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HomeMy WebLinkAboutDrainage Report • • • • • • • • • • Drainage Report • • • for • • Polo Estates Subdivision • Brazos County, Texas •• • • January 2015 • Revised March 2015 • • • • Prepared By: • Schultz Engineering, LLC • g • • TBPE Firm No. 12327 P.O. Box 11995 College Station, TX 77842 • • 2730 Longmire Drive, Suite A College Station, Texas 77845 • (979) 764-3900 • • • Developer: • Get Real, LLC • 3850 Corporate Center Drive • College Station, Texas 77845 • Phone: (979) 690-2642 • Drainage Report for Polo Estates Subdivision Brazos County, Texas January 2015 Revised March 2015 Prepared By: Schultz Engineering, LLC TBPE Firm No. 12327 P.O. Box 11995 College Station, TX 77842 2730 Longmire Drive, Suite A College Station, Texas 77845 (979) 764-3900 Developer: Get Real, LLC 3850 Corporate Center Drive College Station, Texas 77845 Phone: (979) 690-2642 • • Polo Estates Subdivision Drainage Report ENGINEER Schultz Engineering,LLC. P.O.Box 11995 College Station,Texas 77842 Phone: (979)764-3900 Fax: (979)764 OWNER/DEVELOPER Get Real,LLC 3850 Corporate Center Drive College Station,Texas 77845 Phone: (979)690-2642 GENERAL DESCRIPTION AND LOCATION Location: Polo Estates Subdivision is located east of South Dowling Road and North Graham Road. Description: • Area: 34.069 acres • Proposed Land Use: Single Family Residential • #of Lots: 22 lots • Existing Land Use: Vacant • Land Description: The terrain slopes towards the southwest. Primary Drainage Facility: Hopes Creek Flood Hazard Information: FEMA FIRM: #48041C0325E(May 16,2012) Floodplain: Un-shaded Zone X HYDROLOGIC CHARACTERISTICS The existing site is predominately wooded. The elevations range from 266 to 294,sloping generally in a south easterly direction.The runoff enters tributaries of Hopes Creek. GENERAL STORMWATER PLAN The drainage plan for this development will involve the construction of ditches,channels and the installation of culvert structures. DRAINAGE DESIGN General Information: Stormwater runoff from this project will be collected in the ditches along Mallet Way and Mallet Court to be discharged into proposed drainage channels.The proposed channels will discharge into existing drainage ways. See Exhibit A for drainage areas for the culvert design locations and the channel design locations. See Exhibit B for drainage areas for the ditch design. Page 1 of 3 • • • T,Methodology: TR 55 • TT Minimum 10 minutes Design Storm Event: 25-year& 100-year-residential street&culvert,drainage channel • Culvert Materials: Culvert pipe material per Brazos County • Manning's n Value: 0.012 Runoff Coefficient: 0.45 The Rational Equation was used for the culvert,ditch and channel design. • 1 • Design Results-Culvert Pipe: I • Culvert No. 1 2 3 Culvert Size 1-18"Pipe 1-18"Pipe 1-24"Pipe • Top of Road Elev. 288.59 288.59 276.43 • Q25 9.49 8.89 13.33 • V25 6.32 6.10 6.10 HW25 287.44 287.24 275.06 40. Qioo 11.25 10.57 15.81 Vloo 7.00 6.71 6.57 HWioo 287.90 287.65 275.34 e 1 10 The data presented above and in the Appendices indicates the culvert sizes are in accordance with the requirements.The head water elevation for the culverts is less than the top of road elevation for the 100-yr storm runoff. The ditch at the outlet of the proposed culverts will be lined with rock riprap to prevent erosion from high velocities. The 46 velocities in the roadside ditches are such that the ditches will not need rock riprap or erosion control blankets to control erosion. S Design Results-Channels: Channel No. 1 2 s Slope 2.35 0.80 01 Q25 12.95 18.17 • V25 3.53 2.66 • D25 0.58 0.90 Qioo 15.34 21.52 • _ V100 3.73 2.77 • D100 0.63 0.98 • Channel No. 1 is a trapezoid channel, 4H:1V side slopes. The channel will have a minimum depth of 1.6' for adequate freeboard. The design velocity is 3.73 fps which is greater than 3.0 fps and less than 4.5 fps which requires curlex blankets to be installed the length of the drainage channels. Channel No. 2 is a trapezoid channel, 4H:1 V side slopes. 1 The channel will have a minimum depth of 2.0' for adequate freeboard. The design • velocity is 2.77 fps which is less than 4.5 fps which would require curlex blankets to be installed the length of the drainage channels. i Page 2 of 3 Applicable Exhibits: Exhibit A— Drainage Area Map—Culvert and Channel Design Exhibit B- Drainage Area Map—Roadside Ditch Design Appendix A— Drainage Area Summary Appendix B— Time of Concentration Computations Appendix C— Culvert Design Summary&Culvert Reports Appendix D- Ditch Design Summary Appendix E- Channel Design Summary and Reports CONCLUSION The culverts, roadside ditches, and drainage channel for this subdivision were designed in • accordance with appropriate engineering standards. • • 414 CERTIFICATION • I,Joseph P. Schultz,Licensed Professional Engineer No.65889,State of Texas,certify that this report for the drainage design • for Polo Estates Subdivision, was prepared by me in accordance with the requirements of the Brazos County Road and Bridge Department. •• OF retts, • * Jos P. chultz,P.E. ir.f.f.f.ii .i.iNN • J P. AVM ernd.011110.09telti. 1.11, • 65889 • ;,,` r • • ' r3,( • F-12427 +mu. • • • • • • • • • • • • • • • • Page 3 of 3 • • • • • • • • • • • • • • • • • • • • • • Exhibit A • Drainage Area Map • Culvert and Channel Design • • • • • • e • • • • • • • • • • • • • lily 1 ah 1 lir 1 • 1 • • • • • • • • • • • I . • • • • • • Exhibit B • Drainage Area Map • I • Roadside Ditch Design • • • • • • • . • • • • • • • I : I • 1 • • vir • • • • • • • • • • • • • • • • • • • • • Appendix A • Drainage Area Summary • • • • • • • • • • • • • • • • • • • • Ili Polo Estates Subdivision • Appendix A Drainage Area Summary • Rational Method • 25 year storm 100 year storm • Area,A C tc Area# 125 025 1100 0100 • (acres) (min) (in/hr) (cfs) (in/hr) (cfs) • 310 3.27 0.45 24.0 6.448 9.49 7.647 11.25 311 2.07 0.45 24.0 6.448 6.01 7.647 7.12 • 312 0.43 0.45 18.0 7.521 1.46 8.899 1.72 ' 313 0.77 0.45 10.0 9.861 3.42 11.639 4.03 • 320 3.55 0.45 31.0 5.566 8.89 6.619 10.57 410 321 2.19 0.45 31.0 5.566 5.49 6.619 6.52 322 1.35 0.45 27.0 6.033 3.66 7.163 4.35 • 330 0.78 0.45 10.0 9.861 3.46 11.639 4.09 • 331 0.39 0.45 10.0 9.861 1.73 11.639 2.04 332 0.10 0.45 10.0 9.861 0.44 11.639 0.52 • 333 0.13 0.45 10.0 9.861 0.58 11.639 0.68 334 0.16 0.45 10.0 9.861 0.71 11.639 0.84 • 340 1.00 0.45 10.0 9.861 4.44 11.639 5.24 • 341 0.22 0.45 10.0 9.861 0.98 11.639 1.15 342 0.33 0.45 10.0 9.861 1.46 11.639 1.73 • 343 0.45 0.45 10.0 9.861 2.00 11.639 2.36 • 350 1.09 0.45 10.0 9.861 4.84 11.639 5.71 351 0.10 0.45 10.0 9.861 0.44 11.639 0.52 • 352 0.25 0.45 10.0 9.861 1.11 11.639 1.31 353 0.50 0.45 10.0 9.861 2.22 11.639 2.62 • 354 0.24 0.45 10.0 9.861 1.07 11.639 1.26 • The Rational Method: • Q =CIA I = b/(tc+d)e tc = L/(V*60) • Q = Flow(cfs) tc=Time of concentration (min) L = Length (ft • A=Area(acres) V=Velocity(ft/sec) C = Runoff Coeff. • I = Rainfall Intensity(in/hr) • Brazos County: • 25 year storm 100 year storm 411b= 89 b= 96 d = 8.5 d = 8.0 • e= 0.754 e= 0.730 • • • • • • • • • • 0 0 • • • • • • • • • • • • • • • • • • • • • Appendix B • Time of Concentration Computations • • • • • • • • • • • • • • • • • • • • c °1I E <t 7 co r r I. I; E N N r M M N Gi 1 C E 2 E .o- N M (+ ) N 0) cr o $ c $ E U Z I- -o L -C (9 _- • a N 1. OE 4- Cl) N j 0. a. Z II II• N I, II II II (..9 7) o F-- J > - - Q L O C J n a O $ C O N N • U e • Z cl O 01 e- N m P- • c- Q O 3 j ,- (.7 .- N 13 "i3O y Z a z• O CO W N W • UJU45 C9 0 O O N '-, 0 • Q Z //� s C 0I V/ d $ • Z o m ` � � � � � � W11 co N N N V W lA N .p. j j J • a oal o o < w w 3• a II a $ G ,- C ii p p $ . • G 0 8 II N E I, n .5 > En > (q • 3• z • Z a Er: o 0 t rn rn ro y N N W lil > CL E • o .) N N • W ccor N N Oto O O J I• 0 • a L _&' C N N of CO CO F 'E N N N N N C I • • I cq o co c') 3 co p o o m U- • ii 5 c m N 0 .0 L U) m, 000 000 c 0 0 0 0 0 0 L 0 NNN NNN C J O N C N U .c N V 7 d' <I- C C.2 C C NN ' • p =O _ 0 0 0 0 0 0 Dill n c, O .- N O N • II C II N II E. N N N °' it �' : :,- M M M M M M N II II a • J C I (n • • • • • • • • • • • • • • • • • • • • • • Appendix C • Culvert Design Summary • & Culvert Reports • • • • • • • • • • • • • • • • • • • S isi oN. a o 1 > ti CO Co ,� N I d coV o tri � 1- r e- • • NN O_ _O > CO CO CO • • N C3) a) M • o NI- Oce) M ai co • a) • c 0 }, o = co a) _O O M • c �+ 4, 2 Q M M N • I U 0 M ts c • cu 0 asy A& oa o Q N. aoO CO O• ; Illpr a • i 241 .c C V CO CO 3 a) J c 0 N -Q a) ,Q N_ M C d0 OC) NI- CO tV) a _ N a r a) fl. Z.1 0 ii ,_ N M 1 • W 0 0 • a 0 a 0 Culvert Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk, Inc. Friday,Dec 12 2014 Culvert No. 1 - 25 year Storm Invert Elev Dn (ft) = 284.14 Calculations Pipe Length (ft) = 56.00 Qmin (cfs) = 9.49 Slope (%) = 2.07 Qmax (cfs) = 11.25 Invert Elev Up (ft) = 285.30 Tailwater Elev (ft) = (dc+D)/2 Rise (in) = 18.0 Shape = Circular Highlighted Span (in) = 18.0 Qtotal (cfs) = 9.49 • No. Barrels = 1 Qpipe (cfs) = 9.49 n-Value = 0.012 Qovertop (cfs) = 0.00 0 Culvert Type = Circular Concrete Veloc Dn (ft/s) = 5.68 • Culvert Entrance = Square edge w/headwall (C) Veloc Up (ft/s) = 6.32 • Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5 HGL Dn (ft) = 285.48 • HGL Up (ft) = 286.49 Embankment Hw Elev (ft) = 287.44 • Top Elevation (ft) = 288.59 Hw/D (ft) = 1 .42 • Top Width (ft) = 24.00 Flow Regime = Inlet Control • Crest Width (ft) = 24.00 • • • • Elev(9) Culvert No.1-25 year Stam Hw Depth(9) 239.00 3.70 • • 298.00 _ ... .___ __. ..... 270 217.00 ! .. 1.70 4. • k • 0.70 210.00 „ s ..�- • ....... _ __......-_............ 28.00 -0.30 284.00 -1:30 • • 20.0.00 -2.30 0 6 10 16 20 26 30 35 40 46 60 65 00 66 70 76 90 Girne�ar Cidaert 1-101. Embank • Reach(11 • • • • • • • al 488/118. - 111111111111111111081018.11.881101111011•11111111118 0 Culvert Report • • Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk, Inc. Friday,Dec 12 2014 Culvert No. 1 - 100 year Storm Invert Elev Dn (ft) = 284.14 Calculations Pipe Length (ft) = 56.00 Qmin (cfs) = 9.49 Slope (%) = 2.07 Qmax (cfs) = 11.25 Invert Elev Up (ft) = 285.30 Tailwater Elev (ft) = (dc+D)/2 Rise (in) = 18.0 Shape = Circular Highlighted Span (in) = 18.0 Qtotal (cfs) = 11.25 • No. Barrels = 1 Qpipe (cfs) = 11.25 n-Value = 0.012 Qovertop (cfs) = 0.00 • Culvert Type = Circular Concrete Veloc Dn (ft/s) = 6.58 1„ Culvert Entrance = Square edge w/headwall (C) Veloc Up (ft/s) = 7.00 • Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5 HGL Dn (ft) = 285.53 ' HGL Up (ft) = 286.58 Embankment Hw Elev (ft) = 287.90 Top Elevation (ft) = 288.59 Hw/D (ft) = 1.74 • Top Width (ft) = 24.00 Flow Regime = Inlet Control Crest Width (ft) = 24.00 •• • • • Elev(np Culvert No.1-100 year Stam! nw Depth(5 239.00 - - - _ --__.__-_. _ 3.70 • • 231300 2.70 • Plir ' 287.00 1.70 • 28600 0.70 • ......................... ................_....................... 28600 ......._...._.. - _...__._____.. -030 - • 114 204.00 -1.30 283.00 -2.30 0 6 10 15 20 26 30 36 40 45 60 55 60 86 70 75 80 Circular Culvert NCtL Embank Reach(6) ...,:.. :;. acv,,,,, V., ....�-..:..;w..)..4,uw-;a:,,s.-.,r,,,.,., ,.:..............i;: ,-..--,.-:»:..eTm,x....-s. ',...,, ,,,,.x.,:*,M,..,a..,;.-,,;:.....-,-.x-::.<ar,.....aaws;;.ar.:xs.a..:.skss-.ax::. a a a 0 a a a • Culvert Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk, Inc. Sunday, Mar 22 2015 Culvert No. 2 - 25 year Storm Invert Elev Dn (ft) = 284.73 Calculations Pipe Length (ft) = 62.00 Qmin (cfs) = 8.89 Slope (%) = 0.81 Qmax (cfs) = 10.57 Invert Elev Up (ft) = 285.23 Tailwater Elev (ft) = (dc+D)/2 Rise (in) = 18.0 Shape = Circular Highlighted Span (in) = 18.0 Qtotal (cfs) = 8.89 No. Barrels = 1 Qpipe (cfs) = 8.89 n-Value = 0.012 Qovertop (cfs) = 0.00 Culvert Type = Circular Concrete Veloc Dn (ft/s) = 5.38 Culvert Entrance = Square edge w/headwall (C) Veloc Up (ft/s) = 6.10 Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5 HGL Dn (ft) = 286.06 HGL Up (ft) = 286.38 Embankment Hw Elev (ft) = 287.24 Top Elevation (ft) = 288.59 Hw/D (ft) = 1.34 Top Width (ft) = 24.00 Flow Regime = Inlet Control Crest Width (ft) = 24.00 Elm'tn) Culvert No.2-25 year Storm He Depth 01) MOO 3R MOO 2n wm,d 267.00 P. 1.77 : — 20800 On 28600 az3 _ ____........,.... ,Igir.. _MN= il Ell 264.00 -1.23 283.00 -223 0 5 10 16 20 25 30 25 40 46 50 56 80 05 70 75 80 66 Circular Culvert MGI Embank Rech Ml Culvert Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk, Inc. Sunday, Mar 22 2015 Culvert No. 2 - 100 year Storm Invert Elev Dn (ft) = 284.73 Calculations Pipe Length (ft) = 62.00 Qmin (cfs) = 8.89 Slope (%) = 0.81 Qmax (cfs) = 10.57 Invert Elev Up (ft) = 285.23 Tailwater Elev (ft) = (dc+D)/2 Rise (in) = 18.0 Shape = Circular Highlighted Span (in) = 18.0 Qtotal (cfs) = 10.56 No. Barrels = 1 Qpipe (cfs) = 10.56 n-Value = 0.012 Qovertop (cfs) = 0.00 Culvert Type = Circular Concrete Veloc Dn (ft/s) = 6.23 Culvert Entrance = Square edge w/headwall (C) Veloc Up (ft/s) = 6.71 Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5 HGL Dn (ft) = 286.10 HGL Up (ft) = 286.48 Embankment Hw Elev (ft) = 287.65 Ilk Top Elevation (ft) = 288.59 Hw/D (ft) = 1.61 • Top Width (ft) = 24.00 Flow Regime = Inlet Control i Crest Width (ft) = 24.00 Elev(n) Culvert No.2-100 yaw Stolle Ho Depth(51 20'0.00 3.77 256.00 _ ....... 2.T7 �MEI...... • mntrot-._ pr- I287 00 !� 77 ............................ .. 285.00 0 77 28500 INN -0.23 �-00 -1.23 • • 203.05 -2.29 0 5 10 15 20 25 30 95t0 46 50 65 50 K 7075 86 Circular Culvert HOL 88461011 • Ruch(5) • R..:s„ ,Wt 4 ,... ,.r...,.. .ca.............::.. .. ..„.„..«„ .... .. ,. zx.:.T..,,,m«, ..... ., w..a,...,.a.>,.,w;»,._... - a:..a::.n....w...,,,..,.,, uza .-:,.,,,,;,s,,.,:,,: ..-..-- -_.::.. - ...uauasz ..amu..s�»..,...,a,.,,., • • • • • 0 Culvert Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk, Inc. Sunday, Mar 22 2015 Culvert No. 3 - 25 year Storm Invert Elev Dn (ft) = 272.57 Calculations Pipe Length (ft) = 54.00 Qmin (cfs) = 13.33 Slope (%) = 0.80 Qmax (cfs) = 15.81 Invert Elev Up (ft) = 273.00 Tailwater Elev (ft) = (dc+D)/2 Rise (in) = 24.0 Shape = Circular Highlighted Span (in) = 24.0 Qtotal (cfs) = 13.33 No. Barrels = 1 Qpipe (cfs) = 13.33 n-Value = 0.012 Qovertop (cfs) = 0.00 Culvert Type = Circular Concrete Veloc Dn (ft/s) = 4.79 Culvert Entrance = Square edge w/headwall (C) Veloc Up (ft/s) = 6.10 Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5 HGL Dn (ft) = 274.23 HGL Up (ft) = 274.31 Embankment Hw Elev (ft) = 275.06 Top Elevation (ft) = 276.43 Hw/D (ft) = 1 .03 Top Width (ft) = 24.00 Flow Regime = Inlet Control Crest Width (ft) = 24.00 • • • • 9N D) Culvert N0.3-?5 year Strom rm Depfi Ent 27!.00 d) • • 27600 100-"Ralm • biaLcorer • 276_00 ._......... ..........._ x-€:. r,n, ... a._ 2.00 • 274 00 ....._... ..... , : :: 00 • • 273.00• _ ........ .. _ 0.00 272_00 -1.00 • • 271.®0 -2.00 a 5 10 tb 20 25 $A 96 40 46 ea 56 60 66 70 75 CGrcndu Gdvdt HOL Emb.nk • Roach(R) .:.,.stt«ec a .a.r..:- .,..,,., «.„ .,-..::. . .,_\;.; ,.,...,.,.,..;.:a:...... sa............ .»wa:=xs ccw.,-......w:.,-.,,,xb.,.,�,., ,s M:.ss .•;,;. .a. ..:,: ,.>.,,,-a,.:... 'sm5.,».x,,,,,,.,.. ;,:,.,. ,.«...,, ,.....,..,. • • • • • • • Culvert Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk, Inc. Sunday, Mar 22 2015 Culvert No. 3 - 100 year Storm Invert Elev Dn (ft) = 272.57 Calculations Pipe Length (ft) = 54.00 Qmin (cfs) = 13.33 Slope (%) = 0.80 Qmax (cfs) = 15.81 Invert Elev Up (ft) = 273.00 Tailwater Elev (ft) = (dc+D)/2 Rise (in) = 24.0 Shape = Circular Highlighted Span (in) = 24.0 Qtotal (cfs) = 15.81 No. Barrels = 1 Qpipe (cfs) = 15.81 n-Value = 0.012 Qovertop (cfs) = 0.00 Culvert Type = Circular Concrete Veloc Dn (ft/s) = 5.51 Culvert Entrance = Square edge w/headwall (C) Veloc Up (ft/s) = 6.57 Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5 HGL Dn (ft) = 274.29 HGL Up (ft) = 274.43 Embankment Hw Elev (ft) = 275.34 Top Elevation (ft) = 276.43 Hw/D (ft) = 1.17 Top Width (ft) = 24.00 Flow Regime = Inlet Control Crest Width (ft) = 24.00 Slav p0 Culvert No.3-100 par Stone Hw Deal,(41 277.00 400 276.00 .. '1411111111111113 00 PPIF. wawa.... 275.00 __..._._._....._. 2.00 274.00 .......................... 4.00 ........................... ...._.._.._........ 273.00 0.00 272 00 -1.00 271.00 2.00 0 5 10 16 m 25 90 96 40 45 W 55 50 65 70 75 CircularCulvert HOL Embolic Reach(0) • • • • • • • • • • • • • • • • • • • • • Appendix D • Ditch Design Summary • • • • • • • • • • • • • • • • • • • • CO CO co a) a) 0) co N M CO N ,�+ U) 0) Cl CO U) 0) M N. co CO N. N n c O O O O O O O O O O O O • N N. 0 AT Ns N N. CO CO M co N. O a CO N- CD 0) U) f0 N O Cl 0 ,� - - - N ,- '- '- N '- N N- Cl N M • NU) N N U) ofCAl 0 U) OD co a) 7 1- co a w .- co co co O Cl N. CO O a) N V O O 4 N r O O 7 N ,_ U) 0 a) O) CO O CO co N. O co I-- co Lc)G "+ 7 CO N CO U) O M I. M U) CO h O O O O O O O O O O O O y) CO O M M a) co N d' CO Co O N. O. O O) CO CO 01 N CD CO U) Cl O) N CO r O N N N N N is N 001 Tr 4 COO N, O O w Op co v CD CD 4 v 4 (0 • a u O U) O M CO 1 O M N O0 Ti oi • O OJ CNC O co M C d M M N M M M 0 d a N M M CO M M N N co C ▪ N M M M M M N N co M M M N fr � C• C M M co K U co cncoLn is C 01 CI) .- 0. co Q a aO O r 0 M co CO (Si N 0 O co 0 U c CO CO CD O a0 M M0 U) CO CO CO CD 2 .c o O O M M +— O C') (Si M C+) O O '— . N V :''' O 0 t C N • C 2 O C • C) J L L L L t L ' L � N O .� co (D co N G) N m N O) m O) N co cg N N J O) k -J k '-' k J k J 'Q'. J a'. J a. J CO .t.. • 0 a U O O O L • Y a Cl.) C "O • N � O c O N DO n n N. n N. n h 01 CO co co C Cl) y N NN. N d' O O 1,- CO 0) 0 O CO y ri 01 O 0 a) VN' O O O N0 a)aco CO + + M N NC + + + + + + + a) a) + + + + O CQ y N N N N. N. N. N. co Tr O) 0) 'N co O CD U) d L C z N O O �U N a N CO • o m m �o m m co m m m co m ccD m m m 7 d J J J J N N IN d N d d (U N N N N d . .• Y . N fi 11 N to CD co co co m co a) a) m co co > > j a a= } 2 2 2 2 2 2 2 2 2 2 U U U U o 2 V) 0 L LI w 1— ai O o O a Z z Appendix E Channel Design Summary & Reports M a0 e = (IR O) o C r n . > 2- M N o a L d C) ' ,- N a0 O lf1 W O O U) O. u C M N MI • 0 • t) N a0 • • u) g ii o el M a Eco G C M O • W XCi) U M • C cs) d N • G 0 a) )n o Q 41 C J M a0 C N N O C l0 0 U • as o • ) a v v a • y • • a m • t N N CU• ai C • C co > U 0 C O N N o o a Z 2 d 1 U. -0c c m• m 7 t t U) 0 0 N CU Y CI Y U) W r O O a Channel Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk, Inc. Sunday, Mar 22 2015 Polo Estates Subdivision - Channel No. 1 - 25 Year Storm Trapezoidal Highlighted Bottom Width (ft) = 4.00 Depth (ft) = 0.58 Side Slopes (z:1) = 4.00, 4.00 Q (cfs) = 12.95 Total Depth (ft) = 1.50 Area (sqft) = 3.67 Invert Elev (ft) = 275.62 Velocity (ft/s) = 3.53 Slope (%) = 2.35 Wetted Perim (ft) = 8.78 N-Value = 0.035 Crit Depth, Yc (ft) = 0.57 Top Width (ft) = 8.64 Calculations EGL (ft) = 0.77 Compute by: Known Q Known Q (cfs) = 12.95 Elev (ft) Section Depth (fi 278.00 2.38 277.50 1.88 • • 277.00 .. m.. �� 1.38 I • 276.50 0.88 276.00 0.38 • 275.50 -0.12 275.00 -0.62 0 2 4 6 8 10 12 14 16 18 20 I Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk, Inc. Sunday, Mar 22 2015 Polo Estates Subdivision - Channel No. 1 - 100 Year Storm Trapezoidal Highlighted Bottom Width (ft) = 4.00 Depth (ft) = 0.63 Side Slopes (z:1) = 4.00, 4.00 Q (cfs) = 15.34 Total Depth (ft) = 1.50 Area (sqft) = 4.11 Invert Elev (ft) = 275.62 Velocity (ft/s) = 3.73 Slope (%) = 2.35 Wetted Perim (ft) = 9.20 N-Value = 0.035 Crit Depth, Yc (ft) = 0.63 Top Width (ft) = 9.04 Calculations EGL (ft) = 0.85 Compute by: Known Q Known Q (cfs) = 15.34 Elev (ft) Section Depth (fl 278.00 2.38 277.50 1.88 1 11 277.00 1.38 276.50 I 0.88 �r _ _ -4„, - - 276.00 0.38 • 1 lir a„,_ 275.50 -0.12 • 275.00 -0.62 0 2 4 6 8 10 12 14 16 18 20 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk,Inc. Sunday,Mar 22 2015 Polo Estates Subdivision - Channel No. 2 - 25 Year Storm Trapezoidal Highlighted Bottom Width (ft) = 4.00 Depth (ft) = 0.90 Side Slopes (z:1) = 4.00, 4.00 Q (cfs) = 18.17 Total Depth (ft) = 1.50 Area (sqft) = 6.84 Invert Elev (ft) = 270.01 Velocity (Ws) = 2.66 Slope (%) = 0.80 Wetted Perim (ft) = 11.42 N-Value = 0.035 Crit Depth, Yc (ft) = 0.69 Top Width (ft) = 11.20 Calculations EGL (ft) = 1 .01 Compute by: Known Q Known Q (cfs) = 18.17 Elev (ft) Section Depth (fi 272.00 1.99 • 271.50 1.49 • 271.00 0 0.99 +i ...._.._._..... • • 270.50 0.49 1111 ������L 11 270.00 -0.01 • 41 • • 269.50 -0.51 0 2 4 6 8 10 12 14 16 18 20 • • I-,_ -_L /ll\ Channel Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk,Inc. Sunday,Mar 22 2015 Polo Estates Subdivision - Channel No. 2 - 100 Year Storm Trapezoidal Highlighted Bottom Width (ft) = 4.00 Depth (ft) = 0.98 Side Slopes (z:1) = 4.00, 4.00 Q (cfs) = 21.52 Total Depth (ft) = 1.50 Area (sqft) = 7.76 Invert Elev (ft) = 270.01 Velocity (ft/s) = 2.77 Slope (%) = 0.80 Wetted Perim (ft) = 12.08 N-Value = 0.035 Crit Depth, Yc (ft) = 0.75 Top Width (ft) = 11.84 Calculations EGL (ft) = 1 .10 Compute by: Known Q Known Q (cfs) = 21.52 IV • Elev (ft) Section Depth (fi • 272.00 1.99 Pk w • ___ ... • 271.50 1.49 • • • 271.00 © 0.99 270.50•040.49 v. • 270.00 -0.01 • ii 269.50 -0.51 0 2 4 6 8 10 12 14 16 18 20 1 • Reach (ft) • • • • • • • • • I • • • • • • • • • • • • • • I • I • • • • • • • • • • • • • I • Drainage Report for Polo Estates Subdivision Brazos County, Texas January 2015 Prepared By: Schultz Engineering, LLC TBPE Firm No. 12327 P.O. Box 11995 College Station, TX 77842 2730 Longmire Drive, Suite A College Station, Texas 77845 (979) 764-3900 Developer: Malechek & Westmoland Family LP 3850 Corporate Center Drive College Station, Texas 77845 Phone: (979) 690-2642 Polo Estates Subdivision Drainage Report ENGINEER Schultz Engineering,LLC. P.O. Box 11995 College Station,Texas 77842 Phone: (979)764-3900 Fax: (979)764 OWNER/DEVELOPER Malechek&Westmoland Family LP 3850 Corporate Center Drive College Station,Texas 77845 Phone: (979)690-2642 GENERAL DESCRIPTION AND LOCATION Location: Polo Estates Subdivision is located east of South Dowling Road and North Graham Road. Description: • Area: 34.069 acres • Proposed Land Use: Single Family Residential • #of Lots: 21 lots • Existing Land Use: Vacant • Land Description: The terrain slopes towards the southwest. Primary Drainage Facility: Boggy Creek Flood Hazard Information: FEMA FIRM: #48041C0375E(May 16,2012) Floodplain: Un-shaded Zone X HYDROLOGIC CHARACTERISTICS The existing site is predominately wooded. The elevations range from 238 to 302,sloping generally in a south easterly direction.The runoff enters tributaries of Boggy Creek. GENERAL STORMWATER PLAN The drainage plan for this development will involve the construction of ditches,channels and the installation of culvert structures. DRAINAGE DESIGN General Information: Stormwater runoff from this project will be collected in the ditches along Mallet Way and Mallet Court to be discharged into proposed drainage channels. The proposed channels will discharge into existing drainage ways. See Exhibit A for drainage areas for the culvert design locations and the channel design locations. See Exhibit B for drainage areas for the ditch design. Page 1 of 3 T�Methodology: TR 55 71.Minimum 10 minutes Design Storm Event: 25-year& 100-year-residential street&culvert,drainage channel Culvert Materials: HDPE Pipe or ADS HP Pipe with cement stabilized sand backfill Manning's n Value: 0.012 Runoff Coefficient: 0.45 The Rational Equation was used for the culvert,ditch and channel design. Design Results-Culvert Pipe: Culvert No. 1 2 Culvert Size 1-18"Pipes 1-18"Pipe Top of Road Elev. 288.59 290.18 Q25 9.49 6.36 V25 6.32 5.24 HW25 287.44 288.29 Qioo 11.25 7.56 V100 7.00 5.64 HW100 287.90 288.50 The data presented above and in the Appendices indicates the culvert sizes are in accordance with the requirements. The head water elevation for the culverts is less than the top of road elevation for the 100-yr storm runoff. The ditch at the outlet of the proposed culverts will be lined with rock riprap to prevent erosion from high velocities. The velocities in the roadside ditches are such that the ditches will not need rock riprap or erosion control blankets to control erosion. Design Results-Channels: Channel No. 1 2 Slope 2.35 2.00 Q25 12.95 13.02 V25 3.40 3.25 D25 0.56 0.58 Qioo 15.34 15.42 V100 3.57 3.42 __ D100 0.61 0.63 Channel No. 1 is a trapezoid channel, 5H:1 V side slopes. The channel will have a minimum depth of 1.6' for adequate freeboard. The design velocity is 3.6 fps which is less than 4.5 fps which would require curlex blankets to be installed the length of the drainage channels. Channel No. 2 is a trapezoid channel, 5H:1 V side slopes. The channel will have a minimum depth of 1.6' for adequate freeboard. The design velocity is 3.4 fps which is less than 4.5 fps which would require curlex blankets to be installed the length of the drainage channels. Page 2 of 3 Applicable Exhibits: Exhibit A— Drainage Area Map—Culvert and Channel Design Exhibit B- Drainage Area Map—Roadside Ditch Design Appendix A— Drainage Area Summary Appendix B— Time of Concentration Computations Appendix C— Culvert Design Summary&Culvert Reports Appendix D- Ditch Design Summary Appendix E- Channel Design Summary and Reports CONCLUSION The culverts, roadside ditches, and drainage channel for this subdivision were designed in accordance with appropriate engineering standards. CERTIFICATION I,Joseph P. Schultz,Licensed Professional Engineer No.65889,State of Texas,certify that this report for the drainage design for Polo Estates Subdivision,was prepared by me in accordance with the requirements of the Brazos County Road and Bridge Department. —`tS `J Fe— Pr k '''1— '* Josep . Sc ltz,P.E. JOSEPH P. SCHULTZ . lijSCH 65889 ...) NitativONALf. r ,(` .( 5 F-1 2327 SCHULTZ ENGINEERING, LLC. Page 3 of 3 Exhibit A Drainage Area Map Culvert and Channel Design Exhibit B Drainage Area Map Roadside Ditch Design l'c;21 - r- -)1---Fri"M 11''7-: W/aa'77. "T. -- \-' - A. A ) /i f /�7/ ) 1 / ' 7 ��- .�- 1, �.�- /,�, r ) ) J) 1 \ LOT 17 LOT ( k /1 /�` NJC::,, I I' t \OT 16 I I 1.03 -\ / /// - ({ ((I( ( \ H 1 ------ N ,--- ) \ . \ \ z// \ -- I __., 1, �� I._-:\A i ( / ,-- `\....ice \ ---- -f-\ , .� 1/ l / >\, / ,-- -___ .N , I /A — — w, \ / 12 .\,---"iy-- \ iii) / / / *\N yl:c /\ i i \ 0.23 j ) i ' " \VI '°F LOT 14 \ �� �,.. ( � I i 1/ 0.0,----- gm--F 4 * fieRV / ri x - 1 /-: .--- -_____ __, �� J \___ - -• --har-rS \ \ ‘ • // 1- r ( -5- -.1-5 c / \- ._. -7 \ \-( \‘ '.• / -f7 - /- ? \ '-' /,..- --1 . zyr\ \-z_ __,/ 1 L -- __ ,- —_�... I - --1--.1 /- ,..:: ---,--// II) r / ( --. \ ____ I \,_ / /~\ N --2\ ` , -�- fes-- \ -� \ _ \ 1 ) 7 \ N \ N LQ`T 12 N ) v "\ ` , \ \ LL- 1 i / / \ �, - - �-� / /, RACT `.\ l',/ *.. , 1 - -r-r- - -f- / `\ ' '' N- --_ LOT 11 l \ / ' -1 / r \4/ ' ---- \ 1 ? 1 i 1 \ -- ..-- NJ ) 1 I , ) , , ��11Lr' /i ) ---,,r / / / / i 1 X >\' I I ( t i jiiii \ \ " \,,, \ ------, k 0 I / ILL. \ \ ______ , '-• •••• ._.L.L.L.........L... ......1..gcla.L.ciaLt....m, p �...�._..■ ic� 7"--------7,� �� E EXHT ADn . , .. , Appendix A Drainage Area Summary Polo Estates Subdivision Appendix A Drainage Area Summary Rational Method 25 year storm 100 year storm Area,A C tc Area# 125 025 1100 0100 (acres) (min) (in/hr) (cfs) (in/hr) (cfs) 310 3.27 0.45 24.0 6.448 9.49 7.647 11.25 311 2.07 0.45 24.0 6.448 6.01 7.647 7.12 312 0.43 0.45 18.0 7.521 1.46 8.899 1.72 313 0.77 0.45 10.0 9.861 3.42 11.639 4.03 320 2.49 0.45 30.0 5.675 6.36 6.746 7.56 321 1.03 _ 0.45 30.0 5.675 2.63 6.746 3.13 322 1.45 0.45 27.0 6.033 3.94 7.163 4.67 330 0.78 0.45 10.0 9.861 3.46 11.639 4.09 331 0.39 0.45 10.0 9.861 1.73 11.639 2.04 332 0.10 0.45 10.0 9.861 0.44 11.639 0.52 333 0.13 0.45 10.0 9.861 0.58 11.639 0.68 334 0.16 0.45 10.0 9.861 0.71 11.639 0.84 340 1.50 0.45 10.0 9.861 6.66 11.639 7.86 341 0.11 0.45 10.0 9.861 0.49 11.639 0.58 342 0.04 0.45 10.0 9.861 0.18 11.639 0.21 343 0.21 0.45 10.0 9.861 0.93 11.639 1.10 344 0.33 0.45 10.0 9.861 1.46 11.639 1.73 345 0.21 0.45 10.0 9.861 0.93 11.639 1.10 346 0.36 0.45 10.0 9.861 1.60 11.639 1.89 347 0.23 0.45 10.0 _ 9.861 1.02 11.639 1.20 The Rational Method: Q=CIA I =b/(tc+d)e t, = L/(V*60) Q= Flow(cfs) tc=Time of concentration(min) L = Length (ft A=Area(acres) V =Velocity (ft/sec) C= Runoff Coeff. I = Rainfall Intensity(in/hr) Brazos County: 25 year storm 100 year storm b= 89 b= 96 d = 8.5 d = 8.0 e= 0.754 e= 0.730 Appendix B Time of Concentration Computations CCp : E N ss}�Nv M M N 0 12 C EC N N f`07 c9, N E m` 5 a) O .1 c „cc,) 'Z' H E 7 m a O p N ,4' v 2 .- •.--▪ i., u_. U) > 0) y V/ E" > 7 S Z 1 1 11 11 or O I- —1 > I— Qg I— J a Z �.. CD ,- M e- '- N 0 1 C > i 'v W Z •E 7 S co (O N co n LU ;, LI OON 60 .- x5 Z L 3 0 ,w Z O N 2 :�c •:lJm WV m m m d aI• d ao n Q W ILI ,1 0 73, o 11515 ,1 ° a Yg 2 0 y II II" 5 E H > . > (/) za LL .2a N NNop W ,a > CL • - -- CL p • s'o � 4-44-4. ,,W 0 y N N W o LUD I— N 0 at C N NCO N N N z ) E II 30 0 0 N, E: N Eic 888gNN z • Ofc�I N N N ng N 8 Q - 0 0 0 0 0 0 13 .-..-----of O G p� E c IC '5, a mm # O c .- N O N 11 � NII 11N 1714MMMMMM 1—J . ., O Appendix C Culvert Design Summary & Culvert Reports o Q $ > a- N. ui c ti Q. (c i N > - CO L ryN g3 V V Co rC. 3p N Q M M O G E V � K N c w a � m Q --- 0 CD t ycsi o U NI C Ln J C O .N .; d _ y CO CO (/) Q. T T N a w 4' aT Nz N W a 0 O a Appendix D Ditch Design Summary g co co co 4 0) 0) 0) co N co N 0 O N CO N (O 0) C') N co (O (O O 0 O O o O O CD O O O O r O r 8NM r N N- a) 0 coO N 0 00 . M V CO et (O r'...- M O) O N r r ,- N r r r N r N r r (N N g O N 0 to CO CO O O) r V CO O N N (O O N O W M O '7 N N. to O ai M r O O Cf 0 0 O 0 O O O O r O O M N NO M N W COO U) 0 0A N. N N N N MNO NV(O g N O N a0 CO� co hv:} ON N O M - (O r V O M r N- N 0) 4 7O) d N M M 7 a � co M aN f� CI a y N (r� r M M M M M N O) M M M C') N N M M M _ E p C N M M O ' U Q co N c) �C y C') N C M C CD .13)� Q N Q D O O O in M CO M 0) N N O CO e0 O co O O co N to W 00 00 V — O O N r r O ') N M C') r O r r .7= 0 C a• z= 3 L . L• ,) L .a t L = �Lp7� .� L .may 0) a) a) a) J O) J co J co J te 0 J Of J d J O 0 O ) C C N ' L C O 0 (p (p (p (p00 co 0 Co.0 (00 (00 f0 t0 (O CO lA to O O N N pC CO + (NO coNCO 1 `r (g `r + + + CO+ R. R c "y O + + + + + + + N N N N 'CJ) O O O CO CO CO CO CO+ co+ 'N y 2 N C C co Oa N a ) U t 3 3 3 3 3 3 3 3 3 3 0 ° co 0 2 2 2 2 3 2 2 2 2 2 2 2 2 2 o COr U) 65 LU 0 O o a _ _ z L I Appendix E Channel Design Summary & Reports . . . . . . . . . . . . . . . . . , . . . . . . . . , . . j £ § k g k § Csi � > J t 7 \ J £ f § k 3 § > agl CA t \ \ � ■ CU S E ] k § cc s 2 ) 2 R ) '13 & C O. « o r^ § c § . S coo 2 & & 0 in ! _ k K f ) ) k 0 § CNI (/) ) k § / cn k k § tA u ; 0 0 a Channel Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk, Inc. Thursday,Jan 15 2015 Polo Estates Subdivision - Channel No. 1 - 25 Year Storm Trapezoidal Highlighted Bottom Width (ft) = 4.00 Depth (ft) = 0.56 Side Slopes (z:1) = 5.00, 5.00 Q (cfs) = 12.95 Total Depth (ft) = 1.50 Area (sqft) = 3.81 Invert Elev (ft) = 275.62 Velocity (ft/s) = 3.40 Slope (%) = 2.35 Wetted Perim (ft) = 9.71 N-Value = 0.035 Crit Depth, Yc (ft) = 0.55 Top Width (ft) = 9.60 Calculations EGL (ft) = 0.74 Compute by: Known Q Known Q (cfs) = 12.95 Elev (ft) Section Depth (fi 278.00 2.38 277.50 - 1.88 277.00 1.38 276.50 0.88 4 276.00 0.38 275.50 -0.12 275.00 -0.62 0 2 4 6 8 10 12 14 16 18 20 22 24 Raarh (ft) Channel Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk,Inc. Thursday,Jan 15 2015 Polo Estates Subdivision - Channel No. 1 - 100 Year Storm Trapezoidal Highlighted Bottom Width (ft) = 4.00 Depth (ft) = 0.61 Side Slopes (z:1) = 5.00, 5.00 Q (cfs) = 15.34 Total Depth (ft) = 1.50 Area (sqft) = 4.30 Invert Elev (ft) = 275.62 Velocity (ft/s) = 3.57 Slope (%) = 2.35 Wetted Perim (ft) = 10.22 N-Value = 0.035 Crit Depth, Yc (ft) = 0.60 Top Width (ft) = 10.10 Calculations EGL (ft) = 0.81 Compute by: Known Q Known Q (cfs) = 15.34 Elev (ft) Section Depth (fi 278.00 2.38 277.50 1.88 277.00 1.38 276.50 0.88 \ $ 276.00 0.38 275.50 -0.12 275.00 -0.62 0 2 4 6 8 10 12 14 16 18 20 22 24 Channel Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk, Inc. Thursday,Jan 15 2015 Polo Estates Subdivision - Channel No. 2 - 25 Year Storm Trapezoidal Highlighted Bottom Width (ft) = 4.00 Depth (ft) = 0.58 Side Slopes (z:1) = 5.00, 5.00 Q (cfs) = 13.02 Total Depth (ft) = 1.50 Area (sqft) = 4.00 Invert Elev (ft) = 273.04 Velocity (ft/s) = 3.25 Slope (%) = 2.00 Wetted Perim (ft) = 9.91 N-Value = 0.035 Crit Depth, Yc (ft) = 0.55 Top Width (ft) = 9.80 Calculations EGL (ft) = 0.74 Compute by: Known Q Known Q (cfs) = 13.02 Elev (ft) Section Depth (fi 275.00 1.96 274.50 , 1.46 274.00 0.96 Q 273.50 0.46 273.00 -0.04 272.50 -0.54 0 2 4 6 8 10 12 14 16 18 20 22 24 o,..,. , ia\ Channel Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk, Inc. Thursday,Jan 15 2015 Polo Estates Subdivision - Channel No. 2 - 100 Year Storm Trapezoidal Highlighted Bottom Width (ft) = 4.00 Depth (ft) = 0.63 Side Slopes (z:1) = 5.00, 5.00 Q (cfs) = 15.42 Total Depth (ft) = 1.50 Area (sqft) = 4.50 Invert Elev (ft) = 273.04 Velocity (ft/s) = 3.42 Slope (%) = 2.00 Wetted Perim (ft) = 10.42 N-Value = 0.035 Crit Depth, Yc (ft) = 0.60 Top Width (ft) = 10.30 Calculations EGL (ft) = 0.81 Compute by: Known Q Known Q (cfs) = 15.42 Elev (ft) Depth Section 275.00 - 1.96 274.50111,\\ T 1.46 _ I 274.00 - 0.96 273.50 r 0.46 273.00 -0.04 272.50 -0.54 0 2 4 6 8 10 12 14 16 18 20 22 24 11_ -_1_ /21\