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Detention & Storm Drain Report
DETENTION AND STORM DRAIN SYSTEM REPORT FOR CASTLEGATE II SUBDIVISION, SECTION 202 COLLEGE STATION, TEXAS April 2012 Revised June 2012 Prepared by. - Phillips Engineering 4490 Castlegate Drive College Station, Texas 77845 (979)690-3141 GENERAL INFORMATION AND BACKGROUND The Castlegate II Subdivision is a 202-acre development located immediately southwest of the existing Castlegate Subdivision in south College Station. It is a single-family residential development that has 645 lots under its current configuration. The new subdivision is split roughly in half by the extension of Victoria Avenue through the tract. Sections 100-107 are located on the northwest side of Victoria and Section 200-207 are located to the southeast. To date, Section 200 has been built and Section 201 is under construction with completion anticipated in the summer of 2012. The 202-acre tract lies across the drainage divide that separates the Spring Creek Drainage Basin in the north and the Peach Creek Drainage Basin to the south. As a result, the development requires two independent drainage systems and two detention ponds. The larger of the two detention ponds is in the Spring Creek Basin and was construction with Section 200 near the intersection of Victoria Avenue and WS Phillips Parkway. It was designed to serve Sections 100-107 and Sections 200, 201, and 203. The second pond will be built in conjunction with Section 202 at the south end of the development and will serve Sections 202, 204-208. The Detention and Drainage Report that follows analyzes this second pond (referred to as Pond B). In January, 2012, an application for a grading permit was submitted for the excavation of Pond B. As part of that application, a full detention analysis was prepared and submitted, including the design of the outlet control structure. That plans for the pond were approved and excavation has been initiated at the site. The designs of the detention pond and outlet control structure have not changed, and those same exhibits are being resubmitted with this report. The outlet control structure was not part of the grading permit application, but it is being presented for approval with this submittal. DETENTION SYSTEM DESIGN Hydrologic Analysis Design Software: HEC-HMS 3.3 Soil Group Type C & D Design Storm 24 hr, SCS Type III distribution Storm Intervals 2, 10, 25, 50 and 100 year events Note: The HEC-HMS includes analysis of both Pond A and Pond A No changes to the analysis of Pond A have been made in this analysis. Only the drainage areas and associated hydrologic characteristics for Pond Bare modified with this analysis. Pond Information Pond B in Castlegate II Outlet Structure: Concrete, two -staged broad crested weir with 3-48" HDPE pipes carrying outflow to the adjacent natural channel, see plans for details Emerg. Spillway: Grass lined trapezoidal channel 350 feet long Elevation = 310.70 Top of Berm: Elevation = 311.50 Summary of Results The Pre- and Post -development flowrates were analyzed immediately downstream pond at the Greens Prairie Road culvert pipe. HEC HMS Output Summary Ca, Studv Pt B Greens Prairie Road Recurrance Int. (yr) 2 10 25 50 100 100 yr blocked Pre -Development (cfs) 162 330 388 471 541 Post -Development (cfs) 162 327 383 461 530 Pond WSEL (ft) 309.3 310.0 310.2 310.5 310.7yr3ll.O, Emerg. Spillway = 310.7 Top of Berm = 311.5 These results indicate that the detention pond and outlet control structure proposed with Section 202 serve to maintain or reduce post -development runoff as compared to pre -development rates. Applicable Exhibits: Exhibit A — Summary of HEC-HMS Modeling Information Exhibit B — Drainage Area Map — Pre -Development Exhibit C — Drainage Area Map — Post -Development Exhibit D — CN Computation Worksheet Exhibit E — Drainage Area & Reach Lag Time Computations Exhibit Fl — Two -Stage Outlet Control Weir Design Exhibit F2 — Stage/Flow Computation for Weir Design Exhibit G — Castlegate II Pond B Elevation/Storage Calculation Appendix 1 — HEC-HMS Summary Output File — Pre -Development Appendix 2 —HEC- HMS Summary Output Files — Post -Development Appendix 3 — HEC-HMS Summary Output Files — Blocked Outlet Exhibit A CASTLEGATE II SUBDIVISION - POND B HEC HMS MODELING INFORMATION SCS Lag Method January 16, 2012 (Highlighted lines represent Drainage Areas associated with Pond B) DA # Area CN % Imp Lag Time sq. mi. % min Pre -Development 111 0.16464 79.7 0.0 45 120 0.02370 79.0 0.0 10 100 0.09288 85.5 0.0 48 110 0.01916 79.0 0.0 18 112 0.00733 79.0 0.0 20 101 0.02513 86.7 0.0 23 102 0.00873 87.0 0.0 12 HEC HMS MODEL DIAGRAM DA 113 ,.., Stdy Pt B DA 121 Basins contributing to Study Pt B downstream of Castlegate II. Post -Development 210 0.19660 79.7 57.9 56 220. 0.02370 79.0 0.0 10- 201 0.02513 86.7 0.0 23 202 0.00873 87.0 0.0 12 200 0.09288 85.5 0.0 48 27 0�647� $1 9 0,0 66 Basins contributing to Study Pt B r, Q.1,tjQ�; �61 downstream of Castlegate II. HEC HMS MODEL DIAGRAM DA 211 Castle2 South Pond DA 221 Stdy Pt B HEC HMS Output Summary A Stdy Pt B Recurrance Int. 2 10 25 50 100 Pre -Development 162 330 388 471 541 Post -Development 162 327 383 461 530 Pond WSEL 309.3 310.0 310.2 310.5 310.7 Top of Berm = 311.5 N Imo- OG6 5 - pi_ ._m ontot "•... D ,-. "_ -- _V\�.-��/� �'V �"P'1_%� � or tr�`^A . "'"_ 4 / W c � m m 65 n t v� •' \ l I Stu YV i w r t- \ W uj (D FW- ((rl a T' I A. 4 5 a ! >' V� \., AV If 14 tan U�•�m ' JJ LLI i = - -- - - - - • i Cr` , _. wig a I - ., _ - - dwI % pa745!aM (roe) vary a5eu!wQ Ee!oy h d m m !e!aiawwop io ssaNsng •V d !.� Rpuap!say,q!s-0 qS!y b N C y!epaappa q!saoa wnlp.w ,Nn a" !epuap!say q!suaQ m07 m yb (SSMD) coeds Wo i7 o W NO Pal4510M O S b VV i.i ('ae)ealy 05uu!eiQ !eloy W A •� ,o � y y y ! � y 2 �O � d ped aseg aeo!sam!� C •� CA y F c d y � R!nmpul P NI Rivawwo� °` � m m d o b a m r a+�tl 6/!R!leay!saN b �09 y M v asatl i Rp'aP!Tay ,�,y yatlZR!wapiny wsaw�..ay O RS a papoa/� 0 U a!!peop 6 C U q 'o '91!^S A9 'oN MV a5eu!vQ o 0000 0 oa�o" o000 .r o ^ M m.' 3� M N N y C `e u r A r M x J"ram x` - u., a O N q 'r N O 09'[9 d" cacaggUqq Q,-` ggqoa��q`". w z �• f m M V (MD M M V N W N V b N O O L N C � "mac OJ M N M r M KQ- J = - a < N N N � N Qa�„•, LQ C O N k h a M M O M . t W t W 01 W O N N O M k•'' N ',-� U W�(( �L { N<< v r ctt, m M M< J �F 0 0 0 0 0 O O 0 0= -' O Q y N r d U fLl 10 < N N G Exhibit F1 Weir Report Two Stage Outlet Control Design .. HydraflowExpress Extension for AutoCADSCivil 3D®2009byAutodesk,Inc. Monday, Jan 162012 Castelgate II South Pond Weir Compound Weir Highlighted Crest = Broad Depth (ft) = 6.00 Bottom Length (ft) = 32.00 Q (cfs) = 398.55 Total Depth (ft) = 6.00 Area (sqft) = 87.00 Length, x (ft) = 4.00 Velocity (ft/s) = 4.58 Depth, a (ft) = 3.75 Top Width (ft) = 32.00 Calculations Weir Coeff. Cw = 2.60 Compute by: Q vs Depth No. Increments = 24 Depth (ft) 7.00 6.00 - 5.00 - 4.00 - 3.00 - 2.00 - 1.00 - 0.00 - -1.00 Castelgate 11 South Pond Weir 5 10 15 Weir W.S. 20 25 Depth (ft) 7.00 6.00 5.00 4.00 3.00 2.00 1.00 0.00 -1.00 35 40 45 Length (ft) Exhibit F2 N1 V V Obi N N r' O i M v ui vi ui � fd I �o ojo oho 0 o;oio o(o 0!0 515 6 ojo o1g,o 0 0 0'0 aja alv�v a�ala v�v a v v;v v aNi�cNi; MM�� M rNi�MjM M WIN W <�i[� � Owl M1NIfmp�0Wp, O O! r;Ft OD m C41 V N < < N N fY M I th M M V 't .0 I a I"r N 't ; M I m M C] V' v �t -t O<I NIM(a�N�O rZ cd 6 � Ml�oi NI mI v�0�N�Mi M 71NI m�nIr�� M! 9191 m I N i It l 4 i N I S I�� N� N i l� r f N I N� N� M I tm'1 Exhibit G Castlegate II - Pond B Detention Pond No.1 Area -Capacity Data V = H - ([A1+A2 + (A1•A2)v2] / 3) V = volume, ft2 A = area, ft2 H = difference in elevation, it Pond B - Revised 12-13-11 Area - Capacity Data Elevation (ft) Depth (ft) Area (ft) Area (acres) Volume ac-ft 90% of Volume ac-ft Cumulative Volume ac-ft 305.60 0.00 0 0.000 0.000 0.000�'r0 306.00 0.40 1,284 0.029 0.004 0.004 _ ,004 306.60 1.00 8,037 0.185 0.058 0.052 ;4 065 w, 307.00 1.40 16,815 0.386 0.112 0.100 307.60 2.00 32,784 0.753 0.336 0.302 40 308.00 2.40 47,922 1.100 0.368 0.332 Q 789 308.60 3.00 72,873 1.673 0.826 0.743, 309.00 3.40 55,411 2.190 0.770 0.693 309.35 3.75 110,639 2.540 0.827 0. 444 970 309.60 4.00 121,982 2.800 0.667 0.601 310.00 4.40 142,135 3.263 1.211 1.090 �;,861 MI 310.60 5.00 156,308 3.588 2.055 1.849 w 51iJv.'; 311.00 5.40 164,131 3.768 1.471 1.324%$34 311.6 6.00 164,810 __1.784_j 2.265 2.039 873 .; The outlet structure for the Castle2 Pond B is a compound rectangular weir that can be seen in the Hydraflow, model'South Pond Outlet'. APPENDIX 1 HEGHMS SUMMARY OUTPUT FILES - PRE DEVELOPMENT P N � L N N T CL CQ C O t�L) 3 a) U U o '0 N (n :P 2 O `O C6 C O O E N a C co O O o mZ>U °D 0 N C O O In a o00 L 7 O O N 0 1 r r N N N C C C O CQ Co O N N LO 0 000 a) m E � � w a�i 0° a :0, my E a U) w U a) E i N M 0 N N N N N N N N N N N N N N O U') 0 0 0 L) LO O O LO Lo LO O 0 LO LO 0 LO N r N LO N LO r r W) r N r LO r O �- Y N N N CV fV N N N M N M M M N M M M c- O O O O O O O O O O C7 6 O O O O O O (L v- O O O O O O r O r O r O r O r O r O r O r O r O r O r 0 O N N N N N N N N N N N N N N N N N O C C C C C C C C G C C G C C C C C N N (0 N (0 N l6 O N (0 N (6 (6 (0 N (0 N M I- r 01010 r r r ol r Oj r of r ol r ol r O r 010101010 r r r r r CDJ r ol r O N m (6 L Y (n Ca LL N O N M M W V O m M 0), I� co O 00 CL N r rr r N m r N r r r r r M cu Q O 0) 0 0 0 0 0 0 0 0 00 0 0 0 O 0 0 00 ''T CO O C'O 00 M r M h CO r d' (O M M CO CO O ' CO V i, V O f-- O N V M O N M O M r m C N ' N LLO 00 m d' h to co M M co N M N m O m 0 N 0 O 0 r O CO O O N r N O CO r �--' N N O N N M r N N r M M N M (O O O O O r O O CD O O O O O O O O 0 C rn N m tT d a° a CD C) N N � N O O N C6 w n. U U 0(� m D a o � _ � ry N L O) ""' W Q Q Q m O o a) � `� Q a a a m E O O co 0 "" ca T T T T (0 m w r O r r r r .N - c- r N r N CN U R' � 0 (n (n (n I— a) >. (L N O CO a -o Co 0 �L P 7 N 'E5) N O ca C O O N N co: E (B m:2U O 0 oo(�n a coo L j O O N O •'ter N N N C C C O m (6 O N N it m o0O w N O C N O O C. o f -o E a` in w U a) E O, co (O co Ih m (o 't m (O t, LO (0W N w mil' Z (O CR CO m O O O M .- O w 0 0 0 N O �-- �... 0 m m 4 tYi V 4 V 64 to 4 (o (O (O lO O (o (o O O (o m O O (0 in (o (o O (o O m 0 N , N (O N (O (O , N (O (O , O 0 Y N N N N N N N N M N M M N N M M M O O 0 0 O O O O O O C O 0 0 0 0 O' O O O O O O O O O O O O 0 0 0 0 0 0 0 N N N N N N N N N N N N N N N N N O C C C C C C C G C C C C C C C C C (6 N N l6 l9 l6 N N N N N N n1 N N N N I- 0 O O 0 O 0 O 0 0 O 0 O O 0 0 O O 0 0 O 0 O r O r O r O r O r O O O N m al L U ti Y � O V- O co O W 0 co Cl) co CO O N d U co0)Itw"t Nt N 0 O w (O O (O M (o co 0 Ih (o N M N 0 N (O N N N M m a) ID Q 0 0 0 0 0 0 0 0 o w 0 0 0 0 0 0 w m O O a3 M Lo fo m O M 00 w I� V d' M N M m N 0 O m M m O C N N N (O co m M CY), N N (O O) O O O N O O O O (O (o - O O O N N N O CD O 7 N N N O N N W M 7 N N �- M CO N M (O O O O O O O 7 O O O O O O O O O O 0 c CO n m m a m a a a) N G y C m c Q) Q) a) (/) f// U C o a) mM c, n o U U m U w n J Lo 0) Q % � Q a ao mo TO O , NCO N0 N N P , S W 0 — N — U 0 0 0 0 I— ❑ L L >`1 dNN N C (D O a O Co N 'E5) N 0 0 O U) (V O 0 OL E N O O U) m2U CD ❑ r O Lo o G O O U) L O O N 0 r r r N N N C C C O M (0 O m (6 r N U7 a o00 U) Qj E N O O O- o o E IL(0WU a O r LO T 00 O Z U) I� cO 00 0A 00 00 00 c O I� O cq O r 0 0 > O (O (O U) U) U) 0 0 (0 U) 0 0 m (O (0 (O M O U) 0 O O 0 0 O 0 U7 U) U) U) O U) O U) U) N T N U) N U) T T U) T N U) LO r 0 0 ,Y N N N N N N N N M N M M N N M M 615 cu r r T T T T T T T T T T T T r r r /N O O O O O O O O O O O O O O' O O O LL r O T O 0 T O T O T O T CD T CD T T O T O T O T O r O r O r O r O 0 N N N N N N N N N N N N N N N N N N C C C C C C C C C C C C C C C C C (0 (6 (Q (Q (0 (6 (0 (0 (0 (0 (0 (6 (0 (Q (0 N f0 I- r O T O r O r O r O r O r O r 01010 r r r 010101010 r r r T T ol T O ro o) R U co Y (n N U- N Lo O r T r M U) V N c0 0 V U) N 00 1� It U) h co O O 0 r h r M M N T (p N T T h N M n M N M V m 00 m Q O) 0 0 0 0 0 0 0 0 00 0 0 0 0 0 o m o0 (6 M M M (O -ItM W CD r O O V O w -t T C N 00 N T U) co 00 T Q1 (q d' M ti M U) co co V co V m cM N N M c0 N N O U) M O O O O N O T (p O N N 0 r N N W N T 00 M O O O O T O r O r N O N r N M N (O ❑ ...� 0 0 0 0 0 0 0 0 0 0 0 0 0 O O O O u 0 m d a° a N N C N C CI N C N N U O U N L f0 m (� U)n ° T N U L OG UJQQQQmm o i s a a a a O T N O-> -� :-R-1 = L1.1 O r O r O r r r T r T r T T N r N T U � (n l N F N d LO N LO (n N O ° O M ° 2w N � N O 0 CL O C N N O (n m�co) ° � m C OLo O LO) d O O O L O O � O O (V O N N N c c c O N (6 7 M (6 N U) a) O O Cl +' N (a c E LL N D °pa -° E co a in w U E 2, V V M M h 00 M O O O W O CO h M O Z M N t N c- N N M V M V h W W h h h h h h h h h h h h h h O U) U) O O O U) O O O U) O U) O U) O U) U) N N U) N LO U) , N U) to c- O O Y N N N N N N N N M N M M N N M M M coa- O O O O O O O O O O O O O O O O O O 0 N N N N N N N N N N N N N N N N N (D C C C C C C C C C C C C C C C C C t0 (0 (0 (0 N (6 N l6 (6 (6 l6 (0 (0 (0 N N (6 F r CDI r ol r O r CDJ r ol r ol o r ol r O r ol r ol ol r ol r O r CDJ r ol r O N i 2) (6 L U U 0 Y (n O U- a) U) U) 00 U) M O "t �- M iL V 00 T Cl) h �- �- N (O LO h (D 00 M 00 N h M .- h M Lo M N N 00 N M 00 M co M LO V' M (a Q ° O) o 0 0 0 0 0 0 0 0o O o 0 0 0 0 00 0 (o 00 M M UD I�t Cl) 00 O co h -It O O V O 00 V C N 00 N , U) h, 00 M (O 'V M h 00 L() h co V co M h M N N M 00 N N O U) M M M O M N O 1 (0 O N N (O 1 N N 00 N , 00 M 0 0 0 0 r O - O -: N O N -: N M N O .� O O O C) 0 0 0 O O O O O O O O O O O (n a? Cod Q dM N Q n N N a U m V ) X D o J ' O C LLl r. Q (y N M �] ._ 0 co o ° a) (� (� a M a T O c- N O �- N M O .-p -ppp 2 W o 0 0 U w !n U) !n !n E° 00 i+ 't 00 a N N o a O: Co " U U N '5 p 2 U .;m m 2 p O c CD E Co N O <A m75U o c 0 C) LO a L O O j O O N p N N N c c c m m m c m 04LO m N to a) O O O m E U c c j= c NO O Q � -o E a U) LU 0 N E O �- 1-- N (0 N N M O M M N It I.- N r 'It p z �-- M Cl? M M M M M 0't N ItM It(0 It i O. m m m w o0 (0 o0 o0 o0 o0 o0 o0 o0 o0 W o0 6 O 0 0 0 0 0 M O O O (C) O (n O LO O If) (I') N 1 N m N (n I I (n , N Lf) LO 1 0 0 Y N N N N N (V N N M CV M M N fV M M M cu O O O O O O O O O O O O O O O 6 O O a r r 0 r 0 r 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O N N N N N N N N N N N N N N N N N N N C G G C C C C C C C C C C C C G c m m m m m m m m m m m m m m m m m E I"' r O r 0101010 r r O r O r O r O r O ol 0101010 0101 N m m L U w CU m L.L O N N M m (n O r r V a V V h (0 -It (0 m m co -It m M ITM W 'd' 0� _ N 00 m C0 M N N O N m m m Q rn 0 0 0 0 0 0 0 0 w 0 0 0 0 0 0 m 00 0 M m m 'r M w 0 to r- 'It O O It 0 c0 v I C N 00 N , (n r� 00 1 m O 'P M h W to h M V co co ti co N N M o0 N N O (c') M m m 0 m N 0 1 (0 O N N (0 1 N N M N I W M O O O O .- O .- 0 N O N N M N 0 O o a? CDm a` a a c m m 3 V U m U Mn X oa. D p J r. i ..'0 O C LL1 a a Q Q m m o m Q a a m a x w �- IN N, U D� co cn w m N APPENDIX 2 HEGHMS SUMMARY OUTPUT FILES — POST 111_ kvWI o'U- L_I to 'O c O a t 0 O c ro t 0 0 z 3 i Y L d N N N i/1 0 °. a)a.. -o 0 ro C � w N N O CL 0 L ca c o O E ro v� m oc mU ro LO o. C (p O C.,)d oo� L : O O C% O c c c " "Co RS , N CO oo� CD N E m CD °D f 'o E a.0) ca W U a� E O, N to O) O co I-- c0 co O co O m (O 0 N M <P O Z O O O M CO (M M Ci V. (O M co V M N O �..� N m M m m N N co co m N M M m M M M O M In 0 0 0 0 O 0 (O 0 0 0 0 0 0 to (0 N, O M , M, N M O LO CO N CO N M N N M M -- M M N <} N M M M M ro�- O a w o 0 O N N N N N N N N N N N N N c N c N c. ro c c. c c C c c c c c c c C c ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro 1= r o r 0.010.0.0 r r r r r 0.0.0.0 r r r r 0 r 0 r 0 r 0 0.0.0. r- N L 0 Y N 0 n r N V CD M (0 0 O -. 0M M 0 to (NO n. t-- N a- M N 0) a- h. N a- a- M ro Q CD CA' c0 M M O O O O c0 M O O O O CO O ro LO 00 O 0 m m v M V h .- M e- 0 O M 0) G N ' N N ao O M M l� O O M O f� M 0 O -� O N N O O m N N O <7' N N N 0 O N �O 0 d' W M O O O i � O, N N, O N N N M N O O O CD C> 0 0 0101010 C> O O O O O 0 a p` cl W m ro L IL d d a� d N ca c d m o U Cg CO 0 0 t= a 1 'O) Y z° 10= a a a m m of a� ro ro a a a 1 O e- N O Ot� w w w V 'O 'O _O 3 NNN N N f� 0 I—O . NN N c O a w 7 O U) C f6 0 0 Z } N Ot o a�N N a -O O N C � w N m O O � U) N C O Q -W E co m28 U) O co ❑ O 0 O O M a 0000 j O O N 0�- c c c a) ca ca w ci �Nccoo O O c- Y E cQ 46 it w E. a a inw0 E E .-. M .- O CO e-- V' W co O r r f, 0 N v � ui cn f0 CO V' cn CO f0 f0 V' CO l0 cD cn � cn o cn u� o in o o 0 o 0 o m 0 w O m 0 cn N s- O cn N �- �- cn 0 to N 0 , N Y c6•-- •-- �- �- •-- •-- .- i- �- e- .- �- i- N O O O O O O 0- O O O O O O O O O o O O O O O O O 0 N N N N N N N N N N N N N N N N N O C C C C C C C C C C C C C C C C C m m m m ca m m co m m m m m ca m m m E 1= r o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 r 0 r 0 r 0 r 0 N 2) c6 V N Y (n cu LL co co O co U) pppp D) n 0)M 1h co a V Cl)d' d' 01l f0 O co f� 00 V' 00 h a- 1, CO N O- N N In a N N �- to N cocM N Cn co c0 m d Q f0 M C-7 0 0 0 0 M O O O t0 O CO O c OD a0 .- !� CO V' I� N V M V f� �- M �- O 0 O m d) ' N N LO co co O M co an O O. M V O d' 1` M O m O N O O O O �- N N O CO qf N N N O to N in V M CD co ❑ .... 0 0 0 0 0 0 .- 0 N 0 N, 0 0 0 N 0 N 0 -N 0 0 N 0 0 0 a p` C t a C O O N (n N a�) L a 0 U m o v E o U m r a m Z in Q Q¢ ccUyy Q m o O C m E E a) o n O N 0 0 Na N CO 0) 0 >O 0ON ' 'a N N NU N U U a U VNNN !n N O 0 a 0 O co m f 0 z 3 j n `o r aN(N ro N !"Jq N •• G 00 (1) O y a O CL U) m = O E 0 U) ca m�U p Lo M v 0 O O CM a CD Co<�o L =$ 005N 0 N N N 0 m m m �N C�0 CO oo� E cma i' IL U) w U aD E Z3, 0 r, M M ti r, M .- 0 r, M O M o O Cn r, O z L; �; co cy g M 7 o O M co rn 7 o cw co r` > �. m o m r` r: ui m is n vi co is co co m o rp rn o ro o O ro 0 00 ro rn ui o uo 0 0N �- O M , , N � a 0 0 0N- C0 � N m fV (V N M N N M M M M (V (M N M M M M N CT O O o 0 0 Cj CJ 0 0 0 0 0 0 6 6 O V0 — O o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 c c c c c c c c c c c c c c c c c m m m m m m m m m m m m m m m m m 1- r o r 0 r 0 r 0 r 0 0 0 r 0 r 0 r 0 0 0 0 0 0 0 r 0.010.0 r 0 0 a) E' m v w o .� Y U- d 0CA d• s- O O M M n d• O M 0Cn IL N co O CA O, N M r, CA N O N M W ... CO N M N Cl) M CO M m M m M r, m a> rn co c+) M O o o O M o 0 o co o m �t o It m a0 , h CO �t r, co V cl) a r. , M , O O CA C C^ ' N t0 co CO O M M VIM O M V O d' M O M O N O O O M N N O CO V' N N N O In N C0 N d' M co N co CO g �— 0 0 0 N 0 N 0 �— 0 0 N 0 N 0 0 0 0 0 a o` a co a a o d c 0 m to U v O C O a p J U z O _r ¢ M ¢ m ,*6 0 c Io E E a) w m w o w a Z W N N N N N N N U U U [L' CA I CQ N N F- y n 0 O (L L 0 O U) n c ro L O Z 07 T L O (L t00 N LO N d .0 o. O7 7 O '0I N N O. O U) — O7 O O 2 E wZ oo U) m2U CD o M . 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K \kk )I) � m j k > CD CD C3 k/k/ £o=o IL a. 0 O a 0 O a Z r 3 O O O V N a +- N d � 0 N O y 0 a.is Q ,o _ = O U C• 0 o o (Aa) = aNi o 6 o 0 - N } lU a) Or cc[- U w a° � U m O 1p O O r- N ac ooi- C O O' N O m cu (a E -� in oo� ai P CC cc Y'a co K A d E • 3 0 3 � 5 O t f0 )i a ai a. cL 0 0 rn E E o d t--mw Y N Y N N d 0 o a a aU- N _z z_^ O 0) t0 M OY a7 N N Oi Oi APPENDIX 3 HEC-HMS SUMMARY OUTPUT FILES - BLOCKED OUTLET Project: Castlegate II South Pond De p r3 Simulation Run: Post 100 Yr - Blocked Reservoir: Castle2-South-Pond / a� Start of Run: 01 Jan2010, 00:00 Basin Model: End of Run: 02Jan2010, 00:05 Meteorologic Model: Compute Time: 24Apr2012, 11:02:38 Control Specifications: Volume Units: IN puted Resu South Pond Emerg Spillway 100yr 24hr Peak Inflow: 01Jan2010, 12:55 01Jan2010, 13:00 (C-FT) A9 � 311.0 (FT) 260 (CFS) Date/Time of Peak Inflow: Peak Outflow: 259 (CFS) Date/Time of Peak Outflow: Total Inflow: 9.90 (IN) Peak Storage : Total Outflow: 8.82 (IN) Peak Elevation : Project: Castlegate II South Pond De Simulation Run: Post 100 Yr - Blocked Start of Run: 01Jan2010, 00:00 Basin Model: South Pond Emerg Spi End of Run: 02Jan2010, 00:05 Meteorologic Model: 100yr Compute Time: 24Apr2012, 11:02:38 Control Specifications: 24hr Hydrologic Element Drainage Area (M12) Peak Dischar (CFS) Time of Peak Volume (IN) 200 0.09288 210 01Jan2010, 12:50 9.10 201 0.02513 84 01Jan2010, 12:25 9.31 202 0.00873 37 01Jan2010, 12:15 9.37 210 0.19660 413 01Jan2010, 13:00 9.81 211 0.12040 260 01Jan2010, 12:55 9.90 220 0.02370 99 01Jan2010, 12:10 8.33 221 0.16347 293 01Jan2010, 13:10 8.59 Castle 1 -Modified 0.24543 436 01Jan2010, 13:25 9.51 Castle2-North-Pond 0.22030 451 01Jan2010, 13:10 9.55 Castle2-South-Pond 0.12040 259 01Jan2010, 13:00 8.82 R1 - A2A Upper 0.02370 96 01Jan2010, 12:50 8.28 R2 - A2A Lower 0.25416 440 Ol Jan2010, 13:55 9.44 Stdy Pt Al - WS Philli 9.122WO 497 01Jan2010, 12:50 9.64 Stdy Pt A2 - Castlegat sOM5416 440 01 Jan2010, 13:25 9.50 Stdy Pt A3 - Confl A2 0.34704 526 01 Jan2010, 13:50 9.35 Stdy Pt B - Greens Pr 0.28387 546 01Jan2010, 13:05 8.69 Total - Both Basins 0.63091 981 01Jan2010, 13:10 9.05 Channel Report Hydraflow Express Extension for AutoCAD® Civil 3D®2009 by Autodesk, Inc 31F= Trapezoidal Bottom Width (ft) = 350.00 Side Slopes (z:1) = 3.00, 3.00 Total Depth (ft) = 1.00 Invert Elev (ft) = 310.70 Slope (%) = 1.00 N-Value = 0.035 Calculations Compute by: Q vs Depth No. Increments = 20 Elev (ft) Section 312.00 311.50 311.00 310.50 310.00 D 50 100 150 200 250 Reach (ft) Tuesday, Apr 24 2012 Highlighted Depth (ft) = 0.30 Q (Cfs) = 199.84 Area(sgft) = 105.27 Velocity (ft/s) = 1.90 Wetted Perim (ft) = 351.90 Crit Depth, Yc (ft) = 0.18 Top Width (ft) = 351.80 EGL (ft) = 0.36 300 350 400 450 500 Depth (ft) 1.30 M 0.30 -0.20 _n 7n 0.05 ( 10.08 17.51 j 0.58 350.32 0.01 0.10 32.00 ' 35.03 0.91 350.63 0.03 0.15 62.91 52.57 1.20 1_.. 350.95 0.07 0.20 { 101.6 70.12 1.45 351.26 0.11 0.25 { 147.4 87.69 _ j 1.68 351.58 0.14 .i 030 ........ .._M... 199.8 . .19 ..._.,. 1053 - j L._�_. .. .. .......... 1 90 ... ..:. 351.90 __.....__ . 0.18 ._.. .____....,. 0.35 258.4 �.. 122.9 2.10 352.21 0.22 0.40 ' 322.9 140.5 2.30 352.53 0.26 0.45 393.0- 158.1 2.49 352.85 0.30 0.50 _.. 468.5 ...__. 175.8 2.67 -2.84 353.16 ._..._.. 0.34 _. __.0.55 549.2.. 193.4 ,.. 353.48 0.39...__. 0.60 i____ 635.0- 211.1 3.01 - 353.79 0.43� 0.65 725.7 228.8 3.17 354.11 0.47 0.70 - 821.3 246.5 3.33 354.43 0.52 0.75 921.5 264.2 _ 3.49 ...... L.. 354.74 ... .____. 0.56 ....__.__.. 0.80 ___.. 1,026 281.9 3.64 355.06 0.60 0.85 > 1,136 299.7 3.79 355.38 0.65 0.90 1,249 317.4 f 3.94 355.69 0.69 0.95 1,367 335.2 4.08 356.01 0.74 1.00 1,489 353.0 4.22 356.32 0.78 Hydraflow Express - Channel Report - 04/24/12 1 350.30 0.06 350.60 E - 0.11 350.90 0.17 351.20 0.23 351.50 _.._ 0.29 _._ _.. ... 35180 ... _. 036 352,10 0.42 352.40 ,. 0.48 352.70 0.55 353.00 0.61 353.30 0.68 353.60 ! 0.74 353.90 0.81 354.20 0.87 354.50 0.94,_-- 354.80 1.01 355.10 1.07 355.40 1.14 355.70 1.21 366.00 i 1.28 Hydraflow Express - Channel Report - 04/24/12 2 Project: Castlegate II South Pond De Simulation Run: Post 100 Yr - Blocked Reservoir: Start of Run: 01Jan2010, 00:00 Basin Model: End of Run: 02Jan2010, 00:05 Meteorologic Model: Compute Time: 05Jun2012, 14:41:05 Control Specifications: Volume Units: IN ted Results Peak Inflow: 483 (CFS) Date/Time of Peak Inflow: Peak Outflow: 480 (CFS) Date/Time of Peak Outflow Total Inflow: 8.15 (IN) Peak Storage: Total Outflow: 8.15 (IN) Peak Elevation Castle l-Modified ' Nync� South Pond Emerg Spillway 100yr 24hr 01Jan2010, 13:05 01Jan2010, 13:10 12.7 (AC -FT) 309.9 (FT) Project: Castlegate II South Pond De Simulation Run: Post 100 Yr - Blocked Reservoir: Castle2-North-Pond Start of Run: 01Jan2010, 00:00 Basin Model: South Pond Emerg Spillway End of Run: 02Jan2010, 00:05 Meteorologic Model: 100yr Compute Time: 05Jun2012, 14:41:05 Control Specifications: 24hr Volume Units: IN Peak Inflow: 01Jan2010, 12:50 01Jan2010, 13:05 27.4 (AC -FT) 315.7 (FT) 497 (CFS) Date/Time of Peak Inflow: Peak Outflow: 454 (CFS) Date/Time of Peak Outflow: Total Inflow: 9.64 (IN) Peak Storage: Total Outflow: 8.02 (IN) Peak Elevation : STORM DRAIN SYSTEM REPORT General Hydraulic and Hydrologic Characteristics Section 202 of the subdivision is characterized by scattered large trees with gently sloping topography to the south. The eastern half of Section 202 shows evidence of rock outcroppings. These same formations were encountered at shallow depths during the construction of underground utilities in Section 200. While these outcroppings have little impact on the drainage design, they pose potential problems for all underground utilities during the construction phase. Storm Drain Design Parameters Street Design: • Standard cross-section (3% cross -slope) • Laydown curb, Standard Curb • Asphalt pavement • Standard recessed curb inlets T, Methodology: TR 55 T. Minimum 10 minutes Design Storm Event: 10-year Pipe Materials: RCP and HDPE Manning's n Value: 0.013 Runoff Coefficients: 0.55 for surrounding development Design Constraints: Max water depth: Laydown curb = 4.5 in. or 0.38 ft. Standard curb = 6 in. or 0.5 ft Min flow velocity = 2.5 fps Max flow velocity = 15 fps 100-yr storm runoff maintained within the ROW (4 inches above curb) Design Software: AutoCAD 2011 w/ Civil 3D Hydraflow Storm Sewer Design Package Applicable Exhibits: Exhibit H — Storm Sewer Drainage Area Map Exhibit I — Time of Concentration Calculation Worksheet Exhibit I — Gutter Depth Calculation Worksheet Exhibit K — Inlets on Grade Size Computation Worksheet Exhibit L — Inlets in Sump Size Computation Worksheet Exhibit M — Hydraflow Pipe Analysis Summary (10-yr storm) Exhibit N — Hydraflow Pipe Analysis Summary (100-yr storm) To the City Engineer for the City of College Station, Texas: Re: Castlegate II Subdivision, Sections 202, 204-20'7 Certification Statement I have conducted a topographic review and field investigation of the existing and proposed flow patterns for stormwater runofffrom the Castlegate Subdivision, Sections 202, 204-207. At build - out conditions allowable by zoning, restrictive covenant, or plat note, the stormwater flows from the subject subdivision or site project will not cause any increase in flooding conditions to the interior of existing building structures, including basement areas, for storms of magnitude up through the 100 yr event. /,tea G 00- S` 2 3 Engineer's Signature ate Tx License No. DA'. 863 0.51 ac. D& 861 0.44 ac. W" )jAT1 IM I I I I A: 842 U ac A OOC . fib ac ------ DA: 771 0.77 ac. 2 1 3 ij tu -770 TN .6 ac. 1 DA- 762 832A DA: 8AB If 0.61 ac .71 ac. 1.56 a If z! :2.23 ac. 1' Dk I 2.S '4 ��IDA- 762A I 6 if 0.42 aG. DA: 820 0 aC 063 0 42 ac .63ac. — --------- I'll IM ac. 0.14a 16 ac.. ac :750 6 4 ac. C N: 742A DA: 142B DA- 1129A 1) -�MBI 1.65 ac. 0.81 Jac. 0.6 .. 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M r W (MO, W N O O M tOD U (WO `W N rM1 ((yy V r� N W W � 0 M (V U m m M O rMIW W(MO N y O> 1n (O W (p r W W 6M6 4--- O N Yl D M Q V O N tM I� 6 (7 y NN LL a 7 O O O O o O N W W M W W N N V 1n a 1n O O O W W M M O V V IfJ N N N N W r r y O O N 1� N N ("J M M t� W W W W W W V W W a V O7 h M W W E th •- M N M N M �- M � M N M N M N M N M N M N M N M N M N M N M N M N M N M N M N M N M N M N M N M N M N M N M N M N M N M N M N M M M M M d N r O M MM WM Wr ( WN W( Wr Wh M M hM OO WO W1� h W W W W W Om D O O N M M V V N W 6 w W N w W M M M M M M M N M (V M N M N M N M N M N M M M M M M N M N M N M N M N M N M N M N M N M N M N M N M M N M N M N M = M N t� q t`J M W r V0� 'C W N f0 t0 f0 O N O d; C'1 O O 1n CJ W r N V(y N h N c O O O O O O O In W W O W O M M O V m M O O N O N N (") M M r� 1� M M N O (O (O IQ V fD V d; V A N W M W M V N N N e- W (p h (� O N m Ol 47 N V N ti N N N 1n N tp N OI N N O N O N O N O N N N C N (V N V N V N V N W N V N 1� N n N r N F N r N r N r N O M � M I(l W N O OI Ol r W W W W N r M O IA In (O N (O W M r M r o r O V W O O M N r r V th a7 D7 W ml W V r C V N I� N V V N (O N O O O N� W N r N N r N N N N N N N N N N N N N N N N N N N N N N = M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M C C N . O W V V N O� m V h O IW(l O V N W O }} N N� (r0 (r0 V OM] N Ul W O) m ( . CWJ W r M 1n V 1[1 fD Ip W r r M r N �- N N t0 N N N N N N N N N N N N C M CJ M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M N C W W W O W O V' W W W W. W W W W W O V W O W O W '•f W W V W W W W N O C N m 07 0 M w m w NW N . . W J N N N r r r r r r n r r n r r W W W W W W W . . . W W SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY The Cities of Bryan and College Station both require storm drainage design to follow these Unified Stormwater Design Guidelines. Paragraph C2 of Section III (Administration) requires submittal of a drainage report in support of the drainage plan (stormwater management plan) proposed in connection with land development projects, both site projects and subdivisions. That report may be submitted as a traditional prose report, complete with applicable maps, graphs, tables and drawings, or it may take the form of a 'Technical Design Summary'. The format and content for such a summary report shall be in substantial conformance with the description in this Appendix to those Guidelines. In either format the report must answer the questions (affirmative or negative) and provide, at minimum, the information prescribed in the "Technical Design Summary" in this Appendix. The Stormwater Management Technical Design Summary Report shall include several parts as listed below. The information called for in each part must be provided as applicable. In addition to the requirements for the Executive Summary, this Appendix includes several pages detailing the requirements for a Technical Design Summary Report as forms to be completed. These are provided so that they may be copied and completed or scanned and digitized. In addition, electronic versions of the report forms may be obtained from the City. Requirements for the means (medium) of submittal are the same as for a conventional report as detailed in Section III of these Guidelines. Note: Part 1 — Executive Summary must accompany any drainage report required to be provided in connection with any land development project, regardless of the format chosen for said report. Note: Parts 2 through 6 are to be provided via the forms provided in this Appendix. Brief statements should be included in the forms as requested, but additional information should be attached as necessary. Part 1 — Executive Summary Report Part 2 — Project Administration Part 3 — Project Characteristics Part 4 — Drainage Concept and Design Parameters Part 5 — Plans and Specifications Part 6 — Conclusions and Attestation STORMWATER MANAGEMENT TECHNICAL DESIGN SUMMARY REPORT Part 1 — Executive Summary This is to be a brief prose report that must address each of the seven areas listed below. Ideally it will include one or more paragraphs about each item. Name, address, and contact information of the engineer submitting the report, and of the land owner and developer (or applicant if not the owner or developer). The date of submittal should also be included. 2. Identification of the size and general nature of the proposed project, including any proposed project phases. This paragraph should also include reference to applications that are in process with either City: plat(s), site plans, zoning requests, STORMWATER DESIGN GUIDELINES Page 1 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY or clearing/grading permits, as well as reference to any application numbers or codes assigned by the City to such request. 3. The location of the project should be described. This should identify the Named Regulatory Watershed(s) in which it is located, how the entire project area is situated therein, whether the property straddles a watershed or basin divide, the approximate acreage in each basin, and whether its position in the Watershed dictates use of detention design. The approximate proportion of the property in the city limits and within the ETJ is to be identified, including whether the property straddles city jurisdictional lines. If any portion of the property is in floodplains as described in Flood Insurance Rate Maps published by FEMA that should be disclosed. 4. The hydrologic characteristics of the property are to be described in broad terms: existing land cover; how and where stormwater drains to and from neighboring properties; ponds or wetland areas that tend to detain or store stormwater; existing creeks, channels, and swales crossing or serving the property; all existing drainage easements (or ROW) on the property, or on neighboring properties if they service runoff to or from the property. 5. The general plan for managing stormwater in the entire project area must be outlined to include the approximate size, and extent of use, of any of the following features: storm drains coupled with streets; detention / retention facilities; buried conveyance conduit independent of streets; swales or channels; bridges or culverts; ouffalls to principal watercourses or their tributaries; and treatment(s) of existing watercourses. Also, any plans for reclaiming land within floodplain areas must be outlined. 6. Coordination and permitting of stormwater matters must be addressed. This is to include any specialized coordination that has occurred or is planned with other entities (local, state, or federal). This may include agencies such as Brazos County government, the Brazos River Authority, the Texas A&M University System, the Texas Department of Transportation, the Texas Commission for Environmental Quality, the US Army Corps of Engineers, the US Environmental Protection Agency, et al. Mention must be made of any permits, agreements, or understandings that pertain to the project. 7. Reference is to be made to the full drainage report (or the Technical Design Summary Report) which the executive summary represents. The principal elements of the main report (and its length), including any maps, drawings or construction documents, should be itemized. An example statement might be: "One -page drainage report dated , one set of construction drawings (______sheets) dated and a -page specifications document dated comprise the drainage report for this project." STORMWATER DESIGN GUIDELINES Page 2 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 2 - Project Administration Start (Page 2.1) ,and°DBsi nzPr"otessiortais jWo rrimlon ., ,r= „ En rteeriryg Firm Name and Address: lI ,� r Eh4� ,nee / m qq q,/q Ca S�/ega/e A/. Jurisdiction City: Bryan ✓ College Station C. S 7 7 Date of Su mitt Lead En%gi� Is Name and Contact Infoo.(phone, e-mail,e-Qfax): Other: Supporting Engineering / Consulting Firm(s): Other contacts: „ti,,, Deuelo .er/,Oilvnera/'Pi" aicati#In#brmation; , `., Developer ✓/ 1A1pplicant Name and "pddress: 3d0 RJ?V.%O/YJPnJ /)4C yggo Cas/i�/e at(• !/cJr. -7 7f ys Phone and e-mail: 979. Z 2 i— c/c� �O Property O er(s) if not Developer / Applicant (& address): Phone and e-mail: Pro/ect,identiftc #ton rf ,eN Development Name: Cos � lecla-1 e Lr S"' L Se o r n ZO z Is subject property a site project, a sin a -phase subdivision, or part of a multi -phase subdivision? /•jeU /f 4 0 S e If multi -phase, subject property is phase 3 of Legal description of subject property (phase) or Project Area: (see Section ll, Paragraph B-3a) /{/�� / / / /tote e✓PH S'O /'I f. eaquc 4 -5-vl If subject property (phase) is second or later phase of a project, describe general status of all earlier phases. Form st rec n earli r has Include submittal and review dates., P g @ y P / 11: k�'?x%e. Sa C�feh i200 tr Ca.h//��+ rA IS l.Ir 7"Ne Ye an a! �lq#ecl Yee- ito-t 2of /t C.J/iWe con srIrve7,in. Gerieral Location of Project Area, or subject property (pha�,sg)) , A'(.lJ1 0 �ie�rf��j /�u��//'t f1k-1- 4 0�f (�3'"i es SDu fhwesf m � �rr/ h Inn Raj 16,e, rrs �ra -� e ,��P s In City Limits? E-ktraterritorial Jurisdiction (acreage): Bryan: acres. Bryan: College Station: College Station: /, acres. Acreage Outside ETJ: STORMWATER DESIGN GUIDELINES Page 3 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 APPENDIX D — TECHNICAL DESIGN SUMMARY Part 2 — Project Administration Continued (page 2.2) �<, s , ,xPoj2ctldentifica#i�,{ao�itmpej Roadways abutting or within Project Area or Abutting tracts, platted laqd, or built subject property: developments: l os{/pgo4 = j seeP_n zd Named Regulatory Watercourse s) & Watershed(s): Tributary Basin(s): r a. 0 C -0 &nnaw-' Plat Mnfox ...... for, Pxaj� t of Subject Property (or?)'has��, _ . , xx 1,01 Preliminary Plat File #: Final Plat File #: Date: Name: Status and Vol/Pg: If two plats, second name: File #: Status: Date: Zoning InfoCmaflon Far Project qr $ubject Property (or Phase) t Zoning Type: R I xistin >or Proposed? Case Code: Case Date Status: Zoning Type: Existing or Proposed? Case Code: Case Date Status: r Storxrmraer Management PJa Wing Fo% Project pr &tbject,Property,(or°Phasej,3 Planning Conferences) & Date(s): Participants: Preliminary Report Required? Submittal Date Review Date Review Comments Addressed? Yes _ No _ In Writing? When? Compliance With Preliminary Drainage Report. Briefly describe (or attach documentation explaining) any deviation(s) from provisions of Preliminary Drainage Report, if any. STORMWATER DESIGN GUIDELINES Page 4 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 APPENDIX D - TECHNICAL DESIGN SUM Part 2 — Project Administration Continued (page 2.3) %�„ �`��, Cots�dl���to� Fa�Project dY�Subjeo# PtpPerty�(o��Hase) ��s> � �€�� Note: For any Coordination of stormwater matters indicated below, attach documentation describing and substantiating any agreements, understandings, contracts, or approvals. Dept. Contact: Date: Subject: Coordination With Other Departments of Jurisdiction City (Bryan or College Station) Coordination With Summarize need(s) & actions taken (include contacts & dates): Non -jurisdiction City Needed? / Yes No (/ Coordination with Summarize need(s) & actions taken (include contacts & dates): Brazos County Needed? Yes No Summarize need(s) & actions taken (include contacts & dates): Coordination with TxDOT Needed? V Yes No Summarize need(s) & actions taken (include contacts & dates): Coordination with TAMUS Needed? Yes _ No ? k 1 `� � � �' � Perms FO��Pt`Oject or Subje�'Prope'r�i �qr Phase) �� �' �, � 3` rs.'3 'z ,� As to stormwater management, are permits required for the proposed work from any of the entities listed below? If so, summarize status of efforts toward that objective ins aces below. Entity Permitted or Status of Actions (include dates) Approved ? US Army Crops of Engineers No ✓ Yes _ US Environmental Protection Agency No _� Yes _ Texas Commission on Environmental Quality No Yes _ Brazos River Authority No Yes STORMWATER DESIGN GUIDELINES Page 5 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 3 — Property Characteristics Start (Page 3.1) Existing: Land proposed for development used, including extent of impervious cover? �cu`rrenntly �2S/,le4, .of .iu.IOOT. Gs47e r� to✓Gi Redevelopment of one platted lot, or two or more adjoining platted lots. Site Development Building on a single platted lot of undeveloped land. Project Building on two or more platted adjoining lots of undeveloped land. (select all Building on a single lot, or adjoining lots, where proposed plat will not form applicable) a new street (but may include ROW dedication to existing streets). Other (explain): Subdivision Construction of streets and utilities to serve one or more lap tted lots. Development construction of streets and utilities to serve one or more proposed lots on Project lands represented by pending plats. Site projects: building use(s), approximate floor space, impervious cover ratio. Subdivisions: number of lots by general type of use, linear feet of streets and Describe drainage easements or ROW. Nature and Size of Proposed Project Is any work planned on land that is not platted If yes, explain: or on land for which platting is not pending? ✓No Yes FEMA Floodpja tts nN n Is any part of subject property abutting a Named Regulatory Watercourse No Yes (Section II, Paragraph B1) or a tributary thereof? Is any part of subject property in floodplain No Yes Rate Map area of a FEMA-regulated watercourse? _� Encroachment(s) into Floodplain Encroachment purpose(s): Building site(s) Road crossing(s) areas planned? Utility crossing(s) Other (explain): ✓ No Yes If floodplain areas not shown on Rate Maps, has work been done toward amending the FEMA- approved Flood Study to define allowable encroachments in proposed areas? Explain. STORMWATER DESIGN GUIDELINES Page 6 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 3 — Property Characteristics Continued (Page 3.2) f ���� ������;Hydt'itioglCAttribufesyofSub�eatProp�ity(ar:Phass)���� ��%�'�,��{ Has an earlier hydrologic analysis been done for larger area including subject property? Reference the study (& date) here, and attach copy if not already in City files. Yes Is the stormwater management plan for the property in substantial conformance with the earlier study? Yes ✓ No If not, explain how it differs. If subject property is not part of multi -phase project, describe stormwater management No plan for the property in Part 4. If property is part of multi -phase project, provide overview of stormwater management plan for Project Area here. In Part 4 describe how plan for subject property will comply therewith. Do existing topographic features on subject property store or detain runoff? No Yes Describe them (include approximate size, volume, ouffall, model, etc). Any known drainage or flooding problems in areas near subject property? No Yes Identify: Based on location of study property in a watershed, is Type 1 Detention (flood control) needed? (see Table B-1 in Appendix B) ✓Detention is required. Need must be evaluated. Detention not required. What decision has been reached? By whom? If the need for How was determination made? Type 1 Detention must be evaluated: STORMWATER DESIGN GUIDELINES Page 7 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 APPENDIX D — TECHNICAL DESIGN SUMMARY Part 3 — Property Characteristics Continued (Page 3.3) s����$� � lllydrologia Atfr3btltes of $ubj�ot ProperCy�(tir�Phase) (contittited}�� Does subject property straddle a Watershed or Basin divide? V No Yes If yes, describesplits below. In Part 4 describe design conce t for handling this. Watershed or Basin Larger acreage Lesser acreage Above -Project Areas(Section II, Paragraph B3-a) Does Project Area (project or phase) receive runoff from upland areas? _ No _ Yes Size(s) of area(s) in acres: 1) IS- 2) 3) 4) Flow Characteristics each instanc (overland sheet, allow concentrated, recognizable concentrated section(s), small creek a ory , regulatory Watercourse or tributary); Flow determination: Outline hydrologic methods and assumptions: Doqes�s torm runoff drain from public easements or ROW onto or across subject property? V No Yes If yes, describe facilities in easement or ROW: Are changes in runoff c�aracteri tics subject to chan a in future? E�X{plain YES, 'iS f P noiTln ri%va� r �� e P ' s1 e //�y // "� / // r✓�'t'( ..eo �i �9 /V �"`i c S'fG)�m �r �'F1�:� -5497� S@cy.ra� 20 Conveyance Pathways (Section Il, Paragraph C2) Must runoff from study property drain across lower properties before reaching a Regulatory Watercourse or tributary? ✓ No Yes Describe length and characteristics of each conveyance pathway(s). Include ownership of property(ies). STORMWATER DESIGN GUIDELINES Page 8 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 3 — Property Characteristics Continued (Page 3.4) 4,;F'r"rta� H)idcolo�r�Att)•ibytesotSUbjec#,l?ropedi�(c1r�Phase�z(�o�tin��dj��;k� am Conveyance Pathways (continued) Do drainage if yes, for what part of length? % Created by? _ plat, or easements instrument. If instrument(s), describe their provisions. exist for any part of pathway(s)? _✓No Yes Where runoff must cross lower properties, describe characteristics of abutting lower property(ies). (Existing watercourses. asement or Consent aq irep �s� R�'t Pathway vn a / 16 cn GI Ccirrr'so� ��7q en Areas v(r a r ../ o u POn Describe any built or improved drainage facilities existing near the property (culverts, bridges, lined channels, buried conduit, swales, detention ponds, etc). //�� / --// i /JOlt'i1 s�r�P.//..ne/ o�f2- ev,�1oyt dl c+/r /pn CB/73�f-✓a te6l Nearby Drainage Facilities Do any of these have hydro gic or hydraulic influence on proposed stormwater design? No Yes If yes, explain: / Re�vees �f ��✓ �� �/e o%Y. >10.w«. / STORMWATER DESIGN GUIDELINES Page 9 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4£ — Drainage Concept and Design Parameters Start (Page 4.1) Discharge(s) From Upland Area(s) If runoff is to be received from upland areas, what design drainage features will be used to accommodate it and insure it is not blocked by future development? Describe for each area, flow section, or discharge point. Discharge(s) To Lower Property(ies) (Section 11, Paragraph E1) Does project include drainag (existing or future) proposed to become public via ,features platting? No Yes Separate Instrument? ✓ No Yes Per Guidelines reference above, how will Establishing Easements (Scenario 1) runoff be discharged to neighboring JG Pre -development Release (Scenario 2) property(ies)? Combination of the two Scenarios Scenario 1: If easements are proposed, describe where needed, and provide status of actions on each. (Attached Exhibit # ) Scenario 2: Provide general description of how release(s) will be managed to pre -development conditions (detention, sheet flow, partially concentrated, etc.). (Attached Exhibit # ) Combination: If combination is proposed, explain how discharge will differ from pre - development conditions at the property line for each area (or point) of release. If Scenario 2, or Combination are to be us9d, has proposed design been coordinated with owner(s) of receiving property(ies)? ✓ No Yes Explain and provide documentation. STORMWATER DESIGN GUIDELINES Page 10 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.2) >� ��� �� '�t4rmWater`ManagetnA�tl;�rscept(dgntin�iedl,,zs ��uh� `v� ` ,��; ,'F Within Protect Area Of Multi -Phase Project Identify gaining Basins or Watersheds and acres shifting: Will project result in shifting runoff between Basins or between What design and mitigation is used to compensate for increased runoff Watersheds? from gaining basin or watershed? V No Yes How will runoff from Project 1. With facility(ies) involving other development projects. Area be mitigated to pre- 2 Establishing features to serve overall Project Area. development conditions? Select any or all of 1, 2, 3. On phase (or site) project basis within Project Area. and/or 3, and explain below. 1. Shared facility (type & location of facility; design drainage area served; relationship to size of Project Area): (Attached Exhibit# ) 2. For Overall Proiect Area (type & location of facilities): (Attached Exhibit # ) 3. By phase (or site) proiect: Describe planned mitigation measures for phases (or sites) in subsequent questions of this Part. Are aquatic echosystems proposed? No —Yes In which phase(s) or project(s)? r,• Q Are other Best Management Practices for reducing stormwater pollutants proposed? a. No Summarize type of BMP and extent of use: N C —Yes O) N O 0 Z .5 If design of any runoff -handling facilities deviate from provisions of B-CS Technical n Specifications, check type facility(ies) and explain in later questions. rn Detention elements Conduit elements Channel features Swales Ditches Inlets Valley gutters _ Outfalls Culvert features Bridges Other STORMWATER DESIGN GUIDELINES Page 11 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.3) Within ProiectArea Of Multi -Phase Project (continued) Will Project Area include bridge(s) or culvert(s)? V No Yes Identify type and general size and in which phase(s). If detention/retention serves (will serve) overall Project Area, describe how it relates to subject phase or site project (physical location, conveyace pathwas ,onstuction sequnce): 74S@ ya eZe/T / Tp,va./ S"V)i q1-6 Within Or Serving Subject Property (Phase, or Site) If property part of larger Project Area, is design in substantial conformance with earlier analysis and report for larger area? ✓ Yes No, then summarize the difference(s): Identify whether each of the types of drainage features listed below are included, extent of use, and general characteristics. Typical shape? Surfaces? v Steepest side slopes: Usual front slopes: Usual back slopes: N } N Flow line slopes: least Typical distance from travelway: typical greatest (Attached Exhibit # ) o .N Z N ° vly Are longitudinal culvert ends in compliance with B-CS Standard Specifications? Yes No, then explain: N At intersections or otherwise, do valley gutters cross arterial or collector streets? ° ��•r J� No Yes If yes explain: U � � N Are valley gutters proposed to cross any street away from an intersection? mZc ✓No Explain: (number of locations?) ——Yes N m m STORMWATER DESIGN GUIDELINES Page 12 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.4) Within Or Serving Subject Property (Phase, or Site) (continued) Gutter line slopes: Least 9, 70 `% Usualy 9 - !. 2 areatest o �% Are inlets recessed on arterial and collector streets? Yes _ No If "no", identify where and why. /moo a� er:w( o� ae r� or-t Will inlets capture 10-year design stormflow to prevent flooding of Intersections (arterial with arterial or collector)? Yes No If no, explain where and why not. C1• W m Will inlet size and placement prevent exceedingallowable water spread for 10-year 4) design storm throughout site (or phase)? Yes No If no, explain. rn c o a c Sag curves: Are inlets placed at low points? No Are inlets and g _Ll-�'Yes condui sized to prevent 100-year stormflow, from ponding at greater than 24 inches? = 0 Yes No Explain "no" answers. m v� 2 Will 100-yr stormflow, be contained in combination of ROW and buried conduit on ' whole length of all streets? � Yes No If no, describe where and why. Do designs for curb, gutter, and inlets comply with B-CS Technical Specifications? L--� Yes No If not, describe difference(s) and attach justification. Are any 12-inch laterals used? No Yes Identify length(s) and where used. Ny Pipe runs between system Typical % Longest ) access points (feet): aEi Are junction boxes used at each bend? L/ Yes No If not, explain where and why. c o Z E Are downstream soffits at or below upstream soffits? Least amount that hydraulic N Yes ✓ No If not, explain where and why: grade line is below gutter line (system -wide): ��- STORMWATER DESIGN GUIDELINES Page 13 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.5) -��� '�; � r Ma���r►hen�+��i��ept j'�p�tinuesl� �% ���; �'2 � �� S�ot�nWatBt' �s ; ,�1� Within Or Serving Subject Property (Phase, or Site) (continued) Describe watercourse(s), or system(s) receiving system discharge(s) below m (include design discharge velocity, and angle between converging flow lines). U Y 1) Watercourse (or system), velocity, ad ang(e?� ( �^ Tem�ofet�y c aNne S °� 0 0 0 E 2) Watercourse (or system), velocity, and angle? _ o o U C aa)i E " 3) Watercourse (or system), velocity, and angle? w oo o O •� o v n € For each outfall above, what measures are taken to prevent erosion or scour of Nreceiving and all facilities at juncture? 0 1) m `m a 2) m N 0 3) Are swale(s) situated along property lines between properties? No Yes Number of instances: For each instance answer the following questions. Surface treatments (including low -flow flumes if any): N N d } Flow line slopes (minimum and maximum): 0 4) o Z 3 N Outfall characteristics for each (velocity, convergent angle, & end treatment). d < Will 100-year design storm runoff be contained within easement(s) or platted drainage ROW in all instances? Yes No If "no" explain: STORMWATER DESIGN GUIDELINES Page 14 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 s. SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.6) Within Or Serving Subject Property (Phase, or Site) (continued) Are roadside ditches used? No Yes If so, provide the following: s Is 25-year flow contained with 6 inches of freeboard throughout ? Yes No w _ Are top of banks separated from road shoulders 2 feet or more? _ Yes _ No Are all ditch sections trapezoidal and at least 1.5 feet deep? Yes No _ a For any "no" answers provide location(s) and explain: 0 0 of If conduit is beneath a swale, provide the following information (each instance). Instance 1 Describe general location, approximate length: r Is 100-year design flow contained in conduit/swale combination? —Yes No N If "no" explain: U 0 �cm Space for 100-year storm flow? ROW Easement Width Z c Swale Surface type, minimum Conduit Type and size, minimum and maximum and maximum slopes: slopes, design storm: 0 1. v m Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): c � m � L U �- C 0 o Access Describe how maintenance access is provided (to swale, into conduit): o `0 o = c Instance 2 Describe general location, approximate length: E N v Is 100-year design flow contained in conduittswale combination? Yes —No ° o If "no" explain: m a C E a) Space for 100-year storm flow? ROW Easement Width v Swale Surface type, minimum Conduit Type and size, minimum and maximum and maximum slopes: slopes, design storm: c m a) Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): 3 ° N Access Describe how maintenance access is provided (to swale, into conduit): STORMWATER DESIGN GUIDELINES Page 15 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Desian Parameters Continued (Page 4.7) K Stamuitatgt` fjllaiage$art#oric�pk (continued) s" x Within Or Serving Subject Property (Phase, or Site) (continued) If "yes' provide the following information for each instance: Instance 1 Describe general location, approximate length, surfacing: c M o W w t� y is 100-year design flow contained in swale? —Yes —No Is swale wholly j.. within drainage ROW? Yes No Explain "no" answers: m 02 Access Describe how maintenance access is provide: 0 •5 z v c 0 0 Instance 2 Describe general location, approximate length, surfacing: a 0 w s c d o E L N 3 Is 100-year design flow contained in swale? —Yes No Is swale wholly `o within drainage ROW? Yes No Explain "no" answers: _ N O o Access Describe how maintenance access is provided: U a n Instance 3. 4, etc. If swales are used in more than two instances, attach sheet providing all above information for each Instance. "New" channels: Will any area(s) of concentrated flow be channelized (deepened, widened, or straightened) or otherwise altered? No ✓ Yes If only slightly shaped, see "Swales" in this Part. If creating side banks, provide information below. c Will design replicate natural channel? Yes No If "no", for each instance 0 0. _ _% describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year o W N " design flow, and amount of freeboard: Instance 1: T aq a Zo"Wi ch an »s �� �'7o s �o�o e 4� d�o c } ar E o Instance 2: n E 0 - z c Instance 3: � M U STORMWATER DESIGN GUIDELINES Page 16 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.8) Within Or Serving Subject Property (Phase, or Site) (continued) Existing channels (small creeks): Are these used? V No Yes If "yes" provide the information below. Will small creeks and their floodplains remain undisturbed? _ Yes —No How many disturbance instances? Identify each planned location: For each location, describe length and general type of proposed improvement (including floodplain changes): For each location, describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year design flow. v c c Watercourses (and tributaries): Aside from fringe changes, are Regulatory Watercourses proposed to be altered? _ No Yes Explain below. c Submit full report describing proposed changes to Regulatory Watercourses. Address E existing and proposed section size and shape, surfaces, alignment, flow line changes, length affected, and capacity, and provide full documentation of analysis procedures o and data. Is full report submitted? Yes No If "no" explain: E C C UAll Proposed Channel Work: For all proposed channel work, provide information requested in next three boxes. If design is to replicate natural channel, identify location and length here, and describe design in Special Design section of this Part of Report. Will 100-year flow be contained with one foot of freeboard? _ Yes No If,/ not, identify location and explain: �o ��w�� /�pj onw . / (I, �l y/1,, t !'calif "re/ /�+,f,,�}yN-///f/V In Sfyq!/l N//�O'•15�5. ,/SU/.(O C41.1s erne Gt.i hli+ /,fl /d wrYw/'{"roti gaol ha r�i'tic l ev/'e e pv Are ROW / easements sized to contain channel and required space? �maintenance Yes �No If not, identify location(s) and explain: STORMWATER DESIGN GUIDELINES Page 17 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 r0f �y SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.9) Within Or Serving Subject Property (Phase, or Site) (continued) How many facilities for subject property project? I For each provide info. below. For each dry -type facilitiy: Facility 1 Facility 2 Acres served & design volume + 10% IS 2 9 sac 100-yr volume: free flow & plugged , 0 7 ao Vq7 Design discharge (10 yr & 25 yr) 3:2 7 38 3 Spillway crest at 100-yr W SE? ✓ yes no yes no Berms 6 inches above plugged WSE? ✓ yes _ no yes _ no Explain any "no" answers: N N } For each facility what' 25-yfdesign Q, and design of outlet structure? Facility 1: 17.3 c4f Pl A 0 Z Facility 2: Do outlets and spillways discharge into a public facility in easement or ROW? Facility 1: _Yes _✓No Facility 2: Yes No If "no" l' ^ fr explain: F(owr o%�ed o 0 I o. 0 - For each, what is velocity of 25-yr design discharge at outlet? & at s ilD Iwav? m Facility 1: j �13 & Facility 2: & .6 Are energy dissipation measures used? No _ Yes Describe type and ca u- location: c 0 7E For each, is spillway surface treatment other tIVn concrete? Yes or no, and describe: AF Facility Yes. G G ^*wf 0evot ZrMo.. s�,,,�.. H 1: �o,p Facility 2: 40. d,JP. i S �✓ d For each, what measures are taken to prevent ero.; or scour at receiving facility? ck ock r'P r-,p Ra Facility 2: If berms are used give heights, slopeand surface treatments of sides. Facility 1: q !/;z Facility 2: STORMWATER DESIGN GUIDELINES Page 18 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 pees SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.11) Within Or Serving Subject Property (Phase, or Site) (continued) Named Reaulatory Watercourses M Tributaries): Are culverts proposed on these facilities? No —Yes, then provide full report documenting assumptions, criteria, analysis, computer programs, and study findings that support proposed design(s). Is report provided? Yes —No If "no", explain: Arterial or Maior Collector Streets: Will culverts serve these types of roadways? wNo Yes How many instances? For each identify the location and provide the information below. } a Instance 1: N Instance 2: c o Instance 3: c 0 o W z Yes or No for the 100-year design flow: 1 2 3 E o Headwater WSE 1 foot below lowest curb top? C E Spread of headwater within ROW or easement? w y Is velocity limited per conditions (Table C-11)? N Explain any "no" answer(s): N O cc U - A U 3 o Minor Collector or Local Streets: Will culverts serve these types of streets? N No Yes How many instances? for each identify the o location and provide the information below: an Instance 1: Nc Instance 2: � m N o Instance 3: For each instance enter value, or "yes" / "no" for: 1 2 3 U cg N Design yr. headwater WSE 1 ft. below curb top? c 100-yr. max. depth at street crown 2 feet or less? E Product of velocity (fps) & depth at crown (ft) = ? Is velocity limited per conditions (Table C-11)? Limit of down stream analysis (feet)? Explain any "no" answers: STORMWATER DESIGN GUIDELINES Page 20 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.12) . ....... fu..n_Y .._... .✓i"*_m...'.>.A .._,... en}`.� +, na.�-,`?. x.xe^.3.d.: <. Within Or Serving Subject Property (Phase, or Site) (continued) All Proposed Culverts: For all proposed culvert facilities (except driveway/roadside ditch intersects) provide information requested in next eight boxes. Do culverts and travelways intersect at 90 degrees? _Yes No If not, identify location(s) and intersect angle(s), and justify the design(s): Does drainage way alignment change within or near limits of culvert and surfaced approaches thereto? No _ Yes If "yes" identify location(s), describe change(s), and justification: Are flumes or conduit to discharge into culvert barrel(s)? No —Yes If yes, identify location(s) and provide justification: Are flumes or conduit to discharge into or near surfaced approaches to culvert ends? No —Yes If "yes" identify location(s), describe outfall design treatment(s): c c 0 U Vl r Is scour/erosion protection provided to ensure long term stability of culvert structural U components, and surfacing at culvert ends? Yes _ No If "no" Identify locations and provide justification(s): Will 100-yr flow and spread of backwater be fully contained in street ROW, and/or drainage easements/ ROW? _ Yes _ No if not, why not? Do appreciable hydraulic effects of any culvert extend downstream or upstream to neighboring land(s) not encompassed in subject property? No Yes If "yes" describe location(s) and mitigation measures: Are all culvert designs and materials in compliance with B-CS Tech. Specifications? Yes No If not, explain in Special Design Section of this Part. STORMWATER DESIGN GUIDELINES Page 21 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.13) Within Or Serving Subject Property (Phase, or Site) (continued) Is a bridge included in plans for subject property project? No —Yes If "yes" provide the following information. Name(s) and functional classification of the roadway(s)? What drainage way(s) is to be crossed? y N m .0 m A full report supporting all aspects of the proposed bridge(s) (structural, geotechnical, hydrologic, and hydraulic factors) must accompany this summary report. Is the report provided? —Yes No If "no" explain: Is a Stormwater Provide a general description of planned techniques: Z� Pollution Prevention Plan (SW3P) a established for w? project construction? m No _Yes Special Designs — Non -Traditional Methods Are any non-traditional methods (aquatic echosystems, wetland -type detention, natural stream replication, BMPs for water quality, etc.) proposed for any aspect of subject property project? No _ Yes If "yes" list general type and location below. Provide full report about the proposed special design(s) including rationale for use and expected benefits. Report must substantiate that stormwater management objectives will not be compromised, and that maintenance cost will not exceed those of traditional design solution(s). Is report provided? Yes No If "no" explain: STORMWATER DESIGN GUIDELINES Page 22 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.14) „, h Stprrovuaterilll �,nayelnen00"Ww",(continued).+#.mom Within Or Serving Subject Property (Phase, or Site) (continued) Special Designs — Deviation From B-CS Technical Specifications If any design(s) or material(s) of traditional runoff -handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain by specific detail element. Detention elements Drain system elements Channel features Culvert features Swales Ditches Inlets _Outfalls Valley gutters Bridges (explain in bridge report) In table below briefly identify specific element, justification for deviation(s). Specific Detail Element Justification for Deviation (attach additional sheets if needed) 1) 2) 3) 4) 5) Have elements been coordinated with the City Engineer or her/his designee? For each item above provide "yes" or "no", action date, and staff name: 1) 2) 3) 4) 5) Hydrology Is a map(s) showing all Design Drainage Areas provided? ✓ Yes No Briefly summarize the range of applications made of the Rational Formula: ['JSPOE �( 7X e de-s-f K oT S1Orm -011aril 1-yd-41, What is the size and location of largest Design Drainage Area to which the Rational Formula has been applied? 2. 2 3 acres Location (or identifier): tj/4 —7S1 STORMWATER DESIGN GUIDELINES Page 23 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 PENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.15) Hydrology (continued) In making determinations for time of concentration, was segment analysis used? _ No _Yes In approximately what percent of Design Drainage Areas? /00 % As to intensity -duration -frequency and rain depth criteria for deter fining runoff flows, were any criteria other than those provided in these Guidelines used? No _Yes If "yes" identify type of data, source(s), and where applied: For each of the stormwater management features listed below identify the storm return frequencies (year) analyzed (or checked), and that used as the basis for design. Feature Analysis Year(s) Design Year Storm drain system for arterial and collector streets ah( Storm drain system for local streets • 0 od 10 Open channels /V* Swale/buried conduit combination in lieu of channel NA Swales 424 Roadside ditches and culverts serving them NA Detention facilities: spillway crest and its ouffall Z- 1 p 0 100 Detention facilities: outlet and conveyance structure(s) t0 p 100 Detention facilities: volume when outlet plugged Z _ g 100 Culverts serving private drives or streets AM Culverts serving public roadways Ik A Bridges: provide in bridge report. NA Hydraulics What is the range of design flow velocities as outlined below? Design flow velocities; Gutters Conduit Culverts Swales Channels Highest (feet per second) 2, 7 -74 2 Lowest (feet per second) /, - O Streets and Storm Drain Systems Provide the summary information outlined below: Roughness coefficients used: For street gutters: 0 / For conduit type(s) Coefficients: , 0 13 .O 11 STORMWATER DESIGN GUIDELINES Page 24 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 APPENDIX D — TECHNICAL DESIGN Part 4 — Drainage Concept and Design Parameters Continued (Page 4.16) Hydraulics (continued) Street and Storm Drain Systems (continued) For the following, are assumptions other than allowable per Guidelines? Inlet coefficients? ✓ No —Yes Head and friction losses _ No Yes Explain any "yes" answer: In conduit is velocity generally increased in the downstream direction? ✓ Yes _ No Are elevation drops provided at inlets, manholes, and junction boxes? ✓ Yes _ No Explain any "no" answers: Are hydraulic grade lines calculated and shown for design storm? ✓ Yes —No For 100-year flow conditions? L,,� Yes —No Explain any "no" answers: What tailwater conditions were assumed at outfall point(s) of the storm drain system? Identify each location and explain: /e5. Fv/I af'eYe. Tr n /nu" a/ °'� 10 Y� Open Channels If a HEC analysis is utilized, does it follow Sec VI.F.5.a? _ Yes _ No Outside of straight sections, is flow regime within limits of sub -critical flow? _ Yes _ No If "no" list locations and explain: Culverts If plan sheets do not provide the following for each culvert, describe it here. For each design discharge, will operation be outlet (barrel) control or inlet control? Entrance, friction and exit losses: Bridges Provide all in bridge report STORMWATER DESIGN GUIDELINES Page 25 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.17) g."?. Computer Software What computer software has been used in the analysis and assessment of stormwater management needs and/or the development of facility designs proposed for subject property project? List them below, being sure to identify the software name and version, the date of the version, any applicable patches and the publisher NFc l-lms v, 3. E- 646 2C9l2. w/ Hyo(rcv7/ow EX�tnsi'vn M1'Cr•--smA 'Elccel ZOO Part 5 — Plans and Specifications Requirements for submittal of construction drawings and specifications do not differ due to use of a Technical Design Summary Report. See Section III, Paragraph C3. Part 6 - Conclusions and Attestation Add any concluding information here: r "':";;.�,' $ ' ,.,',''s r 7 , A2teSftlon ' .. rr. .. .. ... e. smv.. ... r. _. ,. ., v...'m. �..... Provide attestation to the accuracy and completeness of the foregoing 6 Parts of this Technical Design Summary Drainage Report by signing and sealing below. "This report (plan) for the drainage design of the development named in Part B was prepared by me (or under my supervision) in accordance with provisions of the Bryan/College Station Unified Drainage Design Guidelines for the owners of the property. All /i/tcavQfl permits required by any and all state and federal regulatory agencies fornage improveme shave been issued or fall under applicable general p its6' It 1 (Affix Seal) lll ..�, ......M:LA7.. Licensed Professional E ineer 88823 .�Q. State of Texas PE No. 65 qZ > ••�/ONgL�EN STORMWATER DESIGN GUIDELINES Page 26 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009