Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
Drainage Reports - 07/22/2016
NA, Incorporated /► 25 Old Town Square ' �� "" `a `�� of For#. . , L Collins Suite 200 ""Pro, p� *Oved Fat Collins, CO M524 May 19, 2016 by: 970.225.9099 Heather McDowell, P.E. City of Fort Collins - Water Utilities Engineering www.jvaiva.com ' 700 Wood Street Fort Collins, CO 80521 ' RE: Aggie Village North Redevelopment — West Parking Lot Extension Drainage JVA No 2025c — Addendum to Final Drainage Report dated January 23, 2015 ' Dear Heather, I ' JVA, Inc. has analyzed the drainage impact of the west parking lot expansion for Aggie Village North Redevelopment site. The original drainage report, Final Drainage Report for Colorado State University Aggie Village North Redevelopment dated January 23, 2015, provides the ' drainage details for the site and is attached. The primary purpose of this letter is to address the pre and post development runoff and modifications to Pond 4 and its outlet structure. PROJECT DESCRIPTION The expansion of the parking lot will increase the sites area from its original area of 9.43 acres to ' approximately 10.1 acres. The existing houses along Whitcomb Street will be demolished and replaced with the proposed parking lot. With the additional site area, the historical percent impervious decreased to 40.3% from 41.2% while the sites developed percent impervious ' increased to 63.5% from 60.1%. The project will consist of asphalt, curb and gutter, green space, and a detention pond. The existing basins D1, 136-1, D6-2, 136-3, D64, and D6B were the only basins affected by the parking lot expansion. The parking lot within the D6 basins will continue ' to slope to the south and runoff will be collected in Pond 4 before discharging into the existing 42 inch RCP storm sewer system. The northern portion of the parking lot within the D 1 basin will drain to the north onto Lake Street and be captured in the Lake Street inlets which are also ' connected into the 42 inch storm pipe. Roof drains were added to the southwest side of the west building. Basin D613 was adjusted to only capture the southeast side of the western building decreasing the basins area from 0.32 acres to 0.16 acres, as shown in the table and map on Figure ' 2. The west side of the building was spilt between basins D6-1 and D6-2. All other aspects and basin delineation for drainage patterns of the developed site will remain the same. HISTORIC AND DEVELOPED RUNOFF The sites historical and developed peak runoff rates both increased with the parking lot ' expansion. Historically the flow from the residential lots along Whitcomb Street drain from the front of the homes to the east and into a drainage swale between the houses and Aggie Village North. The flow is then collected to the north and south in area drains connected to the existing ' 42 inch RCP storm sewer system. The proposed parking lot will change the direction of flow within historical basins H4 and H1, but the runoff will still eventually discharged into the existing 42 inch RCP storm system after being collected in Detention Pond 4. The historical and ' developed drainage maps for the proposed parking lot expansion are attached in Figures 1 and 2. BOULDER FORT COLLINS WINTER PARK GLENWOOD SPRINGS DENVER Aggie Village North Redevelopment- W. Parking Lot Expansion lLJll`J1""' Drainage Report Addendum 5/19/2016 CONSULTING ENGINEERS 2 of 3 The historical and post -developed flow rates are outlined in the tables below. Peak runoff rates ' and areas were only adjusted for the basins affected by the parking lot expansion. Design and flow calculations are attached. Table 1. Historic Site Basin Areas and Peak 100-year Runoffs Basin ID Area (acre) Expanded Site Q 100 (cfs) H1 1.52 6.61 H2 2.91 11.69 H3 4.67 18.12 H4 0.80 3.27 H5 0.20 1.01 New Total 10.10 40.70 Original Total 9.43 33.68 Table 2. Developed Expanded Site Basin Areas and Peak 100-year Runoffs Basin ID Area acre Expanded Site Q 100 (cfs) DI 1.22 7.00 D 1 A 0.21 1.99 DiB 0.10 0.93 D2 1.22 7.02 D2A 0.10 0.83 D2B 0.15 1.15 D3 1.02 7.75 D4/5 3.43 16.51 D6A 0.22 1.50 D6B 0.19 1.91 D6-1 0.57 5.33 D6-2 0.91 8.09 D6-3 0.29 2.65 D6-4 0.50 2.89 Total 10.10 65.54 Original Total 9.43 60.58 ' With the decrease in basin area, the runoff rate from basin D613 decreased from 3.15 cfs to 1.91 cfs. The runoff from the D6 basins and the Dl basin all increased with the parking lot expansion. The offsite runoff to basin D 1 increased by 0.40 cfs and the total runoff from the D6 ' basin increased by 4.56 cfs. Specific information for each parking lot basin is attached in the drainage calculations. ' DETENTION FACILITIES As stated in the Final Drainage Report there are four detention ponds throughout the site with water quality control occurring in the regional water quality pond located near spring creek. The total outflow rate from those ponds is required to be equal to or less than the peak historical flow rate. The offsite flows and the outflows from Ponds 1, 2 and 3 have a total 100-year runoff rate Aggie Village North Redevelopment- W. Parking Lot Expansion Drainage Report Addendum 5/19/2016 3 of of 25.57 cfs. With a total 100-year peak historical runoff rate of 40.70 cfs, Pond 4 can therefore have a maximum outflow rate of 15.13 cfs, see Table 3 below. Table 3. Detention Pond Inflow and Outflow Values Detention Pond ID Ex anded Site Q100 Inflow (cfs) Q100 Outflow (cfs) Pond 1 (133, D3A, D3B, D3C) 7.75 1.03 Pond 2 (D2, D2B) 8.17 3.09 Pond 3 (134, D5, D5A, D5B) 16.51 7.29 Pond 4 6-1, D6-2, 136-3, D6-4 17.14 15.13 Offsite Not Captured (D 1, D 1 A, D 1 B,) 9.92 9.92 Offsite Captured in Pipe No Detention 136A, D6B, D2A 4.24 5.48 Total 63.73 40.70 1 Using the rational method calculations the weighted average percent impervious and runoff coefficient for basins 136-1, D6-2, D6-3, and 136-4, are 79.5% and 0.87, respectively. Using these values and the modified FAA method, Pond 4 has an inflow rate of 17.18 cfs. The required 1 pond volume is 0.034 acre-ft with an outflow rate of 15.13 cfs. The designed Pond 4's total volume with 0.69 feet of freeboard is 0.091 acre-ft with the pond having a total depth of 3.55 ft at a top of pond elevation of 5010.0 ft. The free board will be contained in both the pond and 1 less than 1 ft in the adjacent parking lot. The 100-year water surface elevation is 5009.31 ft and does pond in the parking lot. The ponds outlet structure will be flush with the pond bottom and be a drop structure with the outlet pipes invert elevation at 5000.95 ft in order to be connected to 1 the existing 42" storm system. The outlet structures 18 inch pipe discharge flow will be restricted to 15.13 cfs with a restrictor plate placed 0.86 ft above the pipe invert. Pond volume and restrictor plate calculations are attached. 1 SUMMARY The sites updated storm design, detention pond, and outlet structure have been designed to 1 capture and convey the proposed peak stormwater runoff through the site and discharge equal to or less than the historical peak runoff rate. Through review of the sites runoff calculations and storm system design there appears to be adequate capacity to convey the proposed flows. 1 Sincerely, JVA, INCORPORATED Ppi�0 L/C .o By:196 1 Brian J. p� 1, P.E. ', -:97/Z�l, • !t Regional Manager ''� ..•�,, 1 Enclosure: 1) Drainage and Pond Volume Calculations 2) Historical and Developed Drainage Maps ' 3) Final Drainage Report for Colorado State University Aggie Village North Redevelopment by JVA Inc, dated January 23, 2015. 1 CC: I _ _ _ __ > p _ ____{g•r-'- s---.r-bras - I CONC.•-•LUNG -WALK ---_--.__-----••--_ \ : \ 1'Y Lei)/ L/Y � .n• ">`i-- ' ` �_�\ -�-mac _- _ss S !_,-1 h'E ST/i'E�\T _ o _ ---------------- —tss „r ss— J ' -- ------'�-_ --__-------------==�J�1�£;'rrr_AKE sTXFF"r—�=------� _ __------- CR. �cI. R — C CURB G PRA co.C. wR1F ' \ /GO ❑ ❑ IXRTNG IXiF STOR! - - - IXIS ING NE STORY, \\\\ M1n S \ dl` L.C. u.�'vS \itfiB'fi.D 1 I> I rCO�NCW� ,.GNEC � - I �-Y_ GRwss i � % i o� SD �`„\ s so—s —s s/ so-=- s m Go :11cIs.In iI IL- pIIIII I .D ; r u d129 00 ° ;1 , I 1 I I \1 I £ \ I� I I GIASS ` I Iaf19N$rJul/tN I }y \ \ � I I� � ✓ \Wc GNuce LAR65,RLt: 1111 ctiaruII ay. C i Is 1 1 If La — NC. um I I s >r £I 51 I\\ G Y / ` li') I t•S� 1 I MULT-l£TLN SIDNE j In JII \1 IG r I G d �FgF a-izeNs'oF;M.� 16 / }' ;IIR / II \ ,1 -- I n I W� �•m ® / LS IY III ^ I { bl rRu.->r«euRl •:. 1= I I ` DGI I £ a RA 1 V ❑ 4 �° I / ly4 I `I� �f I /1 I/ 111 1 i t7m I 141 DESIGNED BY: .- G 00 ® sD s ® ®I ® I DRAWN BY: KRBMT ❑' SD s S S ❑ r: I I I CHECKED BY: ••• y7P \ couc ♦ �0 III G9S5 �Y, �1 .r v 0— o i \ _ JK I 1 \ JOB NUMBER. 2025 Jc -- III I ,0 11Goeh ^p\ uu,c% sNcos \ �\ '('!� 3 ,FF[�j I J DALE: Y1L2016 JI iIG 5G / 1i 111 a \ /p 't�s\ \\\ mNA INC \ - - - - - - ______ ____ _ _ ____ _-___ _ _ W „� ______ CON U — CONC B k CURFA 1. uESTo€rT Xoan f -_------------pii,Jys--------------=-- / _ J' 1'XCT.Sl� -R --------------------=-----------------------' �I�sT vhp3��cT hoax-----I:a CONCRETE CURB k GUTTER - TIC-CUR66CL CuifEP-________-________-_______-- / - _________-________-____ _ s .� _ _ __- ____________- 31Z _________ CURB J' / k GUTTER _ � O • Oo-____ ___ ` _ i +- - - - GONG. IYFIJL. . NC ONCpB WALK W Q W Co ---� ---� �------------- eLe--- ? w Z Q (D E z O 10 D ID J Y F- �_ QCy: X%1 W a 2 c� LEGEND a WSTOK W NIGE WIR BOUNDARY (W" MM) N . M HISTORIC MYNAGE BASF! BWNDW/ (SIB BA9N) U —o DIRECTION OF RDN (N6TORIC) 0 BI�SIN DESIGN PONT d - DEVEIDlm RASA OBCNATION SHEET NUMBER DRAADE BAsa DBID.,DM oN mnff 8 - RUNOFF COEFFICIENT FIGURE 1 00 q MMSF�JPMENc �Y m � S F� EIm-� HISTORIC RUNOFF TABLE �� DESIGN POINT AREA (ACRES) 2 M RUNOFT (CFS) 100 Tit PEAK (CFS) M 1 152 f.73 6b1 IQ 2 291 SD4 1188 W 3 Ib7 K.ro 18.12 IM 4 080 081 327 NB 5 OYO 026 1D1 roIK ID.Io loss �D.ro .. / SOUTH I WH.ITCOMB STREET / x � I I I I I 14�NEW / _ _�_ I � • 1'\\ '`1' "" , � - ryII F_� r' • 1 I "_ - - I 1 I II II '( 12 • I I i `i. '— • `\ III , I I 1 B �wr—ar—u1'v ur ar r—ur—ar _ atv—ulr u i ur�—ur—_ ar''.. iwr i7ar— r—ary III li I� — _ ------------------ I R II N o -- I'■ - u+ __________________. D5_1 `. `. "9 ■^\ ._._.—_ __ '�\ _ ._yam I 1 Ip - - - �5- -O i • ,,,, _ S- _ US 5 _ -_ �—+-05- Ig • 5 -r 4_ 1 IR �\ • 0-49' I IRR , Rfl . IRfl IRR IRR IRO IP IRR IRR, IPR R IRfl IRN—:.RR-1 -RR. IWV R 0-1 . � I • UE UE VE—UE UE W—UE UE . • \ I I I 1 ' o Ar 71 RE— " "V �XXXXI XX� 'g ■ apes ■ ■ I I I DO .t 1 a I i i 11 DESIGNED BY: DRAWN BY: NRBUT D6B I • f f 1 � � i � �I Illi � aECNEo BY. .000.1 a '- L1= ; JOB NUMBER. m5k - . • _ - _ _ _ \ \ \,\ \ I I i _I \ I 1 �� GATE: L1G201fi =�mrvn INC �� —� ■ DEVELOPED RUNOFF TABLE BASIN DESK POINT N AREA (ACRES) 2 YR RUNOFT (OFS) 1DO YR PEAK (CFS) DI t 122 Ib5 7A0 06-1 6-1 057 1." 573 06-2 6-2 091 21 8D9 D6-J 6-3 022 0.72 2E5 06 4 64 050 0.76 2BB OF68 0.1B 052 191 FbR £rA lbNabpm—SrT( OTUIUli MAP EL I OJ wz a > Q m OLLJZ w i 'i T t I jj T w 7 I I lil - z 0 T-� IIII. i O �0 w o 20 0 20 AO j uj (24- i6`1 a � a Lu o LEGEND a l0 WAINADE MANVE BASIN BOUNDARY (MAJOR BASIN) P/) M04AiE WUNAGE SUN BOUNDARY (A® BASNQ U DBEDTION OF RDII 0 BASIN DESM POINT A v DEY'E 100 BASIN SHEET NUMBER GA 5 1 WTANMA RUN IDDOMTM BABE 5 � R� 2 11.0 . AREA AM FIGURE 2 JVA Incorporated Job Name: Aggie Village North 25 Old Town Square Job Number: 2025.3c Fort Collins, CO � 524 D ate 011: 4/21/16 Ph: 970.225.9099 By: LAT/KRB Fax: 970.225.6923 Aggie Village North Historic Runoff Coefficient & Time of Concentration Calculations Location: Fort Collins Minor Design Storm:PB� Major Design Storm: Soil Type: aa�in Warn 1% C2 C5 C10 C1D0 Streets Paved 100% 0.95 0.95 0.95 1.00 Concrete Drives/Walks 90% 0.95 0.95 0.95 1.00 Roof 90% 0.95 0.95 0.95 1.00 Gravel 40% 0.50 0.50 0.50 0.63 Landscaping (B soll) 2% 0.25 0.25 0.25 0.31 Landscaping (C/D soil) 0% 0.25 0.25 0.25 0.31 Playground 10% 0.11 0.11 0.11 0.14 Artificial Turf 25% 0.20 0.20 0.20 0.25 1 (%) = 100 % 90% 90% 40 % 10% 25% 2% 011-1. 1 (%) Runoff CoefPs Initial Overland Time (Q Travel Time (Q tt=Length/(Velocity x >Com < P tc Urbanized Check I,, 60) ON Final Basin Design Ap.K Adn,revo° Arm As rave, Aors „d Aan I„N A:=a°eB Ascape A Totai A Too, Im p Up"I mast Sloe t, Length 9 Sloe p Velocity y t Time of Total t = U180 1 ( ) Name Point (Sf) rr (SO A (Sf) (Sf) (Sf) sap [uo s„n (Sf) ( ) ac ( ) (%) C2 C5 C10 C100 Length °p (/) min (min) (ft) (%) Type of Land Surface C, (fps) (P) (min) Conic Length ` 1D (min.) Min (Sf) (sf) III) 4' I, = 4 (n) t H1 1 19.988 11,781 34,243 66,012 1.52 47.4% 0.59 0,59 0.59 0.64 163 1.3% 11.0 478 0 9% Paved areas & shallow 20 1.9 4.2 15.2 641 13.6 13.6 paved swales H2 2 10,084 44,836 71,810 126,730 2.91 40.9% 0.55 0.55 0.55 0.61 234 0.3% 23.6 594 0 5% Paved areas & shallow 20 1 A 7.1 30.7 828 14.6 14.6 paved swales H3 3 42.948 39.543 121,023 203,514 4.67 39.8% 0.53 0.53 0.53 0.59 240 0.3% 24A 610 0.8% Paved areas & shallow 20 1.8 5.6 29.9 B50 14.7 14.7 Paved swales H4 4 2,836 8.296 23,542 34,774 0.80 31.0% 0,47 0.47 0.47 0.53 85 6.5% 5.7 254 02% Paved areas & shallow 20 1.0 4.3 10.0 339 11.9 10.0 pa ed swales H5 5 2358 0 158 6393 8,909 1 0.20 28.6% 0.44 0.44 0.44 0.50 25 1.9% 4.9 0 0.0°/ Paved areas & shallow 20 0.0 0.0 4.9 25 10.1 5.0 1 paved swales I U I AL N I t I (6,214 U 1Uap5tiI 1b6 1 0 1 0 1257,1111 0 1439.9391 10.10 1 40.3% 1 0.54 10.54 10,54 I 0.60 1 Runoff Coeffs Rainfall Intensities (in/hr) Area Flow Rates (cfs Basin Name Design Point Time of Conc (tc) C2 CS C10 C100 2 5 10 100 AT.,., (sf) A Total (ac) 02 05 010 Q100 H1 1 13.6 0.59 0.59 0.59 0.64 1.94 0.00 3.33 6.79 66,012 1.52 1.73 0.D0 2.96 6.61 H2 2 14.6 0.55 0.55 0.55 0.61 1.89 0.00 3.23 6.60 126,730 2.91 3.04 0.00 5.20 11.69 H3 3 14.7 0,53 0.53 0,53 0,59 1.89 0.00 3,22 6.58 203,514 4.67 4.70 0.00 8.03 18.12 H4 4 10.0 0.47 0.47 0.47 0.53 2.21 0.00 3.78 7.72 34,774 0,80 0.84 0.00 1.43 3.27 H5 5 5.0 0.44 0.44 1 0.44 0.50 2.85 0.00 4,87 9.95 6,909 0.20 0.26 0.00 0.44 1.01 TOTAL SITE 439,939 10.10 10.56 0.00 18.06 40.70 2025.3c - Rational Calculations.xlsx Historic Page 1 of 1 JVA Incorporated 25 Old Town Square Fort Collins, CO 80524 Ph: 970.225.9099 Fax: 970.225.6923 Aggie Village North Composite Runoff Coefficient Calculations Location: Fort Collins Minor Design Storm: 10 Major Design Storm: 100 Sal Type: B Job Name: Aggie Village North 1% C2 C5 o10 C100 Job Number. 2025.3c streets paved 100% 0.95 0.95 0.95 1.00 Date: 5/18116 Cormte DnveslWalks 90% 0.95 0.95 0.95 1.00 By: LAT/KRB Roar 90% 0.95 0.95 0.95 1.00 Gravel 40% 0.50 0.50 0.50 M63 Landscaping Is sdi) 0% 0.25 0.25 0.25 0.31 Landscaping (CID solll 0% 0.25 0.25 0.25 0.31 Playground 10% 0.11 0.11 0.11 0.14 Artificial Turf 25% 0.20 0.20 0.20 0.25 Entire Basin Dealt In Data I (%) = 100% 90% 90% 10'% 25% 0% 0% 1 (%) Runoff CoeB's Basin Name Design Point Apaved speets (sf) a Adnveslc (5f) A roor (sf) p40% ' `gravel (sf) • pIygnd (sf) Aan. wd (sf) Aqsapa is s0i0 (sf) Aqa,� (00 son) (0) ATatal (sf) ATolai (ac) Imp (% C2 CS C70 C100 D7 1 31,019 528 3, 187 18,201 52,935 1.22 61.90% 0.68 0.68 0.68 0.74 D68 66 8,377 8,377 0.19 90.00% 0.95 0.95 0.95 1.00 D6-1 6-1 17,294 5,292 2,351 24,937 0.57 88.45 % 0.88 0.88 0.88 0.93 D6-2 6-2 29,726 5,084 4,956 39,766 0.91 86.26% 0.86 0.86 0.86 0.91 D6-3 6-3 11,150 1,493 12.643 0.29 B8.19% 0.87 0.87 0.87 0.92 D6-4 6-4 11,225 10,418 21,643 0.50 51.86% 0.61 0.61 0.61 0.67 p,al Site W10 D1 8 D6's X 59.356 r. ❑)8,967 6,988 0 0 104,402 0 279,713 6.42 57.3% 0.68 0.68 0.68 0.73 TOTAL SITE 159,770 0 128,248 10,175 0 0 141,821 1 0 1 440,014 10.10 63.5% 0.71 0.71 0.71 0.77 D1 1 8.394 0 1,681 10,065 0.23 83.3% 0.83 0.83 0.83 0.88 D6-1 6-1 17,294 5,292 2,351 24,937 0.57 88.5% 0.88 0.88 0.88 0.93 D6-2 6-2 29,726 5,084 4,956 39,766 0.91 86.3% 0.86 0.86 0.86 0.91 D6-3 6-3 11,150 IA93 12,643 0.29 88.2% 0.87 0.87 0.87 0.92 06-4 6-4 11.225 10,418 21,643 0.50 51.9% 0.61 0.61 0.61 0.67 TOTAL SITE 77.779 0 10,376 0 0 0 20,899 0 109,054 2.50 1 79.9% 1 0.82 1 0.82 1 0.82 0.87 2025.3c - Rational Calculations.xlsx Developed C Page 1 of 1 � W JVA Incorporated \"'1\!!(!1\ 25 Old Town Square re y� %sy _"' Ph:ins, CO 0524 Fax: 970.225.6923 Aggie Village North Time of Concentration Calculations Location: Fort Collins Minor Design Storm: 10 Major Design Stonn: 100 Soil Type. B Job Name: Aggie Village North Job Number. 2025.3c Date: 5116/16 By: LAT/KRB Sub -Basin Data Initial Overland Time (t) Travel rime (4) tc Comp tc Urbanized Check t� 4=Length/(Velocity x 60) ON Final Upper Time of Total Basin Design Ard„ CS must Slope f, Length Slope (%) Type of Land Surface C, Veloclry 4 Corp Length t,=(U180M Min Name Point (ac) �engtr� 1 % (min) (Ill (fps) (min) 10 (min) Ito L * L = t,, (fU 01 1 1.22 0.68 61 2 6% 4.4 650 1.0 % Paved areas & shallow 20 2.0 54 9.8 712 14.0 9.8 paved swales D6B 68 0.19 0.95 0 2.0% 0.0 0 0.0% Paved areas & shallow 20 0.0 0.0 0.0 0 10.0 5.0 paved swales D6-1 6.1 0.57 0.88 160 3.0 % 3.5 25 0.2 % Paved areas & shallow 20 0.9 0.5 4.0 185 11.0 5.0 paved swages D6-2 6-2 0.91 0.86 171 2.3% 4.3 127 1.0 % Paved reas & shaliow 20 20 1.1 5.4 298 11.7 5.4 avaed swages D6-3 6-3 0.29 0.87 178 2.3% 4.3 23 0.4 % Paved areas & shallow 20 1.3 0.3 4.6 201 11.1 5.0 paved swales D6-4 1 6-4 1 0.50 1 0.61 1 128 3.0 % 7.0 27 2 0% Paved areas & shallow 20 1 2.9 1 0.2 1 7.2 155 1 10.9 7.2 aved swales ' 2025.3c - Rational Calculations.xlsx Developed Tc Page 1 of 1 JVA Incorporated 25 Old Town Square Fort Collins, CO 80524 Ph: 970.225A099 Fax:970.225.6923 Aggie Village North Design Storm : 1 2 Year Job Name: Aggie Village North Job Number: 2025.3c Date: 5/18/16 By: LAT/KRB Developed Storm Runoff Calculations Point Hour Rainfall (P,) : 0.82 Direct Runoff Total Runoff Inlets Pie Pipe/Swale Travel Time C c ,Qi N O 'E L d ¢ L .L'It ' asa° LL 2 0 E F m e °iE � z 01 1 1.22 0.68 9.80 0.83 2.23 1.85 9,80 0.83 2.23 1.85 D66 68 0.19 0.95 5.00 0.18 1 2.85 0.52 5.00 0,18 2.85 0.52 D6-1 6-1 0.57 0.88 5.00 0.51 2.85 1.44 5.00 0,51 2.85 1.44 INLET 4.16 0.00 0.00 15 in PVC 0.5% 1.4 6A 224 1.2 3.18 8.18 D6-2 6.2 0.91 0.86 5.40 0.79 2.78 2.19 5,40 0.79 2.78 2.19 INLET Total DS to Inlet 136-2 (D6-2, 06-1) 8.18 1.29 2.39 3.09 3.09 0.00 0,00 21 in PVC 0.5% 3.1 15.6 64 1.3 0.83 9.01 D6-3 6-3 0.29 0.87 5.00 1 0.25 1 2.85 1 0.72 5.00 0.25 2.85 0.72 INLET 0.72 0.00 0,00 Total DS of Inlet D6-3 (136-3, D6-2, D6-1) 9.01 1.55 2.30 3.55 3.55 0.00 0.00 21 in PVC 0.5% 3.6 15.6 106 1 5 1.20 10.20 D6-4 6-4 0.50 0.61 T20 1 0.30 1 2.50 D.76 7.20 0-30 2.50 0.76 NONE Chnc, Pon,! Total to Pond (136-4, 06.3, D6.2, D6.1) 10.20 1 .85 2.19 4.06 POND 4 (D6-1, D6-2, D6-3, D6-4) 4.06 Q100 HISTORICAL TOTAL 10.56 Total Runoff 4.06 2025.3c - Rational Calculations.xlsx Q2 Page 1 of 1 JVA Incorporated 25 Old Town Square Fort Collins, CO 80524 Ph:970.225.9099 Fax: 970.225.6923 Aggie Village North Design Storm : 1 100 Year Job Name: Aggie Village North Job Number: 2025.3c Date: 5/18/16 By: LAT/KRB Developed Storm Runoff Calculations Point Hour Rainfall (Pi): 2.86 Direct Runoff Total Runoff Inlets Pie Pi a/Swale Travel Time m c y m v Z N N c HmE .O M U o o Eo '2 O O oE a i a. u > z5 D1 1 1.22 0.74 9.80 0.90 7.78 7.00 9.80 0.90 7.78 7.00 D66 6B 0.19 1.00 5.00 0.19 9.95 1.91 5,00 0.19 9.95 1.91 D6-1 6-1 0.57 0.93 5.00 0.54 9.95 5.33 5.00 0.54 9.95 5.33 INLET 4.16 0.00 0.00 15 in PVC 0.5% 5.3 6.4 224 4.3 0.86 5.86 D6-2 6-2 0.91 0.91 5.40 0.83 9.69 8.09 5,40 0.83 9.69 8.09 INLET Total DS to Inlet D6-2 (D6-2, D6.1) 5.86 1.37 9.44 12.93 12.93 0.00 0.00 21 in PVC 0.5% 12.9 15.6 64 :; 4 0.20 6.06 D6-3 6-3 0.29 0.92 5.00 1 0.27 1 9.95 2.65 5.00 0.27 9,95 2.65 INLET 2.65 0.00 0.00 Total DS of Inlet 1016-3 (DW, 136.2, D6.1) 6.06 1.64 9.31 15.23 15.23 0.00 0.00 21 in PVC 0.5% 15.2 15.6 106 6.3 0.28 6.34 D6-4 6-4 0.50 0.67 7.20 1 0.33 1 8.72 1 2.89 7.20 0.33 8.72 2.89 NONE 5nase n: •one, Total to Pond (D6.3, D6-2, D6.1) 7.20 1.97 8.72 17.15 POND 4 (D6-1, D6-2, D6-3, 06-4)1 17.15 Q100 HISTORICAL TOTAL 40.70 Total Runoff 17.15 2025.3c - Rational Calculatlons.xlsx 0100 Page 1 of 1 JVA Incorporated Job Name: Aggie Village North 25 Old Town Square Job Number: 2025.3c Fort Ph: 970225.9 99ns, CO 0524 Date: By: LAT/KRB Fax: 970.225.6923 Aggie Village North Detention Pond Volume Calculations: Modified FAA Procedure From UDFCD UD-Detention v2.34 Design Information (Input): Catchment Drainage Impervious la = 0.80 percent Catchment Drainage Area A = 2.27 acres Predevelopment NRCS Soil Grc Type = 8 A, B. C, or D Return Period for Detention Cor T = 100 years (2, 5, 10, 25, 50, or 100) Time of Concentration of Water; Tc = 7.2 minutes (Max Tc Basin 6-1 to 6-4) Allowable Unit Release Rate q = 6.66 cfs/acre One -hour Precipitation P, = 2.86 inches Design Rainfall IDF Formula i = C1' P1/(C2+TJ4C, Coefficient One C, = 28.50 Coefficient Two Cz = 10 Coefficient Three C3 = 0.786 Determination of Average Outflow from the Basin (Calculated►: Runoff Coefficient C = 0.87 Inflow Peak Runoff Qp-in = 17.18 cfs Allowable Peak Outflow Rate Qp-out = 15.13 cfs Mod. FAA Major Storage Volume = 1,494 cubic feet Mod. FAA Major Storage Volume = 0.034 acre-ft Rainfall Duration minutes (input) Rainfall Intensity inches / hr (output) Inflow Volume acre-feet (output) Adjustmerl Factor "m" (output) Average Outflow cfs (output) Outflow Volume acre-feet (output) Storage Volume acre-feet (output) 0.0 0.00 0.000 0.00 0.00 0.000 0.000 1.0 12.38 0.034 1.00 15.13 0.021 0.013 2.0 11.56 0.063 1.00 15.13 0.042 0.021 3.0 10.86 0.088 1.00 15.13 0.063 0,026 4.0 10.24 0.111 1.00 15.13 0.083 0.028 5.0 9.70 0.132 1.00 15.13 0,104 0,028 6.0 9.22 0.150 1.00 15.13 0,125 0.025 7.0 8.79 0.167 1.00 15.13 0.146 0.021 8.0 8.41 0.183 0.95 14.37 0.158 0.024 9.0 8.05 0.197 0.90 13.62 0.169 0.028 10.0 7.74 0.210 0.86 13.01 0.179 0.031 11.0 7.45 0.222 0.83 12.52 0.190 0.033 12.0 7.18 0.234 0.80 12.10 0.200 0.034 13.0 6.93 0.245 0.78 11.75 0.210 0,034 14.0 6.70 0.255 0.76 11.46 0.221 0.034 15.0 6.49 0.265 0.74 11.20 0.231 0.033 16.0 6.30 0.274 0.73 10.97 0,242 0.032 17.0 6.11 0.282 0.71 10.77 0.252 0,030 18.0 5.94 0290 0.70 10.59 0.263 0.028 19.0 5.78 0.298 0.69 10.43 0.273 0.025 20.0 5.63 0.306 0.68 1029 0.283 0.022 21.0 5.48 0.313 0.67 10.16 0.294 0.019 22.0 5.35 0.320 0.66 10.04 0.304 0.015 23.0 5.22 0.326 0.66 9.93 0.315 0.011 24.0 5.10 0.332 0.65 9.83 0.325 0.007 25.0 4.98 0.338 0.64 9.74 0.336 0.003 26.0 4.87 0.344 0.64 9.66 0.346 -0.002 27.0 4.77 0.350 0.63 9.58 0.356 -0.006 28.0 4.67 0.355 0.63 9.51 0,367 0.011 29.0 4.58 0.361 0.62 9.44 0.377 -0,017 30.0 4.49 0.366 0.62 9.38 0.388 -0.022 2025.3c - Rational Calculations.xlsx Modified FAA 100-yr Page 1 of 2 JVA Incorporated 25 Old Town Square Fort Collins, CO 80524 Ph: 970.225.9099 Fax: 970.225.6923 POND VOLUME CALCULATIONS - STAGE / STORAGE Pond Volume = Prismoidal Formula Volume Equation = (A1+A2+SQRT(A1`A2)'D/3 Staae / Storaae Input Table Job Name: Aggie Village North Job Number: 2025.3c Date: 5/18/16 By: LAT/KRB ELEVATION ft DEPTH (D) ft AREA (Al) ft2 WEIGHTED AVG AREA (A2) ft2 INCREMENTAL VOLUME ft3 CUMMULATIVE VOLUME ft3 5006.45 0 0 0 5007.0 0.6 118 59 22 22 5008.0 1.0 456 287 269 290 5009.0 1.0 1,090 773 750 1,041 5009.5 0.5 1,823 1,457 720 1,761 5010.0 0.5 7,697 4,760 2,211 3,972 Top of Pond Depth ft TOTAL VOLUME 5010.0 3.55 3,972 cf F 0.091 ac-ft Volume Summary Table Required_ Volume (ft') Required Volume (ac-ft) I Water Surface Elevation Water Depth V100 1,494 cf 1 0.034 ac-ft 5009.31 ft 2.86 ft Volume Interpolation Calculations V100 Vol Elev 1040.63 5009.00 1494.50 5009.31 1761.06 5009.50 2025.3c - Rational Calculations.xlsx Vol Pond Page 1 of 2 50' 0 50 5010.00 5009.50 ZO 5009.00 F R W W 5008.50 WW am LL Q 19 w 5008.00 yW K � W F 3 5007.50 5007.00 671DbIY11 JVA Incorporated Job Name: Aggie Village North 25 Old Town Square Job Number: 2025.3c Fort Collins, CO 80524 Date: 5/18/16 Ph:970.225.9099 By: LAT/KRB Fax: 970.225.6923 STAGE VS. STORAGE Water Quality Detention Pond op of Pond 3,972 cf 5010.0 V 00 500 .31 ft 5006.00 0 500 1.000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 POND VOLUME (CF) 2025.3c - Rational Calculations. xlsx Vol Pond Page 2 of 2 JVA Incorporated 25 Old Town Square Fort Collins, CO 80524 Ph: 970.225.9099 Fax: 970.225.6923 ORIFICE PLATE AT OUTLET PIPE WORKSHEET Orifice Plate using Headwater above opening and Q=cA(2gH)A.5 C= 0.65 Summary of Available Pine RPIP.ASP.S Pipe Dia Area Head H Q Outfall Pipe atcentroid avail out (in) (sf) (ft) (cfs) 12 0.79 T86 11.48 15 1.23 7.74 17.79 f8 1'.77 7 frY' 25.42 I 24 3.14 7.36 44.43 30 4.91 7.11 68.24 36 7.07 6.86 96.52 Q=cA(2gH)A.5 C= 0.65 Iteration process Q 15.13 cfs c 0.65 Hhead 761 ft Needed Area 1.05 sf Using Area- determine Ao 1.05 sf Apipe 1.77 sf theta 2.843 rad Ao-calced 1.05 sf Job Name: Aggie Village North Job Number: 2025.3c Date: 5/18/16 By: LAT/KRB QMAJOR allowable release rate: 15.13 cfs 100-yr Water Surface Elev: 500931 ft Inv Elev at Outlet Struct: 5000.95 ft Outlet Pipe at Structure: 18 in A _[Apip, (2z-0 + rsi 9 *rco 9 2z ) 2) 2) J J m 0.11 ft distance above(+) or below(-) center m = r Cos � 2 2 H 0.86 ft Height above pipe invert H = r + m 2025.3c - Rational Calculations.xlsx Restrictor Plate Page 1 of 1 ENCLOSURE - FINAL DRAINAGE REPORT FOR CSU AGGIE VILLAGE NORTH REDEVELOPMENT FINAL DRAINAGE REPORT FOR COLORADO STATE UNIVERSITY AGGIE VILLAGE NORTH REDEVELOPMENT (PROJECT NO. 13-012) AT 500 WEST LAKE STREET FORT COLLINS, COLORADO 80525 PREPARED FOR COLORADO STATE UNIVERSITY FORT COLLINS, COLORADO JANUARY 23, 2015 t TABLE OF CONTENTS SITELOCATION........................................................................................................................2 DESCRIPTIONOF PROPERTY......................................................................................................2 BENCHMARK INFORMATION......................................................................................................2 ' HISTORIC BASINS.....................................................................................................................3 PROPOSED DEVELOPED BASINS................................................................................................3 PROPOSED DETENTION/WATER QUALITY POND..........................................................................4 HISTORIC/DEVELOPED BASIN COMPARISON.............................................................................. 5 STORMWATER MODELING.......................................................................................................5 I APPENDIX APPENDIX — DRAINAGE SUPPORTING DOCUMENTS 1 . SOIL MAP - NATURAL RESOURCES CONSERVATION SERVICES (NRCS) 2. FEMA FLOOD INSURANCE RATE MAP 3. FIGURE 1- EXISTING DRAINAGE MAP 4. FIGURE 2 - DEVELOPED DRAINAGE MAP 5. RATIONAL CALCULATIONS SUMMARY 6. DETENTION VOLUME CALCULATIONS a. OVERALL SITE MODIFIED FAA DETENTION VOLUME REQUIREMENT b. INDIVIDUAL POND VOLUMES C. INDIVIDUAL POND WATER QUALITY PLATE SIZING ' d. INDIVIDUAL POND OUTLET ORIFICE SIZING 7. HYDRAFLOW STORM SEWERS REPORT AND PROFILE ' CSU Aggie Village North Redevelopment Drainage Narrative Page 1 of 5 ' SITE LOCATION I The Aggie Village North Redevelopment project is bounded to the north by West Lake Street, to the south by Prospect Street, to the east by Center Avenue, and to the west by South Whitcomb Street in the City of Fort Collins, Colorado. DESCRIPTION OF PROPERTY ' The site is owned by Colorado State University, and consists of approximately 9.43 acres. The property is currently occupied by the existing Aggie Village North student housing facility, to be entirely demolished in the scope of the project. The site generally slopes from northeast to ' southwest with grades from 1% to 3%. The soils within the site consist of Altvan-Satanta loams which have been classified by the Natural Resources Conservation Services (MRCS) as having a Type B hydrologic soil group with a moderate inflation rate. There are no irrigation canals passing through the site. A Geotechnical Engineering Report was performed for the site by Terracon (dated October 11, 2013) and ongoing weekly ground water monitoring has recorded measured ground water depths of I F to 14' below existing grade. The property is not located within the 100-year floodplain as shown on the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Panel # 08069C0979H, revised May 2, 2012. The main purpose of this study is to analyze existing and developed drainage patterns in order to design a storm system to adequately convey stormwater through the property and discharge into the historic drainage way (consisting of a 42" diameter storm trunk running north to south along the western boundary of the property) without negatively impacting the capacity of the existing storm system or the downstream storm infrastructure. A new parking lot to the west, new multi- story buildings, and other site improvements have been analyzed for stormwater conveyance and water quality. Runoff generated from the site will be collected into a new storm main through a series of roof drain connections and inlets, detained in one or more of 4 onsite detention ponds located throughout the site, and treated for water quality before being released into the existing stonn system at the historic rate, where it is eventually discharged to Spring Creek to the south. a BENCHMARK INFORMATION ' Topographic and survey information was provided by King Surveyors, Inc. Horizontal datum is Colorado State Plane Coordinates NAD 83(2007) Datum and vertical datum is referenced from Fort Collins Benchmark 19-97, Record Elevation = 5,025.62, NAVD 1988. CSU Aggie Village North Redevelopment Drainage Narrative Page 2 of 5 HISTORIC BASINS The site has been divided into four separate basins. Sub -basin H1, shown on Figure 1: Historic Drainage, represents drainage that sheet flows off the site to the north and east where it is collected by the gutters along West Lake Street and Center Avenue and conveyed to the existing storm inlet at the corner of West Lake Street and Center Avenue. Sub -basins H2 and H4 capture runoff in the northern branch of existing stonn main running east -west through the site and discharging into the existing 42" storm trunk line, while sub -basin H3 captures runoff in the southern storm branch discharging into the same trunk line. All four basins convey stormwater into the western trunk line and eventually discharge into Spring Creek south of the site. Rational method calculations with peak flows are shown on the drainage figure and summarized in the attached Rational method calculations table. ' PROPOSED DEVELOPED BASINS CSU proposes to construct four buildings with an associated western parking lot, roadway curb & gutter improvements, walks, retaining walls, game courts, and other features throughout the site. The overall imperviousness of the site will increase from approximately 41.2% to 60.1 %. The site has been divided into ten separate basins; see Figure 2: Developed Drainage. Sub -basin DI to will continue to drain north and east undetained to Lake Street & Center Avenue as in the historical condition, eventually being conveyed to the existing inlet (which will remain a part of the proposed storm system) at the northeast corner of the site. This basin consists of two paved drive entrances, sidewalks and lawn area. The overall 100-year runoff from this basin will increase by 1.17cfs in comparison to existing sub -basin H1. Sub -basins D1A, D1B, & D2A consist of roof areas from the North Building that will be hard piped into manholes on the main storm line. ■ Sub -basins D2 & D2B represent drainage from the majority of the interior corridor and consist of landscaped areas, roofs, and walks. This runoff is detained in on -site detention Pond 2, a long ' shallow pond stretching across the center of the site. An outlet structure with a water quality plate controls the release of stormwater into the main storm system. Sub -basin D3 is defined by the depressed amphitheater feature to the west of the central corridor of sub -basin D2. The two separate areas on the north and south sides of the walk are hydraulically connected and together represent on -site detention Pond 1. Runoff captured by field inlets and the combined roof areas of sub -basins D3A, D3B, & D3C contribute to the stormwater volume detained in Pond 1. A two -stage outlet structure has been designed for this pond to limit the rate of runoff entering the storm system. Sub -basins D4, D5, DSA, & D5B are the contributory basins that are captured in on -site detention Pond 3, another hydraulically connected pair of graded ponds sited along the southern boundary 1 of the property. The inner courtyards of the South Building (consisting of landscaping, sidewalks, and paved gathering areas) and associated roof areas, along with a large area of undisturbed landscaping to the south make up these sub -basins. An outlet structure with a water quality plate ' controls the release of stormwater into the main storm system. ' CSU Aggie Village North Redevelopment Drainage Narrative Page 3 of 5 Sub -basin D6 represents the portion of the western parking lot that flows south into on -site detention Pond 4. Three Type 13 inlets capture the majority of runoff in this basin and discharge directly into Pond 4. An outlet structure with a water quality plate controls the release of stormwater into the main storm system. Sub -basins D6A and D6B consist of roof areas and some landscaping adjacent to the West and South Buildings that will be hard piped into manholes on the main storm line. Orifice plates have been designed on the four detention pond outlet structures to limit the flow of incoming stormwater from the proposed storm main through the site to match the historic 100- year release rate of 33.68 cfs. Refer to the attached orifice plate calculations as well as the Rational method calculations summary for the developed drainage basins. PROPOSED DETENTION/WATER QUALITY PONDS The existing Aggie Village North development consists of single story student housing facilities with approximately 42% imperviousness over 9.43 acres, with a peak 100-year storm runoff rate of 33.68 cfs. The proposed CSU re -development of the site will substantively increase imperviousness to 60%, producing a peak 100-year storm runoff rate of 60.58 cfs. The four proposed detention/water quality ponds have been designed to capture stormwater runoff from each contributing developed basin and detain for the difference in the required I00-year storm rainfall event volume calculated using the spreadsheet provided by UDFCD (version 2.33 Modified FAA Method). For an increase of 0.15 in the composite "C" factor for the site over the historic condition, the required detention volume is approximately 17,700 cubic feet (0.406 ac-ft), which includes a 20% increase in volume to account for sedimentation. See the attached FAA Detention Storage calculations. The following lists each pond and the proposed detention volumes based on grading design: Pond Contributing Basins 100-31 Max 100-31 WSE Detention WO Depth Inflow Volume Pond 1 D3, D3A, D3B, D3C 7.75 cfs 5007.50 0.121 ac-ft 4.29 ft Pond 2 D29 D2B 8.17 cfs 5007.50 0.075 ac-ft 2.39 ft Pond 3 D4, D5, DSA, D5B 16.51 cfs 5005.50 0.179 ac-ft 2.65 ft Pond 4 D6 13.17 cfs 5009.32 0.040 ac-ft 2.57 ft Total Volume:0.415 ac-ft Water quality treatment of stormwater runoff had not previously been provided for on -site. Water quality capture volume is set to the 100-year detention capacity, therefore the ponds will treat for the total 0.415 ac-ft released over a 40-hr period. See the attached calculations for design of the water quality plates on each pond outlet structure as well as the calculated pond volume tables. CSU Aggie Village North Redevelopment Drainage Narrative Page 4 of 5 HISTORIC/DEVELOPED BASIN COMPARISON As previously discussed, the majority of the site historically drains west and into the existing 42" storm trunk line at the western edge of the property. The developed drainage basins will alter the ' existing drainage patterns by providing on -site detention for the additional runoff generated by the increase in impervious area as a result of the proposed improvements. The total developed flow to the west from all basins is approximately 60.58 cfs for the 100 year storm event, resulting in a net increase over the historic of 26.90 cfs. The increase in runoff to the west and into the existing system will have limited to no significant impact on the downstream conveyance to Spring Creek due to the controlled release of stormwater at the historic rate of 33.68 cfs through the utilization ' of flow restrictor plates installed in each of the four detention pond outlet structures. STORM WATER MODELING The storm drain piping has been modeled using Hydraflow Storm Sewers to determine pipe size and Hydraulic Grade Line profiles (HGL). See attached report and profile. The pipe has been designed to handle the 100-yr flow. If this system becomes clogged, stormwater will pond within the parking areas and back up into the series of 4 on -site detention areas. An emergency spillway at Pond 3 has been designed to overflow into the street at Center Avenue. CSU Aggie Village North Redevelopment Drainage Narrative Page 5 of 5 40° 34'rN 40' 34' 1' N 3 Hydrologic Soil Group—Larimer County Area, Colorado 3 (CSU Aggie Village North) 0 a 492660 492690 492720 492750 492780 492810 3 r Map Scale: 1:1,380 if printed on A landscape (11" x 8.5") sheet. Meters N 0 20 40 80 120 Feet 0 50 100 200 300 Map projection: Web Mercator Career coordinates: WGS94 Edge tics: UTM Zone 13N WGS84 USDA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 492840 492870 492900 492930 3 40` 37 N omo O n n O ti pn 01 40' 34' 1' N 12/9/2013 Page 1 of 4 Hydrologic Soil Group—Larimer County Area, Colorado (CSU Aggie Village North) MAP LEGEND MAP INFORMATION Area of Interest (AOI) ■ C The soil surveys that comprise your AOI were mapped at 1:24,000. Area of Interest (AOI) ■ C/D Warning: Soil Map may not be valid at this scale. Soils Soil Rating Polygons ■ D Enlargement of maps beyond the scale of mapping can cause A 0 Not rated or not available misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting A/D Water Features soils that could have been shown at a more detailed scale. Streams and Canals 0 B Transportation Please rely on the bar scale on each ma sheet for ma Y P P 0 B/D +.FF Rails measurements. 0 C Interstate Highways Source of Map: Natural Resources Conservation Service 0 C/D Web Soil Survey URL: http://websoilsurvey.nres.usda.gov RV-*.# US Routes Coordinate System: Web Mercator (EPSG:3857) 0 D Major Roads Maps from the Web Soil Survey are based on the Web Mercator 0 Not rated or not available Local Roads projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Soil Rating Lines Background Albers equal-area conic projection, should be used if more accurate AM Aerial Photography calculations of distance or area are required. ^� A/D This product is generated from the USDA-NRCS certified data as of ti B the version date(s) listed below. ,y B/D Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 7, May 1, 2009 .v C Soil map units are labeled (as space allows)for map scales 1:50,000 .v C/D or larger. ^" D Date(s) aerial images were photographed: Apr 22, 2011—Nov 18, 0 0 Not rated or not available 2011 Soil Rating Points The orthophoto or other base map on which the soil lines were ■ A compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting ■ A/D of map unit boundaries may be evident. ■ B ■ B/D USDA Natural Resources Web Soil Survey 12/9/2013 Conservation Service National Cooperative Soil Survey Page 2 of 4 Hydrologic Soil Group—Larimer County Area, Colorado CSU Aggie Village North Hydrologic Soil Group Hydrologic Soil Group— Summary by Map Unit — Larimer County Area, Colorado (CO644) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 3 Altvan-Satanta loams, 0 to 3 percent slopes B 8.9 100.0% Totals for Area of Interest 8.9 100.0% Description tHydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the ' soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and ' three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. ' Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. ' Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or ' soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is ' for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options ' Aggregation Method: Dominant Condition ' Component Percent Cutoff. None Specified USDA Natural Resources Web Soil Survey 12/9/2013 t;Iii—M Conservation Service National Cooperative Soil Survey Page 3 of 4 Hydrologic Soil Group—Larimer County Area, Colorado CSU Aggie Village North Tie -break Rule: Higher USDA Natural Resources ' � Conservation Service Web Soil Survey National Cooperative Soil Survey 12/912013 Page 4 of 4 44T ,ljsj i aF file i,fill a } o Ic`e . H i!°i IB �� �et 4 i i Ba �� ` � Yi =1 a a�t Elfin LLD w �. aii ➢ .�� } } f �° lE / j� Z �` t a a �� �H ! l S�j �i� 1 �,llj S t �• �' � H I a ,•€� fill����I�3�� �. ���8 �cunjaf➢li s��b �hp�ist �s�i-�•z�� s �!F ��ia� itt` av2a➢�Eaaa �a° eE�2fill! 1liaafpill a , DDa�gl� 1 1 lieaga; �I�$j➢; Jill! a IN Ill tb� V it E ��aa ieit�n�s $Ee �B $ ➢ gg ns a gg� I am ll a Ho c' is 8_n �6 nlei P ➢ ➢ 1 g a 1 1 r1a�6 1 �� 11 if a �ia ill p l)' }e 1 -1 fill jig i11111i P.i Ila 3 oC $ a m 8 n Jill AA 4-11"Id _ I _.—' i CON. WALK u. WALn •—••• •�• j- �CpJG. WALK ____ IJNC. WALK zv-WIJG 1 wv lb .9n.9.YN CONC. ^_ —' CQ4C CUfl06 CUTTER ____________ �_a •'1. Nn. CV>� GUTTER ___-_--- i{F4T %..-IkT_ S'TREFT ____ ____ __—_-__ ___—_ aAr --.—..--.-.— w.'cm>.,rlw \ ___w\____ HG57 %AAT s'%77GE1- ._'�_____ r'x vwsnv.[ vaY -55 SS — — ss 55 51SS SS 55 S5 5 _ 1 f�.___y rtn lwel sl __—__�____— _ _ __ __ _ _ __`_____ ___ _ 55- --- `— __ _ Q1 ,' my®.—� __— —__ _rc____ —____ �__3L t___--_—____________ �_ —_yam _ _— ____ RZ _ __—___ ___ __ __� 55 SS CFAIEL—, , .� CONC. CIIRH 4 GUtiER _ "CMc CURR h OJ i1ER ..-- I -(YtgP LtURD N GHMR 55 ... \ �\ `•` •H•• un,.. w. •\H\\i\ \H•H\\IHiN\H\\Hi.\\\\\i\•• .,n •H\H v. \ - __w (y wse� xv rvc .. .. C • — � r 7-FIN4 ♦ CCN WALK _ __ .5 J' L9A /hf�L�T _ ^\•♦ I �GR S / GRASS CONO APB a CRA55 Hl ` ^\ GRASS \ ,\ c 6 s VGRAS< I it . • I — -- �v>u1 `ruwt \J NAGGLL IE \i I I w1)n>-z la nve -. I 11\• . I_w —wFM1 5016II •GI'✓11A1 55` \.II III I ;l �E%Iunrl>. 4�2------_—CX ° yewn�—n4tiurui---------- ..-�=ARE___CGRASS n -r,Zp \1//P 1 I l•• iI ]e> SGVILLAE m•wrnaVI �. \ I 1 f--. r......_J r� � r........1 - - - - � III • y o-1 R / i.RA55 CM1 _ • R I e l 1) / 1 ; I \ ♦ I '1 ♦ /m GSA 5016.4 • �1r 1 1' / � 1 1 p I e e II � •'_ I I I • � � �I I I I c°"��/' I 1 I �1�I �� ` • �I1I/' •I � I / i \ : �I1 I�^....•'♦;\\\ i � a-.. 'IcC� I $I •ai'C �i m°w,.v9... _ `' I I I c I I ' �� 1 1. I -.✓ �dg- b.��'� 11 uw. a •° u i j I L v IV w9ao N cDRa, T x4 I� ; I ' �' Ali .,Id«9 ' I .d 9 ..PA-.♦-1 F; a-�•�I \-I 'xa wY� w w... I •°„w(,^^'RI 1 I ..HIT. 11 4-- - � 1-�. I lo..•.. I /' _- e\ow. I I pl I I I � � i"+ \ /� ' 6� I 2.Liswvigz®III 111 j I w' vill �L° ASPHALT (N i �11,i bnl I ; MAS5 1LIP y so16 0 `- \ • LGLII IAA; 1A1..5��.5 1 tiI )?^/..�. i , I III _� II tl Fa I I \ MASS Mf1 1 I 1 / RoIV _ _ • ahs 1 I I l a 1 � uk I I¢ �_ I.�. I � CMrz.yq).9 I dN = Q pyy I I� „v lx x sp' 110 • I / 1 I KNI I ¢ ASPHALT I{J I KNi I i m 1 �iM,ry I l j v l51 •99f1 .N' 9m :GRASS / 5015.0 17, 'I : DECK • I I! I C21x y 1 I I j I �aNw K• NI j r., I �I Icac. .sHEo�oo Al -._.� �.�...�II�-------___' > j r I l f 1 I'I / I II UI i� L— _ — — --I I I I---��.... .r� I______4 m.rn \ / 50t5.2 CITIES M. a wULS� V �• I ms 11 �11 MpLTE Cv£LGSTONE 1 i g I .V I a I I IDw� AI \ I a. OCY .aj1� I II; I ARKING GARAGE I I« I Al ! I K � I I I If AEII ii 1 `��l ESD ASPHALT — /' 5 LI MASS AI V i= I g9 YLL[m Ili w I.9 FF_ gm k Ism I '3 s I 1:9M1I e'aw, 1 5015.0 GRd55 e GRASS \I Y� 1 \\ I s 1 1 v I cm ' I { III II i III .I.1rPx°I:; 7z �•\ fY CONC.11 I_1. ASPHALT / gi ..p.",: III I5014.9 I I ( / y 1( / xral ✓� O� v� I DESIGNED BY: ••. SHE 1 bn - _. I ' ® ' 1 1 / DRAWN BY: INS I/ CHECKED BY: I\_�__ \\_ Y I I \\ I 1 JOB NUMBFA. ID34 DATE: IDE&i3 5014.�'rf. Nli R\\ / `mac\\ w - \\ F '�\ 1 mu. m• —'- _ H, ^ I a �v' ppp _ \ µ\' �•f \ ] xv (xl• 1 b'vn ©JV0.1NC I > I 11 1a�6• � �.4�• \ /�\ \ -__ ____ \\ \\,.:•� I ' xv Rl •»,.r x'R� v vwn ____-___—___-_ — — — — — i z J ••\\•w•=u.w\\•\\....,yH•eHw\\f•.••s•e.eNlfH..•\\• __ •\\H\HHi>H>\\.�.w..\ __ 'Erf !/ �^ 13�/ as •••. ••"®.as— ... - _-__ uH.....w\.y.. i _ _ _ -____ _ ____ __ co u A c _____ CURB CUiIER — — — — ____________—__"`R"! °°°:'"` NE.S'T /'/7l7tpM 7- _f7h4[l ___ ____ __ �I�'!i7 zwois E,77, RU-172 _ ________ ___ _- CL HZ7T % eOVILY'T' R2-1/) ______— __________ ' w �_—______ _______ _________________-_____ _ ___ win I ______—____-___________—_______________ vtro %.T .a Rc4 _____ ----------------------------------_--_------- _____ a ----------------- NR6'b GUTTER — c LLI --- CONE, CURB k - m e: '?DNC .WILL ___ 0 wemii Lu ED ______ °9[ a _ M \i p1D❑ORB k�WiIER wr is mmx ]r+n , _____________________'I=wg+e� { I I 1 I Q w E,? HISTORIC RUNOFF TABLE BASIN DESM PONT AREA (AGES) 2 YR RUNOFF (CPS) 100 IR PEAT! (CFS) HI I 1.52 1.41 5A3 H2 2 291 270 10.39 H3 3 1 4.45 4.12 15.89 H4 4 0.55 0.51 1.9T TOTAL 9.43 R-; 33.68 o 40 0 40 BD SCALE INFEET 5; En = w 0 LEGEND a R\\pll\p\pp\\p\H HISTORIC DRAINAGE BASIN BOUNDARY (MA" BASIN) M ••..•........... HISTORIC DRAINAGE BASIN BOUNDARY (SLID BASIN) CJ �o DIRECTION Of FLOW (HISTORIC) Q BASIN DESIGN POINT = DEVELOPED BASIN DESONATKN SHEET NUMBER A MANAGE BASIN IDENTIFICATION BUBBLE GFIGUA .5 = RUNOFF CCCMCIENT .5 L 1.0 = AREA ACRES RE 1 PROPOSED RUNOFF TABLE BARD DESIGN POINT AREA (AGES) 2 XI RUNOFF (C75) IOD 1B PENT (DPI) Dl 1 1.16 1.74 6.60 D1A IA 0.21 ON 1.99 D18 19 DID 0.25 0.93 D2 2 L22 IN 7.02 D2A 2A 0.10 D22 0.83 D2B 2B 0.15 0.31 1.15 D3 3 1.02 A07 7.75 D15 5 3.43 4.31 16.51 D6 6 1.51 2.9D 13.17 D6A 6A 0.22 Q40 1.50 D6B 6B 032 0.86 315 TOTAL 9.43 VL13 60.5U DESIGNED III DRAWN By-. WJS CHECKED iP _ JOB NULBEN 2M DATE. lmit Q NA NJC H Z W 0 W C1 2 Q � Z Q 0 Ell Z 0 M W � LLJ U 0 5 0 w o w 60 o SCALE INRET W (Y . _ CL U LEGEND Q DEVELOPED DRAINAGE BAR! BOUNDARY (NA.IOR BASIN) ................ DEVELOPED DRAINAGE BASH BOUNDAN7 ($N BARN) U �o DNECTION OF FL0W (HSTOBIC) Q BASIN OLSON POINT A . OEYFIOPED BASIN DESGNATION SHEET NUMBER DRAINAGE BARD [ENi/ICAiIOFJ BU�1E .5 = RUNDEF COEFnMT 5 I 10 = AREA ACRES FIGURE 2 CSU - Aggie Village North Redevelopment SUMMARY Project Number: 2025c Design Engineer: KRB Date: 7/14/2014 DRAINAGE SUMMARY TABLE DESIGN POINT TRIBUTARY SUB -BASIN AREA (acres) CZ C10 C100 Q2 (cfs) Quo (cfs) Q100 (cfs) DRAINAGE STRUCTURE REMARKS 1 Lake St 0.36 0.95 0.95 1.00 0.87 1.49 3.20 Existing inlet at NE corner (Lake and Center) 1 D1 1.16 0.67 0.67 0.73 1.74 2.97 6.60 Existing inlet at NE corner (Lake and Center) 1A D1A 0.21 0.95 0.95 1.00 0.54 0.93 1.99 Hard piped to manhole 1B D1B 0.10 0.95 0.95 1.00 0.25 0.43 0.93 Hard piped to manhole 2 D2 1.22 0.75 0.75 0.81 1.88 3.21 7.02 Pond 2 Outlet Structure 2A D2A 0.10 0.80 0.80 0.85 0.22 0.38 0.83 Hard piped to manhole 2B D26 0.15 0.76 0.76 0.81 0.31 0.52 1.15 Pond 2 Outlet Structure 3 D3 1.02 0.73 0.73 0.79 2.07 3.53 7.75 Pond 1 Outlet Structure 5 D4/5 3.43 0.60 0.60 0.66 4.31 7.36 16.51 Pond 3 Outlet Structure 6-1 D6-1 0.53 0.91 0.91 0.96 1.34 2.29 4.94 West PL Inlet 1 6-2 D6-2 0.26 0.87 0.87 0.93 0.64 1.10 2.38 West PL Inlet 2 6-3 D6-3 0.26 0.90 0.90 0.95 0.00 1.11 2.39 West PL Inlet 3 6-4 D6-4 0.46 0.74 0.74 0.79 0.92 1.58 3.46 Pond 4 Outlet Structure 6A D6A 0.22 0.66 0.66 0.72 0.40 0.68 1.50 Hard piped to manhole 6B D613 0.32 0.95 0.95 1.00 0.86 1.46 3.15 Hard piped to manhole Developed 9.43 0.68 0.68 0.73 16.13 27.54 60.58 Historic 9.43 0.55 0.55 0.60 8.74 14.92 33.68 Page 1 of 1 2025c Rational -CoFC Runoff Coef 2014-07-14.xlsx - Summary JVA, Inc. JVA Incorporated Job Name: CSU Aggie Village North 25 Old Town Square Job Number: 2025c Fort Collins, CO 80524 Date: 9/19/14 CONSULTING ENGINE-Ph:970.225.9099 Fax: 970.225.6923 By: KRB CSU Aggie Village North ' Detention Pond Volume Calculations: FAA Procedure Based on FAA Procedure. per Federal Aviation Agency "Airport Drainage" Manual ' Drainage Basin Historic vs. Developed Design Storm 100 year Composite "C" Factor 0.15 Change in "C" for historic vs. developed 100yr ' Basin Size 9.43 ac "C" historic = 0.60 "C" Developed = 0.75 Release Rate Calculations Allowable Release Rate for Site 0.00 cfs Less Undetained Offsite Flows 0.00 cfs Allowable Release Rate for Pond 0.00 cfs Rainfall Intensity Calculations Point Hour Rainfall (P,) Rainfall Intensity: 2.86 1 = (28.5 P1) / ((10 + TC) 0.786) Volume Calculations Inflow Volume = C ' I ' A ' time (sec) Outflow Volume = Allowable Release Rate ' time (sec) Storage Volume = Inflow Volume - Outflow Volume Detention Stoage Calculations Time t (min) Time t (sec) Intensity I (in/hr) Inflow Vin (ft) Outflow Vout (ft) Storage Vstor (ft) 5.0 300 9.70 4,116 0 4,116 10.0 600 7.74 6,567 0 6,567 15.0 900 6.49 8,266 0 8,266 20.0 1,200 5.63 9,549 0 9,549 25.0 1,500 4.98 10,575 0 10,575 30.0 1,800 4.49 11,425 0 11,425 35.0 1 2,100 4.09 1 12,151 0 12,151 40.0 2,400 3.77 12,783 0 12,783 45.0 2,700 3.49 13,343 0 13,343 50.0 3,000 3.26 13,845 0 13,845 55.0 3,300 3.06 14,301 0 14,301 60.0 3,600 2.89 14,719 0 14,719 Maximum Volume (ft') 14,719 Total Detention Required (Ac-Ft) 0.338 17662.433 FAA-100-yr 2025c - FAA Detention Storage.xlsx Page 1 of 1 Aggie Village North Critical Pond Elevations - Pond 1 Design Engineer: K. Brigman Design Firm: JVA, Inc. Project Number: 2025c Date: July 14, 2014 DESIGN CRITERIA Urban Storm Drainage Criteria Manual, Urban Drainage and Flood Control District, June 2001 Stage Storage Volume (pond volume calculated using the prismoidal formula): V _ (Al + A, + Ai A, )Deprh 3 CONTOUR (FT) AREA (FT') AREA (ACRE) VOLUME (ACRE -FT) DEPTH (FT) CUMULATIVE VOLUME (ACRE -FT) CF 5004.15 0.000 0.000 0.00 0.000 0.00 5005.0 926.00 0.021 0.006 0.85 0.006 262.37 5006.0 1,621,00 0.037 0.029 1.85 0.035 1519.76 5007.0 2,492.00 0-057 0.047 2.85 0.082 3560.71 5008.0 4,422.00 0.102 0.078 3.85 0.160 6971.90 0.00 1 0.000 1 -169.463 -5004.15 1 -169.303 0.00 1 0.000 1 0.000 -5004.15 1 -169.303 0.00 1 0.000 1 0,000 -5004,15 1 -169.303 Required Water Quality Capture Volume = Acre -Ft Interpolates to an Elev. of ft 100-yr Detention Volume = 0.121 Acre -Ft Interpolates to an Elev. of 5007.50 ft DETENTION POND VOLUME VERSUS ELEVATION 5008.50 5008.00 r 5007.50 a 5007.00 z 5006.50 - O 5006.00 � soossa W 5oos.00 W 5004.50 5004.00 5003.50 0.0 0.1 0.1 0.2 DETENTION POND VOLUME (AC -FT) 0.2 2025c Pond 1 Calcs.xls - Pond Stage Storage #1 JVA, Inc. Aggie Village North Water Quality Pond and Outlet Sizing (Per USDCM) Design Engineer: K. Brigman Design Firm: JVA, Inc. Project Number: 2025c Date: September 22, 2014 DESIGN CRITERIA: Urban Storm Drainage Criteria Manual (USDCM) Volume III, Urban Drainage and Flood Control District, June 2001 REQUIRED WATER QUALITY CAPTURE VOLUME (WQCV): Tributary Area, A 1.D2 acres Composite. Imperviousness, I WQCV (watershed inches) 0.251 inches 40-Hour Drain Time (Fig SO-2) WQCV l Required WQCV Volume = * Area * 1.2 0.026 acre-feet Including 20% for Sedimentation 12 J WATER QUALITY OUTLET SIZING (Per USDCM, Volume 3): Design Water Quality Depth, Dwo 0.50 ft Determine K., K,o = 0.013Dwo2 + 0.22Dwo - 0.10 0.013 Maximum Area per Row, a a = WQCV / K,o 1.931 square inches Circular Perforation Sizing Number of Rows, nr 16 rows Number of Columns, nc (See Table 6a-1 for Max.) columns Choose Hole Diameter 3/4 inches Use USDCM Volume 3, Figure 5 0.750 inches Total Area per Row, ,4° 0.44 square inches Total Outlet Area, A°, 7.07 square inches Does design work? Yes Minimum Steel Plate Thickness 1/4 inch Rectangular Perforation Sizing (Not Used) Number of Rows, nr 1 rows Choose Rectangular Hole Width (w/ 2" Height) Dinches Use USDCM Volume 3, Figure 5 0.000 inches Total Outlet Area. A°, 0.00 square inches Does design work? Yes Minimum Steel Plate Thickness 114 inch 2025c Pond 1 Calcs.xls - WQCV & Outlet Structure Page 1 of 2 Jim Sell Design, Inc. Aggie Village North Circular Orifice Plate Sizing - Pond 1 Design Engineer: K. Brigman Design Firm: JVA, Inc. Project Number: 2025c Date: January 23, 2015 Orifice Equation Q=CA„ 2g h=>A„= Q C 2gOh n„ = 576 A„ n Calculations 100-yr Orifice Sizing Knowns: where: C = Orifice Discharge Coefficient A, = Orifice Area (ft) g = Gravity (32.2 ft/s2) oh = Difference in Elevation Head (ft) Do = Orifice Diameter (in) 100-yr Release Rate 1.05 cfs 100-yr WSEL 5007.50 ft Pond Outlet Invert 5002.21 ft Discharge Coefficient 0.65 Tailwater Elevation Oft Orifice Diameter 4 in Orifice Area 0.087 ft` Centroid Elevation 5002.38 ft Actual Release Rate 1.03 cfs 100-yr Orifice Rating Table Elevation A Discharge cfs Pond Volume ac-ft 5004.15 0.61 0.000 5005.00 0.74 0.006 5006.00 0.87 0.035 5007.00 0.98 0.082 5008.00 1.08 0.160 0.00 0.00 -169.303 0.00 0.00 -169.303 2025c Pond 1 Calcs.xls - Outlet Orifice Plate Sizing Page 1 of 1 Jim Sell Design, Inc. Aggie Village North Critical Pond Elevations - Pond 2 Design Engineer: K. Brigman Design Firm: JVA, Inc. Project Number: 2025c Date: September 15, 2014 DESIGN CRITERIA Urban Storm Drainage Criteria Manual, Urban Drainage and Flood Control District, June 2001 Stage Storage Volume (pond volume calculated using the prismoidal formula): V _ (Al + A, + V AT, A, )Depth 3 CONTOUR (FT) AREA (FT') AREA (ACRE) VOLUME (ACRE -FT) DEPTH (FT) CUMULATIVE VOLUME (ACRE -FT) CF 5005.11 0.000 0.000 0.00 0.000 0.00 5006.0 378.00 0.009 0.003 0.89 0,003 112.14 5007.0 2,511.00 0.058 0.030 1.89 0,032 1399.89 5008.0 5,104,00 0.117 0.08E 2.89 0.118 5131.54 0.00 0.000 -195,599 -5005.11 -195.481 -8515145.79 0.00 0.000 0 000 -5005.11 -195.481 0.00 0.000 0.000 -5005.11 1 -195 481 0.00 0.000 0.000 -5005.111 -195.481 Required Water Quality Capture Volume = Acre -Ft Interpolates to an Elev. of ft Required 100-yr Detention Volume (including WQCV) = 0.075 Acre -Ft Interpolates to an Elev. of 5007.50 ft 5008.50 5008.00 LL 5007.50 Z 5007.00 g 5006.50 j 5006.00 w 5005.50 5005.00 5004.50 0.0 DETENTION POND VOLUME VERSUS ELEVATION 0.0 0.0 0.1 0.1 0.1 0.1 0.1 DETENTION POND VOLUME (AC -FT) 2025c Pond 2 Calcs.xls - Pond Stage Storage #1 JVA, Inc. I 1 II Aggie Village North Water Quality Pond and Outlet Sizing (Per USDCM) Design Engineer: K. Brigman Design Firm: JVA, Inc. Project Number: 2025c Date: September 22, 2014 DESIGN CRITERIA: Urban Storm Drainage Criteria Manual (USDCM) Volume III, Urban Drainage and Flood Control District, June 2001 REQUIRED WATER QUALITY CAPTURE VOLUME (WQCV): Tributary Area, A 1.22 acres Composite. Imperviousness, I WQCV (watershed inches) ( 0.269 inches 40-Hour Drain Time (Fig SQ-2) Required WQCV Volume = WQCV .4 * 1.2 0.033 acre-feet Including 20% for Sedimentation 1 12 WATER QUALITY OUTLET SIZING (Per USDCM, Volume 3): Design Water Quality Depth, Dwo 1.00 ft Determine K,, K,o = 0.013Dwo2 + 0.22DWo - 0.10 Maximum Area per Row, a a = WQCV / K,0 Circular Perforation Sizing Number of Rows, nr Number of Columns, nc (See Table 6a-1 for Max.) Choose Hole Diameter Use USDCM Volume 3, Figure 5 Total Area per Row, A° Total Outlet Area, A°, ' Does design work? Minimum Steel Plate Thickness Rectangular Perforation Sizing (Not Used) Number of Rows, nr Choose Rectangular Hole Width (w/ 2" Height) Use USDCM Volume 3, Figure 5 Total Outlet Area, A°, Does design work? Minimum Steel Plate Thickness 0.133 0.247 square inches 4 rows Ocolumns 1/2 inches 0.500 inches 0.20 square inches 0.79 square inches Yes 1/4 inch 2 rows 0 inches 0.000 inches 0.00 square inches Yes 1/4 inch 2025c Pond 2 Calcs.xls - WQCV & Outlet Structure Page 1 of 2 Jim Sell Design, Inc. Aggie Village North Circular Orifice Plate Sizing - Pond 2 Design Engineer: K. Brigman Design Firm: JVA, Inc. Project Number: 2025c Date: January 23, 2015 Orifice Equation Q = C.4„ 2g4 => A„ = Q C 2gOh _ 576A„ D„ Calculations 100-yr Orifice Sizing Knowns: where: C = Orifice Discharge Coefficient A o = Orifice Area (e) g = Gravity (32.2 ft/s2) oh = Difference in Elevation Head (ft) Do = Orifice Diameter (in) 100-yr Release Rate 3.1 cfs 100-yr WSEL 5007.50 ft Pond Outlet Invert 5001.00 ft Discharge Coefficient 0.65 Tailwater Elevation Oft Orifice Diameter 610116 in Orifice Area 0.238 ft` Centroid Elevation 5001.28 ft Actual Release Rate 3.09 cfs 100-yr Orifice Rating Table Elevation ft Discharge cfs Pond Volume ac-ft 5005.11 2.43 0.000 5006.00 2.69 0.003 5007.00 2.97 0.032 5008.00 3.21 0.118 0.00 0.00 -195.481 0.00 0.00 -195.481 0.00 0.00 -195.481 2025c Pond 2 Calcs.xls - Outlet Orifice Plate Sizing Page 1 of 1 Jim Sell Design, Inc. Aggie Village North Critical Pond Elevations - Pond 3 Design Engineer: K. Brigman Design Firm: JVA, Inc. Project Number: 2104c Date: September 15, 2014 DESIGN CRITERIA Urban Storm Drainage Criteria Manual, Urban Drainage and Flood Control District, June 2001 Stage Storage Volume (pond volume calculated using the prismoidal formula): (Al + A, + ,4, A, )Depth 3 CONTOUR (l AREA (FT') AREA (ACRE) (VOLUME ACRE -FT) DEPTH (FT) CUMULATIVEVOLUME ) CF 5002,85 0.00 0.000 0,000 0.00 0.000 0.00 5003.0 863,00 0.020 0.001 0.15 0.001 43.15 5004.0 2,417,00 0.055 0,036 1.15 0,037 1617.90 5005.0 4,127.00 0.095 0.074 2.15 0.111 4852.01 5006.0 7,907.00 0.182 0.136 3.15 0.247 10767.49 5007.0 0.00 0.000 0.061 1 4.15 0.308 5008.0 0.00 0.000 0.000 5.15 0,308 5009.0 0,00 0.000 0.000 6.15 0.308 Required Water Quality Capture Volume = Acre -Ft Interpolates to an Elevof ft Required 100-yr Detention Volume (including WQCV) = 0.179 Acre -Ft Interpolates to an Elev. of 5005.50 ft DETENTION POND VOLUME VERSUS ELEVATION 5010.00 - 5009.00 LL 5008.00 - Z 5007.00 O 5006.00 - - - j 5005.00 Z 5004.00 - - - W 5003.00 5002.00 0.0 0.1 0.1 0.2 0.2 0.3 0.3 0.4 DETENTION POND VOLUME (Al 2025c Pond 3 Calcs.xls - Pond Stage Storage #1 JVA, Inc. Aggie Village North Water Quality Pond and Outlet Sizing (Per USDCM) Design Engineer: K. Brigman Design Firm: JVA, Inc. Project Number: 2104c Date: September 22, 2014 DESIGN CRITERIA: Urban Storm Drainage Criteria Manual (USDCM) Volume 111, Urban Drainage and Flood Control District, June 2001 REQUIRED WATER QUALITY CAPTURE VOLUME (WQCV): Tributary Area, A 3.43 acres Composite. Imperviousness, I WQCV (watershed inches) 0.200 inches 40-Hour Drain Time (Fig SQ-2) WQCV �* Aiea * 1.2 Required WQCV Volume= 0.069 acre-feet Including 20% for Sedimentation ' l 12 WATER QUALITY OUTLET SIZING (Per USDCM, Volume 3): ' Design Water Quality Depth, DN,c 1.75 ft Determine K., K,o = 0.013Dwo2 + 0.22Dwo - 0.10 0.325 ' Maximum Area per Row, a a = WQCV / K,, 0.212 square inches Circular Perforation Sizing Number of Rows, nr 4 rows ' Number of Columns, nc (See Table 6a-1 for Max.) columns Choose Hole Diameter 1/2 inches ' Use USDCM Volume 3, Figure 5 Total Area Row, A° 0.500 inches per 0.20 square inches Total Outlet Area, A°, 0.79 square inches ' Does design work? Yes Minimum Steel Plate Thickness IA inch Rectangular Perforation Sizing (Not Used) Number of Rows, nr Choose Rectangular Hole Width (w/ 2" Height) Use USDCM Volume 3, Figure 5 Total Outlet Area, A°, Does design work? Minimum Steel Plate Thickness 3 rows 0 inches 0.000 inches 0.00 square inches Yes 1/4 inch 2025c Pond 3 Calcs.xls - WQCV & Outlet Structure Page 1 of 2 Jim Sell Design, Inc. Aggie Village North Circular Orifice Plate Sizing - Pond 3 Design Engineer: K. Brigman Design Firm: JVA, Inc. Project Number: 2104c Date: January 23, 2015 Orifice Equation Q = CA„ 2g�h A„ = Q C 2gAh D _ 576A„ Calculations 100-yr Orifice Sizing Knowns: where: C = Orifice Discharge Coefficient A o = Orifice Area (ft) g = Gravity (32.2 ft/s2) Ah = Difference in Elevation Head (ft) Do = Orifice Diameter (in) 100-yr Release Rate 7.3 cfs 100-yr WSEL 5005.50 ft Pond Outlet Invert 4997.82 ft Discharge Coefficient 0.65 Tailwater Elevation Oft Orifice Diameter 912116 in Orifice Area 0.518 W Centroid Elevation 4998.23 ft Actual Release Rate 7.29 cfs 100-yr Orifice Rating Table Elevation ft Discharge cfs Pond Volume ac-ft 5002.85 5.82 0.000 5003.00 5.91 0.002 5004.00 6.50 0.054 5005.00 7.04 0.147 5006.00 7.54 0.301 5007.00 8.01 0.369 5008.00 8.46 0.369 2025c Pond 3 Calcs_Alternate.xls - Outlet Orifice Plate Stagg 1 of 1 Jim Sell Design, Inc. Aggie Village North Critical Pond Elevations - Pond 4 Design Engineer: K. Brigman Design Firm: JVA, Inc. Project Number: 2025c Date: September 15. 2014 DESIGN CRITERIA Urban Storm Drainage Criteria Manual, Urban Drainage and Flood Control District, June 2001 Stage Storage Volume (pond volume calculated using the prismoidal formula): (Al + A, + A, A, Depth 3 CONTOUR (FT) AREA (FT') AREA (ACRE) (VOLUME) ACRE -FT DEPTH (FT) CUMULATIVE VOLUME ACRE -FT ) CF 5006.75 0.000 0.000 0.00 0.000 0.00 5007.0 47.00 0.001 0.000 0.25 0.000 3.92 5008.0 325.00 0.007 0.004 1.25 0.004 169.11 5009.0 803.00 0.018 0.013 2.25 0.016 715.40 5010.0 6,580.00 0.151 0.074 3.25 0.091 3942.61 0.00 1 0.000 1 -252.264 -5006,75 -252.173 0.00 0.000 0.000 -5006,75 -252. 173 0.00 0.000 0.000 -5006.75 -252,173 Required Water Quality Capture Volume = Acre -Ft Interpolates to an Elev. of ft Required 100-yr Detention Volume (including WQCV) _ 0.040 Acre -Ft Interpolates to an Elev. of 5009.32 ft 5010.50 5010.00 LL 5009.50 Z 5009.00 g 5008.50 j 5008.00 5007.50 ul 5007.00 5006.50 0.0 DETENTION POND VOLUME VERSUS ELEVATION 0.0 0.0 0.1 0.1 0.1 DETENTION POND VOLUME (AC -FT) 2025c Pond 4 Calcs.xls - Pond Stage Storage #1 JVA, Inc. Aggie Village North Water Quality Pond and Outlet Sizing (Per USDCM) Design Engineer: K. Brigman Design Firm: JVA, Inc. Project Number: 2025c Date: September 22, 2014 DESIGN CRITERIA: Urban Storm Drainage Criteria Manual (USDCM) Volume III, Urban Drainage and Flood Control District, June 2001 REQUIRED WATER QUALITY CAPTURE VOLUME (WQCV): Tributary Area, A 1.65 acres Composite. Imperviousness, I WQCV (watershed inches) 0.363 inches 40-Hour Drain Time (Fig SQ-2) f6QC6 Required WQCV [ blunae = "' Area * 1.2 0.060 acre-feet Including 20%for Sedimentation 1? WATER QUALITY OUTLET SIZING (Per USDCM, Volume 3): Design Water Quality Depth, Dwo 1.75 ft Determine K<0 Ke0 = 0.013Dwo2 + 0.22Dwo - 0.10 0.325 Maximum Area per Row, a a = WQCV / Ka0 0.164 square inches Circular Perforation Sizing Number of Rows, nr 4 rows Number of Columns, nc (See Table 6a-1 for Max.) 0columns Choose Hole Diameter 3!6 inches Use USDCM Volume 3, Figure 5 0.375 inches Total Area per Row, A° 0.11 square inches Total Outlet Area, AO1 0.44 square inches Does design work? Yes Minimum Steel Plate Thickness 1/4 inch Rectangular Perforation Sizing (Not Used) Number of Rows, nr 3 rows Choose Rectangular Hole Width (w/ 2" Height) Dinches Use USDCM Volume 3, Figure 5 0.000 inches Total Outlet Area, A°, 0.00 square inches Does design work? Yes Minimum Steel Plate Thickness 1/4 inch 2025c Pond 4 Calcs.xls - WQCV & Outlet Structure Page 1 of 2 Jim Sell Design, Inc. Aggie Village North Circular Orifice Plate Sizing - Pond 4 Design Engineer: K. Brigman Design Firm: JVA, Inc. Project Number: 2025c Date: January 23, 2015 Orifice Equation Q = C.4„ 2gAh =:, A„ = Q C 2gAh n _ s76A„ >t Calculations 100-yr Orifice Sizing Knowns: where: C = Orifice Discharge Coefficient A, = Orifice Area (ff ) g = Gravity (32.2 ft/sz) Ah = Difference in Elevation Head (ft) Do = Orifice Diameter (in) 100-yr Release Rate 10.2 cfs 100-yr WSEL 5009.35 ft Pond Outlet Invert 5002.50 ft Discharge Coefficient 0.65 Tailwater Elevation Oft Orifice Diameter 11 15/16 in Orifice Area 0.777 ft` Centroid Elevation 5003.00 ft Actual Release Rate 10.22 cfs 100-yr Orifice Rating Table use 12" Elevation ft Discharge cfs Pond Volume ac-ft 5006.75 7.85 0.000 5007.00 8.11 0.000 5008.00 9.07 0.004 5009.00 9.93 0.017 5010.00 10.73 0.051 0.00 0.00 -87.896 0.00 0.00 -87.896 2025c Pond 4 Calcs.xls - Outlet Orifice Plate Sizing Page 1 of 1 Jim Sell Design, Inc. 3n0 IS'LOOS'13'AUI Z9'000S "13 WIN EL :Ul LSL"ZZ+LL g1S C0 �� o o0 0 0 ul ZL1009 *13'^UI o 0 0 0 1nOZL'W09'13'^UI o `ro 917 N Zl :Ul uI 3n0 0 3 L :Ul ul 0 o 3n0 03 :ul UI 0 rn 3n0 L 6 :Ul 0 00 � I 3n0 S :u� o r O L O U ul m m 1n0 6 L 0 0 ul 1n0 l S :ul a O Q UI 3nO 691966V AU 0 4 :ul 0 Cl) UI g 3�0 S W S" o N E .Ul J o C7 O = UI 0, 1nO 6 0 o m 0 C. 0 0 6 Q) 0 � uoi voi a, a) W i LO s m N 41 C m O m f E Z Line Capacity Invert Invert Known Line Line Line n-value Flow No. Full Dn Up Q Length Size Slope Pipe Rate Ids) (ft) (ft) (cfs) (ft) (in) (°/a) (cfs) 1 83.82 4993.20 4993.69 0.00 70.556 42 0.69 0.013 65.00 2 14.15 5002.45 5002,50 10.20 12.729 24 0.39 0013 10.20 Pond 4 outfall to existing 42" storm main 3 47.04 4994.20 4995.15 0.00 190893 36 0.50 0.013 25.32 Storm line outfall to existing 42" storm main 4 28.94 4995.65 499669 000 208,835 30 0.50 0 013 1909. 5 16.11 4997.19 4997.39 0.00 39.480 24 0.51 0.013 19.11 6 7.37 5002.00 5002.21 1.05 42.578 18 0.49 0.013 1.05 7 16.01 4997.49 4997,82 0.00 65.752 24 0.50 0.013 18.09 8 16.02 4997.92 4999.31 0.00 277220 24 050 0.013 18.23 9 15.96 4999.41 4999.73 0.00 64.203 24 0.50 0.013 13.43 10 15.94 4999.83 5000.33 0.00 100.673 24 0.50 0.013 12.66 11 7.45 5000.43 5001.12 0.00 137.243 18 0.50 0.013 11.76 12 1.21 5001.62 5001.72 0.00 20.829 8 0.48 0.009 9.80 13 1.25 5001.72 5001.81 9.80 17.634 8 0.51 0.009 9.80 14 16.04 5000.94 5001.00 3.10 11.948 24 0.50 0.013 3.10 15 16.02 4997.15 4997.58 0.00 85.760 24 0.50 0.013 5.20 16 15.84 4997,68 499782 5.20 28.465 24 0.49 0.013 5.20 17 84.10 4993.69 4994.28 29.65 84.420 42 0.70 0.013 29.65 1