,c""...r .. ( Environmental Quality he. f /f,J 07 {0 .__irc~ .p . + r-JD~ fo v e_r,,...... No --Yes --( S'c cD o Brazos River Authority No V Yes - STORMWATER DESIGN GUIDELINES Effective February 2007 Page 5 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Start (Page 3.1) Nature and Scope.of Pr9posed Work ·. , . · '., · ., Existing: Land proposed for development currently used, including extent of impervious cover? \)at:..tir.. +:-,,. fJo ('.-.pvt1 lo ... s Site Development Project (select all applicable) Subdivision Development Project __ Redevelopment of one platted lot, or two or more adjoining platted lots. __ Building on a single platted lot of undeveloped land. __ Building on two or more platted adjoining lots of undeveloped land. __ Building on a single lot, or adjoining lots, where proposed plat will not form a new street (but may include ROW dedication to existing streetL v Other (explain): (J ,.../--( -r SA-e. .,.....,.J fJre<J.'o~ •171r o./e.J . __ o. • O I} "'-°' c~ '\"r <.. __ Construction of streets and utilities to serve one or more platted lots. ~ Construction of streets and utilities to serve one or more proposed lots on lands represented by pending plats. Describe Nature and Size of Proposed Project Site projects: building use(s), approximate floor space, impervious cover ratio. Subdivisions: number of lots by general type of use, linear feet of streets and drainage easements or ROW. 5' o P--3 y.,. "''" h\\.,,...( [ ,.t 5 f2.ol>.J~ 'fo~' Is any work planned on land that is not platted If yes, explain : or o~d for which platting is not pending? __ No __ Yes Is any part of subject property abutting a Named Regulatory Watercourse v (Section II, Paragraph B1) or a tributary thereof? No --Yes Is any part of subject property in floodplain area of a FEMA-regulated watercourse? No Yes Rate Map ____ _ Encroachment(s) into Floodplain areas~d? No __ Encroachment purpose(s): __ Building site(s) __ Road crossing(s) __ Utility crossing(s) __ Other (explain): Yes If floodplain areas not shown on Rate Maps, has work been done toward amending the FEMA- approved Flood Study to define allowable encroachments in proposed areas? Explain. rv If.\- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 6 of 26 APPENDIX. D: TECH . DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Pro[!ertv Characteristics I Continued (Page 3.2) Hydrologic Attributes of Subject Property (or Phase} Has an earlier hydrologic analysis been done for larger area including subject property? y~y Reference the :-(lu~ (&date) here, and attach copy if not already in City files. 0 es:~.,.._ C) ifc,,""' f<vv--v fl1¥-vv-. w-J ~+ ).-...-pecw J wd · c) ~~ "": (--\,._ (Jl·v1 ' 1 . J.,. l1 Zoo~) Is the stormwater ma~ plan for the property in substantial conformance with the earlier study? Yes No If not, explain how it differs . .. No If subject property is not part of multi-phase project, describe stormwater management plan for the property in Part 4. --If property is part of multi-phase project, provide overview of stormwater management plan for Project Area here. In Part 4 describe how plan for subject property will comply therewith. / Do existing topographic features on subject property store or detain runoff? _L No --Yes Describe them (include aploximate size, volume, outfall, model, etc). r ~ T~ p~~ ~ ""' ;c.\.-c:..>1--:tt<J t'l'-" ~ s:·~ W"t.J......_ ~Mo\I<) ""' Uv-..s.\-~ of Pl---cu j_ f .a..r ~ f h~H j_ plc.--. / Any known drainage or flooding problems in areas near subject property? ~ No Yes --Identify: Based on location of study property in a watershed, is Type 1 Detention (flood control) needed? :21e B-1 in Appendix B) etention is required. Need must be evaluated. __ Detention not required . -- What decision has been reached? By whom? If the need for D~~..;\-~ f'!!:f~\~Jr J .'fo-JfeJ IA-pre lP-~ """-c:e.f...<-. J J Type 1 Detention How was determinatl'On made? must be evaluated: O~e ..ra (,~ ~~tli..4.5 p,,-~ .-W .. ,...-J-~J ,.f-1 {,..J : ~ ef'.-l;h; f'r-J r f'€t"' :r•) ~ Lt~ c..... &J S· . .,.i'er STORMWATER DESIGN GUIDELINES Effective February 2007 Page 7 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Pro12ertv Characteristics I Continued (Page 3.3) Hydrologic Attributes of Subject Property (or Ph!!se) (continued), Does subject property straddle a Watershed or Basin divide? ~No __ Yes If yes, describe splits below. In Part 4 describe desiQn concept for handling this. Watershed or Basin Larger acreage Lesser acreage Above-Project Areas(Section II, Paragraph 83-a) i - Does Project Area (project or phase) receive runoff from upland areas? __ No V Yes Size(s) ofarea(s) in acres: 1) jO 2) 3) 4) Flow Characteristics (each instance) (overland sheet, shallow concentrated, recognizable concentrated sec~(s), small creek (non-regulatory), regulatory Watercourse or tributary); f<_ul'\b.µ_ A"" f2e c¢..__ Pro.'.rL.. ~J lJ\Jt:;f-.-.) e,.._.f!'L-l ~f>f-/e•-' 0f '1 ~ en..~ I° ~) ft;:,,~LJ-.$ ~-k ~""' c.._ C.i, '1-<._+ 1A..-J..>./ ~~ Pro·~~~ Flow determination: Outline hydrologic methods and assumptions: )-e (_ (J [,._. 5' ( 1_ r(_ (J (J~ +- Does storm run~ drain from public easements or ROW onto or across subject property? __ No __ Yes If yes, describe facilities in easement or ROW: (._., \ \f'Vt 11'-''Jv (L,J-r. Prat,.;~ ~ Are changes in runoff characteristics subject to change in future? Explain U--f6.f.n<Y'(\. ~f A.....-'1 f'~ 'J e,.,..( j ~ e 5', ~ ~:f prt>;wt, • ~ /c..~"'O .Cf t '"if~•Je Conveyance Pathways (Section II, Paragraph C2) Must runoff from study property drain across lowe~perties before reaching a Regulatory Watercourse or tributary? No Yes Describe length and characteristics of each conveyance pathway(s). Include ownership of property( ies). ff ~ H.&>.oJfJ-\'r~J--Bc-r5~ (red-J TJ.-.<<"'""~ c:J05fef I , ~}v./ 51> b u II\ : .r-v-r:,, Ft-r..~ J d....ui'(_,~ o V\. c~.... (. b<O'v<'-GV'. A-~J , . J . +-r:J .._~4/ J f-1...t V\ ;_'-';) .~ t-\ 5 'lt il-t-\tv''":I \.,_ ei{_-J.f-J ~ ~~lr.,,J ~ J;:-M <.tS'4 /2DW vr~ ~+ ... ~r "+,-11 .~ 6-f-/) ee c_,.J-z: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 8 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Property Characteristics I Continued (Page 3.4) .. : Hydrologic Attribu~es of Subject'Property1(or Phase) (co!1tinued) :. >':· ., Conveyance Pathways (continued) Do drainage If yes, for what part of length? % Created by? __ plat, or easements __ instrument. If instrument(s), describe their provisions. exist for any part of · path~ay(s)? _V_INo __ Yes Wher~unoff must cross lower properties, describ'e characteristics of abutting lower prope((ies). (Existing watercourses? Easement or Consent aquired?) !; . .,. +tth k, e¥.-l1<f-1 "'"''' .-rt._ f"f .kl-.. Pathway Areas Nearby Describe any built or improved drainage facilities existing near the property (culverts, bridges, lined channels, buried conduit, swales, detention ponds, etc). ( 4 fr ;..;-~ ro ,.) ~ 15 .,_) o..... 4-\..t... H G'ft-+r,....J- W c J \A"l)J-~-f1<_) tAJ f ,.,-\~ of f\.q_.. ~ ~f' (JJ--c~e 1 . Drainage t--------------------------------< Facilities Do any of thes!Yflave hydrologic or hydraulic influence on proposed stormwater design? _v_ ~No __ Yes If yes, explain : STORMWATER DESIGN GUIDELINES Effective February 2007 Page 9 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters I Start (Page 4.1) "< ~. Stormwater ·Management Concept . . . ,,,~'." z~ Discharge(s) From Upland Area(s) If runoff is to be received from upland areas, what design drainage features will be used to accommodate it and insure it is not blocked by future development? Describe for each area, flow section , or discharge point. -r~ °' 1+,~.,""' on.°' fC,\AJ r : ~ ~ O~~t~ A~J f . /)I j L f4..tv ~ P"u~ .1.. r'f•A-~r d.J-.ll1) ~"'-~ l~ "": ~ I r...rJ < . Discharge(s) To Low~r Property(ies) (Section II, Paragraph E1) Does project inc.16de drainagP features (existing or future) proposed to become public via platting? V No Yes Separate Instrument? No Yes Per Guidelines reference above, how will runoff be discharged to neighboring property(ies)? ~tablishing Easements (Scenario 1) -V-__ P Prr•e-development Release (Scenario 2) __ Combination of the two Scenarios Scenario 1: If easements are proposed, describe where needed, and provide status of actions on each. (Attached Exhibit# l Scenario 2: Provide general description of how release(s) will be managed to pre-development conditions (detention, sheet flow, partially concentrated, etc} (Attached Exhibit# ) Combination: If combination is proposed, explain how discharge will differ from pre- development conditions at the property line for each area (or point) of release. If Scenario 2, or Combination are to be used , has proposed design been coordinated with owner(s) of receiving property(ies)? No __ Yes Explain and provide documentation. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 10 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.2) Stormwater Management Concept (continued) .,,. •, ~ Within Project Area Of Multi-Phase Project Identify gaining Basins or Watersheds and acres shifting: Will project result in shifting runoff between Basins or between What design and mitigation is used to compensate for increased runoff Wa~eds? from gaining basin or watershed? __ No Yes --. ,,,.,,,...- How will runoff from Project 1. V With facility(ies) involving other development projects. Area be mitigated to pre-2. __ Establishing features to serve overall Project Area. development conditions? Select any or all of 1, 2, 3. __ On phase (or site) project basis within Project Area. and/or 3, and explain below. 1. Shared facility (type & location of facility; design drainage area served ; relationship to size of Project Area): (Attached Exhibit# ) 2. For Overall Project Area (type & location of facil ities): (Attached Exhibit# ) 5~e_ p"") (_ 1-kJ;5\)\ r<-p1v+ -PA.d e i ~~"' pei"'J 3. By phase (or site) project: Describe planned mitigation measures for phases (or sites) in subsequent questions of this Part. Are aquatic echosystems proposed? __ No --Yes In which phase(s) or project(s)? C'-· -c Q) en c: Q) Are other Best Management Practices for reducing stormwater pollutants proposed? ~ >- 0:: No VYes Summarize type of BMP and extent of use: en --c: s: !t ~ e_ I Cn"-5rf-/.t~ e-f--: + / IA 'tko ... J c ~ r~~cJ '-1 .Ql en Q) 0 Oz !Ji If design of any runoff-handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain in later questions. Q) --Detention elements --Conduit elements --Channel features I... <{ Swales Ditches Inlets __ Valley gutters __ Outfalls ------ --Culvert features __ Bridges Other STORMWATER DESIGN GUIDELINES Effective February 2007 Page 11 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised Februarv 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.3) ,. ~->' Stormwater Management Concept (continued) •.1 .. ; '·, .;,1· -: Within Project Area Of Multi-Phase Project (continuedv Will Project Area include bridge(s) or culvert(s)? ___y_ No __ Yes Identify type and general size and In which phase(s). If detention/retention serves (will serve) overall Project Area, describe how it relates to subject phase or site project (physical locat~onveyance pathway(s), construction sequence): ~ ~ 1,,_J . f-.L._ e~rro.Jq 0.,.1 olr«M l:Ju,..,._ eu""-fl-r... j .,, ... ~~ /)L~5( f · Within Or Serving Subject Property (Phase, or Site) If property part of larger Projec~a, is design in substantial conformance with earlier analysis and report for larger area? Yes No, then summarize the difference(s): Identify whether each of the types of drainage features listed below are included, extent of use, and general characteristics. Typical shape? I Surfaces? C'-· "O (I) (/) Steepest side slopes: Usual front slopes: Usual back slopes: (/) :J (I) (/) ~ (I) I .s=. Flow line slopes: least Typical distance from travelway: u ~ "O (Attached Exhibit# ) ir1 typical greatest Are longitudinal culvert ends in compliance with B-CS Standard Specifications? '-Yes No, then explain: <( (/) At i~sections or otherwise, do valley gutters cross arterial or collector streets? _Q ~ No __ Yes If yes explain: ~b I .s=. (I) ..... (/) ·~ ~ Are valley gutters proposed to cross any street away from an intersection? (/) (I) CD~ o ~No __ Yes Explain: (number of locations?) ~ OJZ u; "O I (I) c: .._ ro <( STORMWATER DESIGN GUIDELINES Effective February 2007 Page 12 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters I Continued (Page 4.4) Stormwater Managerr)ent Concept ,(continued) -.. Within Or Serving Subject Property (Phase, or Site) (continued) C'· -c Q) (/) ::J L.. Q) ~ ::J O> -c-c: -c ro Q) .0 ~ L.. ·-B "E 0 ..c: (.) ..... _ "§: C'· -c Q) (/) 111 (/) c: ·-0 ~z Gutter line slopes: Least 0.1 ~ cf-' Usual 0 .1 3°/... Greatest /. 3 •/ D Are inlets recessed on arterial and collector streets? VYes __ No If "no'', identify where and why. Will inlets capture 10-year de~stormflow to prevent flooding of intersections (arterial with arterial or collector)? __ Yes __ No If no, explain where and why not. Will inlet size and placement prevent exceed~llowable water spread for 10-year design storm throughout site (or phase)? __ Yes __ No If no, explain. Sag curves: Are inlets placed at low points? V Yes __ No Are inlets and co~ sized to prevent 100-year stormflow from ponding at greater than 24 inches? __ Yes __ No Explain "no" answers. Will 100-yr stormflow be contained ,K1 combination of ROW and buried conduit on whole length of all streets? __ V_ v Yes __ No If no, describe where and why. Do desefns for curb, gutter, and inlets comply with B-CS Technical Specifications? __ v_ Y Yes __ No If not, describe difference(s) and attach justification. Are any 12-inch laterals used? ~No used. __ Yes Identify length(s) and where ( Pipe runs between system I Typical l o u 1 Longest 1--q 0 access points (feet): ----'---- Are junction boxes used at each bend? v Yes and why. __ No If not, explain where -c ..... § I ~-------------------.-----------1 (/) Are dowl)Stream soffits at or below upstream soffits? Least amount that hydraulic ..!!! Yes _v_ No __ If not, explain where and why: grade line is below gutter line ,.--r /J (system-wide): J ci:-v-c .. ff-1"-<.rr :f-< lZ\ .... k.:cl.-vu1 ;f.-1 J '3 3 \)S Q,95 f.'1-=~ 0 -\~1 bc:lo-.1 P:('< /(O !1ff;~ Pi ~c. (lo~ ..... ,...;-~--< lov......,. J.N4• dC>.,_{.{,AJ C!lcv .. H .. -1 l'qy..f~rt~+s. ( k:; h,. s· loee .. , t-ih .~ ~~ 'tc,J :_"'\;) f-1. kf~.,, J rk 5.fu.r-rf~w-v STORMWATER DESIGN GUIDELINES Page 13 of26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce12t and Design Parameters I Continued (Page 4.5) Stormwater Management Concept (continued) . •" Jl Within Or Serving Subject Property (Phase, or Site) (continued) Ul Describe watercourse(s), or system(s) receiving system discharge(s) below Q) (include design discharge velocity, and angle between converging flow lines). () c: 1) Watercourse (or system), velocity, and angle? ro ...... c}.L> .r..5 ~(~ .,_) u,.,,_ f·/v-.J.. ~ J v. : k.. en Qv4-fc-\l.. ~ 5 6J-1 :v")< (_ h.G"'-"J. c: Q) VJ~<! -c. 1.-.:...J. ; ... .,. h-l.. J r. <-K ~ C-.c.~ rEpr, f .... -o ~ E 2) Watercourse (or system), velocity, and angle? ::J .... c: 0 ·--...... c: . 0 .E .. () c: -·-~ E w w E 3) Watercourse (or system), velocity, and angle? ...... ro ~ ~en en Ql ::J c: :g 0 ·-> ~ e "C a. E ...... For each outfall above, what measures are taken to prevent erosion or scour of .... Q) 0 Q) receiving and all facilities at juncture? ...... .s::: en en ~ch..~ ~ f!-;.tJnr Q) 1) iii .... ro a. 2) Q) en c: 3) .£. / Are swale(s) situated along property lines between properties? V No --Yes Number of instances: For each instance answer the following questions. Surface treatments (including low-flow flumes if any): C'-· en ...... Q) ~ en ...... Q) Flow line slopes (minimum and maximum): en >-c: ~ I "C ~!I Outfall characteristics for each (velocity, convergent angle, & end treatment). en Q) .... Will 100-year design storm runoff be contained within easement(s) or platted drainage <( ROW in all instances? --Yes --No If "no" explain: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 14 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters J Continued (Page 4.6) < ' 1 Stormwater Management Concept (continued) I \ > ~ T " "' Within Or Serving Subject Property (Phase, o~Site) (continued) (/) Are roadside ditches used? _jL'No __ Yes If so, provide the following : Q) Is 25-year flow contained with 6 inches of freeboard throughout? __ Yes --No £ u Are top of banks separated from road shoulders 2 feet or more? __ Yes No ..... --0 Are all ditch sections trapezoidal and at least 1.5 feet deep? Yes No Q) ----u For any "no" answers provide location(s) and explain: "iii u ro 0 a:: If conduit is beneath a swale, provide the following information (each instance). Instance 1 Describe general location, approximate length : (/) Q) Is 100-year design flow contained in conduit/swale combination? Yes No >-----I~ If "no" explain: c: Space for 100-year storm flow? ROW Easement Width \ 0 ro ..... z (/) Swale Surface type, minimum Conduit Type and size, minimum and maximum ~,~ and maximum slopes: slopes, design storm: 0 :+;:; C'· :0 (/) Q3 u Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): ro c: c: >. ro c: £ ro u ..... c: .E Q) c: Access Describe how maintenance access is provided (to swale, into conduit): a. 0 0 :+;:; ...... ro 0 E ::J ..... .~ .E c: c: Instance 2 Describe general location, approximate length: Q) u E Q) ro (/) (/) ::J (/) Q) Is 100-year design flow contained in conduit/swale combination? No c: u Yes .Q ·::; ----0 If "no" explain: ro ..... c: a. :.a ..... Q) Space for 100-year storm flow? E Q) ROW Easement Width 0 £ u (/) Swale Surface type, minimum Conduit Type and size, minimum and maximum ~ Q) ::J ro and maximum slopes: slopes, design storm: u ..... c: ro 0 a. u Q) Inlets Describe how conduit is loaded (from streets/storm drains, in lets by type): --(/) .!E c: ro ~ ~ (/) Q) ..... Access Describe how maintenance access is provided (to swale, into conduit): < STORMWATER DESIGN GUIDELINES Effective February 2007 Page 15 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised Februarv 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters I Continued (Page 4. 7) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) c ·n; a. E x 0 w ~ If "yes" provide the following information for each instance: Instance 1 Describe general location, approximate length, surfacing: :i:: vi Is 100-year design flow contained in swale? __ Yes __ No Is swale wholly 0 Q) c within drainage ROW? __ Yes __ No Explain "no" answers: ·i ~I ~A-cc_e_s_s_D_e_s_c-ri_b_e_h_o_w_m_·_a-in-te_n_a_n_c_e_a_c_c_e-ss-is_p_r-ov_i_d-e:-------------i ·"C~I~~~~~~~~~~~~~~~ Instance 2 Describe general location, approximate length, surfacing: Q) ·;: C'-· ::J (/) .0 c ....... Q) 6 E ~ ~ f--ls_1_0_0_--ye_a_r_d_e_s-ig-n-flo_w_c_o_nt-a-in_e_d_i_n_s_w_a_le_?_.:==.-=_-y-e-s-=.:=_-=_-N-o--l-s_s_w_a_le_w_h_o_lly _ _, "' ~ within drainage ROW? __ Yes __ No Explain "no" answers: ~ 0 ro S ~ 0 1------------------------------------i 5 a::: > .~ Access Describe how maintenance access is provided: :0 ::J a. C'-· "C c ~ l!! 0 a. a. x e w a. (/) (/) ....... Q) c >-i I ~~I () Instance 3, 4, etc. If swales are used in more than two instances, attach sheet providing all above information for each instance. "New" channels: Will any area(s) of concentrated flow be channelized (deepened, widened, or straightened) or otherwise altered? __ · No __ Yes If only slightly shaped, see "Swales" in this Part. If creating side banks, provide information below. Will design replicate natural channel? __ Yes __ No If "no", for each instance describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year design flow, and amount of freeboard: Instance 1: Instance 2: Instance 3: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 16 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised Februarv 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters J Continued (Page 4.8) Stormwater Management Concept (continued) .• Within Or Serving Subject Property (Phase, or Site) (continued) / Existing channels {small creeks}: Are these used? ~ No --Yes If "yes" provide the information below. Will small creeks and their floodplains remain undisturbed? __ Yes --No How many disturbance instances? Identify each planned location: For each location, describe length and general type of proposed improvement (including floodplain changes): .. For each location, describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year design flow. -'O Q) :J c: :;:; Watercourses {and tributaries}: Asid~ringe changes, are Regulatory c: 0 ~ Watercourses proposed to be altered? No __ Yes Explain below. (/) c Submit full report describing proposed changes to Regulatory Watercourses. Address Q) existing and proposed section size and shape, surfaces, alignment, flow line changes, E Q) length affected, and capacity, and provide full documentation of analysis procedures > 0 and data. Is full report submitted? Yes No If "no" explain: ..... a. -- E tJ \ f\ -a; c: c: ro All Proposed Channel Work: For all proposed channel work, provide information .r:::. (.) requested in next three boxes. If design is to replicate natural channel , identify location and length here, and describe design in Special Design section of this Part of Report. ('J) Pr Will 100-year flow be contained with one foot of freeboard? --Yes --No If not, identify location and explain: fJ I A- Are ROW I easements sized to contain channel and required maintenance space? --Yes --No If not, identify location(s) and explain: ~1~ STORMWATER DESIGN GUIDELINES Effective February 2007 Page 17 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.9) ''" Stormwater Management Concept (continued) "~-/" :.>~ '{,, f' Within Or Serving Subject Property (Phase, or Site) (continued) How many facilities for subject property project? For each provide info. below. For each dry-type facilitiy: Facility 1 Facility 2 Acres served & design volume + 10% 100-yr volume: free flow & plugged Design discharge (10 yr & 25 yr) Spillway crest at 100-yr WSE? __ yes --no __ yes --no Berms 6 inches above plugged WSE? __ yes --no __ yes --no Explain any "no" answers: I en Q) >- I For each facility what is 25-yr design Q, and design of outlet structure? ~~ Facility 1: \ '>IJ Facility 2: Do outlets and spillways discharge into a public facility in easement or ROW? ~~ Facility 1: __ Yes --No Facility 2: --Yes --No Q) .... If "no" explain: ~ ) e-~ Cl. ..[_ ~J For each, what is velocity of 25-yr design discharge at outlet? & at spillway? := ....,.... Facility 1: & Facility 2: & ~J Are energy dissipation measures used? --No --Yes Describe type and c: location: 0 :;::; c: Q) -Q) I 0 Q) "-For each, is spillway surface treatment other than concrete? < Yes or no, and describe: Facility 1: Facility 2: For each, what measures are taken to prevent erosion or scour at receiving facility? Facility 1: Facility 2: If berms are used give heights, slopes and surface treatments of sides. Facility 1: Facility 2: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 18 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage ConceQt and Design Parameters I Continued (Page 4.10) "" · · Stormwater.. Management Concept (continued) ~ Within Or Serving Subject Property (Phase, or Site) (continued) Do structures comply with B-CS Specifications? Yes or no, and explain if "no": (/) Facility 1; Q) :.;::::; =:o-~ Q) Facility 2: LI.. ::J c c:.;::; 0 c :.;::::; 0 c (.) Q) -a; For additional facilities provide all same information on a separate sheet. a Are parking areas to be used for detention? __ No --Yes What is maximum depth due to required design storm? Roadside Ditches: Will culverts serve access driveways at roadside ditches? --No --Yes If "yes", provide information in next two boxes. Will 25-yr. flow pass without flowing over driveway in all cases? --Yes --No Without causing flowing or standing water on public roadway? --Yes --No Designs & materials comply with 8-CS Technical Specifications? __ Yes --No Explain any "no" answers: C'-· (/) Cl c 'iii Are culverts parallel to public roadway alignment? __ Yes No Explain: (/) 0 --.... (/) (.) Q) Q) iii >- > I ·c Creeks/at Private Drives: Do private driveways, drives, or streets cross drainage c. -wayijlat serve Above-Project areas or are in public easements/ ROW? C1l ~I __ No __ Yes If "yes" provide information below. How many instances? Describe location and provide information below. Q) Location 1: ~ ::J (.) Q) Location 2: .... ~ Location 3: For each location enter value for: 1 2 3 Design year passing without toping travelway? Water depth on travelway at 25-year flow? Water depth on travelway at 100-year flow? For more instances describe location and same information on separate sheet. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 19 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.11) , Stormwater Management Concept (continued)". .. ~· ,i ., Within Or Serving Subject Property (Phase, or Site) (continued) Named Regulatorl Watercourses (&Tributaries}: Are culverts proposed on these facilities? No __ Yes, then provide full report documenting assumptions, criteria, analysis, computer programs, and study findings that support proposed design(s). Is report provided? __ Yes --No If "no", explain: -Arterial or Major Collector Streets: Will culverts serve these types of roadways? .... Q) Q) No Yes How many instances? For each identify the ..c:: (/) ---- Q) location and provide the information below. .... rn ro Instance 1: Q) .... >-[ I~ Instance 2: Instance 3: c: .Q Yes or No for the 100-year design flow: o ro 1 2 3 '\ z E ~1i Headwater WSE 1 foot below lowest curb top? Spread of headwater within ROW or easement? E C'· ro Is velocity limited per conditions (Table C-11 )? (/) (/) g>-c Explain any "no" answer(s): ·-c: ~ ro 0 c: .... 0 o~ >-ro ro u 3: ..Q -c Q) <1l LI Minor Collector or Local Streets: W ill culverts serve these types of streets? e ·;:: u u No Yes How many instances? for each identify the ·-(/) -Q) ----.g -c location and provide the information below: a. Q) .... a. Instance 1; ro ~ -c >-Instance 2: Q) c: rn ro :::J ...... Instance 3: (/) 0 t::: (/) Q) Q) 1! u For each instance enter value, or "yes" I "no" for: 1 2 3 :::J c: u ro Design yr. headwater WSE 1 ft. below curb top? Q) ii) .... c: <{ ·-100-yr. max. depth at street crown 2 feet or less? Q) .... 0 Product of velocity (fps) & depth at crown (ft) = ? E .... g Is velocity limited per conditions (Table C-11 )? Limit of down stream analysis (feet)? Explain any "no" answers: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 20 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.12) , Stormwater Management Concept (continued) . >\ ' " .. ,. ., Within Or Serving Subject Property (Phase, or Site) (continued) All Proposed Culverts: For all proposed culvert facilities (except driveway/roadside ditch intersects) provide information requested in next eight boxes. Do culverts and travelways intersect at 90 degrees? --Yes --No If not, identify location(s) and intersect angle(s), and justify the design(s): Does drainage way alignment change within or near limits of culvert and surfaced approaches thereto? -··-No --Yes If "yes" identify location(s), describe change(s), and justification: i Are flumes or conduit to discharge into culvert barrel(s)? --No --Yes If yes, identify location(s) and provide justification : ......... Are flumes or conduit to discharge into or near surfaced approaches to culvert ends? "O Q) :J No Yes If "yes" identify location(s), describe outfall design treatment(s): c:: ----:;::; c:: 0 ~ en t Q) ~ :J Is scour/erosion protection provided to ensure long term stability of culvert structural u components, and surfacing at culvert ends? --Yes --No If "no" Identify locations and provide justification(s): Will 100-yr flow and spread of backwater be fully contained in street ROW, and/or drainage easements/ ROW? __ Yes --No if not, why not? Do appreciable hydraulic effects of any culvert extend downstream or upstream to neighboring land(s) not encompassed in subject property? --No --Yes If "yes" describe location(s) and mitigation measures: Are all culvert designs and materials in compliance with 8-CS Tech. Specifications? --Yes --No If not, explain in Special Design Section of this Part. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 21 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage ConceRt and Design Parameters J Continued (Page 4.13) ' .Stormwater Management Concept (continued) ,,.:,, . ' Within Or Serving Subject Property (Phase, or Site) (continued) / Is a bridge included in plans for subject property project? v No Yes ----If "yes" provide the following information. Name(s) and functional classification of the roadway(s)? What drainage way(s) is to be crossed? VJ a> O'l -0 .. ·;:: en A full report supporting all aspects of the proposed bridge(s) (structural, geotechnical, hydrologic, and hydraulic factors) must accompany this summary report. Is the report provided? --Yes --No If "no" explain: Is a Stormwater Provide a general description of planned techniques: ~ Pollution Prevention 5,'(f ~rce 1 C.P'fV..J-..,. ~;fJJ ('.,.,_fd-ro Plan (SW3P) :J f <o ·-kj-;,"' 1 e fh~/:ch m.J of-5rvS I a established for ..... project cons7'on? (J.) ~ __ No __ Yes I Special Designs -Non-Traditional Methods Are any non-traditional methods (aquatic echosystems, wetland-type detention, natural stream re~tion, BMPs for water quality, etc.) proposed for any aspect of subject property project? _·_No __ Yes If "yes" list general type and location below. Provide full report about the proposed special design(s) including rationale for use and expected benefits. Report must substantiate that stormwater management objectives will not be compromised, and that maintenance cost will not exceed those of traditional design solution(s). Is report provided? STORMWATER DESIGN GUIDELINES Effective February 2007 Yes -- -- Page 22 of26 No If "no" explain: APPENDIX. D: TECH. DESIGN SUMMARY As Revised Februarv 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters I Continued (Page 4.14) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Special Designs -Deviation From B-CS Technical Specifications If any design(s) or material(s) of traditional runoff-handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain by specific detail element. __ Detention elements __ Drain system elements __ Channel features __ Culvert features __ Swales __ Ditches __ Inlets __ Outfalls __ Valley gutters __ Bridges (explain in bridge report) In table below briefly identify specific element, justification for deviation(s). Specific Detail Element Justification for Deviation (attach additional sheets if needed) 1) I 2) 3) 4) 5) Have elements been coordinated with the City Engineer or her/his designee? For each item above provide "yes" or "no", action date, and staff name: 1) 2) 3) 4) 5) . " Design Parameters Hydrology / Is a map(s) showing all Design Drainage Areas provided? V Yes __ No Briefly summarize the range of applications made of the Rational Formula: t2_1;"'JJ-cLJ.v~"':.,,..M...._ ~-v 5v--~ ctry\ I c'"'f.._+; J jfu,.,,_, j e_ vv-a r p ~f e £lo~ <Jv- What is the size and location of largest Design Drainage Area to which the Rational Formula has been applied? l./ S acres Location (or identifier): ~"" /f 3 lo . k ) 't-c.rc r ~h-.\ STORMWATER DESIGN GUIDELINES Effective February 2007 Page 23 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.15) . "" -Design Parameters (continued) '" ' " r : "~ Hydrology (continued) In making det~nations for time of concentration, was segment analysis used? No · Yes In approximately what percent of Design Drainage Areas? % As to intensity-duration-frequency and rain depth criteria for de~ning runoff flows, were any criteria other than those provided in these Guidelines used? __ No __ Yes If "yes" identify type of data, source(s), and where applied: .. For each of the stormwater management features listed below identify the storm return frequencies (year) analyzed (or checked), and that used as the basis for design. Feature Analysis Year(s) Design Year Storm drain system for arterial and collector streets /()~(()() ('U Storm drain system for local streets l () ~ I ti t:> f '0 Open channels rv) ,+ N/ /+ Swale/buried conduit combination in lieu of channel l \ \( Swales I I c, Roadside ditches and culverts serving them .. fr Detention facilities: spillway crest and its outfall (I I r Detention facilities: outlet and conveyance structure(s) II \I Detention facilities: volume when outlet plugged ! I \( Culverts serving private drives or streets \ \ ( ( Culverts serving public roadways \\ ( r Bridges: provide in bridge report. I l ( r Hydraulics What is the range of design flow velocities as outlined below? /D'ir)loOy(" Design flow velocities; Gutters Conduit .. Swales Channels Culverts Highest (feet per second) -I.~ I 1. .4 --- Lowest (feet per second) --b.k / 8.1 --- Streets and Storm Drain Systems Provide the summary information outlined below: Roughness coefficients used: For conduit type(s) ).+!)PE STORMWATER DESIGN GUIDELINES Effective February 2007 For street gutters: ecP Page 24 of 26 o. () \ ~ Coefficients: O. DI~ APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce12t and Design Parameters I Continued (Page 4.16) •! .• Design Parameters (continued) ... '\ .... Hydraulics (continued) Street and Storm Drain Systems (continued) For the following, are 7umptions other than allowable per Guidelinesv: Inlet coefficients? __ No __ Yes Head and friction losses __ No Yes -- Explain any "yes" answer: / In conduit is velocity generally increased in the downstream direction? V Yes --No Are elevation drops provided at inlets, manholes, and junction boxes? ~Yes --No Explain any "no" answers: .. Are hydraulic grade lines calculatrvd shown for design storm? v Yes __ No For 100-year flow conditions? __ Yes __ No Explain any "no" answers: What tailwater conditions were assumed at outfall point(s) of the storm drain system? Identify each location and explain: Ti;~/w,~ ~ 5off:_f-t /.: vo-~ J p/~~ Open Channels If a HEC analysis is utilized, does it follow Sec Vl.F.5.a? __ Yes __ No Outside of straight sections, is flow regime within limits of sub-critical flow? __ Yes __ No If "no" list locations and explain: NI A- Culverts If plan sheets do not provide the following for each culvert, describe it here. For each design discharge, will operation be outlet (barrel) control or inlet control? Entrance, friction and exit losses: Bridges Provide all in bridge report STORMWATER DESIGN GUIDELINES Effective February 2007 rv I A- rJ I ftl. fV} f} Page 25 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters Continued (Page 4.17) Design Parameters•(continued) Computer Software What computer software has been used in the analysis and assessment of stormwater management needs and/or the development of faci lity designs proposed for subject property project? List them below, being sure to identify the software name and version, the date of the version, any ·applicable patches and the publisher f; .. /c e.I Sf<r.Jf~s J ~~d.s~"' \-\1Jv-o.Q_ir\L (--\1JJ-c__.\;c~ Part 5 -Plans and Specifications Requirements for submittal of construction drawings and specifications do not differ due to use of a Technical Design Summary Report. See Section Ill, Paragraph C3. Part 6 -Conclusions and Attestation ' · Conclusions Add any concluding information here: 0--0_) ;5V\ c_~ mp );e f vJ ,' ~ e c s /1 s:;LA ~u r°Jt/,·N 5 Attestation Provide attestation to the accuracy and completeness of the foregoing 6 Parts of th is Technical Desi n Summa Draina e Re art b si nin and sealin below. State of Texas PE No. __ (?_·_)_~-~-~- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 26 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised Februarv 2008 APPENDIXB Drainage Area Calculations The Barracks Subdivision -Phase 2 Drainage Area Summary Area# Area, A (acres) 120 0.408 121 0.097 122 0.966 131 0.688 140A 0.109 140B 0.632 140C 0.620 141 0.654 142 0.986 143 1.152 144 1.107 145 0.839 210 0.759 220 0.666 320 0.158 330 0.617 The Rational Method: Q=CIA Q = Flow (cfs) A = Area (acres) C = Runoff Coeff. I = Rainfall Intensity (in/hr) Brazos County: c tc 10 year storm 110 010 (min) (in/hr) (cfs) 0.69 10 8.635 2.43 0.69 10 8.635 0.58 0.69 10 8.635 5.76 0.69 10 8.635 4.10 .. 0.69 10 8.635 0.65 0.69 10 8.635 3.77 0.69 10 8.635 3.69 0.69 10 8.635 3.90 0.69 10 8.635 5.87 0.69 10 8.635 6.86 0.69 10 8.635 6.60 0.69 10 8.635 5.00 0.69 10 8.635 4.52 0.69 10 8.635 3.97 0.69 10 8.635 0.94 0.69 10 8.635 3.68 I = b I (tc+d)9 tc = Time of concentration (min) 1 O year storm b = 80 d = 8.5 e = 0.763 100 year storm b = 96 d = 8.0 e= 0.730 100 year storm 1100 (in/hr) 11.639 11 .639 11 .639 11 .639 11 .639 11 .639 11 .639 11 .639 11.639 11 .639 11 .639 11 .639 11 .639 11 .639 11 .639 11 .639 0100 (cfs) 3.28 0.78 7.76 5.53 0.88 5.08 4.98 5.25 7.92 9.25 8.89 6.74 6.10 5.35 1.27 4.96 tc = U(V*GO) L = Length (ft V = Velocity (ft/sec) APPENDIXC Depth of Flow in Gutter Calculations The Barracks Subdivision Phase 2 Depth of Flow in Gutter (Refer to Exhibit A for Gutter Locations) Gutter A Location Area# (acres) 140 140C 0.620 141 141 0.654 130 -N 140A 0.109 130 -s 1408 0.632 131 - N 131 - N 0.198 131 -s 131 -S 0.688 120 120 0.408 210 210 0.759 220 220 0.666 c Slope tc 1,. (ft/ft) (min) (In/hr) 0.69 0.0073 10.0 8.635 0.69 0.0073 10.0 8.635 0.69 0.0072 10.0 8.635 0.69 0.0073 10.0 8.635 0.69 0.0072 10.0 8.635 0.69 0.0073 10.0 8.635 0.69 0.0080 10.0 8.635 - 0.69 0.0130 10.0 8.635 0.69 0.0130 10.0 8.635 Sergeant Drive & Lieutenant Avenue -Laydown Curb -10-yr storm max design depth -4" General Parkway -Standard Curb -10-yr storm max design depth -4.5" Transverse (Crown) slope (ftlftl 27' street= 0.0330 38' street= 0.0315 Straight Crown Flow (Solved to find actual depth of flow In gutter, yl: Q = 0.56 * (z/n) * S112 * y113 ¢ y ={QI [0.56 * (z/n) * S112)}318 n = Roughness Coefficient = S = StreeVGutter Slope (ft/ft) y = Depth of flow at inlet (ft) z = Reciprocal of crown slope: 27' street= 38' street= 30 32 0.018 10-year storm 100-year storm a,. Y10-actual 1, .. a, .. Y100 (cfs) (ft) (In) (in/hr) (cfs) (ft) (in) 3.69 0.315 3.78 11.639 4.98 0.352 4.23 3.90 0.321 3.85 11.639 5.25 0.359 4.31 0.65 0.164 1.97 11.639 0.88 0.184 2.21 3.77 0.317 3.80 11.639 5.08 0.355 4.26 1.18 0.206 2.47 11.639 1.59 0.230 2.76 4.10 0.327 3.93 11.639 5.53 0.366 4.39 2.43 0.264 3.17 11 .639 3.28 0.296 3.55 4.52 0.305 3.66 11 .639 6.10 0.341 4.09 3.97 0.290 3.48 11 .639 5.35 0.325 3.90 APPENDIXD Storm Sewer Inlet Design Summary The Barracks Subdivision -Phase 2 Storm Sewer Inlets on Grade -Design Analysis Inlet Length Street Q10 L10,ft. Bypass Q10 L 100, ft. Bypass No. ft. Slope,% cfs Design cfs cfs Design cfs 210 20 1.30% 4.52 14.50 0.00 6.10 16.30 0.00 220 20 1.30% 3.97 13.60 0.00 5.35 15.40 0.00 140 10 0.73% 3.69 10.63 0.13 4.98 12.05 0.42 141 10 0.73% 3.90 10.88 0.17 5.25 12.32 0.50 The Barracks Subdivision -Phase 2 Storm Sewer Inlets in Sump -Design Analysis Inlet Length Q10 010 010 Q100 0100 0100 No. ft. cfs ft. in . cf s ft. in. 120 5 2.43 0.319 3.83 3.28 0.389 4.67 130 10 4.55* 0.305 3.66 6.38* 0.382 4.58 131 10 4.27* 0.292 3.50 6.03* 0.368 4.42 * Includes bypass flow from upstream inlets on grade APPENDIXE Storm Sewer Pipe Design Summary The Barracks Subdivision -Phase 2 Storm Sewer Pipe Summary (10-yr Storm) Pipe Pipe Length Slope Contributing Size No. Drainage Areas (in) (ft) (%) Channell 67.62 0.25 All Areas 110 36 96.00 0.25 120, 121 ,122, 131 , 140A, 140B, 140C, 141 , 142, 143, 144, 145 120 36 20.35 0.25 120, 131.1 40A.140B.140C, 141, 14 2,143,144,145 121 24 145.38 0.51 121,122 122 24 80.00 0.69 122 123 36 77.74 0.20 131, 140A, 140B, 140C, 141, 142, 14 3,144,145 131 36 31 .00 0.20 131 , 140C, 141 , 142, 143, 144, 145 140 36 289.50 0.43 140C, 141, 142,143.144, 145 1418 18 40.00 0.80 140C 141A 18 31 .00 0.80 140C 142 30 96.50 0.46 142, 143, 144, 145 143 30 125.50 0.40 143, 144, 145 144 24 42.00 0.82 144,145 145 18 109.50 0.70 145 210 2-24 280.51 0.30 210,220,320,330 220 2-24 42.00 0.30 220,320,330 230 24 119.50 0.30 320,330 310 24 113.19 0.65 320,330 320 18 5.50 1.30 320,330 330 18 29.50 0.85 330 Contributing Area (Acres) 10.458 8.258 7.195 1.063 0.966 6.787 6.046 5.358 0.620 0.620 4.084 3.098 1.946 0.839 2.200 1.441 0.775 0.775 0.775 0.617 Contributing Pipes c Tc 110 Q10 v Travel Time (min) (in/hr) (cfs) (fps) (sec) (min) All Pipes 0.69 12.46 7.850 56.65 5.57 12 0.20 P120,P121,P122,P123,P131 ,P14 0.69 12.14 7.943 45.26 5.07 19 0.32 O,P141A,P142,P143,P144,P145 P123,P131 ,P140,P141A,P142, 0.69 12.10 7.956 39.50 7.60 3 0.04 P143,P144,P145 P122 0.69 10.25 8.545 6.27 4.82 30 0.50 -0.69 10 8.635 5.76 5.26 15 0.25 P131 ,P140,P141A,P142,P143, 0.69 11 .93 8.004 37.48 7.96 10 0.16 P144,P145 P140,P141A,P142,P143,P144, 0.69 11.86 8.025 33.48 7.24 4 0.07 P145 P141A,P142,P143,P144,P145 0.69 11 .08 8.269 30.57 6.16 47 0.78 -0.69 10.11 8.595 3.68 4.62 9 0.14 P141A 0.69 10 8.635 3.69 4.62 7 0.11 P143,P144,P145 0.69 10.83 8.352 23.53 6.36 15 0.25 P144,P145 0.69 10.46 8.474 18.11 5.72 22 0.37 P145 0.69 10.36 8.510 11.43 6.69 6 0.10 -0.69 10 8.635 5.00 5.14 21 0.36 P220,P230,P31 O,P320,P330 0.69 11.26 8.212 12.47 3.95 71 1.18 P230, P310 ,P320 ,P330 0.69 11.06 8.275 8.23 3.55 12 0.20 P31 O,P320,P330 0.69 10.51 8.457 4.52 3.63 33 0.55 P320,P330 0.69 10.12 8.592 4.59 4.83 23 0.39 P330 0.69 10.11 8.597 4.60 6.33 1 0.01 -0.69 10 8.635 3.68 4.62 6 0.11 The Barracks Subdivision -Phase 2 Storm Sewer Pipe Summary (100-yr Storm) Pipe Pipe Length Slope Contributing Contributing Size No. Drainage Areas Area Contributing Pipes c Tc 1100 Q100 v Travel Time (in) (ft) (%) (Acres) (min) (in/hr) (cfs) (fps) (sec) (min) Channel 1 67.62 0.25 All Areas 10.458 All Pipes 0.69 12.46 10.600 76.49 6.16 11 0.18 110 36 96.00 0.25 8.258 P120,P121 ,P122,P123,P131 ,P14 0.69 12.06 10.754 61.27 5.35 18 0.30 120, 121, 122,131 ,140A, 140B, 140C, 141, 142, 143, 144, 145 O,P141A,P142,P143,P144,P145 120 36 20.35 0.25 7.195 P123,P131 ,P140,P141A,P142, 0.69 12.02 10.770 53.47 7.89 3 0.04 120, 131, 140A, 140B, 140C, 141, 14 2, 143, 144, 145 P143,P144,P145 121 24 145.38 0.51 121,122 1.063 P122 0.69 10.23 11.530 8.46 5.20 28 0.47 122 24 80.00 0.69 122 0.966 -0.69 10 11.639 7.76 5.70 14 0.23 123 36 77.74 0.20 6.787 P131 ,P140,P141A,P142,P143, 0.69 11 .86 10.832 50.73 8.33 9 0.16 131, 140A, 140B,140C, 141, 142, 14 3, 144, 145 P144,P145 131 36 31 .00 0.20 131, 140C, 141 , 142, 143, 144, 145 6.046 P140,P141A,P142,P143,P144, 0.69 11 .79 10.859 45.30 7.60 4 0.07 P145 140 36 289.50 0.43 140C, 141, 142, 143, 144, 145 5.358 P141A,P142,P143,P144,P145 0.69 11 .03 11.175 41.32 6.32 46 0.76 1418 18 40.00 0.80 140C 0.620 -0.69 10.10 11 .594 4.96 5.39 7 0.12 141A 18 31 .00 0.80 140C 0.620 P141A 0.69 10 11 .639 4.98 5.39 6 0.10 142 30 96.50 0.46 142, 143, 144, 145 4.084 P143,P144,P145 0.69 10.78 11 .285 31.80 6.36 15 0.25 143 30 125.50 0.40 143, 144, 145 3.098 P144,P145 0.69 10.43 11.440 24.45 6.02 21 0.35 144 24 42.00 0.82 144,145 1.946 P145 0.69 10.33 11.484 15.42 7.16 6 0.10 145 18 109.50 0.70 145 0.839 -0.69 10 11.639 6.74 5.48 20 0.33 210 2-24 280.51 0.30 210,220,320,330 2.200 P220,P230,P310,P320,P330 . 0.69 11.15 11.124 16.89 4.23 66 1.11 220 2-24 42.00 0.30 220,320,330 1.441 P230,P31 O,P320,P330 0.69 10.97 11.202 11.14 3.84 11 0.18 230 24 119.50 0.30 320,330 0.775 P310,P320,P330 0.69 10.46 11.426 6.11 3.93 30 0.51 310 24 113.19 0.65 320,330 0.775 P320,P330 0.69 10.10 11.591 6.20 5.25 22 0.36 320 18 5.50 1.30 320,330 0.775 P330 0.69 10.09 11.597 6.20 6.84 1 0.01 330 18 29.50 0.85 330 0.617 -0.69 10 11.639 4.96 5.51 5 0.09 --The Barracks Subdivision (April 2, 2009) Storm Sewer Pipe Design Analysis (1 O yr Storm) Pipe Pipe Size Length Slope No. (In) (ft) (%) Surcharged Q10 V10 HGL10 cfs fps Slope Downstream Top Pipe HGL10 Structure Elev. FL Elev. Upstream Top Pipe HGL10 Structure Elev. FL Elev. Upstream Structure Minor Los• Minor HGL10 Structure Coe ff. Loss Elev. Channel 1 67.62 0.25 56.65 302.20 302.37 110 1-36 96.00 0.25 45.26 6.41 0.40% Channel 302.63 305.63 JB 110 308.50 302.87 306.01 JB 110 0.25 0.04 306.05 120 1-36 20.20 0.25 39.5 5.59 0.31% JB 110 308.50 303.00 306.05 1120 308.23 303.05 306.11 1120 0.50 0.02 306.14 . '' 121 -. ' 24 145.38 0.51 6.27 JB 110 308.50 303.49 1121 309.54 304.23 1121 122. 24 80.00 0.69 5.76 1121 309.54 304.33 1122 308.82 304.75 1122 123 1-36 77.90 0.20 37.48 5.31 0.27% 1120 308.23 303.22 306.14 1130 308.16 303.38 306.35 1130 0.50 0.04 306.39 131 1-36 31.00 0.20 33.48 4.74 0.25% 1130 308.16 303.51 306.39 1131 308.16 303.57 306.47 1131 0.50 0.03 306.50 140 1-36 289.50 0.43 30.57 4.33 0.19% 1131 308.16 303.73 306.50 1141 310.20 304.97 307.05 1141 0.50 0.09 307.14 1418 18 40.00 0.80 3.68 2.78 0.24% 1141 310.20 306.06 307.14 JB 145 310.65 306.38 307.23 JB 145 0.50 0.00 307.23 141A 18 31.00 0.80 3.69 2.79 0.27% JB 145 310.65 306.48 307.23 1140 310.57 306.73 307.31 1140 1.25 0.15 307.47 142 30 94.00 0.46 23.53 1141 310.20 305.07 JB 311.33 305.50 JB 143 30 125.50 0.40 18.11 JB 311.33 305.61 1143 310.82 306.09 1143 ---144 24 42.00 0.82 11.43 1143 310.82 306.59 1144 310.79 306.93 1144 ., 145 18 109.50 0.70 5.00 1144 310.79 307.43 JB 312.49 308.20 JB 210 2-24 280.51 0.30 12.47 2.65 0.15% Flume 302.57 305.13 1210 307.55 303.41 305.55 1210 0.25 0.02 305.57 220 2-24 42.00 0.30 8.23 1.75 0.08% 1210 307.55 303.46 305.57 1220 307.55 303.59 305.60 1220 0.50 0.00 305.59 230 24 119.50 0.30 4.52 1.92 0.08% 1220 307.55 303.64 305.59 JB 305 307.20 304.00 305.68 JB 305 1.25 0.07 305.75 ; ·310 :"' 24 113.19 0.65 4.59 JB 305 307.20 304.05 JB 310 308.98 304.79 JB 310 320:· 18 5.50 1.30 4.60 JB 310 308.98 305.29 1320 309.03 305.36 1320 330 ', 18 29.50 0.85 308.46 1320 309.03 305.46 1330 Note: Losses for 18" pipe are computed as for a 15.6" pipe (25% reduction in area) and losses for a 24" pipe are computed as for a 20.6" pipe (25% reduction in area). The Barracks Subdivision (April 2, 2009) Storm Sewer Pipe Design Analysis (100 yr Storm) Pipe Pipe Size Length Slope No. (In) (ft) (%) Surcharged Q100 V100 HGL100 cfs fps Slope Downstream Top Pipe HGL100 Structure Elev. FL Elev. Upstream Top Pipe HGL100 Structure Elev. FL Elev. Upstream Structure Minor Los• Minor HGL100 Structure Coe ff. Loss Elev. Channel 1 67.62 0.25 76.49 302.20 302.37 110 1-36 96.00 0.25 61.27 8.67 0.72% Channel 302.41 305.41 JB 110 308.50 302.65 306.10 JB 110 0.25 0.07 306.17 120 1-36 20.20 0.25 53.47 7.57 0.54% JB 110 308.50 302.75 306.17 1120 308.23 302.8 306.28 1120 0.50 0.04 306.32 121 ,. 24 145.38 0.51 8.46 JB 110 308.50 303.49 1121 309.54 304.23 1121 122. 24 80.00 0.69 7.76 1121 309.54 304.33 1122 308.82 304.75 1122 123 1-36 77.90 0.20 50.73 7.18 0.53% 1120 308.23 302.90 306.32 1130 308.16 303.06 306.74 1130 0.50 0.08 306.82 131 1-36 31.00 0.20 45.3 6.41 0.46% 1130 308.16 303.16 306.82 1131 308.16 303.22 306.96 1131 0.50 0.05 307.01 140 1-36 289.50 0.43 41.32 5.85 0.34% 1131 308.16 303.32 307.01 1141 310.20 304.56 308.00 1141 0.50 0.16 308.16 1418 18 40.00 0.80 4.96 3.74 0.45% 1141 310.20 306.06 308.16 JB 145 310.65 306.38 308.34 JB 145 0.50 0.00 308.33 141A 18 31.00 0.80 4.98 3.76 0.50% JB 145 310.65 306.48 308.33 1140 310.57 306.73 308.49 1140 1.25 0.27 308.76 . ···142"' .. 30 94.00 0.46 31.8 1141 310.20 305.07 JB 311 .33 305.50 JB 143 30 125.50 0.40 24.45 JB 31 1.33 305.61 1143 310.82 306.09 1143 144 24 42.00 0.82 15.42 1143 310.82 306.59 1144 310.79 306.93 1144 145 18 109.50 0.70 6.74 1144 310.79 307.43 JB 312.49 308.20 JB 210 2-24 280.51 0.30 16.89 3.59 0.26% Flume 302.57 304.41 1210 307.55 303.41 305.14 1210 0.25 0.03 305.17 220 2-24 42.00 0.30 11.14 2.37 0.13% 1210 307.55 303.46 305.17 1220 307.55 303.59 305.22 1220 0.50 -0.01 305.21 230 24 119.50 0.30 6.11 2.59 0.14% 1220 307.55 303.64 305.21 JB 305 307.20 304.00 305.38 JB 305 1.25 0.13 305.51 ... 310 24 113.19 0.65 6.2 JB 305 307.20 304.05 JB 310 308.98 304.79 JB 310 320 18 5.50 1.30 6.20 JB 310 308.98 305.29 1320 309.03 305.36 1320 330 18 29.50 0.85 308.46 1320 309.03 305.46 1330 Note: Losses for 18" pipe are computed as for a 15.6" pipe (25% reduction in area) and losses for a 24" pipe are computed as for a 20.6" pipe (25% reduction in area).