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Home My WebLink AboutFolderCITY OF COLLEGE STATION Pla11ni11g er Dn ,rloprnmt SrruirrI FOR OFFICE USE ON P&Z CASE NO.: OG , ,:) l DATE SUBMITTED: lJ .)._ 6 FINAL PLAT APPLICATION (Check one) D Minor ($300.00) D Amending ($300.00) [9"Final ($400.00) D Vacating ($400.00) D Replat ($600.00)* *Includes public hea ring fee Is this plat in the ET J? 0 Yes Ga' No The following items must be submitted by an established filing deadline date for P&Z Commission consideration. MINIMUM SUBMITTAL REQUIREMENTS: v Filing Fee (see above) NOTE: Multiple Sheets -$55.00 per additional sheet 1fJf Variance Request to Subdivision Regulations -$100 (if applicable) ~ Development Permit Application Fee of $200.00 (if applicable). ~ Infrastructure Inspection Fee of $600.00 (applicable if any public infrastructure is being constructed) ~ Application completed in full. ~Copy of original deed restrictions/covenants for replats (if applicable). _.:::::_ Thirteen (13) folded copies of plat. (A signed mylar original must be submitted after staff review.) __:::.___ One (1) copy of the approved Preliminary Plat and/or one (1) Master Plan (if applicable). ~ Paid tax certificates from City of College Station, Brazos County and College Station I.SD ~ A copy of the attached checklist with all items checked off or a brief explanation as to why they are not. ~ Two (2) copies of public infrastructure plans associated with this plat (if applicable). _I_ Parkland Dedication requirement approved by/ the/Parks & Recreation Board, please provide proof of approval (if applicable). )ti t>..-PPr'Ov--tc.::l it-Z-o 7-LL"'lt- Date of Preapplication Conference: __ tt ..... /_it__./_·-_t.-l_":_o_'J_-________________ _ NAME OF SUBDIVISION ~\.,l ~· L L\ll'rV\<) VexJ.---, y:'l<it.U l I SPECIFIED LOCATION OF PROPOSED SUBDIVISION (Lot & Block) .x1.rl--c.t &.e<_v-,' --rv--<Y ,--<-f<cj F h<._+v_c-<Lv~ i0 l..l--Prz>..,:..-i:e.... -l 0'-'h.."-4--c ..-...; ....+- APPLICANT/PROJECT MANAGER'S INFORMATION (Primary Contact for the Project): Name J .?!2 S J~e_ ..\--Jo "'-Vl.~•'J Street Address "f Q. bi r OCb State -ti, Zip Code --··n,<(, 3it Phone Number {--) 2)) l, -z..:.;--1.J 2...4- City C.~lc: vVl<>-n E-Mail Address ~joh,,.,s,0,-1 112:0<'1 f': i-.cfr.-,µJ:_/ < ,:r-;-.1 Fax Number (3-z...s )(:, Z. S---"%] '--- PROPERTY OWNER'S INFORMATION (ALL owners must be identified . Please attach an additional sheet for multiple owners): \ Name .J·'K-S .) o....v--.t--\-,Job.¥\ s.-v n Street Address ~ .. ' . })ox 'i:)oo State SJ<. Zip Code t\i,~)~L\-- Phone Number ( '.)(...;;'J C.£L'\. -~ 2\ l.!-r <: E-Mail Address -~---------- Fa x Number c~-z.S)~?.-S -· ?:i,,.]-L ARC HITECT OR ENGINEER'S INFORMATION Name C ~v~\ ))t,..i'-tlorvY1±:,S 1 Lf-c\ -Jc.e ~ cJ1 vJ -be. L P. ~ -. . StreetAddress Z:'h;c L-c ~w1tr< .S~G-f"..--· City (.J.-,l(t:'(:L _Sft.f;,).r, J 1-tP s State -r1' Zip Code 1. t."O Lt\ E-Mail Address j w_ 0; c.,-tR L: s . (l'TLY"'~--- Phone Number --~ 1°0J_l~ ----l~~lJ___ Fax Number ('11~') f~-~r-LS1---·----- 611:1103 I tit..; Mar 21 07 11:21a To: Fax: Phone: Carol, Ginger Urso 979-764-7759 * GwL DEVELOPMENT, Ltd.* CIVIL ENGINEERING & DESIGN-BUILD SERVICES 2900 Longmire Drive, Suite K • College Station, Texas 77845 P.O. Box 11929 • College Station, Texas 77842 (979) 764-7743 • Fax: (979) 764-7759 Fax Transmittal Carol Cotter Date: March 21 , 2007 764-3496 From: Kent Laza 764-3570 Pages: 3 (including cover) Following is a revised estimate for Williams Creek Phase 7 that accounts for the reduced street length and changes in the drainage outfall. Please call if you have questions. You should now have everything you needed to release the plans, but if not let me know. Thanks. Kent p. 1 Har 21 07 11:21a Ginger Urso 979 -764-7759 p.2 Item No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 - 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 *CIVIL DEVELOPMENT, Ltd.* CIVIL ENGINEERING & DESIGN-BUILD SERVICES P.O. Box 11929 · College Station, Texas 77842 · Phone: 979-764-7743 · Fax: 979-764-7759 WILLIAMS CREEK, PHASE 7 REVISED ENGINEER'S ESTJMATE March 21, 2007 Description Streets & Sitework Mobilization/Construction Staking Clearing & Grubbing (ROW & Easements) Strip and remove 6" topsoil Earthwork Mixing & Incorporation of Lime,~" depth Lime (hydrated) 6" Crushed Limestone Base Hot Mix Asphaltic Concrete -2" depth 2-4" Landscape Sleeves, structural backfill 24" Ribbon Curb Storm Drainage 18" HOPE stonn drain pipe, structural backfill 24" HOPE storm drain pipe, non-structural backfill RockRiprap Headwall w/footing and handrail base plates (handrail not included) ~tandard Headwall for 18" pipe w/dissipator blocks Standard Headwall for 24" pipe w/dissipator blocks Concrete clitch lining (stamped & patterened) Concrete splash pad with dissipator blocks Concrete splash pad without dissipator blocks Concrete channel lining 6:1 SET for 18" HOPE pipe 4:1 SET for 18" HOPE pipe Hydromulch Seeding (ditches & easements) Silt Fence Barriers in roadside ditches Construction Exit Area Inlet Water 8" Water PVC CL200 (C909) structural backfill 8" Water PVC CL200 (C909) non-structural backfill 6" Water PVC CL200 (C909) structural backfill 6" Water PVC CL200 (C909) non-structural backfill 3" Water PVC Sch 40 (D224 l) non-structural backfill Page 1 of2 l Estimated Quantity 1 3.8 l 1 6,200 97 5,851 4,806 40 I I i i ' 952 i LS AC LS LS SY TON SY SY LF LF Unit Price 6,000.00 3,800.00 8,000.00 20,000.00 2.00 100.00 8.00 8.75 14.00 8.75 Subtotal -Streets & Sitework 234 ! LF 32.00 ; 10 i LF 30.00 23 j SY 60.00 ! 0 i LF 300.00 0 i EA 2,000.00 1 i EA 2,500.00 0 ! SY 60.00 0 i SF 8.00 I 0 I SF 4.00 0 SY 45.00 6 EA 1,400.00 2 EA 1,300.00 14,166 SY 0.65 300 LF I 3.00 1 EA l 1,000.00 1 EA 3,000.00 Subtotal -Storm Drainage 341 LF 30.00 905 I LF 27.00 0 LF 25.00 435 ; LF 22.00 228 LF 16.00 Estimated Cost 6,000 14,440 8,000 20,000 12,400 9,700 46,808 42,053 560 8,330 $168,291 7,488 300 1,3 80 0 0 2,500 0 0 0 0 8,400 2,600 9,208 900 1,000 3,000 $36,776 1,020 24,435 0 9,570 3,648 Har 21 07 11:21a Ginger Urso 979-764-7759 Item No. 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 WILLIAMS CREEK, PHASE 7 REVISED ENGINEER'S ESTIMATE March 21, 2007 Description Estimated Quantity 8" M.J. Gate Valve 4 6" M.J. Gate Valve I 3" M.J. Gate Valve I 8"x 8" M.J. Tee 2 8"x 6" M.J. Reducer I 8"x 3" M.J. Reducer 1 6"x 3" M.J. Reducer 0 8" x 22.5° M.J. Bend 1 8" x 11.25° M.J. Bend I 611 x 45° M.J. Bend 4 6" x 11.25° M.J. Bend 4 Fire Hydrant Assembly (w/vert. extension, 8"x 6" tee, all necessary fittings) l Fire Hydrant Assembly (w/vert. extension, 6"x 6" tee, all necessary fittings) l 2" Blow Off Assembly 2 I Connect to existing water line 1 ! 1" Water Service, Type K Copper:'.:: 1 S' (avg. length= 2 ft.) 4 l" Water Service Type K Copper > J 5' (avg. length = 51 ft.) 1 1.5" Water Service, Type K Copper:'.:: 15' (avg. length= 2 ft.) 2 1.5" Water Service Type K Copper> 15' (avg. length= 85 ft.) 3 i I I i p.3 EA EA EA EA EA EA EA EA EA EA - EA EA EA EA EA i i EA I I EA I I EA I EA Unit Price 900.00 650.00 500.00 400.00 375.00 350.00 325.00 325.00 325.00 300.00 300.00 2,900.00 2,800.00 750.00 500.00 500.00 1,400.00 600.00 1,500.00 Subtotal -Water Estimated Cost 3,600 650 500 800 375 350 0 325 325 1,200 1,200 2,900 2,800 1,500 500 2,000 l,400 1,200 4,500 $64,798 ESTIMATED CONSTRUCTION/ $269,864 Page 2 of2 .· Item No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 '{;{CIVIL DEVELOPMENT, Ltd.'{;{ CIVIL ENGINEERING & DESIGN-BUILD SERVICES P.O. Box 11929 · College Station, Texas 77842 · Phone: 979-764-7743 · Fax: 979-764-7759 WILLIAMS CREEK, PHASE 7 REVISED ENGINEER'S ESTIMATE March 21, 2007 Description Streets & Sitework Mobilization/Construction Staking Clearing & Grubbing (ROW & Easements) Strip and remove 6" topsoil Earthwork Mixing & Incorporation of Lime, 6" depth Lime (hydrated) 6" Crushed Limestone Base Hot Mix Asphaltic Concrete -2" depth 2-4" Landscape Sleeves, structural backfill 24" Ribbon Curb Estimated Quantity l 3.8 l 1 6,200 97 5,851 4,806 40 952 LS AC LS LS SY TON SY SY LF LF Unit Price 6,000.00 3,800.00 8,000.00 20,000.00 2.00 100.00 8.00 8.75 14.00 8.75 Subtotal -Streets & Sitework Storm Drainage 18" HOPE storm drain pipe, structural backfill 234 LF 32.00 24" HDPE storm drain pipe, non-structural backfill 10 LF 30.00 Rock Riprap 23 SY 60.00 Headwall w/footing and handrail base plates (handrail not included) 0 LF 300.00 Standard Headwall for 18" pipe w/dissipator blocks 0 EA 2,000.00 Standard Headwall for 24" pipe w/dissipator blocks l EA 2,500.00 Concrete ditch lining (stamped & patterened) 0 SY 60.00 Concrete splash pad with dissipator blocks 0 SF 8.00 Concrete splash pad without dissipator blocks 0 SF 4.00 Concrete channel lining 0 SY 45 .00 6:1 SET for 18" HOPE pipe 6 EA 1,400.00 4 :1 SET for 18" HDPE pipe 2 EA 1,300.00 Hydromulch Seeding (ditches & easements) 14, 166 SY 0.65 Silt Fence Barriers in roadside ditches 300 LF 3.00 Construction Exit l EA 1,000.00 Area Inlet 1 EA 3,000.00 Subtotal -Storm Drainage Water 8" Water PVC CL200 (C909) structural backfill 34 LF 30.00 8" Water PVC CL200 (C909) non-structural backfill 905 LF 27.00 6" Water PVC CL200 (C909) structural backfill 0 LF 25.00 6" Water PVC CL200 (C909) non-structural backfill 435 LF 22.00 3" Water PVC Sch 40 (02241) non-structural backfill 228 LF 16.00 Page I of2 Estimated Cost 6,000 14,440 8,000 20,000 12,400 9,700 46,808 42,053 560 8,330 $168,291 7,488 300 1,380 0 0 2,500 0 0 0 0 8,400 2,600 9,208 900 1,000 3,000 $36,776 l,020 24,435 0 9,570 3,648 Item No. 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 WILLIAMS CREEK, PHASE 7 REVISED ENGINEER'S ESTIMATE March 21, 2007 Description Estimated Quantity 8" M.J. Gate Valve 4 6" M.J. Gate Valve 1 3" M.J. Gate Valve 1 8"x 8" M.J. Tee 2 8"x 6" M.J. Reducer 1 8"x 3" M.J. Reducer 1 6"x 3" M.J. Reducer 0 8" x 22.5° M.J. Bend 1 8" x 11.25° M.J. Bend 1 6" x 45° M.J. Bend 4 6" x 11.25° M.J. Bend 4 Fire Hydrant Assembly (w/vert. extension, 8"x 6" tee, all necessary fittings) l Fire Hydrant Assembly (w/vert. extension, 6"x 6" tee, all necessary fittings) 1 2" Blow Off Assembly 2 Connect to existing water line 1 l" Water Service, Type K Copper _::; 15' (avg. length = 2 ft.) 4 l" Water Service Type K Copper > 15' (avg. length = 51 ft.) 1 1.5" Water Service, Type K Copper _::; 15' (avg. length = 2 ft.) 2 1.5" Water Service Type K Copper > 15' (avg. len-gth = 85 ft.) 3 EA EA EA EA EA EA EA EA EA EA EA EA EA EA EA EA EA EA EA Unit Price 900.00 650.00 500.00 400.00 375.00 350.00 325.00 325.00 325 .00 300.00 300.00 2,900.00 2,800.00 750.00 500.00 500.00 1,400.00 600.00 1,500.00 Subtotal -Water Estimated Cost 3,600 650 500 800 375 350 0 325 325 1,200 1,200 2,900 2,800 1,500 500 2,000 1,400 1,200 4,500 $64,798 ESTIMATED CONSTRUCTIONJ $269,864 Page 2 of 2 Phase 5 Street Name Williams Creek Drive Williams Ridge Court Phase 7 Street Name Ginger Court Williams Creek Subdivision Driveway Culverts Block# Lot# Driveway Culvert (in) 7 1 18 ---------------------· -----------7 2 15 -----------·----6 1 12 ------------------------6 2 12 ---------6 3 12 6 4 12 7 11 12 7 12 12 7 13 12 7 14 15 7 15 18 7 16 18 7 17 18 7 18 18 -----7 19 15 ---7 20 12 7 21 12 7 22 12 -7 23 12 7 24 12 Block# Lot# Driveway Culvert (in) 8 1 12 8 2 12 8 3 15 8 4 12 8 5 12 8 6 12 8 7 12 Campbell 8 1 12 Court 8 7 15 8 8 15 --8 9 18 8 10 12 ----------8 11 12 -8 12 12 ---------8 13 15 -------------·--8 14 15 -----------------------8 15 12 --------------8 16 12 -------8 17 12 8 18 12 8 19 12 Williams Creek Subdivision -Phase 7 Ditch Velocity Data -Revised October, 2006 Campbell Court Left Ditch From To Station Station 0+00.00 1+00.00 1+00.00 1+50.00 1+50.00 3+22.00 --3+22.00 4+50.00 --4+50.00 7+25.00 --7+25.00 8+75.00 8+75.00 9+45.00 9+45.00 10+10.00 10+10.00 10+54.00 --10+54.00 10+63.00 10+63.00 11+08.00 11+08.00 11+28.00 ---11+28.00 11+37.00 11+37.00 11+80.00 11+80.00 13+60.00 13+60.00 13+96.92 Ginger Court Left Ditch From To Station Station 0+00.00 00+50.00 0+50.00 01 +35.00 -----1+35.00 02+50.00 -2+50.00 03+24.00 3+24.00 04+30.00 ---4+30.00 04+89.53 Campbell Court Right Ditch From To Station Station 0+00.00 1+00.00 1+00.00 1+50.00 1+50.00 3+22.00 -- 3+22.00 4+27.00 ---4+27.00 5+15.00 --5+15.00 6+50.00 --6+50.00 8+30.00 ---8+30.00 9+45.00 -- 9+45.00 9+75.00 9+75.00 10+29.00 10+29.00 10+40.00 10+40.00 10+84.00 10+84.00 11+02.00 -11+02.00 11+13.00 --11+13.00 11+60.00 11+60.00 12+05.00 12+05.00 13+60.00 13+60.00 13+96.92 Ginger Court Right Ditch From To Station Station 0+00.00 00+50.00 0+50.00 02+50.00 2+50.00 03+24.00 3+24.00 04+89.53 (n = O 035 for grass) Slope Drainage Area # 1.94% 36 1.00% 35 -0.60% 34,35 -0.50% 23,32,33,34,35 3.55% 22,23,32,33,34,35 3.55% 21 ,22,23,32,33,34,35 3.55% 20,21 ,22,23,32,33,34,35 2.85% 19,20,21,22,23,32,33,34,35 --2.85% 19,20,21,22,23,32,33,34,35 2.85% 18, 19,20,21 ,22,23,32,33,34,3( 1.00% 18, 19,20,21 ,22,23,32,33,34,3! 1.00% 15,16,17 1.00% 15,16 4.46% 15,16 3.43% 15 3.20% 14 (n = 0.035) Slope Drainage Area # 2.78% 32 0.85% 31 -0.85% 30,31 0.60% 29,30,31 0.60% 27,28 ---0.60% 27 (n = O 035 for grass and n = O 014 for concrete) Slope Drainage Area # 1.94% 1 1.00% 2 ---0.60% 2,3 1.15% 2,3,4 3.55% 2,3,4,5 3.55% 2,3,4,5,6 3.55% 2,3.~- 3.55% 2,3,4,5,6,7,8 3.56% 2,3,4,5,6,7,8,9 3.56% 2,3,4,5,6,7,8,9 1.00% 2,3,4,5,6,~ 1.00% 2,3,4,5,6, 7 ,8,9, 10 1.00% 11 ,12 1.00% 11 ,12 3.34% 11 ,12 3 .. 34% 11 ,12 3.43% 12 3.20% 13 (n = 0.035) Slope Drainage Area # 2.78% 23 0.85% 24 0.60% 24,25 0.60% 26 1. Concrete ditch lining depth = 9" 2. Concrete ditch lining depth = 7 .5" 010 (cfs) 0.26 0.17 1.68 2.29 - 3.63 4.53 4.92 5.48 5.48 5.66 5.66 1.04 0.95 0.95 0.65 0.30 010 (cfs) 0.22 0.99 2.72 6.69 5.22 --3.02 010 (cfs) 0.69 0.35 1.73 2.16 2.63 3.37 4.36 4.84 5.14 5.14 5.31 5.31 4.19 4.19 4.19 4.19 1.68 0.82 010 (cfs) 0.22 0.65 0.91 0.86 V10 d10 0100 V100 d100 Driveway Block# Lot # Ditch Lining (fps) (in) (cfs) (fps) (in) Culvert (in) Material 1.3 2.6 0.35 1.4 3.0 --Grass seed 0.9 2.6 0.23 1.0 2.9 -Grass seed -1.4 6.6 2.27 1.5 7.4 12 8 1 Grass seed -1.4 7.7 3.08 1.5 8.6 -Grass seed 3.2 6.4 4.89 3.5 7.1 --Grass seed - 3.4 6.9 6.11 3.7 7.7 15 8 7 Grass seed 3.5 7.1 6.63 3.8 8.0 15 - -Grass seed 3.3 7.7 7.39 3.6 8.6 --Grass seed --3.3 7.7 7.39 3.6 8.6 --Grass sod --r-----Concrete2 6.6 5.5 7.62 7.1 6.2 ------- 4.7 5.1 7.62 5.1 6.0 18 8 9 Concrete 2.8 1.9 1.40 3.0 2.3 - -Concrete' ------ 2.9 3.5 1.28 3.1 3.9 Concrete2 -------2.5 3.7 1.28 2.7 4.1 12 8 10 Grass sod ----------2.1 3.4 0.87 2.2 3.7 -Grass seed 1.6 2.5 0.41 1.8 2.9 12 8 10 Grass sod V10 d10 0100 V100 d100 Driveway Block# Lot # Ditch Lining (fps) (in) (cfs) (fps) (in) Culvert (in) Material 1.5 2.3 0.29 1.6 2.6 --Grass seed 1.4 5.1 1.34 1.5 5.7 12 8 1 Grass seed ----1.8 7.5 3.67 1.9 8.3 12 - -Grass seed ------1---1.9 11 .2 9.02 2.1 12.5 8 2 Grass seed 1.8 10.2 7.04 2.0 11.4 15 8 3 Grass seed -----1.6 8.3 4.07 1.7 9.3 12 8 4 Grass seed V10 d10 0100 V100 d100 Driveway Block# Lot# Ditch Lining (fps) (in) (cfs) (fps) (in) Culvert (in) Material 1.7 3.8 0.93 1.8 4.3 --Grass seed 1.1 3.4 0.47 1.2 3.7 12 8 19 Grass seed ----1.4 6.7 2.33 1.5 7.5 12 8 18 Grass seed ----1.9 6.5 2.91 2.0 7.2 -Grass seed 3.0 5.6 3.55 3.2 6.3 12 8 17 Grass seed 3.2 6.2 4.54 3.4 6.9 12 8 16 Grass seed 3.4 6.8 5.88 3.6 7.6 12 8 15 Grass seed ----3.5 7.1 6.52 3.7 7.9 --~ssseed 3.5 7.2 6.93 3.8 8.1 --Grass seed 3.5 7.2 6.93 3.8 8.1 -Grass Sod 4.4 6.6 7.16 4.7 7.4 - -Concrete2 4.6 4.9 7.16 5.0 5.8 15 8 14 Concretef 4.3 4.3 5.65 4.7 5.1 15 8 13,14 Concrete 4.1 6.0 5.65 4.5 6.7 Concrete2 3.2 4.5 5.65 3.4 5.3 Grass Sod 3.2 4.5 5.65 3.4 5.3 Grass seed 2.6 4.8 2.27 2.8 5.4 12 8 13 Grass seed 2.1 3.7 1.11 2.3 4.2 12 8 11,12 Grass sod V10 d10 0100 V100 d100 Driveway Block# Lot# Ditch Lining (fps) (in) (cfs) (fps) (in) Culvert (in) Material 1.5 2.3 0.29 1.6 2.6 Grass seed 1.2 4.4 0.87 1.3 4.9 Grass seed 1.2 5.3 1.22 1.3 5.9 12 8 7 Grass seed 1.2 5.2 1.16 1.2 5.8 12 8 6 Grass seed Williams Creek Subdivision -Phase 7 Ditch Velocity Data -Revised October, 2006 Campbell Court Left Ditch From To Station Station 0+00.00 1+00.00 1+00.00 1+50.00 --- 1+50.00 3+22.00 ---3+22.00 4+50.00 -4+50.00 7+25.00 ---7+25.00 8+75.00 --8+75.00 9+45.00 --9+45.00 10+10.00 10+10.00 10+54.00 10+54.00 10+63.00 ---10+63.00 11+08.00 11+08.00 11+28.00 11+28.00 11+37.00 11+37.00 11+80.00 ---11+80.00 13+60.00 13+60.00 13+96.92 Ginger Court Left Ditch From To Station Station 0+00.00 00+50.00 0+50.00 01+35.00 ---1+35.00 02+50.00 2+50.00 03+24.00 3+24.00 04+30.00 4+30.00 04+89.53 Campbell Court Right Ditch From To Station Station 0+00.00 1+00.00 1+00.00 1+50.00 ---1+50.00 3+22.00 3+22.00 4+27.00 4+27.00 5+15.00 -5+15.00 6+50.00 --6+50.00 8+30.00 ---8+30.00 9+45.00 9+45.00 9+75.00 9+75.00 10+29.00 --10+29.00 10+40.00 10+40.00 10+84.00 10+84.00 11+02.00 11+02.00 11+13.00 11+1 3.00 11+60.00 11+60.00 12+05.00 12+05.00 13+60.00 13+60.00 13+96.92 Ginger Court Right Ditch From To Station Station 0+00.00 00+50.00 0+50.00 02+50.00 2+50.00 03+24.00 3+24.00 04+89.53 (n = 0.035 for grass) Slope Drainage Area # 1.94% 36 1.00% 35 0.60% 34,35 0.50% 23,32,33,34,35 3.55% 22,23,32,33,34,35 3.55% 21,22,23,32,33,34,35 3.55% 20,21 ,22,23,32,33,34,35 2.85% 19,20,21 ,22,23,32,33,34,35 2.85% 19,20,21,22,23,32,33,34,35 --- 2.85% 18, 19,20,21,22,23,32,33,34,3! ---1.00% 18, 19,20,21 ,22,23,32,33,34,3! 1.00% 15,16,17 ---1.00% 15,16 4.46% 15,16 -3.43% 15 3.20% 14 (n = 0.035) Slope Drainage Area # 2.78% 32 0.85% 31 0.85% 30,31 0.60% 29,30,31 0.60% 27,28 0.60% 27 (n = 0.035 for grass and n = 0.014 for concrete) Slope Drainage Area # 1.94% 1 1.00% 2 0.60% 2,3 1.15% 2,3,4 3.55% 2,3,4,5 3.55% 2,3,4,5,6 3.55% 2,3,4,5,6, 7 3.55% 2,3,4,5,6,7,8 3.56% 2,3,4,5,6,7,8,9 3.56% 2,3,4,5,6,7,8,9 1.00% 2,3,4,5,6,7,8,9 1.00% 2,3,4,5,6, 7,8,9, 10 1.00% 11,12 1.00% 11,12 3.34% 11,12 3 .. 34% 11,12 3.43% 12 3.20% 13 (n = 0.035) Slope Drainage Area # 2.78% 23 0.85% 24 0.60% 24,25 0.60% 26 1. Concrete ditch lining depth = 9" 2. Concrete ditch lining depth= 7.5" 0 10 (els) 0.26 0.17 1.68 2.29 3.63 4.53 4.92 5.48 5.48 5.66 5.66 1.04 0.95 0.95 0.65 0.30 010 (els) 0.22 0.99 2.72 - 6.69 5.22 3.02 010 (els) 0.69 0.35 1.73 2.16 2.63 3.37 4.36 4.84 5.14 5.14 5.31 5.31 4.19 4.19 4.19 4.19 1.68 0.82 0 10 (els) 0.22 0.65 0.91 0.86 V10 d10 0100 V100 d100 Driveway Block# Lot# Ditch Lining (fps) (in) (els) (fps) (in) Culvert (in) Material 1.3 2.6 0.35 1.4 3.0 -Grass seed 0.9 2.6 0.23 1.0 2.9 --Grass seed -----1.4 6.6 2.27 1.5 7.4 12 8 1 Grass seed -1.4 7.7 308 1.5 8.6 --Grass seed 3.2 6.4 4.89 3.5 7.1 --Grass seed 3.4 6.9 6.11 3.7 7.7 15 8 7 Grass seed -----3.5 7.1 6.63 3.8 8.0 15 --Grass seed ----3.3 7.7 7.39 3.6 8.6 --Grass seed ----3.3 7.7 7.39 3.6 8.6 - -Grass sod --6.6 5.5 7.62 7.1 6.2 --Concrete' ------Concrete' 4.7 5.1 7.62 5.1 6.0 18 8 9 2.8 1.9 1.40 3.0 2.3 --Concrete' ------ 2.9 3.5 1.28 3.1 3.9 Concrete' ------2.5 3.7 1.28 2.7 4.1 12 8 10 Grass sod 2.1 3.4 0.87 2.2 3.7 -Grass seed 1.6 2.5 0.41 1.8 2.9 12 8 10 Grass sod V10 d10 0100 V100 d100 Driveway Block# Lot# Ditch Lining (fps) (in) (els) (fps) (in) Culvert (in) Material 1.5 2.3 0.29 1.6 2.6 --Grass seed 1.4 5.1 1.34 1.5 5.7 12 8 1 Grass seed ------1.8 7.5 3.67 1.9 8.3 12 --Grass seed >----- 1.9 11 .2 9.02 2.1 12.5 8 2 Grass seed 1.8 10.2 7.04 2.0 11.4 15 8 3 Grass seed --1.6 8.3 4.07 1.7 9.3 12 8 4 Grass seed V10 d10 0100 V100 d100 Driveway Block# Lot# Ditch Lining (fps) (in) (els) (fps) (in) Culvert (in) Material 1.7 3.8 0.93 1.8 4.3 --Grass seed 1.1 3.4 0.47 1.2 3.7 12 8 19 Grass seed -1.4 6.7 2.33 1.5 7.5 12 8 18 Grass seed - 1.9 6.5 2.91 2.0 7.2 - -Grass seed 3.0 5.6 3.55 3.2 6.3 12 8 17 Grass seed - 3.2 6.2 4.54 3.4 6.9 12 8 16 Grass seed 3.4 6.8 5.88 3.6 7.6 12 8 15 Grass seed 3.5 7.1 6.52 3.7 7.9 --Grass seed 3.5 7.2 6.93 3.8 8.1 --Grass seed 3.5 7.2 6.93 3.8 8.1 --Grass Sod 4.4 6.6 7.16 4.7 7.4 --Concrete2 4.6 4.9 7.16 5.0 5.8 15 8 14 Concrete' 4.3 4.3 5.65 4.7 5.1 15 8 13,14 Concrete 4.1 6.0 5.65 4.5 6.7 Concrete' 3.2 4.5 5.65 3.4 5.3 Grass Sod 3.2 4.5 5.65 3.4 5.3 Grass seed 2.6 4.8 2.27 2.8 5.4 12 8 13 Grass seed 2.1 3.7 1.11 2.3 4.2 12 8 11,12 Grass sod V,o d10 0 100 V100 d100 Driveway Block# Lot# Ditch Lining (fps) (in) (efs) (fps) (in) Culvert (in) Material 1.5 2.3 0.29 1.6 2.6 Grass seed 1.2 4.4 0.87 1.3 4.9 -Grass seed 1.2 5.3 1.22 1.3 5.9 12 8 7 Grass seed 1.2 5.2 1.16 1.2 5.8 12 8 6 Grass seed CITY OF COLLEGE STATION Pla.nning c!r Developmem &rviaJ SITE LEGAL DESCRIPTION: Williams Creek Phase 7 All Lots DATE OF ISSUE: 11/08/06 OWNER: Joe and Janet Johnson P.O. Box 800 Coleman, Texas 77845 TYPE OF DEVELOPMENT: SPECIAL CONDITIONS: DEVELOPMENT PERMIT PERMIT NO. 06-61 FOR AREAS OUTSIDE THE SPECIAL FLOOD HAZARD AREA RE: CHAPTER 13 OF THE COLLEGE STATION CITY CODE SITE ADDRESS: 9500 Rock Prairie Road DRAINAGE BASIN: Carter's Creek VALID FOR 12 MONTHS CONTRACTOR: Full Development Permit All construction must be in compliance with the approved construction plans All trees required to be protected as part of the landscape plan must be completely barricaded in accordance with Section 7.5.E., Landscape/Streetscape Plan Requirements of the City's Unified Development Ordinance, prior to any operations of this permit. The cleaning of equipment or materials within the drip line of any tree or group of trees that are protected and required to remain is strictly prohibited. The disposal of any waste material such as, but not lim ited to, paint, oil, solvents, asphalt, concrete, mortar, or other harmful liquids or materials within the drip line of any tree required to remain is also prohibited. ****TCEQ Phase II Rules in effect**** The Contractor shall take all necessary precautions to prevent silt and debris from leaving the immediate construction site in accordance with the approved erosion control plan as well as the City of College Station Drainage Policy and Design Criteria. If it is determined the prescribed erosion control measures are ineffective to retain all sediment onsite, it is the contractors responsibility to implement measures that will meet City, State and Federal requirements. The Owner and/or Contractor shall assure that all disturbed areas are sodden and establishment of vegetation occurs prior to removal of any silt fencing or hay bales used for temporary erosion control. The Owner and/or Contractor shall also insure that any disturbed vegetation be returned to its original condition, placement and state. The Owner and/or Contractor shall be responsible for any damage to adjacent properties, city streets or infrastructure due to heavy machinery and/or equipment as well as erosion, siltation or sedimentation resulting from the permitted work. In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to insure that debris from construction, erosion, and sedimentation shall not be deposited in city streets, or existing drainage facilities. I hereby grant this permit for development of an area outside the special flood hazard area. All development shall be in accordance with the plans and specifications submitted to and approved by the City Engineer in the development permit application for the above named project and all of the codes and ordinances of the City of College Station that apply. Date fl-C.7-o~ Date WILLIAMS CREEK, PHASE 7 Engineer's Estimate September 27, 2006 Item No. Description Streets & Sitework l jMobiliz~ti~n/Co;struction St~king 2 Clearing & Grubbing (ROW & Easements) 3 Strip and remove 6" topsoil (1500 c.y.) 4 Earthwork (est. cut = 4000 cy.) -~ ~~!ng & Incorpo~at~on ~f Lime, 6" ~~pth 6 Lime (hydrated) 7 6" Crushed Limestone Base 8 Hot Mix Asphaltic Concrete -2" depth 9 24" Ribbon Curb Estimated Quantity 4.9 7,779 126 7,332 5,994 l ,031 Unit Price LS 6,000.00 AC 3,000.00 LS 9,000.00 LS I 25 ,000.00 SY TON SY SY LF 2 .00 100 .00 8.00 8.75 8.75 Subtotal -Streets & Sitework Storm Drainage l 0 rl S"-HDPE-;-tormd~ainpipe~ structural backfill 11 Rock Riprap 12 Headwall w/footing and handrail base plates (handrail not included) 13 Standard Headwall for 18" pipe w/dissipator blocks 14 Concrete ditch lining (stamped & patteren~d) 15 Concrete splash pad with dissipator blocks 16 Concrete splash pad without dissipator blocks I 1 7 Concrete channel lining 18 6: I SET for 18" HOPE pipe 19 4: 1 SET for 18" HOPE pipe 20 Hydromulch Seeding (ditches & easements) 21 Silt Fence Barriers in roadside ditches 22 Construction Exit Water -23 1 8-;;Water PVC CL200 (C909)~t~uct~ral backfill 24 8" Water PVC CL200 (C909) non-structural backfill 25 6" Water PVC CL200 (C909) structural backfill 26 6" Water PVC CL200 (C909) non-structural backfill 27 ~· Wa~~~_PVC Sch 40 (02241) non-structural backfill 28 8" M.J. Gate Valve 29 6" M.J. Gate Valve 30 3" M.J. Gate Valve 31 l8"x 8" M .J. Tee 32 8"x 6" M.J. Reducer 33 8"x 3" M.J. Reducer 34 6"x 3" M.J. Reducer 35 8" x 22.5° M.J. Bend 36 8" x 11.25° M.J. Bend 37 6" x 45° M.J. Bend 773 28 128 l 80 80 LF SY I LF EA SY 1 SF 1 60 SF 12 SY 6 EA I 3 I EA -1 -23)I6 1 SY- 300 LF 32.00 60.00 300.00' 2,000.00 60.00 8.00 4 .00 45.00 1,800.00 1,700.00 0 .65 3.00 EA 1,500.00 Subtotal -Stom1 Drainage 34 905 34 663 522 4 2 I 4 LF LF LF LF LF EA EA EA EA EA EA EA EA EA EA 30.00 27 .00 25 .00 22.00 16 .00 900.00 650.00 500.00 400.00 375.00 350.00 325.00 325.00 325.00 300.00 Estimated Cost 6,000 14,700 9,000 25,000 15,558 12,600 58,656 52,448 9,021 $202,983 24,736 1,680 38,400 2,000 4,800 640 240 540 10,800 5, 100 15,415 900 1,5 00 $106,751 1,020 24,435 850 14,586 8,352 3,600 650 500 800 375 350 325 325 325 l ,200 Item No. 38 6" x 11.25° M.J. Bend WILLIAMS CREEK, PHASE 7 Engineer's Estimate September 27, 2006 Description 39 Fire Hydrant Assembly (w/vert. extension, 8"x 6" tee, all necessary fittings) 40 Fire Hydrant Assembly (w/vert. extension, 6"x 6" tee, all necessary fittings) 41 J211 Blow Off Assembly 42 tConnect to existing water line _ _____ ____ _ ________ _ 43 l" Water Service, Type K Copper S 15' (avg. length = 2 ft.) 44 l" Water Service Type K Copper > 15' (avg. length = 51 ft.) 45 1.5" Water Service, Type K Copper S 15' (avg. length = 2 ft.) 46 1.5" Water Service Type K Copper > 15' (avg. length = 85 ft.) I I Estimated Unit Quantity Price 4 I EA 300.00 I 1 I EA 2,900.00 1 , EA 2,800.00 3 EA 750.00 1 EA 500.00 ----- 3 EA 500.00 2 EA 1,400.00 3 EA 600.00 4 EA 1,500.00 Subtotal -Water! ESTIMATED CONSTRUCTIONJ Estimated Cost 1,200 2,900 2,800 2,250 500 1,5001 2,800 1,800 6,000 $79,443 $389,177 Water System Report for Williams Creek Subdivision, Phase 7 College Station, Texas October 2006 Prepared By: Civil Development, Ltd. 2900 Longmire Drive, Suite K College Station, Texas 77845 (979) 764-7743 (X.(a/ I Df rJ. /bi.t; q: '):;;_ l1t. GENERAL INFORMATION l ocation: Williams Creek Subdivision, Phase 7 is located south of Williams Creek, Phases 1-5 in southern College Station. It is near the intersection of Greens Prairie Road and Rock Prairie Road. General Note: The subdivision has 19 lots. Domestic water for those 19 lots will be provided by the Wellborn Special Utility District through connections with lines in Phases 1-5 . There is no public sewer service in this area at this time. On-Site Sewer Systems for each lot will be installed when the houses are built. land Use: Design Criteria Primary Water Supply: Domestic Demand: Avg. Pop Density: Single Family Residential WATER SYSTEM ANALYSIS Existing 8" line along Williams Creek Drive 2.67 people per lot Average Flow: Peaking Factor: 100 gpd/cap or 267 gpd per lot = 0.18 gpm per lot 4 Peak Flow: Design Flow: Fire Demand: 0.74 gpm per lot 1.50 gpm per lot Fire Flow: 1000 gpm @ hydrant nearest the most hydraulically remote point Hydrant Number: WC7 FH 1 Pipe: PVC DR-14 C909 Roughness Coeff: 150 (Hazen Williams) Hydraulic Software: Haestad Methods WaterCAD v.6.0 Existing City System Pressure Tests Flow Hydrant #: Last hydrant of Williams Creek Drive in Ph 4. Flowrate: 1160 gpm Pressure Test Location: Home at NW comer of Joseph Creek Ct & Williams Creek Dr. Static Pressure: 68 psi (157 ft water) Residual Pressure: 60 psi (139 ft water) Applicable Exhibits: Exhibit A -Water System Schematic Exhibit B -Flow Test Report Water System Summary Criteria Min. Pressure -fire (psi) Max. Velocity (fps) Max. Length of 6 "pipe (ft) (connected to 2:_ 8 "on both ends) Max length of 6 "pipe (ft) (not connected on both ends) Max. Length of 3 "pipe (ft) i t ! Required ! i i i 20 l ' ' 12 1500 800 500 As Designed 43 6.57 NA 699 229 Applicable Exhibits: Exhibit C -Junction Sununary for Static Conditions Exhibit D -Juncti on Summary for Fire Flows Exhibit E -Pipe Sunm1ary for Fire Flows Conclusion location WC7-3 P34 8 The proposed water system fo r Williams Creek, Phase 7 invo lves the extension of lines from Phases 1-5. It has been designed to meet all criteria fro m the B/CS Design Standards and the analys is above indicates it wi II exceed the minimum performance requirements ofTCEQ and the C ity of College Station W'C4-6 E x h ibit A w illiuMS w uter Creek Syster1 Phuse 7 Scher1u tic W'C6-2 W'CS- .0 <>_,. W'CS-8 i> W'CS-2 M " W'CS-3 f:! CS-4 lo W'CS-7 q">"' The wQter systeM for PhQse 7 li es wi thin th is bo x ed QreQ . \./C7 -FH1 M 0 ... ... "' .... "' ... W'C7-6 W'C7-fH2 \./C7-3 ,• Exhibit B Water System Flow Test Report Date: March 2, 2006 Development Project: Williams Creek Phase 5 Flow Test Location: FH at end of Williams Creek Drive Pitot Reading: ~~~~~~~~ Flowrate: 1160 (gpm from chart)* see note below ~~~~~~~~ Pressure Guage Location: New home at Joseph Creek Ct @ Williams Creek Dr. (NW comer) Static (psi): 68 Residual (psi): 60 Kent Laza printed name Others present: Steven Cast ~~~~~~~~~~~~ Note: The f/owrate of 1160 gpm corresponds to a Pitot Reading of 40 psi on the Computation Table from the guage manufacturer (Joseph G. Piiiard Co., Inc, New York). This table was used by Wellborn SUD prior to the implementation of the City's requirement for the use of a similar table in NFPA 291. The flowrate for a 40 psi pitot reading in NFPA 291 is 1180 gpm. The lower flowrate was used for modeling purposes in this report. .· -- Label ' Elevation ------------·-----·- (ft) WC1-1 244 WC1-2 234 WC1-3 233 WC1-4 235 WC1-5 234 WC1-6 232 WC1-7 232 WC1-8 247 WC1-9 246 WC2-1 250 WC2-2 272 WC2-3 281 WC2-4 240 WC2-5 276 WC3-1 234 WC3-2 242 WC3-4 264 WC3-5 282 WC4-1 272 WC4-2 272 WC4-3 266 WC4-4 250 WC4-5 248 WC4-6 232 WC5-1 253 WC5-2 253 WC5-3 252 WC5-4 252 WC5-5 239 WC5-6 232 WC5-7 230 WC5-8 226 WC6-1 252 WC6-2 246 WC7-2 242 WC7-3 247 WC7"4 242 WC7-6 230 WC7-7 237 WC7-F H1 244 WC7-FH2 229 Exhibit C Williams Creek Ph 7 Water System Analysis Static Flow Conditions I Dem:~~ J ---Hydraulic Pressure Grade r (gpm)-1 -~--------. (ft) (psi) 0 403.50 I 69.01 0 403.50 73.33 0 403.50 73.77 0 403.50 72 .90 0 403.50 73 .33 3 403.50 74.20 10.5 403.36 74.14 12 403.49 67.71 10.5 403.35 68.08 0 403.50 66.41 1.5 403.47 56.88 10.5 403.47 52.99 15 403.46 70.72 1.5 403.46 55.15 13.5 403.44 73.31 24 403.43 69.84 10.5 403.43 60.32 18 403.43 52.54 9 403.43 56.86 0 403.43 56.86 I 4.5 403.42 59.45 12 403.24 66.30 7.5 403.39 67.23 6 403.37 74.15 6 403.36 65.05 0 403.36 65.05 0 403.35 65.48 3 403.35 I 65.48 0 403.33 71 .10 12 403.31 74.12 0 403.30 74 .98 9 403.26 76 .69 6 403.35 65.48 6 403.31 68.06 0 r 403.29 69.78 4.5 403.26 67.61 0 :• 403.29 69.78 6 403.25 74.96 0 { 403.29 71 .94 12 . 403.29 68.92 7.5 403.27 75.40 ~owest Pressure in Ph 7 = 67.61 ••• Note: The lowest pressures shown above represent the most hydraulically remote location in the Ph 7 system. The nearest fire hydrant is WC7-FH1. This is the location where a 1000 gpm fire demand is placed for modeling purposes. ·' Exhibit D Williams Creek Subdivision Phase 7 Water System Analysis -Junction Summary Fire Flow Conditions f'- ..c Cl.. ~ 0 en E Cll ----1-·-~---,----1---. . I H draulic __ __Label _ _ -~levat1on _ Deman~_J ---~rad!:'. -J-~ressure (ft) (gpm) I (ft) (psi) WC1-1 244 0.0 386.55 61 .67 WC1-2 234 0.0 386.55 66 .00 WC1-3 233 0.0 386.55 66.43 WC1-4 235 0.0 386.55 65 .57 WC1-5 234 0.0 386.55 66 .00 WC1-6 232 3.0 386.55 66 .87 WC1-7 232 10.5 386.41 66 .81 WC1-8 247 12.0 386.54 60 .37 WC1-9 246 10.5 386.41 60 .75 WC2-1 250 0.0 386.55 59 .08 WC2-2 272 1.5 385.70 49.19 WC2-3 281 10.5 385.70 45.30 WC2-4 240 15.0 386.12 63 .22 WC2-5 276 1.5 385.09 47.20 WC3-1 234 13.5 385.83 65.69 WC3-2 242 24 .0 385.55 62 .11 WC3-4 264 10.5 385.36 52.51 WC3-5 282 18.0 385.24 44.67 WC4-1 272 9.0 383.21 48.12 WC4-2 272 0.0 382.97 48.01 WC4-3 266 4.5 382.96 50.60 WC4-4 250 12.0 382.79 57.45 WC4-5 248 7.5 378.65 56.53 WC4-6 232 6.0 376.52 62.53 WC5-1 253 6.0 374.16 52.42 WC5-2 253 0.0 373.59 52 .17 WC5-3 252 0.0 372.42 52 .10 WC5-4 252 3.0 372.42 52.10 WC5-5 239 0.0 365.99 54.94 WC5-6 232 12.0 360.42 55.56 WC5-7 230 0.0 360.42 56.43 WC5-8 226 9.0 360.38 58.14 WC6-1 252 6.0 374.15 52.85 WC6-2 246 6.0 374.11 55.43 WC7-2 242 0.0 347.81 . 45.78 WC7-3 247 4.5 347.79 43.61 WC7-4 242 0.0 347.81 45.78 ; WC7-6 230 6.0 347.77 50.95 WC7-7 237 0.0 347.81 47.94 WC7-FH1 244 1,012.0 347.81 44.91 WC7-FH2 229 7.5 347.80 51.40 Lowest Pressure in Ph 7 = 43.61 • ' . . Exhibit E Williams Creek Subdivision, Phase 7 Water System Analysis -Pipe Summary Fire Flow Conditions Length ------~ Label ___ (ft-) __ Dia me . ____ Material ~-----1 Hazen--T[)i;-ch~~;-1 Velocity (in) Williams c --(gp~) 1---(ws) ___ P1 12 802 12 PVC 150 0.00 0.00 P2 12 800 12 PVC 150 0.00 0.00 P3 12 575 12 PVC 150 0.00 0.00 P4 12 113 12 PVC 150 0.00 0.00 PS 8 217 8 PVC 150 13.50 0.09 P6 3 373 3 PVC 150 10.50 0.48 P7 8 718 8 PVC 150 22 .50 0.14 PB 3 375 3 PVC 150 10.50 0.48 pg 12 455 12 PVC 150 -36.00 0.10 P10 8 767 8 PVC 150 113.09 0.72 P11 8 579 8 PVC 150 102.59 0.65 P12 8 1078 8 PVC 150 84 .59 0.54 P13 12 300 12 PVC 150 -1 ,027.92 2.92 P14 12 407 12 PVC 150 -1,039.92 2.95 P15 8 687 8 PVC 150 150.59 0.96 P16 8 798 8 PVC 150 137.09 0.87 P17 8 454 8 PVC 150 10.50 0.07 P18 12 793 12 PVC 150 1,111 .00 3.15 P19 12 103 12 PVC 150 1,102.00 3.13 P20 6 440 6 PVC 150 16.50 0.19 P21 3 375 3 PVC 150 12.00 0.54 P2210 786 10 PVC 150 1,085.50 4.43 P23 10 392 10 PVC 150 1,078.00 4.40 P2410 439 10 PVC 150 1,072.00 4.38 P25 10 109 10 PVC 150 1,054.00 4.31 P26 10 224 10 PVC .150 1,054.00 4.31 P27 3 132 3 PVC 150 3.00 0.14 P28 8 419 8 PVC 150 1,051 .00 6.71 P29 8 362 8 PVC 150 1,051.00 6.71 P30 6 231 6 PVC 150 9.00 0.10 P31 3 164 3 PVC 150 9.00 0.41 P32 6 722 6 PVC 150 12.00 0.14 P33 3 31 5 3 PVC 150 6.00 0.27 P34 8 8_52 I< 8 I' PVC .150 1,030.00 6.57 : '"p3s a 103 8 I: PVC I• 150 18.00 0.11 ,'P,36 8 24 8 PVC -150 13.50 '/ .. 0.'09 ,. <P37 6 672 6 . 'I'. ·PVC ;'I t. . 150' 13.so 0.15 I• P38 3 I• 222 . 3 PVC 150 6.00 . 0.27. ' ' -' P39 8 267 8 PVC . 150 0.00 0.00 P40 3 298 3 PVC 150 4.50 0.20 P41 8 855 8 PVC 150 I -16s.sg · 1.06 Highest Velocity in Ph 7 = 6.57 Highest Velocity in System = 6.7.1 Drainage Report for Williams Creek Subdivision -Phase 7 College Station, Texas September, 2006 Developer: Joe and Janet Johnson 1400 South Commercial Street Coleman, Texas 76834 (325) 625-2124 Prepared By: Civil Development, Ltd. 2900 Longmire Drive, Suite K Co11ege Station, Texas 77845 (979) 764-7743 CERTIFICATION I certify that this report for the drainage design for the Williams Creek Subdivision -Phase 7, was prepared by me in accordance with the provisions of the City of College Station Drainage Policy and Design Standards for the owners hereof, with the exception that ston11 water runoff detention is not being proposed for this project since the runoff will discharge directly into tributaries of Carters Creek and then into the l 00-year floodplain and the primary channel of Carters Creek. _ .... ..,.,~"""~·"-\ --'IE. OF l' \\ ~-\ !>-......... $-+-, .. ,,,, 0 •• *··. -<{'fl ;' .. ·· ··. ~ "• t.·:· ··*" ;1!'•••11········ ~ * ~ JOSEPH •• P .................... ~ .••.••.•••••• · •• ~CHULTZ I . . ............ ~ 0 \ ~ 65889 l t$J ;(\ ··.<$'G ~Q .• ~ _, ~r.. •• • .fSTE~;-.••#-6 ' ~iS'; •••••••• ~,0 ... \\:ONAL 'f:.\...._-,,~...,.~ q .-'Z. ~,D& .. ,. TABLE OF CONTENTS DRAINAGE REPORT WILLIAMS CREEK SUBDIVISION -PHASE 7 CERTIFICATION ................................................................................................................................................................. I TABLE OF CONTENTS ....................................................................................................................................................... 2 LIST OF TABLES .................................................................................................................................................................. 2 INTRODUCTION .................................................................................................................................................................. 3 GENERAL LOCATION AND DESCRIPTION ................................................................................................................. 3 FLOOD HAZARD INFORMATION ................................................................................................................................... 3 DEVELOPMENT DRAINAGE PATTERNS ...................................................................................................................... 3 DRAINAGE DESIGN CRITERIA ....................................................................................................................................... 3 STORM WATER RUNOFF DETERMINATION .............................................................................................................. 4 STORM CUL VERT & DRAINAGE CHANNEL DESIGN ............................................................................................... 5 CONCLUSIONS ..................................................................................................................................................................... 7 APPENDIX A ......................................................................................................................................................................... 8 Time of Concentration Equations & Calculations APPENDIX B ........................................................................................................................................................................ 12 Storm Sewer Culvert/Pipe Data & Design Calculations APPENDIX C ....................................................................................................................................................................... 19 Drainage Ditch Data & Lining Material EXHIBIT A ........................................................................................................................................................................... 21 Drainage Area Map -Post-Development, Culverts & Pipes EXHIBIT B ........................................................................................................................................................................... 23 Drainage Area Map -Post-Development, Ditch Velocities LIST OF TABLES TABLE 1 -Rainfall Intensity Calculations .............................................................................................. 4 TABLE 2 -Time of Concentration (tc) Equations .................................................................................. 4 TABLE 3 -Post-Development Runoff Information ................................................................................ 5 TABLE 4 -Headwall Opening Equations & Data ................................................................................... 6 2 DRAINAGE REPORT WILLIAMS CREEK SUBDIVISION -PHASE 7 INTRODUCTION The purpose of this report is to provide the hydrological effects of the construction of the Williams Creek Subdivision -Phase 7, and to verify that the proposed storm drainage system meets the requirements set forth by the City of College Station Drainage Policy and Design Standards. GENERAL LOCATION AND DESCRIPTION The project is located on a portion of a l l 6 acre tract located east of Rock Prairie Road and south of Greens Prairie Road in College Station, Texas. This report addresses Phase 7 of thi s subdivision, which is made up of 25.8 acres. The site is predominantly wooded. The existing ground elevations range from Elevation 206 to Elevation 246. The general location of the proj ect site is shown on the vicinity map in Exhibit A. FLOOD HAZARD INFORMATION The project site is located in the Carters Creek Drainage Basin. This phase of the proposed subdivision is located in a Zone X Area according to the Flood Insurance Rate Map prepared by the Federal Emergency Management Agency (FEMA) for Brazos County, Texas and incorporated areas, Community No. 481195 and 480083, Panel No. 2050, Map No. 4804 l C0205D, effective dated February 9, 2000. The location of the Flood Hazard Area adjacent to this property is shown on Exhibit A as the 100-year floodplain. DEVELOPMENT DRAINAGE PATTERNS Prior to development, the storm water runoff for Phase 7 flows in a northerly or easterly direction into the Carters Creek floodplain or into existing tributaries which discharge into Carters Creek. DRAINAGE DESIGN CRITERIA The design parameters for the storm drainage analysis are as follows: • The Rational Method is utilized to detennine peak storm water runoff rates for the stom1 drainage design for culverts, ditches and channels. • Design Stom1 Frequency Storm culverts Storm pipe & roadside ditches • Runoff Coefficients 25-and l 00-year storm events 10-and 100-year storm events Post-development (I acre minimum lot size) c = 0.50 • Rainfall Intensity eq uations and valu es for Brazos County can be found in Table I . • Time of Concentration, tc -Calculations are based on the method found in the TR-55 publication. Refer to Table 2 for the equati ons and Appendix A for calculati ons. T he runoff flow path used for calculating th e post-development times of concentration for th e larger drainage areas are shown on the exhibits. Smaller drainage areas use a minimum le , ' of l 0 minutes to determine the rainfall intensity values. Exhibit A has the runoff flow paths used for the drainage areas for the culvert and channel design. STORM WATER RUNOFF DETERMINATION The peak runoff values were detennined in accordance with the criteria presented in the previous section for the 10, 25, 50, and 100-year storm events. The drainage areas for the post- development condition are shown on Exhibits A & B. Post-development runoff conditions for the drainage structure design drainage areas are summarized in Table 3. TABLE 1 -Rainfall Intensity Calculations Rainfall Intensity Values (in/hr) Storm Event 110 !is 1100 ~= 10 min 8.635 9.861 11.639 I= b I (tc+dt I = Rainfall Intensity (in/hr) tc = L/(V*60) tc =Time of concentration (min) L = Length (ft) V = Velocity (ft/sec) Brazos County: 10 year storm 25 year storm 50 year storm 100 year storm b= 80 b= 89 b= 98 b= 96 d= 8.5 d= 8.5 d= 8.5 d= 8.0 e= 0.763 e= 0.754 e= 0.745 e= 0.730 (Data taken from State Department of Highways and Public Transportation Hydraulic Manual, page 2-16) TABLE 2 -Time of Concentration (tc) Equations The time of concentration was determined using methods found in TR -55, "Urban Hydrology for Small Watersheds. " The equations are as f ollows: Time of Concentration: For Sheet Flow: For Shallow Concentrated Flow: Tc= Tt(sheet now)+ T1(concentrated sheet now) where: T1 =Travel Time, minutes where: T1 = travel time, hours n =Manning's roughness coefficient L = flow length, feet P2 = 2-year, 24-hour rainfall = 4.5" s = land slope, ft/ft T, = LI (60*V) where: T1 =travel time, minutes V =Velocity, fps (See Fig 3-1 , App . A) L = flow length , feet Refer to Appendix A for calculations. TABLE 3 -Post-Development Runoff Information Area tc 10-year storm 25-year storm 100-year storm Culvert/ c Pipe No. Area# A 110 010 125 02s 1100 0100 (acres) (min) (in/hr) (cfs) (in/hr) (cfs) (in/hr) (cfs) __ Pipe No.~ 1 0.27 0.50 10.0 8.635 1.17 9.861 1.33 11 .639 1.57 -. --------------· ---·-Culvert No. 1 5 4.70 0.50 45.0 3.840 9.02 4.428 10.41 5.291 12.43 .. --------Culvert No. 2 3 0.51 0.50 10.0 8.635 2.20 9.861 2.51 11 .639 2.97 --. -------------·------------·--. Culvert No. 3 4 2.71 0.50 22.2 5.867 7.95 6.731 9.12 7.977 10.81 ·-----. -----------------·-------Culvert No. 4 2 14.33 0.50 33.6 4.611 33.04 5.305 38.01 6.314 45.24 The Rational Method: Q = CIA I = b I (tc+d)0 tc = U(V*60) L = Length (ft Q =Flow (cfs) le = Time of concentration (min) A= Area (acres) C = Runoff Coeff. I = Rainfall Intensity (in/hr) Brazos County: 10 year storm b = 80 d = 8.5 e = 0.763 V = Velocity (fUsec) 25 year storm 100 year storm b = 89 b = 96 d = 8.5 d = 8.0 e = 0.754 e = 0.730 STORM CULVERT & PIPE DESIGN The culverts for this project have been selected to be HDPE stom1 sewer pipe meeting the requirements set forth by the City of College Station Drainage Policy and Design Standards. There will be dissipator blocks at the downstream end of Culvert No. 4 to slow the discharge out of the pipe and to help control erosion. Pipe No. 9 has a headwall and rock riprap at the outfall. Runoff from the proposed streets will be collected by the roadside ditches and conveyed to the culvert structures, Pipe No. 9, or to the Rock Prairie Road ditches. Headwall openings will be used for this development at Culvert No. 4. These openings in the headwalls will allow the ditches to be less deep at the culvert location, thereby reducing the amount of disturbance due to the construction of the street ditch side slopes. The drainage areas for the culverts and storm pipe designs are shown on Exhibit A. The drainage areas for the headwall openings were taken from Exhibit B. The headwall openings for the left and right side ditches will be placed at the low point of the ditch to collect the storm water, which will then be discharged directly through the concrete headwall and onto the concrete splash pads at each end of the culvert. The proposed headwall openings were analyzed using the orifice equation, solving for the depth of water at the opening for the 10-and 100-year storm events. It was assumed that 25 % of the open area would be clogged for the opening desi gn. Design calculations and data for the headwall openings are shown in Table 4. 5 TABLE 4 -Headwall Opening Equations & Data Q = 4.82 * Aq * y 1'2 ¢ y =(QI (4.82 * Aq))2 Where: Q = flow at inlet, cfs Ag =open area, ft2 = 0.56 ft2 for 1-9"x9" opening y = depth at inlet, ft Headwall Actual Design Ag 10-Year Storm Opening Opening Ag 25% Location Size clogging 0 10 Depth, y {ft2) {ft2) {cfs) (ft) Left 7 -9'"x9'" 3.94 2.96 6.70 0.22 --- Right 7 -9'"x9'" 3.94 2.96 9.50 0.44 100-Year Storm 0100 Depth, y {in) {cfs) (ft) 2.7 9.02 0.40 - 5.3 12.81 0.81 As shown by these calculations, the maximum depth of water for the 100-year stonn for the proposed headwall openings is 9. 7" on the right side. The top of the headwall is Elevation 221.0, and the bottom of the headwal l opening is Elevation 219.55. For the 100-year stonn event, this results in 1.05' of freeboard for Headwall Opening Left, and 0.64' of freeboard for Headwall Opening Right. The typical roadway ditch will be constructed such that the ditch between the right-of-way and the edge of pavement is a minimum of 18" in depth, and will be graded as necessary to ensure that the runoff from the 100-year storm event will remain within the street right-of-way. Appendix B presents a summary of the storm culvert design parameters and calculations. The proposed pipes were designed based on the 25-year storm event, and data is also given for the l 00-year storm event. As shown in the summary, the culverts have headwater elevations that are at least one foot below the roadway elevation for the 25-year stom1 event. Also, the culverts pass the 100-year storm event without overtopping the roadway. As required by College Station, the velocity of flow in the pipes is not lower than 2.5 feet per second, and they do not exceed 15 feet per second. As the data shows, even during low flow conditions, the velocity in the pipe will exceed 2.5 feet per second and prevent sediment build-up in the culvert. The maximum velocity for culverts in this development will be 8.5 feet per second occurring in Culvert No. 4. Appendix B contains a summary of the culvert calculator data for the 25-and 100-year storm events. The Culvert No. 4 will discharge onto a concrete pad with dissipator blocks to reduce the velocity. The storm water runoff in the roadside ditches of the northern most portion of Campbell Court will discharge into Pipe No. 9, which wi ll ultimately convey the water into Carters Creek. The maximum velocity for this pipe is 9.2 feet per second. Appendix B contains a summary of th e pipe design parameters and calculations for the 25-and I 00-year storm events. There will be dissipator blocks and rock riprap at the end of the pipe to slow the velocity and reduce erosion. The velocity of the flow in the roadside ditches was evaluated for the I 0-year and 100-year storm events. The drainage areas are shown on Exhibit B. (in) 4.8 9.7 The city requirements for ditch lining material are as follows: Maximum Design Velocities of Various Surface Treatments1 Surface Treatment Exposed Earth* Grass -Seeded Grass -Sodded Impermeable (Concrete, Gunite, Etc.) *Temporary Channels Only Maximum Design Velocity, (ft/sec) 3.0 4.5 6.0 10.0 1From "Erosion and Sediment Control Guidelines for Developing Areas in Texas" by the Soil Conservation Service In Appendix C the ditch velocities are summarized including comments stating the ditch lining material used. The ditch lining material is also shown in the construction drawings. Although concrete or grass block sod are not required, these have been included in areas where erosion is anticipated. CONCLUSIONS The construction of this project will increase the storm water runoff from this site. However, the runoff will be carried through a drainage system to existing drainages and then into the l 00- year floodplain. Due to the location of this project and its proximity to Carters Creek's confluence with the Navasota River, the peak runoff from this development will occur much sooner than the peak runoff in Carters Creek, therefore, the increase in runoff has no affect on the water surface elevation in Carters Creek. The increased flow directly into Carters Creek will not have a significant impact on the surrounding property. No flood damage to downstream or adjacent landowners is expected as a result of this development. 7 APPENDIX A Time of Concentration Equations & Calculations 8 Time of Concentration Calculations Williams Creek Subdivision -Phase 7 Drainage Area #2 Sheet Flow: n= 0.24 (dense grass) P= 4.5 L= 200 Elev1= Elev2= Slope= 0.010 T1= 0.007(L*n)0 8 = 0.461 hours= 27.7 min (P)os*(S)oA Concentrated Flow 1 : V= 2.75 fps (unpaved) L= 455 Elev1= Elev2= Slope= 0.029 T1= L/(60*V) = 2.8 min Concentrated Flow 2: V= 2.85 fps (unpaved) L= 535 Elev1= Elev2= Slope= 0.029 T1= L/(60*V) = 3.1 min ITc= 33.6 min Drainage Area #4 Sheet Flow: n= 0.24 (dense grass) P= 4.5 L= 200 Elev1= Elev2= Slope= 0.020 T1= 0.007(L *n)0 8 = 0.349 hours= 20 .9 min (P)os*(S)o4 Concentrated Flow 1 : V= 2.25 fps (unpaved) L= 175 Elev1= Elev2= Slope= 0.020 T1= L/(60*V) = 1.3 min ITc= 22.2 min Drainage Area #5 Sheet Flow: L= 175 n= P= 0.007(L *n)0 8 = (P)°s*(S)°-4 Concentrated Flow 1 : V= L= 1315 U(60*V) = 0.24 (dense grass) 4.5 Elev1= 0.385 hours= 1.0 fps (unpaved) Elev1= 21.9 min 45.0 min Slope= 0.012 23 .1 min Slope= 0.004 .... <+--.... <+- <1J a. 0 ..- "' <1J "' ~ :::J 0 u ~ <1J ..... "" :JC 3-2 . 50 - .20 - .10 .06 .04 - . 02 - .01 - .005 I 1 ) J I ' J ... J . °l:> .:..q, )-°t>I ~ ...... <U ~~ Q..;1 I I ' I I I I I 2 ~ ~ f ' J I 4 j J I ) I I I 6 I I J J J I Average velocity, ft/sec (2 !0-Vl-TR·55. Second Ed .. June 198Gl u J .· ,. I I I 10 J I I I I I , , I 20 APPENDIXB Storm Sewer Culvert/Pipe Data & Design Calculations 12 W illiams Creek Subdivision -Phase 7 Culvert & Pipe Summary Size Inlet Invert #of Length Slope Elev Culvert No. Barrels (in) (ft) (%) (ft) 1 2 18 60.0 0.50 244.35 2 1 18 60.0 0.50 241.24 3 1 18 54.0 0.50 238.80 4 3 18 64.0 1.00 214.53 Inlet Invert #of Size Length Slope Elev Pipe No. Barrels (in) (ft) (%) (ft) 9 1 18 344.5 5.05 220.20 Outlet Top of Road 25-year storm Invert Elev Design Flow Vis (ft) (ft) (cfs) (fps) 244.05 247.15 10.41 2.9 240.94 244.30 2.51 1.4 238.53 242.51 9.12 5.2 213.89 222.70 38.01 7.2 Outlet Top of Road 10-year storm Invert Elev Actual Flow V,o (ft) (ft) (cfs) (fps) 202.82 ·1 .17 8.5 ·Design Flow used for calculalions assuming 25% reduclion in pipe area: Q 10 = 1.89 cfs and Q100 = 2.54 cfs 100-year storm HW Design Flow V 100 HW (ft) (cfs) (fps) (ft) 245.88 12 43 3.5 246.02 242.52 2.97 1.7 242.55 241.10 10.8 1 6.1 241.39 217.38 45.24 8.5 218.21 100-year storm HW Actual Flow V 100 HW (ft) (cfs) (fps) (ft) • 1.57 9.2 Culve rt 1 -25 Year Storm Cu lvert Calculator Entered Data: Shape ........................ . Number of Barrels ............ . Solving for .................... . Chart Number ................... . Scale Number ................... . Chart Description .............. . Scale Description .............. . Overtopping .................... . Flowrate ....................... . Manning ' s n .................... . Roadway Elevation .............. . Inlet Elevation .............. . Outlet Elevation ............... . Diameter ....................... . Length ......................... . Entrance Loss .................. . Tailwater ...................... . Computed Results: Headwater ...................... . Slope .......................... . Velocity ....................... . Circular 2 Headwater 1 3 CONCRETE PIPE CULVERT ; NO BEVELED RING ENTRANCE GROOVE END ENTRANCE, PIPE PROJECTING FROM FILL Off 10.4100 cfs 0.0120 247.1500 ft 244.3500 ft 244.0500 ft 18.0000 in 60.0000 ft 0.5000 1.5000 ft 245.8772 ft Outlet Control 0.0050 ft/ft 2.9454 fps Culvert 1 -100 Year Storm Culvert Calculator Entered Data: Shape .......................... . Number of Barrels .............. . Solving for .................... . Chart Number ................... . Scale Number ................... . Chart Description .............. . Scale Description .............. . Overtopping .................... . Flowrate ....................... . Manning ' s n .................... . Roadway Elevation .............. . Inlet Elevation .............. . Outlet Elevation ............... . Diameter .................... . Length ......................... . Entrance Loss .................. . Tailwater ...................... . Computed Results: Headwater ................... . Slope ....................... . Velocity .................... . Willi ams Creek Subdivision -Phase 7 Co l lege Station, Texas Circular 2 Headwater 1 3 CONCRETE PIPE CULVERT; NO BEVELED RING ENTRANCE GROOVE END ENTRANCE, PIPE PROJECTING FROM FILL Off 12.4300 cfs 0 .0120 247.1500 ft 244.3500 ft 244.0500 ft 18.0000 in 60.0000 ft 0.5000 1.5000 ft 246.0164 ft Outlet Control 0.0050 ft/ft 3.5170 fps Culvert 2 -25 Year Storm Culvert Calculator Entered Data: Shape .......................... . Number of Barrels .............. . Solving for .................... . Chart Number ................... . Scale Number ..... . Chart Description .............. . Scale Description .............. . Overtopping .................... . Flowrate . . . . . . . . . . . . . . . ....... . Manning 's n .................... . Roadway Elevation .............. . Inlet Elevation . . . . . . ......... . Outlet Elevation ............... . Diameter ....................... . Length ......................... . Entrance Loss .................. . Tailwater ............ . Computed Results: Headwater ...................... . Slope .......................... . Velocity ....................... . Circular 1 Headwater 1 3 CONCRETE PIPE CULVERT; NO BEVELED RING ENTRANCE GROOVE END ENTRANCE, PIPE PROJECTING FROM FILL Off 2 .5100 cfs 0.0120 244.3000 ft 241.2400 ft 240.9400 ft 18.0000 in 60 .0000 ft 0.5000 1.5000 ft 242.5161 ft Outlet Control 0.0050 ft/ft 1.4204 fps Culvert 2 -100 Year Storm Culvert Calculator Entered Data: Shape .......................... . Number of Barrels .............. . Solving for .................... . Chart Number ................... . Scale Number ................... . Chart Description . . . . . ........ . Scale Description . . . . . ........ . Overtopping .................... . Flowrate ....................... . Manning' s n .................... . Roadway Elevation .............. . Inlet Elevation . . .......... . Outlet Elevation ............... . Diameter ....................... . Length ......................... . Entrance Loss .................. . Tailwater ....... . Computed Results: Headwater . . . . . . . . . ......... . Slope . . . . . . . . . . . ........ . Velocity ....................... . Williams Creek Subdivision -Phase 7 College Stat i on, Texas Circular 1 Headwater 1 3 CONCRETE PIPE CULVERT; NO BEVELED RING ENTRANCE GROOVE END ENTRANCE, PIPE PROJECTING FROM FILL Off 2.9700 cfs 0 .0120 244.3000 ft 241.2400 ft 240.9400 ft 18.0000 in 60.0000 ft 0.5000 1 .5000 ft 242.5465 ft Outlet Control 0.0050 ft/ft 1 .6807 fps Culvert 3 -25 Year Storm Culvert Calculator Entered Data: Shape .......................... . Number of Barrels .............. . Solv ing for .................... . Chart Number . . . . . . . . . . . ..... . Scale Number . . . . . . . . . . . ..... . Chart Descript i on .............. . Scale Description .............. . Overtopping .................... . Flowrate ....................... . Manning ' s n .................... . Roadway Elevation .............. . Inlet Elevation ................ . Outlet Elevation ............... . Diameter ....................... . Length ......................... . Entrance Loss ........ . Tailwater ............ . Computed Results: Headwater ...................... . Slope .......................... . Velocity ....................... . Circular 1 Headwater 1 3 CONCRETE PIPE CULVERT; NO BEVELED RING ENTRANCE GROOVE END ENTRANCE, PIPE PROJECTING FROM FILL Off 9.1200 cfs 0.0120 242.5100 ft 238.8000 ft 23 8.5300 ft 18.0000 in 54.0000 ft 0 .5000 1.5000 ft 240.9960 ft Outlet Control 0.0050 ft/ft 5.1609 fps Culvert 3 -100 Year Storm Culvert Calculator Entered Data : Shape .......................... . Number of Barrels .............. . Solving for .................... . Chart Number ................... . Scale Number ................... . Chart Description .............. . Scale Description .............. . Overtopping .................... . Flowrate ....................... . Manning' s n .................... . Roadway Elevation .............. . Inlet Elevation ................ . Outlet Elevation ............... . Diameter ....................... . Length ......................... . Entrance Loss .................. . Tailwater ........... . Computed Results: Headwater . . . ........ . Slope ............... . Velocity ............. . Wil liams Creek Subdivision -Pha se 7 College Stati on, Texas Circular 1 Headwater 1 3 CONCRETE PIPE CULVERT; NO BEVELED RING ENTRANCE GROOVE END ENTRANCE, PIPE PROJECTING FROM FILL Off 10 .8100 cfs 0.0120 242.5100 ft 238.8000 ft 238.5300 ft 18.0000 in 54.0000 ft 0.5000 1.5000 ft 241 .3872 ft Outlet Control 0.0050 ft/ft 6.1172 fps Culvert 4 -25 Year Storm Culvert Calculator Entered Data: Shape ................ . Number of Barrels .... . Solving for .......... . Chart Number ......... . Scale Number ................... . Chart Description .............. . Scale Description .............. . Overtopping .................... . Flowrate ................... . Manning' s n .................... . Roadway Elevation ......... . Inlet Elevation ........... . Outlet Elevation .......... . Diameter .................. . Length ......................... . Entrance Loss .................. . Tailwater ...................... . Computed Results: Headwater ...................... . Slope .......................... . Velocity ....................... . Circular 3 Headwater 1 3 CONCRETE PIPE CULVERT; NO BEVELED RING ENTRANCE GROOVE END ENTRANCE, PIPE PROJECTING FROM FILL Off 38.0100 cfs 0.0120 222.7000 ft 214.5300 ft 213 .8900 ft 18.0000 in 64 .0000 ft 0.5000 1.5000 ft 217.3778 ft Outlet Control 0. 0100 ft/ft 7.1698 fps Cul vert 4 -100 Year Storm Culvert Calculator Entered Data: Shape .......................... . Number of Barrels .............. . Solving for .................... . Chart Number ................... . Scale Number ................... . Chart Description .............. . Scale Description .............. . Overtopping .................... . Flowrate ....................... . Manning 's n .................... . Roadway Elevation .............. . Inlet Elevation ................ . Outlet Elevation ............... . Diameter ....................... . Length ......................... . Entrance Loss ........... · ....... . Tailwater ...................... . Computed Results: Headwater ...................... . Slope .......................... . Velocity ....................... . Williams Creek Subdivision -Phase 7 Co llege Statl on , Texas Circular 3 Headwater 1 3 CONCRETE PIPE CULVERT; NO BEVELED RING ENTRANCE GROOVE END ENTRANCE, PIPE PROJECTING FROM FILL Off 45.2400 cfs 0.0120 222 .7000 ft 214 .5300 ft 213.8900 ft 18 .0 000 in 64.0000 ft 0.5000 1 .5000 ft 218 .2060 ft Outlet Control 0.0100 ft/ft 8.5335 fps Pipe 9 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning's n .................... . Computed Results: Circular Depth of Flow 18 .0000 in 1.8900 cfs 0.0505 ft/ft 0 .0120 Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. 3116 in Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . 1 .7671 ft2 0.2232 ft2 15 .9590 in 56.5487 in 8.4673 fps 2.0141 in 18 .3979 % 25.5727 cfs 14. 4712 fps Pipe 9 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Circular Depth of Flow 18.0000 in 2 .5400 cfs 0 .0505 ft/ft 0.0120 Depth ........................... 3 .8316 in Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Williams Creek Subdiv i sion -Pha se 7 Colle g e Statio n , Texa s 1.7671 ft2 0.2750 ft2 17.2636 in 56.5487 in 9.2351 fps 2.2941 in 21.2866 % 25.5727 cfs 14.4712 fps APPENDIXC Drainage Ditch Data & Lining Material 19 Williams Creek Subdivision -Phase 7 Ditch Velocity Data Campbell Court Left Ditch From To Station Station 0+00.00 1+00.00 1+00.00 1+50.00 ------1+50.00 3+22.00 ---3+22.00 4+50.00 -----4+50.00 7+25.00 --7+25.00 8+75.00 -- 8+75.00 9+45.00 9+45.00 10+10.00 ------10+1 0.00 10+54.00 10+54.00 10+63.00 10+63.00 11+08.00 11+08.00 11+28.00 11+28.00 11+37.00 -----11+37.00 11+80.00 11+80.00 13+60.00 13+60.00 13+96.g2 Ginger Court Left Ditch From To Station Station 0+00.00 00+50.00 0+50.00 01+35.00 ---1+35.00 02+50.00 ---2+50.00 03+24.00 3+24.00 04+30.00 4+30.00 04+89.53 Campbell Court Right Ditch From To Station Station 0+00.00 1+00.00 1+00.00 1+50.00 ------1+50.00 3+22.00 --3+22.00 4+27.00 4+27.00 5+15.00 -5+15.00 6+50.00 ---6+50.00 8+30.00 ----8+30.00 9+45.00 9+45.00 9+75.00 --9+75.00 10+29.00 10+29.00 10+40.00 -10+40.00 10+84.00 10+84.00 11+02.00 11+02.00 11+13.00 11+13.00 11+60.00 11+60.00 12+05.00 12+05.00 13+60.00 13+60.00 13+96.92 Ginger Court Right Ditch From To Station Station 0+00.00 00+50.00 0+50 00 02+50.00 2+50.00 03+24.00 3+24.00 04+89.53 (n = 0.035 for grass) Slope Drainage Area # 1.94% 36 1.00% 35 --0.60% 34,35 0.50% 23,32,33,34,35 3.55% 22,23,32,33,34,35 3.55% ~2,23,32,33,34,35 3.55% 20,21,22,23,32,33,34,35 2.85% 19,20,21,22,23,32,33,34,35 2.85% 19,20,21,22,23,32,33,34,35 1.00% 18, 19,20,21 ,22,23,32,33,34,3! 1.00% 18, 19,20,21 ,22,23,32,33,34,3! 1.00% 15,16,17 1.00% 15~ 4.46% 15,16 -3.43% 15 3.20% 14 (n = 0.035) Slope Drainage Area # 2.78% 32 0.85% 31 -------0.85% ~ ---0.60% 29,30,31 0.60% 27,28 0.60% 27 (n = 0.035 for grass and n = 0.014 for concrete) Slope Drainage Area # 1.94% 1 1.00% 2 0.60% 2,3 1.15% 2,3,4 3.55% 2,3,4,5 3.55% 2,3,4,5,6 3.55% 2,3,4,5,6, 7 3.55% 2,3.4,5,6,7,8 3.56% 2,3.4,5,6,7,8,9 3.56% 2,3.4,5,6,7,8,9 1.00% 2,3.4,5,6,7,8,9 1.00% 2,3,4,5,6,7,8,9, 10 1.00% 11,12 1.00% 11,12 3.34% 11,12 3 .. 34% 11,12 3.43% 12 3.20% 13 (n = 0.035) Slope Drainage Area # 2.78% 23 0.85% 24 0.60% 24,25 0.60% 26 1. Concrete ditch lining depth = 9" 2. Concrete ditch lining depth = 7 .5" 010 (els) 0.26 0.17 1.68 2.29 3.63 4.53 4.92 5.48 5.48 5.66 5.66 1.04 0.95 0.95 0.65 0.30 010 (els) 0.22 0.99 2.72 6.69 5.22 3.02 010 (cfs) 0.69 0.35 1.73 2.16 2.63 3.37 4.36 4.84 5.14 5.14 5.31 5.31 4.19 4.19 4.19 4.19 1.68 0.82 0 10 (cfs) 0.22 0.65 0.91 0.86 V10 d10 0100 V100 d100 Driveway Block# Lot # Ditch Lining (fps) (in) (cfs) (fps) (in) Culvert (in) Material 1.3 2.6 0.35 1.4 3.0 --Grass seed 0.9 2.6 0.23 1.0 2.9 --Grass seed --1.4 6.6 2.27 1.5 7.4 12 8 1 Grass seed -----1.4 7.7 3.08 1.5 8.6 --Grass seed ----3.2 6.4 4.89 3.5 7.1 --Grass seed ---3.4 6.9 6.11 3.7 7.7 15 8 7 Grass seed --- 3.5 7.1 6.63 3.8 8.0 15 -Grass seed ----------3.3 7.7 7.39 3.6 8.6 --Grass seed ---------3.3 7.7 7.39 3.6 8.6 - -Grass sod -----------Concrete2 4.5 6.8 7.62 4.8 7.6 ------ --4.7 5.1 7.62 5.1 6.0 18 8 9 Concrete 2.8 1.9 1.40 3.0 2.3 - -Concrete' ------Concrete2 2.9 3.5 1.28 3.1 3.9 ---2.5 3.7 1.28 2.7 4.1 12 8 10 Grass sod --------------2.1 3.4 0.87 2.2 3.7 -Grass seed 1.6 2.5 0.41 1.8 2.9 12 8 10 Grass sod V10 d10 0100 V100 d100 Driveway Block# Lot # Ditch Lining (fps) (in) (cfs) (fps) (in) Culvert (in) Material 1.5 2.3 0.29 1.6 2.6 - -Grass seed 1.4 5.1 1.34 1.5 5.7 12 8 1 Grass seed ------ 1.8 7.5 3.67 1.9 8.3 12 --Grass seed ------1.g 11.2 g.02 2.1 12.5 8 2 Grass seed 1.8 10.2 7.04 2.0 11.4 15 8 3 Grass seed -------1.6 8.3 4.07 1.7 9.3 12 8 4 Grass seed V10 d1o 0100 V100 d,oo Driveway Block# Lot # Ditch Lining (fps) (in) (cfs) (fps) (in) Culvert (in) Material 1.7 3.8 0.93 1.8 4.3 --Grass seed 1.1 3.4 0.47 1.2 3.7 12 8 19 Grass seed -1.4 6.7 2.33 1.5 7.5 12 8 18 Grass seed --1.9 6.5 2.91 2.0 7.2 --Grass seed 3.0 5.6 3.55 3.2 6.3 12 8 17 Grass seed --3.2 6.2 4.54 3.4 6.9 12 8 16 Grass seed - 3.4 6.8 5.88 3.6 7.6 12 8 15 Grass seed 3.5 7.1 6.52 3.7 7.9 --Grass seed -3.5 7.2 6.93 3.8 8.1 --Grass seed 3.5 7.2 6.93 3.8 8.1 --Grass Sod -4.4 6.6 7.16 4.7 7.4 --Concrete2 4.6 4.9 7.16 5.0 5.8 15 8 14 Concrete' 4.3 4.3 5.65 4.7 5.1 15 8 13,14 Concrete' 4.1 6.0 5.65 4.5 6.7 Concrete2 3.2 4.5 5.65 3.4 5.3 Grass Sod 3.2 4.5 5.65 3.4 5.3 Grass seed 2.6 4.8 2.27 2.8 5.4 12 8 13 Grass seed 2.1 3.7 1.11 2.3 4.2 12 8 11 ,12 Grass sod V10 d10 0100 V100 d100 Driveway Block# Lot # Ditch Lining (fps) (in) (cfs) (fps) (in) Culvert (in) Material 1.5 2.3 0.29 1.6 2.6 Grass seed 1.2 4.4 0.87 1.3 4.9 Grass seed 1.2 5.3 1.22 1.3 5.9 12 8 7 Grass seed 1.2 5.2 1.16 1.2 5.8 12 8 6 Grass seed EXHIBIT A Drainage Area Map -Post-Development, Culverts & Pipes 21 EXHIBIT B Drainage Area Map -Post-Development, Ditch Velocities 23 ·' Drainage Report for Williams Creek Subdivision -Phase 7 College Station, Texas September, 2006 R evised March, 2007 (Revisions bi bold italic!)) Developer: Joe and Janet Johnson 1400 South Commercial Street Coleman, Texas 7683 4 (325) 625 -2124 Prepared By : Civil Developn1ent, Ltd. 2900 Lon gmire Drive, Suite K Col1 ege Statio11 Texas 77845 (979) 764-7743 \ \ '' ' CERTIFICATION I certify that this revised report for the drainage design for the Williams Creek Subdivision - Phase 7, was prepared by me in accordance with the provisions of the City of College Station Drainage Policy and Design Standards for the owners hereof, with the exception that storm water runoff detention is not being proposed for this project since the runoff will discharge directly into tributaries of Carters Creek and then into the 100-year floodplain and the primary channel of Carters Creek. TABLE OF CONTENTS DRAINAGE REPORT -REVISED 312007 WILLIAMS CREEK SUBDIVISION -PHASE 7 CERTIFICATION ................................................................................................................................................................. I TABLE OF CONTENTS ....................................................................................................................................................... 2 LIST OF TABLES .................................................................................................................................................................. 2 INTRODUCTION .................................................................................................................................................................. 3 GENERAL 'LOCATION AND DESCRIPTION ................................................................................................................. 3 FLOOD HAZARD INFORMATION ................................................................................................................................... 3 DEVELOPMENT DRAINAGE PATTERNS ...................................................................................................................... 3 DRAINAGE DESIGN CRITERIA ....................................................................................................................................... 3 STORM WATER RUNOFF DETERMINATION .............................................................................................................. 4 STORM CULVERT & PlPE DESIGN ................................................................................................................................ 5 CONCLUSIONS ..................................................................................................................................................................... 7 APPENDIX A-Revised 3/2007 ............................................................................................................................................. 8 Time of Concentration Equations & Calculations APPENDIX B -Revised 312007 ........................................................................................................................................... 12 Storm Sewer Culvert/Pipe Data & Design Calculations APPENDIX C -Deleted for the 31200 7 Revisio11 ................................................................................................................ 19 Drainage Ditch Data & Lining Material EXHIBIT A -Revised 312007 .............................................................................................................................................. 21 Drainage Area Map -Post-Development, Culverts & Pipes EXHIBIT B -Revised 3/2007 ............................................................................................................................................... 23 Drainage Area Map -Post-Development, Ditch Velocities LIST OF TABLES TAB LE I -Rainfall Intensity Calculations .............................................................................................. 4 TABLE 2 -Time of Concent ration (tc) Equations .................................................................................. 4 TA BLE 3 -Po st-Development Runoff In formatio n -Revised 312007 .................................................... 5 TAB LE 4 -This tahle hos heen deletedfor the 312007 Revision ......................................................... 5 DRAINAGE REPORT -REVISED 312007 WILLIAMS CREEK SUBDIVISION -PHASE 7 INTRODUCTION The purpose of this revised report is to provide the hydrological effects of the construction of the Williams Creek Subdivision -Phase 7, and to verify that the proposed storm drainage system meets the requirements set forth by the City of Coll ege Station Drainage Policy and Design Standards. GENERAL LOCATION AND DESCRIPTION The project is located on a portion of a 11 6 acre tract located east of Rock Prairie Road and south of Greens Prairie Road in College Station, Texas. This report addresses Phase 7 of this subdivision, which is made up of 25.8 acres. The site is predominantly wooded. The existing ground elevations range from Elevation 206 to E levation 246. The general location of the project site is shown on the vicinity map in Exhibit A. FLOOD HAZARD INFORMATION The project site is located in the Carters Creek Drainage Basin. This phase of the proposed subdivision is located in a Zone X Area according to the Flood Insurance Rate Map prepared by the Federal Emergency Management Agency (FEMA) for Brazos County, Texas and incorporated areas, Community No. 481195 and 480083 , Panel No. 205D, Map No. 4804 I C0205D, effective dated Febru ary 9, 2000. The location of the Flood Hazard Area adjacent to this property is shown on Exhibit A as the 100-year floodplain. DEVELOPMENT DRAINAGE PATTERNS Prior to development, the stom1 water runoff for Phase 7 flows in a northerly or easterly direction into the Carters Creek floodplain or into existing tributaries which discharge into Carters Creek. DRAINAGE DESIGN CRITERIA The design parameters for the stonn drainage analysis are as follows: • The Rational Method is uti Ii zed to detern1ine peak stonn water runoff rates for the storm drainage design for culverts, ditches and channels. • Design Stonn Frequency Stonn culverts Storm pipe & roadside ditches • Runoff Coefficients 25-and l 00-year storm events I 0-and I 00-year storn1 events Post-development ( 1 acre minimum lot size) c = 0.5 0 • Rainfall Intensity equations and va lu es for Brazos Coun ty can be found in Table I. • Tim e of Concentrati on, le -Calculati ons arc based on the me thod found in the TR-55 publication. Refer to Table 2 for th e equations and Appendix A for calc ul ati o11 s. The runo ff now path used for calculatin g th e post-development tim es of concentration for th e larger drainage areas arc show11 on th e ex hibits. Small er drainage areas use a rni11i111u111 le of l 0 minutes to determine the rainfall intensi ty values. Exh ibit A has the runoff flow path s used for the drainage areas for the cul vert and channel desi gn. STORM WATER RUNOFF DETERMINATION The peak runoff values were detem1ined in accordance with the criteria presented in the previous section for the I 0, 25, 50, and I 00-year stom1 events. The drainage areas for the post- development condi tion are shown on Ex hibits A & B. Post-development runoff conditi ons for the drainage structure design drainage areas are summarized in Table 3. TABLE 1 ·-Rainfall Intensity Calculations Rainfall Intensity Values (in/hr) Storm Event 110 lis 1100 tc = 10 min 8.635 9.861 11.639 I = b I (tc+d)e I = Rainfall Intensity (in/hr) tc = L/(V*60) !,; = Time of concentration (min) L = Length (ft) V = Velocity (ft/sec) Brazos County: 10 :r:ear storm 25 :r:ear storm 50 :r:ear storm 100 :r:ear storm b= 80 b= 89 b= 98 b= 96 d = 8.5 d = 8.5 d= 8.5 d = 8.0 e= 0.763 e= 0.754 e= 0.745 e = 0.730 (Data taken from State Department of Highwa:r:s and Public Transportation H:r:draulic Manual, page 2-1 6) TABLE 2 -Time of Concentration (tc) Equations The time of concentration was determin ed using methods found in TR-55, "Urban Hydrology for Small Wat ersheds . " Tlie equations are as follows: Time of Concentration: Tc = T1(shcc1 fl ow)+ T1(co11cC11tra1cd sheet 1101\) where: T, =Travel Time, minutes For Sheet Flow: 0.007 (n L)0·8 (Pz)0.5 SOA where: T1 =travel time, hours For Shallow Concentrated Flow: Refer to Appendix A fo r calcul ati ons. n =Manning's roughness coeflicient L = flow length, feet P2 = 2-year, 24-hour rainfa ll = 4.5" s = land slope, ft/ft T, = L I (60*V) where: T, =trave l time, m111ut es V =Velocity, fps (See Pi g 3-1 .. !\pp. A) L = !low length. l"cet TABLE 3 -Post-Development Runoff Information -Revised 312007 Area 10-year storm 25-year storm Culvert/ c tc Pipe No. Area# A (acres) (min) Pipe No. 4 1.2.3 2.26 0.50 10.0 Culvert No. 1 5 4.70 0.50 45.0 Culvert No. 2 3 0.51 0.50 100 Culvert No. 3 4 2.71 0.50 22.2 The Rational Method: Q = CIA I = b I (tc+d)0 Q =Flow (cfs) le = Time of concentration (min) 110 0 10 (in/hr) (cfs) 8.635 9.76 3.840 9.02 8.635 2.20 5.867 7.95 tc = L/(V*60) L = Length (ft 125 (in/hr) 9.861 4.428 9.861 6.731 A= Area (acres) V = Velocity (fl/sec) C = Runoff Coeff. I = Rainfall Intensity (in/hr) Brazos County: 10 year storm b = 80 d = 8.5 e = 0.763 25 year storm 100 year storm b = 89 b = 96 d = 8.5 d = 8.0 e = 0.754 e = 0.730 STORM CULVERT & PIPE DESIGN 0 2s (cfs) 11 .14 10.41 2.51 9.12 100-year storm 1100 0 100 (in/hr) (cfs) 11 .639 13.15 5.291 12.43 11.639 2.97 7.977 10.81 The culverts for this project have been selected to be HDPE stom1 sewer pipe meeting the requirements set forth by the City of Co ll ege Station Drainage Po licy and Design Standard s. Tk@rn will @g €iissiriat©r @l©@lcs at tk€l €i©v,.nstrna1'fl €lft€i ©f C1o1lv@ft N©. 4 t© sl©'oV tk€l €iis@karg@ ©Mt ©f tk@ riifl€l aH€i t© h@lfl €l©ntrnl @rnsi©H. Pifl€l N©. 9 l~as a k@a€ivl'all an€! rn@k ririrari at tk€l ©Mtfall . Runoff from the proposed streets will be collected by the roadside ditches and conveyed to the culvert structures, Pipe No. 4, or to the Rock Prairie Road ditches. Ifoa€iwall ©fl€lHiHgs ·,•,.ill @g M8€l€i fer this €i@v€ll©flm€lftt at C1o1lv@ft N©. 4. Th€l8€l ©fl€lHiHgs iH th@ h@a€iwalls ·.viii all©w th@ €iit@h€l8 t© @g 1@88 €i€l€lfl at th@ @Mlv@ft l©@ati©H, tl1@rn@y rn€i u@ing th@ am©1:111t ©f €iistur@an€l€l €11:rn t© th@ €l©11str1-rnti©t'l ©f th@ strn@t €iit@li si€1€l sl©fl€l8. The drainage areas for the culverts and storm pipe designs are shown on Exhib it A. Tli@ €irai11ag@ arnas fer th@ li@a€i'.vall ©fl€ll'li11gs Vo'€lr€l tairnl'l frnm EJ(hi@it B. Th@ h@a€iwall ©fl€lHil'lg8 fer th@ l@ft an€1 right si€1€l €i it@h€l8 will @g ri la @€l€i at th@ I©\'<' fl©int ©f th@ €iit @k t© €l©ll@€lt th@ st©rm wat@r, 'oVAi@li wjll tl·rnn @g €iis@karg@€1 €iirn@tly thrnugh th@ €l©n@rnt€l h@a€iwall an€! ©nt© tk€l €l©H€lrnt€l Bfl lask 13a€is at €la€lh @11€1 © f tli€l €ll-!IV€lft. Tli@ flr©fl©8€l€i h@a€i'sall ©fl€ll'lings .,.,.gm ~mal yz@€1 1o1si11g th@ ©rifi@0 €l€j1otati©11, s©ki 11g fur the S€lfltk © f "ovat@r at tl10 ©fl€lning ~r th0 I 0 al'l€1 I 00 y0ar st© rm €lV€lnts. H .,.,.as assume€! that 25% ©f tl10 ©fl€ll'l arna \V©til€1 ~€l @l@gg0€1 ~r th0 ©fl€l t'li11 g €l@sig11. D0sign @al@tilat i©1'l8 a11€1 €iata f'0r the h0achvs ll 0p01=i in gs ar@ sh0vo'1=t i11 Ts01e 4. TABLE 4 -Tltis table ltas been deleter/for tlt e 31200 7 Revision. As sh0wn 0y these 0a l0u lati0ns, tl9e maHinrnm €i@J!Jth ©f v:ater t@r the lOO year st0rm fur lh e J!lf0J!l0S@€i hea€iviall ©J!l@nings is 9.7" ©n the right si€ie. The t©J!l ©f the l9ea€iv:all is 6l0vali019 221.0, a1ul tl9e @0H0m ©f th e hea€i'<vall 0J!l@ni 19g is E;l0vati0n 219.55. f0r the 100 year st0rm event, this resu lts in 1.05' ©ffrn000ar€1 fur Hea€i'<vall OJ!J@n i19g Left, an€1 0.64' ©ffrn000ar€1 f@r Hea€1 ·,vall OJ!l@ning Ri ght. The tyf)i@al rna€iv:ay €iiteh v:ill 00 00nstru0t0€1 sue h that the €iiteh 00tv:00Fl the rigl9t ©f way afl€i the 0€ig0 ©f J!lavement is a miF1imt1m ©f 18" in €i@J!Jth , an€1 '<viii 00 grn€10€1 as fl@eessary t0 €lflSt1rn that the run0ff frnm the 100 year st0m9 event v:ill rnmain '<Vithin the strnet right ©f way. Append ix B presents a summary of the storm cul vert des ign parameters and calculations. Th e proposed pipes were designed based on th e 25-year stom1 event, and data is also given for the 100-year stom1 event. As shown in the summary, the culverts have headwater elevations that are at least one foot below the roadway elevation for the 25-year stom1 event. Also, the culverts pass the 100-year stonn event without overtopping the roadway. As required by College Station, the velocity of flow in the pipes is not lower than 2.5 feet per second, and th ey do not exceed 15 feet per second. As the data shows, even during low flow conditions, the velocity in the pipe wi ll exceed 2.5 fee t per second and prevent sedim ent bu ild-up in the culvert. The maximum velocity for cul verts in this development will be 6.1 feet per secolld occurring in Culvert No. 3. Appendix B contains a summary of the culvert calculator data for the 25-and 100-year stom1 events. The Culvert N0. 4 ·.viii €iis0harg0 ©flt© a 00190rnt0 J!la€l ·sith €iissiJ!Jat0r 0100ks t0 rn€iu00 th e v0l00ity. The stonn water runo ff in the roadsid e ditches of the northern most portion of Campbell Court will discharge into Area inlet No. I COllllected to Pipe No. 4, which will ultimately convey th e water into a tributary of Carters Creek and then along the ex isting tributary to Carters Creek. The maximum velocity fo r thi s pipe is 7.6 f eet per secoud. Tlte deptlt of water at tlte illletfor the JO-year storm will be 4. 7 i11c/1es, and for tlte JOO-year event, it will be 8 incites. Appendix B contains a summary of the pipe design parameters and calculations for the I 0-and 100-year stom1 events as well as a summary of tlte inlet calculations. There will be di ssipator blocks and rock riprap at the end of the pipe to slow th e velocity and reduce erosio n. The ve locity of th e flow in the roads ide ditches was eval uated fo r the l 0-year and I 00-year stom1 events. The drainage areas are shown on Exhibit B. The city requirements for ditch lining material are as fo ll ows: Max imum Design Velocities of Various Surface Treatments1 Surface Treatment Exposed Earth* Grass -Seeded Grass -Sodded Impermeable (Concrete. Gunitc. Etc ) *Temporary Cha nnels Only Maximum Design Ve locitv, (ft/sec) 3.0 4.5 6.0 10.0 1From "l::rosion a nd Scd1111c11l Control (iuidelincs l(Jr Dncl opin~ .'\reas in Texas" by the Soil Conscn «il1 011 Scn ·icc In 1\ppcncli .\ C th e dit ch veloc iti es arc surnrn ar1 1cd in cludin g co111111 cnt s st;1t111 g th e dit ch lin ing 111atcri al used Th e ditch linin g rn <it eri ;il is <il sn sil o\\ 11 'in th e co nstru ctio n dr;l\\ i11gs :\I th ough As shev:n l"Jy th0s0 fMtl@l'!latiens , tl'l@ maJCil'l'lUn'l €l@!§Jth ef vial0r fur th@ I GO y0ar slern1 ffir th@ l§Jr€lf'leS0€1 l'l @a€1v,.a ll el§J0nings is 9.7" en Urn right si€10. Th@ le!§J ef th @ l'l@a€lvia ll is 6l0valien 221.Q, an€1 th0 l"Jettem efHrn h0a€1.,vall ef'l©l'ling is ~1 0.,.atien 2 19.55. Fer th@ IQQ y0ar slerm @\'@flt, tl'lis rnsu lts in l.Q5' effrn@l"lear€1 fur ll0a€1v.·all O!§J@l'ling L0fl, a1'l€1 Q.~'I ' ef frn0l"Jear€1 fer II0a€1v,.all Of'l@fliflg Right. Th@ t)1§Ji@al rna€1viay €1it0h .,,,.jll l"J0 0eflstni0l0€1 su0h lhat th@ €1it0h @0hv00fl th@ right ef way an€1 th0 0€1g0 ef f'la'o'@l'l'l@nt is a mi1'limum ef 18" in €101§Jtl'l, afl€1 •,•,.ill l"J0 gra€10€1 as f1000ssary te 01'ls1:ir0 that th@ nmeff frnm tl'l@ IQQ y0ar sterm @';'@flt .,.,,ill rnn'la in 'Nithin Urn strn0t right ef ·.vay. Appendix B presents a summary of the stom1 cul vert design parameters and ca lculations. The proposed pipes were designed based on th e 25-year stom1 event, and data is also given for the lOO-year storm event. As shown in the summary, th e cul verts have headwater elevations that are at least one foot below th e roadway elevation fo r the 25-year stonn event. Also, the culverts pass the 100-year storm event without overtopping th e roadway. As requ ired by Co ll ege Station, th e ve locity of flow in the pipes is not lo wer than 2.5 feet per second, and th ey do not exceed 15 feet per second. As th e data shows, even during low flow co ndi tions, the velocit y in the pipe will exceed 2.5 feet per second and prevent sediment build-up in th e cu lvert. The max imum ve locity fo r culverts in thi s development will be 6. I feet per second occurring in Culvert No. 3. Appendix B contains a summary of th e culvert calculator data for the 25-and l 00-year storm events. Th@ Cul'o'@rt Ne. 4 ·sill €1is0harg0 eflte a 0efl0rnt0 !§Ja€1 1.vith €1issi!§Jater l::lle0ks te rt€1~\0~·01p itl~} ~ t...1 ~ ~ 0 \Vv) ~ c,_. · l ~7 J-.<:l.oJ-v-r ·tc (I\. ( < .., The sto1m w¥7runoff in th e roadside ditches of the north ern most porti on of Campbell Cou11 wi ll discha~e into Area inlet No. 1 connected to Pipe No. 4, which will ultimately convey the water into/Carters Creek. The maximum velocity for this pipe is 7. 6 feet per second. Tlte depth of water at tlt e inlet for tlte 10-year storm will be 4. 7 i11c/1es, and for tlte I 00-year event, it will be 8 incites. Appendix B contains a summary of the pipe design parameters and calcul ations fo r the l 0-and 100-year storm events as well as a summary of the inlet calculations. There wi ll be dissipator bl ocks and rock rip rap at th e end of the pipe to slow the velocit y and reduce erosion . The ve locity of th e flow in th e roadside ditches was evalu ated for the I 0-year and lOO-yea r stom1 events. The drainage areas are shown on Ex hibit B. The city requirements for ditch lining material are as fo ll ows: Maximum Design Velocities of Various Surface Treatments 1 Surface Treatment Exposed Earth* Grass -Seeded Grass -Sodded 1 mpermeable (Concrete. Gunite. Etc.) '''Tc111porary Channels Only Maximum Design Ve locity, (ft/sec) 3.0 4.5 6.0 10.0 1hom ··1:rnsio11 and Scdim.:11t Contrnl (juidcli11.:s for Dn L·lop111g 1\r.:as 111 Texas·· by the Soil Co11scr1·atiu11 Sn1·ice 111 /\ppcndi x C the ditch \'C locitics ;ire su1 11rn;1ri1cd inc luding cornrnc11ts S i(lli n ~ iii'-' ditcl1 li11i11g m;ttcri"I used . The ditch lining rn;1t c ri ;1I is ;ilsu slw11 11 i 11 tilL' cn11s1ruc1 in1 1 dr;1111 11~s .-\l tlwu ~l1 ,, grass block sod or erosion blankets are not required, these have been included in areas where erosion is anticipated. CONCLUSIONS The construction of this project will increase the storm water runoff from this site. However, the runoff will be can-ied through a drainage system to existing drainages and then into the l 00- year floodplain. Due to the location of this project and its proxi mity to Carters Creek's confluence with th e Navasota River, th e peak runoff fro m this development will occur much sooner than the peak runoff in Carters Creek, therefore, the increase in runoff has no affect on the·water surface elevation in Carters Creek. The increased flow directl y into Carters Creek wi II not have a significant impact on the sun-ounding property. No flood damage to downstream or adjacent landowners is expected as a result of this development. APPENDIX A -Revised 312007 Time of Concentration Equations & Calculations ,\ Drainage Area #4 Sheet Flow: n= P= L= 200 T1= 0.007(L*n}08 = (P)os*(S)o4 Concentrated Flow 1: V= L= 175 T1= L/(60*V) = Drainage Area #5 Sheet Flow: n= P= L= 175 T1= 0.007(L*n}08 = (P)os*(S)oA Concentrated Flow 1 : V= L= 1315 T1= L/(60*V) = Time of Concentration Calculations Williams Creek Subdivision -Phase 7 Revised 3/2007 0.24 (dense grass) 4.5 Elev1= Elev2= 0.349 hours= 20.9 min 2.25 fps (unpaved) Elev1= Elev2= 1.3 min ITc= 22.2 min 0.24 (dense grass) 4.5 Elev1= Elev2= 0.385 hours= 23 .1 min 1.0 fps (unpaved) Elev,= Elev2= 21 .9 min ITc= 45.0 min Slope= 0.020 Slope= 0.020 Slope= 0.012 Slope= 0.004 APPENDIX B -Revised 312007 Storm Sewer Culvert/Pipe Data & Design Calculations I' Williams Creek Subdivision -Phase 7 Inlet Capacity Calculations -Revised 312007 10 year storm 100 year storm Inlet# 010 Orotal+50% Y 10-actual l10-Req'd l 10-actual a, .. Orotal+SO•!. Y100 (cfs) (cfs) (ft) I (in) (ft) (ft) (cfs) (cfs) (ft) I (in) 1 9.76 14.64 0.391 I 4.69 10.96 12 13.15 19.73 0.670 I 8.04 *using y,...., = r -= o 583' Transverse (Crown) slope (tuft) z = Reciprocal of crown slope for 27' streets = 0.030 Straight Crown Flow (Solved to find actual depth of flow, y): Q = 0.56 * (z/n) * S112 * y813 ¢ y ={QI [0.56 * (z/n) * S12]}318 n = Roughness Coefficient = S = StreeUGutter Slope (tuft) y = Depth of flow at inlet (ft) 0.018 for 27' streets = 33 Inlets in sumps, Weir Flow: L = QI (3 * /2) ¢ y = (QI 3L)213 L = Length of inlet opening (ft) Q =Flow at inlet (cfs) y = total depth of flow on inlet {ft) max y for inlet in sump = 7" = 0.583' Williams Creek Subdivision -Phase 7 Culvert & Pipe Summary -Revised 3/2007 Size Slope Inlet Invert Outlet #of Length Elev Invert Elev Culvert No. Barrels {in) {ft) (%) (ft) (ft) 1 2 18 60.0 0.50 244.35 244.05 2 1 18 60.0 0.50 241 .24 240.94 3 1 18 54.0 0.50 238.80 238.53 Size Length Slope Inlet Invert Outlet #·of Elev Invert Elev Pipe No. Barrels (in) (ft) (%) (ft) (ft) 4 1 24 9.5 1.00 216.16 216.06 Top of Road 25-year storm Design Flow V2s (ft) (cfs) (fps) 247.15 10.41 2.9 244.30 2.51 1.4 242.51 9.12 5.2 Top of Road 10-year storm Aclual Flow V,o (ft) (cfs) (fps) ·9.76 7.3 ·Design Flow used for calculations assuming 25% reduction in pipe area: 0 10 = 15.76 cfs and 0 100 = 21 .24 cfs 100-year storm HW Design Flow V100 HW (ft) (cfs) (fps) (ft) 245.88 12.43 3.5 246.02 242.52 2.97 1.7 242.55 241 .10 10.81 6.1 241.39 100-year storm HW Aclual Flow V,oo HW (ft) (cfs) (fps) (ft) -·13.15 7.6 Culvert 1 -25 Year Storm Culvert Calculator Entered Data: Shape ........... . Number of Barrels Solving for .. Chart Number ...... . Scale Number ...... . Chart Description ... . Scale Description ... . Overtopping ....... . Flowrate ............ . Manning 's n .................... . Roadway Elevation .............. . I n let Elevation ................ . Ou tlet Elevation ... . Diameter . . . . . . .... . Length ............. . En t rance Loss ...... . Tailwater ...... . Compu ted Results: Headwater .... . Sl ope ........ . Velocity ..... . Circular 2 Headwater 1 3 CONCRETE PIPE CULVERT; NO BEVELED RING ENTRANCE GROOVE END ENTRANCE, PIPE PROJECTING FROM FILL Off 10.4100 cfs 0.0120 247.1500 ft 244.3500 ft 244.0500 ft 18.0000 in 60.0000 ft 0.5000 1.5000 ft 245.8772 ft Outlet Co ntrol 0.0050 ft/ft 2.9454 fps Culvert 1 -100 Year Storm Culvert Ca l culator Entered Data: Shape .......................... . Number of Barrels .............. . Solving f or .................... . Cha r t Number ................ . Sca le Number ................... . Chart Description .............. . Scale Description .............. . Overtopping .................... . Flowrate ....................... . Manning ' s n .................... . Roadway Ele vation .............. . Inlet Elevation . . . . . . . .... . Out let Elevation Diameter ............ . Length .............. . Entrance Loss Tailwater .... Computed Results: Headwater Slope .... Velocity . i ,. ,_,. Circular 2 Headwater 1 3 CONCRETE PIPE CULVERT; NO BEVELED RING ENTRANCE GROOVE END ENTRANCE, PIPE PROJECTING FROM FILL Off 12.4300 cfs 0.0120 247.1500 ft 244.3500 ft 244.0500 ft 18.0000 i n 60.0000 ft 0 .5000 1 .5000 ft 246.0164 ft Outlet Control 0 .0050 ft/ft 3.5170 fps ~:oo·· Culvert 2 -25 Year Storm Culve r t Calculator Enter ed Data: Shape ... Number of Barrels ... . Solving f or . . ..... . Chart Number ....... . Scale Number ...... . Chart Description .. Scale Description .. Ov ertopping ....... . Flowrate ....................... . Manning 's n .................... . Roadway Elevation .............. . Inlet Elevation ................ . Outlet Elevation ............... . Diameter ....................... . Length .................... . Entrance Loss Tailwater .... Computed Results: Headwater ........ . Slope .............. . Velocity ........... . Circular 1 Headwater 1 3 CONCRETE PI PE CULVERT; NO BEVELED RING ENTRANCE GROOVE END ENTRANCE, PIPE PROJECTING FROM FILL Off 2.5100 cfs 0.0120 244 .3000 ft 241.2400 ft 240.9400 ft 18 .0000 in 60.0000 ft 0.5000 1.5000 ft 242.5161 ft Outlet Co ntr ol 0.0050 ft/ft 1.4204 fps Culvert 2 -100 Year Storm Culvert Ca lculator Entered Data: Shape ............... . Number of Barrels ... . Solving for .................... . Chart Number ............... . Scale Number ........... . Chart Description .......... . Scale Description ..... . Ov ertopping ........... . Flowrate .............. . Manning's n ........ . Roadway Elevation .. . Inlet Elevation .... . Outlet Elevation ... . Diameter .......... . Length ............. . Entrance Loss ...... . Tailwater .......... . Comp uted Results: Headwater Slope ... Ve l ocit y . ':!'I I ,1•11:: ~-, eef: ~;•rbLI i · r ~" rr•r: ., .ti <I , •. : Circular 1 Headwater 1 3 CONCRETE PIPE CULVERT ; NO BEVELED RING ENTRANCE GROOVE END ENTRANCE, PIPE PROJECTING FROM FILL Off 2.9700 cfs 0.0120 244.3000 ft 241.2400 ft 240.9400 ft 18.0000 in 60.0000 ft 0 .5000 1 .5000 f t 24 2.5465 ft Out let Con trol 0 .0050 ft /ft 1.6807 fps on·~ Culvert 3 -25 Year Storm Culvert Calculator Entered Data: Shape ... Number of Barrels Solving for . Chart Number ..... . Scale Number . . . . . . . ...... . Chart Description .............. . Scale Description ........... . Overtopping ......... . Flowrate .................... . Manning's n ................. . Roadway Elevation ...... . Inlet Elevation ........ . Outlet El evation ....... . Diameter .... . Length ...... . Entrance Loss Tailwater .... Computed Results: Headwater . . . ........... . Slope ................... . Velocity ................ . Circular 1 Headwater 1 3 CONCRETE PIPE CULVERT; NO BEVELED RING ENTRANCE GROOVE END ENTRANCE, PIPE PROJECTING rROM rILL Off 9.1200 cfs 0.0120 242.5100 ft 238.8000 ft 238.5300 ft 18.0000 in 54.0000 ft 0.5000 1.5000 ft 240 .9960 ft Outlet Control 0.0050 ft/ft 5.1609 fps Culvert 3 -100 Year Storm Cu l vert Calculator Entered Data : Shape .............. . Number of Barrels .. Solving for .... . Chart Number ........ . Scale Number .............. . Chart Description ......... . Scale Description ......... . Overtopping ............... . Flowrate .............. . Manning 's n ...... . Roadway Elevation .... . Inlet Elevation ...... . Outlet Elevation ..... . Diameter .......... . Length ...... . Entrance Loss Tailwater .. Computed Resu lts: ':.' i Headwater Slope ... Velocity . .1•11:; t • · i-~)I I ! J j Circular 1 Headwater 1 3 CONCRETE PIPE CULVERT; NO BEVELED RING ENTRANCE GROOVE END ENTRANCE, PIPE PROJECTING rROM rILL Off 10.8100 cfs 0.0120 242.5100 ft 238.8000 ft 238.5300 ft 18.0000 in 54 .0000 ft 0.5000 1 .5000 ft 241.387 2 ft Outlet Cont r ol 0 .0050 ft /ft 6.1172 fps ' ••. :· -;, ·1·1 Pipe 4 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape ....... . Solving for ...... . Diameter ...... . Flowrate .. . Slope ..... . Manning 's n Computed Results: Depth ............... . Area ...................... . Wetted Area .................... . Wetted Perimeter .... . Perimeter ........... . Velocity ........... . Hydraulic Radius .. . Percent Full ...... . Full flow Flowrate Full flow veloci t y .. Circular Depth of Flow 24.0000 in 15.7600 cfs 0.0100 ft/ft 0.0140 15.5111 in 3.1416 ft2 2 .1475 ft2 44.8256 in 75.3982 in 7.3387 fps 6.8988 in 64.6296 % 21 .0065 cfs 6.6866 fps Pipe 4 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape ......... . Solving for ... . Diameter ...... . Flowrate ...... . Slope .......... . Manning 's n .... . Computed Results: Depth .......... . Area ........... . Wetted Area .... . Wetted Perimeter Perimeter ...... . Velocity ....... . Hydraulic Radius Percent Full .... Full flow Flowrate Full flow veloci t y . ' I · r i ;. Circular Depth of Flow 24.0000 in 21.2400 cfs 0.0100 ft/ft 0. 0140 19.9218 in 3.1416 ft2 2.7877 ft2 55 .0035 in 75.3982 in 7.61 93 fps 7.2982 in 83 .0074 % 21.0065 cfs 6.6866 fps ·., 1 ~ ' : ,1, APPENDIX C -Deleted for th e 312007 Revision Drainage Ditch Data & Lining Material l'I Williams Creek Subdivision -Phase 7 Ditch Velocity Data -Revised March 2007 Campbell Court Left Ditch From To Station Station 0+00.00 1 +00.00 1 +00.00 1 +50.00 1 +50.00 3+00.00 3+00.00 3+ 72.00 3+ 72.00 4+50.00 4+50.00 7+00.00 7+00.00 8+75.00 8+75.00 9+00.00 9+00 00 9+59.14 Ginger Court Left Ditch From To Station Station 0+00.00 00+50.00 0+50.00 01 +35.00 1+35.00 02+00.00 2+00.00 03+24.00 3+24.00 04+30.00 4+30.00 04+89.53 Campbell Court Right Ditch From To Station Station 0+00.00 1 +00.00 1+00.00 1+50.00 1+50.00 3+22.00 3+22.00 4+27.00 4+27.00 5+15.00 5+15.00 6+50.00 6+50.00 8+30.00 8+30.00 9+00.00 9+00.00 9+59.14 Ginger Court Right Ditch From To Station Station 0+00.00 00+50.00 0+50.00 02+00.00 2+00.00 03+24.00 3+24.00 04+89.53 (n = 0.035 for grass) Slope Drainage Area # 1.94% 36 1.00% 35 0.60% 34,35 3.88% 23,32,33,34,35 0.50% 23,32,33,34 ,35 3.55% 22,23,32,33,34 ,35 3.55% 21,22,23,32,33,34,35 4.20% 20.21,22,23,32,33,34,35 1.50% 19,20,21,22,23,32,33,34,35 (n = 0.035 for grass) Slope Drainage Area # 2.78% 32 0.85% 31 0.85% 30,31 2.40% 29,30,31 0.60% 27,28 0.60% 27 (n = 0.035 for grass) Slope Drainage Area # 1.94% 1 1.00% 2 0.60% 2.3 1.15% 2,3,4 3.55% 2,3,4,5 3.55% 2,3,4,5,6 3.55% 2,3,4,5.6,7 4.20% 2.3.4.5.6. 7 .8 4.50% 2,3,4.5,6, 7 .8,9 (n = 0.035 for grass) Slope Drainage Area # 2.78% 23 0.85% 24 2.40% 24,25 0.60% 26 0 10 V10 (els) (fps) 0.26 1.3 0.17 0.9 1.68 1.4 4.23 3.5 2.29 1.4 3.63 3.2 4.40 3.4 4.71 3.7 5.40 2.6 0 10 V10 (els) (fps) 0.22 1.5 0.99 1.4 2.72 1.8 6.69 3.3 5.22 1.8 3.02 1.6 0 10 V10 (els) (fps) 0.69 1.7 0.35 1.1 1.73 1.4 2.16 1.9 2.63 3.0 3.37 3.2 4.36 3.4 4.79 3.7 5.14 3.5 0 10 V10 (els) (fps) 0.22 1.5 0.65 1.2 0.91 2.0 0.86 1.2 d10 0 100 V100 d100 Driveway Block# Lot# Dilch Lining (in) (els) (fps) (in) Culvert (in) Material 2.6 0.35 1.4 3.0 -Grass seed 2.6 0.23 1.0 2.9 Grass seed 6.6 2.27 1.5 7.4 12 8 1 Grass seed 6.6 5.70 3.7 7.4 Grass seed 7.7 3 08 1.5 8.6 Grass seed 6.4 4.89 3.5 7.1 15 8 7 Grass seed 6.8 5.94 3.7 7.6 15 8 8 Grass seed 6.8 6.34 4.0 7.6 Grass seed 8.7 7.27 2.8 9.7 15 8 9,10 Grass seed d 10 0100 V100 d100 Driveway Block# Lot# Ditch Lining (in) (els) (fps) (in) Culvert (in) Material 2.3 0.29 1.6 2.6 Grass seed 5.1 1.34 1.5 5.7 12 8 1 Gra ss seed 7.5 3.67 1.9 8.3 12 Grass seed 8.6 9.02 3.5 9.6 8 2 Grass seed 10.2 7.04 2.0 11 .4 15 8 3 Grass seed 8.3 4.07 1.7 9.3 12 8 4 Grass seed d 10 0100 V100 d100 Driveway Block# Lot# Ditch Lining (in) (els) (fps) (in) Culvert (in) Material 3.8 0.93 1.8 4.3 --Grass seed 3.4 0.47 1.2 3.7 12 8 19 Grass seed 6.7 2.33 1.5 7.5 12 8 18 Grass seed 6.5 2.91 2.0 7.2 Grass seed 5.6 3.55 3.2 6.3 12 8 17 Grass seed 6.2 4.54 3.4 6.9 12 8 16 Grass seed 6.8 5.88 3.6 7.6 12 8 15 Grass seed 6.8 6.46 4.0 7.6 -Grass seed 7.2 6.93 3.8 8.1 15 8 14 Grass seed d 10 0100 V100 d100 Driveway Block# Lot# Ditch Lining (in) (els) (fps) (in) Culvert (in) Material 2.3 0.29 1.6 2.6 Grass seed 4.4 0.87 1.3 4.9 Grass seed 4.1 1.22 2.1 4.5 12 8 7 Grass seed 5.2 1.16 1.2 5.8 12 8 6 Grass seed EXHIBIT A -Revised 312007 Drainage Area Map -Post-Development, Culverts & Pipes ..'I EXHIBIT B -Revised 312007 Drainage Area Map -Post-Development, Ditch Velocities