Loading...
HomeMy WebLinkAbout2001-10-31 Drainage Calculations Revised A � ____. 7 CI Suite n Salem,un New,q-��i�r�psh r 07 MIHF Design iunsult int Ilium . TEL ( 0 ) 3-0 ut -FAX,i 3l 3" 7 ; M .I"w North Andover,Plmuaiag D pnaitar e nt Date: 2,9 August 20,02 From Karl Dubaay 1270 Salern, Turnpike 'treet. Seven Hills Foundation Approved Site:Nan Per my discussion this week with. Clay Mitchell, Esq., the departments Planrnrnirn t:aransultaart; attached aresets of site plansand o:ri irnal rnnypaars for the above-referenced tua'raj sit,, We respectfully request that the plaanvsoamylaars be signed by the Plarming Boaaxd. s you know, this pnrraj u t was approved by both the Planning a ark (Special l Perrnnit Site Plan—l" o is pup" De siarru attached) and the Conservation Cbun tnis ion (NO I ( rd r• c,,)f Conditions aatpaaclnu d), but subsequently appealed, by an. abutter R G. Faarn a , and just recently'this appeal aall was dismissed, (Stipulation oll Dismissal attached). WC a rrnuler•stanrnd that Severn Hills Foundation arid thucir- contractors have been wanrU n direUlyr with the Plarnrnirn�g Department, Co ns; rvantiarrn tJomt7unrssion, and the State regarding any other administrative and field work required in preparation lior commencement ofconstruction. It has been, a.pleaasore working with burn Town on this project, ff y oar have any, questions, tnl ase call 111e,annnytirn'e' DRAINAGE CALCULATIONS Tax Map 107A, Lot 148 N. Andover, Massachusetts PREPARED FOR.- SEVEN HILLS FOUNDATION 81 lope Ave. Worcester, DNA 01603 ���k OF K CL June 22, 2001 IL Revised: October 11, 001 Na 41 H Design Consultants, Inc. ENGIN�ERS • PLANNERS ■ SURVEYOR 103 Stiles Road • Suite one • Salem, NH 03079 TEL (603) 893-07 0 FAX ( 03) 88 -0733 T' Project# 117201 DiRAINAGE CALCULATIONS Tax Map 17 ►., Lot 14 N. Andover, Massachusetts PREPARED VOR: SEVEN HILLS FOUNDATION 1 Mope .Ave. Worcester, MA 01603 June 22, 2001 Revised-, October 11, 2001 milF Project 4 117201 TABLE OF CONTENTS: i Report Cover II Table of Contents Ili Project Description: Existhig Conditions Proposed Work Enviro mnjte jn t a l Impacts Gp,ration & Maintemance Pied Iv Drainage System Design Drainage Sunni r 1 Soil E,valuator laon-ns II Stormwater anagerueat Form& Calcuiations liI Drainage Calculations - Hydrocad Pfffitouts (2, 10 & 100-year Storm Events) IX Maps: Locos Map F.M.M. US Map scs Soils Map Pre &Post-development Drainage Maps PROJECT DESCRIPTION Location: The property consists of 2.2 acres located on the easterly side of Rt. 11.4, approximately 1,000 feet south of the intersection with Juhnson Street. Topography. 'Clue topography of the site consists of relatively flat area sloping at approx. 9% toward wetlands sarromiding the c tral poTtlon of the lot. This office surveyed the topography by an instrument survey. See attached plan for details. Vegetation. The, vegetation consists of mixed.dceiduocL.s and evergrecn trees covering most of the site. portion of the site is developed with a sewer pump station. This area- at the Brent of the property on Rt. 1 l 4 is cl=ed, partially paved or graveled or covered by the building, Flood Plain and Wetlands- No portion of tbo site is within the 100 year tloodplain according to the blood Tusurance Rate Map (included herein). The site has been inspected for wetlands by a wetland scientist. The boundary was flagged and survey located by this office. o rare speoics or habitat areas are known to be onsite. DrainagelSolls: The drainage pattern o-n site consists of flow hi two basic directions: the wetland and the site boundavy to the east. There are no a ist4ig drainage facilities on site. All flow males its way uncomolled toward the wetland at the rear of the property or toward the eastern boundary. I'lle soils on site are mapped by SCS as being Pipestone and Woodbridge. However, on site soil testing bas shown that the area of proposed development was filled (approximately 30 years ago) with poorly drakting material. The drainage characUristics o C the fsil would be categorized as 'U sufl. Utit1tlCS: Currtmtly, there is an existing sewer purnp station on site. And municipal water, telephone and electricity are avnilable ftom Rt. 114. PROPOSED WORK ctler 11 , the pro�cet proposes the eonstf-uction of an office building, water and cleddr- connections in RI. 114, parking and drainage facilities and necessary grading. The office would be accessed by way oI'a drive%YaY esttrauCe from Rt. 114. Topography/Grading, The proposed topography ofthe site would remain as close to existiTig grades as possible. The proposed building would be set approximately 7 leet above existing grade. And the parking 4rea would blend to the existing grade at the entrance to lit. 114. The grading for the building would consist of fill off'approximatcly 5 feet. See attached plan For details. Drainage; The proposed drainage ystctn woild be a closed system, which would provide storra ater treatment for both quality and quantity of runof. Specifically, a catch basin would collect and pipe runoff to a "Downstream DefendeT" s edinellt treatrneo€ unit, ROM which the treated water - as well as roofrur;off- would enter an underground detention facility, which would then disc hargc d rotigh a " pipe toward the wctland. As shown ill the attached calculations, the drainage design would eontrtrl the rate of runoff tct and the wetland, as we.0 as providing more than 800/*TSS removal. The system was designed to work for all storms ap to and including the 100-year event. See the attached Drainage alculations and snaps for farther di-Mails. Utilities: Purposed utilities on this site include a water lute in Route 114, underground elcetric. and telephone litres, aircl a sewer connection at the Pump station. T.nvir oiamentsa l Impacts: As sbown in the drainage siarnmary included herein, drainage acid Tanoffcharactcristics ► ould be controlled in conformance with D.E.P.'s Stermwaler Management Handbook and local regulations ;,preventing possible damage to abutting property or natural features- in the area. The drainage system was designed for severe stoms (up to 100-year•). According to SCS, the soil onsite consists of Pipcstorte and WoGdhridge, which - have been filled-over. Tlme rare, on site test holes were performed to ccr1fim soil type, depth and suitability. And based on this testing, the soils are almost R-apvrvious, with a percolation rate, of>60 NTL Ilierefore, the desi&m"has used a hydrologic group designation vf'D' 14r &ainagc calculations. This produces conservative results. Se.wago disposal is to be a sewer connection to the existing sewer at the pump Station in oonforn3wice with Title 5 and local Board cal'Health Regulations. Thus, there should be no negative environmental Tr act assuciaied with septic systerns. In order to safeguard against oil or gas hitruduction into the drainage system, stormwatvr rturoll'lkom the parking area would be cullected into catch basins with oil hoods and sleep sumps (see Site Plan Details). Such pretreatmerA of storm Ater reduces both suspended solids and oils in the drainage system and is reccirririeoded by DFP's yStorm writer Manage mew Handbook, All ruaioff from the parking area would be muted through a "Downstream Defender" treatment emit, by R.I.L. Technologies. Such units Provide> 80% TSS rcinoval, in c,onforrtiauice with Storr water Polley Standards, and have &eon approved for ose by the Town of North Andover at other locations. It is the designer's belief that such treatment is more than adequate for the site, and would mcct the intent of the Wetland Protection Act. Another safeguard agai3st future intrusion of contaminants into the groundwater is the implementation of an operation & Maintenance Plan, which.provides further'1'SS removal and assures proper function of all drainage components. Rulher safeguards am, proposed on the Site Purr to prevent erosion Include a line of sill feiacing and hay bales. if ad the proposed erosion control devises and procedures are adhered to,then there should be rnininmi or no duniaip to t ighboring properties or the wetland from work on this site. perationf ainten nee_flan The BNVs associated with this project wig he owned by Seven Frills Foundation. Any accumulated sediment should be removed from catch basins, dTy wells and all drainage pipe inlets aixi outlets as soon as possible alter heavy precipitation and every spring. o!js#ructiotY Phase 1 The contractor is to install and n mintain drainage. facilities as shown on plan (117 201, by M14F Design Consultants, Inc., dated My,2001, reAsed October, 2001). ) A11 construction of drainage facilities is to be insTected by inspectors from the Tovm o f North Andover and MHF Design Consultants;Ixrc. to verify con Form nce to the design Plan, Post-Development Pie The o ner/mcupam is to be responsible For t intenence of all drainage structures in the project - including roof drains, drain pipes, sedkmt removal and detention systems. The owner is Seven Hills Foundation, who will be resporsible for compliame with the 0 & M Plan. Regular tnainter xce is to include the following: « 'frash removal is to be contracted on a weekly basin. * Sweeping of pang area is to be done every month. No do-icing chemicals are to be ased within [lie 100-foot buffer zone. • Stow is to be stored outside the f 00-foot buffer zone.sueh that rnelt water flow into t e stor water treatni t facilities for T'SS removal. Cleaning of the Detention System every months ate the "Dottsti� Defender" suggested by manufacturer. * Inspection of all drainage pipe t�fot�ticts and Detention ysterr� every tiu�ee tt�antl�s. • Inspection and cleaning of all Catch Basins every three months or after all severe storms. DRAINAGE SYSTEM DRSIG : The drainage s qi.- 3. was designed utilizing both open and closed sysu nis to achieve reduced rates of runoff at (he boundaries of the developed area and would maintain a si nila r draiiiage pattern to N! existing courses. The methodology is S C S TR- 0, Type 11I rain#alls ( , 10 & 100 year events). This is consistent with the tequirements o N he town of I oilb Andover and DEP,s Storrnwater Management guider-ies. All pertinent calculations represented in the following pages were developed utilizing Hydrocad Stormwater Modclft software. Referenecs: I. S'C, - TR55 (Second Ed., 198 ) - for runoff Curve iriunber& 2.. SUS - Rainfall Distribution Maps. The on-site sons consist ofPipestone and Woodbridge series, described by SCS as follows: Pipestene series (SCvS Classification "Be) comists of very deep, suivie hat poorly drained sails that formed in glacial out wash. These soils are on out ash pla h s and tee raicss. Slopes range Ii om 0 to 5 percent. Pipestone soils area associated with Deerfield, Saluamseott, Searboro, Raynliam and Lim soils. They are redden' in the upper part of the subsoil that Deerfield soils, and unlike those sails, have a mottled subsurface layer. ` bey have less silt and clay in the substraxturn than SquainscotI soils. They do not have the histic epipedon that is characteristic of Scarburo soils. They have less silt and more ,,and in the solani than Raynham soils. Unlik Lim soils, they are charactinized by a regular decrease in content of organic carbon with increasing depth and by horizon development. Woodbridge series (SS Ossification ` ") consist of nearly level to steep, deep (5+ feet), moderately well drained soils on druml ns. They formed in compact glacial till. Woodbridge soils haxve friable fine sanely loam or sandy loarn surface soil acid subsoil with moderate permeability over ar fiiim fhe sandy loam or sandy loam substratum at 15 to 38 inches which has slow or very slow pei ab ity. 1 oodbridge soils have a very stony or ext"rMely stony surface e=pt where storms have been removed, and have stones below the surace. They have a perched, seasonal high water table zt 18 to 24 hiches. Major limitations we related to wetness, slaw permeability in the substratum, stoniness and slope. On site soil tests mmlts were utilized for the calculatiom g, in which the design cnginee�r used a hydrologic soil group of°D", to produce conservative results. The site contains resource areas subject to the Wetlands Protection Act. Therefore, thx!project is subject to DEP"s Storm water Management Policy. The drainage system is required to provide 80% TSS removaii, as follows: Stu rinwater Quality Controls: 1. Catch Basins with Oil Hoods and Deep Sumps to capWre, treat and redirccl stormwater toward the proposed rctentiofil cclxarge basin. TSS Removal Mate= 25% 2. "downstream Defender" —which would treat stormwater prior to discbarge to the ddention system. TSS Removal Rate = 80% + andwater Recharge- 1. B au&-,the sons hydrologic category is 'D,' no rechai-ge is required or proposed. tormwater Quantity Coutrols: The Detention System was desigrned such that it wood detain stoi c( , 10 & 100-year), with eontroHed discharge through are outlet pipe at controlled, lower than predevelopment Fates. The ovt-Ta l system thereby uOieves the following- Control o C runoff rates to abutting properties to below ptvdcvelopinent gates. • Water qjiality njainjenance —I'SS removal from stormwater of more than 80%. Storm damage control - by reduced Tunoff rates &ePosion controls. DRAJAGE SUMMARY AH vaiuos sho m are peak rues in.CFS) Lx+tiv ............... ... .... ._. v,....>, ry` ipue ., v:...w Jewry. . ca•x�rn �°�""`��. ;.;;..;; o:a,i,xmav _'..*cam"''. o 6 w« w 6Sm fix¢a ,ry;, 9 J6 •n:'„ ...;":.[', -- ZWO v ° °' M1 'c ' ►�,:" :' °'o-a "c ao... e•.s .�"::.:.:ti`;;,:vyry"-k,.,......�.14; .':v"%';:i�K:.""�::'„'k' nxvx Grate Capacity Check: (100-year Storm) - — Grate Modes Grate Open Space CavasW (E) sum lDesi n F law CB#5 (R-3570) 2A sl. 8.0 cfs U7 CFS q off. Pipe CapaciU Cheep: I00- eau• Storm Pipe 1aoe tion Size Tyke Slone capacity D"iyn Flow(00) B-1 TO Defeiader 12" HDPE 0.010 3.80 CFS 0,87 CFS 0 FORM 11 - OEL EVALUATOR FOR, Location Ad(iress or LAX NO. Weather �•�� � � �1 � � On-sUg. Review- DeepHole Number Date; . k_acadon WentOy On site Pi3n) Suttee tarxes are Land Use r �,., - slope (%1 ` Vag rtion L andforrn .., . . ._ w position on landscape Eskitch are the bec4 Distatloom frvrn: �- open Water Body t o feet Drainage way .. o fleet Pos9ible Wet Arai 0 feet Proper€Y Line 1 feet Drinking Water Well O/A feat other DEEP OB ERVAT. N HOLE LOG" Sail Tamura 5ci!valor 5ak3 b�tr iQir�#FolYi soil}sgriaorl 5�+rlacs�3��h�sl (�15E�A) I�lun�a3kl l4iat#kin� iStruc=uva. 5#ana��.~oBau�k��. �pr►sistaflo*. w � 1� �� ;�. � �,� � -�� �a.u� I � �•�-ems�> pwa1!! �WNW Ir1 00 F'ldi: FORM 11 - SOM EVALTJA.'TOR FORM Location Address or Lac Igo. raj`fie Rhea Daep Hole N urnber - pets: i Time: 11 ', Weather Location ��dent 0� site piani I and EJae w oE' ^,3Epe9b1 surface Stones Landform p"ition on iandea a (skatrh an the basic) Distances from: Open Water Body � teat �]rstnagi way possibie Wet Area � � feet Propart�r Line ��� #eat Drinking Water Well A feet other DEEP OBSERVATION HOLE LOG' Surfs 3inchrsMSoi kariznn a Storst. 9udars. nnsss#anCY Oipth Own MonNnUSEA 96 Gravda �� r"I j L YR la 0 rrune-wa+i+L 1 - pirgi'turn t o.: -7 o l naA:rMOVM ream- r" 103 ri€es R6ad-Suito One- Salem, N-ow Hampshira 03079 HF Desi§n ans�jltants, Inc, TEL(603)993-07ZU• FAX(603)a93-0733•E-MAIL mhf( xtdE.cum Low,asion Addrssa or Lot No. 1,4 . -siteBe-vie . Deep Hole: Numtier bets: . i..ocatian 11dtntify ark $!00 plan v €.aM i,ise siope {°de} Surface stones Lakndforsz f asition OR i and sraps (ak0tr-fr 0Iti the back . DRetanaea born: ()Perk Wi0tsr aodY feet r inag way feet Pos$iblM Wet Arse faer Property Line feet Orfitking Water-Wall test atnsr IrzEP OBSERVATION HOLE LOG# Safi Horizon5flif iaactura $q�k Caior Sail Cline S�a#li Rlnchaa€ {USDA} {IrlatrE�ili� lattiFn RStructr�r�.Stor .�$w rs,CD fansisaa�zc °tu -- `} rot 14 51 y -7i 3 Jan ' C.o' 1d. "F €N E;R PLANNERSSUF�VE= FRS .......... Massachusetts Department of Environmental Protection 7Bureau of Resour Protection - �#�arlds �+ WPA Appendix C - Stormwater Management Form Massachusetts Wetands Protection Act M.ta,L c- 131, §40 -----................ A. Property Information Important: When filling out Tho proposed pro)ect is. forfns on the gomputerr Use- only the tab New development M Yes trey to move your cursor- El No do not tise the return key. �a Redevelopment Yes No COrnblnation ® Yes (€f yes, distinguish redevelopment components frorn new development components on plans). Note: © No This November 200D v4�rsran of 2- Stormwater runoff to be treated for wafer que ity are based on which of the following salctAattons' the Stomwater M�tnagwent Form supersedes El I inch of-ruwff x total impervious area of post-development site for discharge to critical areas earlier versions (WsWnding Resource Wafers, recharge areas of pub€ic water supplies, shellfish growing areas, including those swimming beaches, cold water fisheries). contained in DEP's torrnwaEer 0-5 inches of rur< # total €mpervious area cf post-deve€opmerrt site for ctl�er�esos�rce afeas- Handbooks. . Lia all plans and documents{e.g, calcu[atiorrs arrd addificnaf narraRves) submitted with this form: Site Ilan by MHF Qesignonisg1tants. Inc,, dated, ,tune, 001 Drainage Palculabons €oy_l IH1= Design Consonants, Inc., dated, June, 200 - S. Stormwater Management Standards DEP's Stormwater Management Policy (March 1997)ineltides crime standards that are listed on the fallowing pages. Check the appropriate boxes for each standard and provide documentation and ad-ditiomd infounatlon when applicable- Standard#1-. Unimted sionnwaWr 0 The project is designed so that new stormwater point discharges do not discharge untreated stcrmwater into, or cause erasion to, vret€ands arrd waters, Massachusetts Department of Environmental Protection —� Bureau of Resource Profection R 1 etlands WPA Appendix C - Stolr mwat r Management Form Ma sachusetts WOands Protection Act M. _L. c. 131, §40 B. Stormwater Management standards {coat.} tan daird##2. Post-development peaR discharges rates © Not applooa>je—projact site contains wale=m subject to tidal action. post-deve€opmeiit peak discharge does not exceed pre-d ve€opment fags on the site at the point of dMharga or downgradient property boundary for the -yr, I D-yr, and I OD-yr, 24-hr storm, © without starrnwat,er Centrals with stormwater controls designed for the 2-yr, and 10-yr storm, 24-hr storrn. 0 the project as designedwi1l not ins; rease of#-sine flooding Impacts from the JOg-yr, 24 hr storm, Standard #3: Recharge to groundwater , Amount Of impervious area(sq, ft.) to be infiltrated- MIA Volume to be recharged is based on, The follovAng Natural Resources ortservatioa Service hydrelcgic soils groups(e.g, A, B, t t7, or UA) or any combination:of gmuW, Hi rok is soil CoFj {96 0€€me¢viaais ore2} {Hyrolagio 9p�f group} (9fo-of irriper+�ioilS 2rea} { '!d o9 g �} 3rnper,+laLM area} ydrokagk soil group) (%of"arvious areal (rEydrafogiG zokl group) Z Site sperafic pre-development conditions. 0-00 ��a_.. ._ ROCNIrge rate V<lUme Describe how there calculations were determined, on site soils were dete.T-mirEed to be impervious by Soil Evaluator, with a emirate of>60 IMPI, List each SIMP or nonstructural measure used to meet Standard#3. (e.g. dry well, InfiltratiC trench . nfa Does the annual groundwater recharge for the post-development site approximates the ann at recharge from a istirig site conditions? Yes 0 No LlMassachusetts Department of Environmental Protection Bureau of Resource Protection - Wet#ands WPA Appendix C - Stor water Management Form Massachusetts Wetlands Protec�on Act M. ,L c. 131, §40 B. Stort"lllwater Management Standards (cons.) Standard#4: 80%TSS Removal The proposed storrnwater rnanagement system will remove 80%of the post-development site's average annual.Total Suspended Solids(T5 ) load. Identify the BMprS proposed for the project and descrbe how the 80%T S removal will be achieved, Mo=stream Detenc#er' systern i H_!.i. Technokogi.es, .... ......... if the project fs redevelopment, explain how much TSS will be removed and briefly explain VVKY 80% removal cannot be achieved. Standard#5: Higher potentiat pollutant loads See Stormmrat Does the project site contain [and uses with higher potential pokrtant [oasts Policy Handbook Vo4, 1, Page 1-23, Yes It yes, describe land uses, for land uses of high poilwant .......... ................ loading - -- � Igo Identify the BMps selected to treat storrnwater Tunoff, It inli[tration measures are proposed, c Scribe the pretreatment. (Nate; if the area of higher potential poll ant loading is upgradient of a critical area, infII" lon is not allowed-"Downstream Deer is " syster nojogies- ........ Standard#6: Protection of crttiaet areas See Stonnyvater Will the pr*c;t discharge to or of art a critical area's Pol'ocy Handbmk Vol- !. pia 1- 5, yes If yes, describe areas: for CrRical areas. � io i + LI__... Massachusetts Department of Environmental Protection Bureau of Resource Protectir�n - etlands PA Appendix C - Stormwater Management Form Massachusetts Wetlands Protection Act M.G.L. c. 131, §40 B. Stormwater Managernant Standards (Cont,) -, Identify the BM Ps selected for stormwater discharges ire these areas and describe haw BUIPs meet restrlaons listed on pages 1- 7 and €- 8 of the Stormwater Policy Handbook—Vol. 1' Dote"oomponerrRs of Standard#7: Redevelopment projects redevdopmant projects WhIGh is the proposed activity a redevelopment project? flan to deue€op V iousiy `R'e's if yes; tie fo€lowing sl7nrniwatet manage€rter�l standards have been met' undeveloped mess do riot fall O, 4-9- under the scope of Standard 7- El o The following stormwater standards have Pot been met for the fa€fawing reasons: tandard# -because no c barge is possible itE rx site soil cost liti ns. _...._. [g The proposed project wi€} reduce the annual pollutant load cn the site with new or improved stormwater control, Standard##S: EreslonfsedIment control ® Erosion and sec€€meat controls are incorporated into the project design to prevent 1 rmsion, =ntrol sed€ments, and stabilize exposed soils daring construction or land disturbance. Standard#9: Dperationimaintenance plan ® An operation and maintenance plait for the post-development stormwater controls have heen developed, The plan inck des ownership of the stormwater l3MPs, parties resportsil}le for atxeratiart and maintenance, schedule for inspection and mainteria€ce, routine and long-term rutalrttorrance rESi]oTtSibliltieS, and provision for approprfate access and maintenance easernenW extending from a public right-of way to the stormwater contrc€s. O & M Plan-irr lutded herein June Q l .-.....-.— - s.. - - -------...... .._.. ---• Rate Planf CB M-v- _ Rafe ....... lanl�H�e I 10, 1 -Yeah" Storm i i I i Oirainage Diagfam far 117�t01-SEVEN HILLS-2-YEAR PREDFNELOP 4fENT Prepared by MHF€asign Oorieuftamts, Inc. JO)l112DO1 HydroCA 6A0 gin d69714 D 198&2001 Appliad d.4ltfa,wmputerSyaam5 117201-EVEN HILLS- 2YEAR PREDEVELOPmENIT TYRE m2 HR R+ ,91&a«0` prepared by UHF Design Consultants, Inc. Page I HdroCADVe &n 001710C1986- ArMlied gaoWm to bms 1011112001 Ti me span=1a0 ,00 m$ m--E1O hrs, 1O1points Runoff by SCS T method, UH=SCE 7YPE m -H B Rai mU=ƒ! YL Reach routing -Ind+Transmethod - Pond routing by Stor-Indmethod Subs tchm lI FLOWS TO BOUNDARY. EAST TEESn cN=86 Area--% o@ Runoff=0,42 GS U-028m Subcatchment2S= FLOWS TO VVEfLAND Tc=3 min CN=7Area=7.60« Runoff-- 139cfs0-120/ Runoff Airea = 1.077ac Voiurne= 0.1413af Average D th = 1.G I17 01-SE EN HILL& -YEAR PREDEVELOPMENT TYPE III 24-HR f ainfaf=3g 0- Prepared by MHF Design Consultants, Inc. e 2 draC. M 6,00 sJn OG1710 0 1986-2001 A led C.rJEcroco tef s ms 1011112001 ubca hment iS: FLOWS TO BOUNDARY - EAST Runoff - 0,42 as 0 11.98 hrs, Volume= 0.028 of Runoff by SCS TR-20 rnethodr UH= CS, Time Span= 10.00- 0,00 hrs, dt-- 0,10 hrs TYPE III 24-HR 'Rairt'{a1l=8.1V' Area m CN Oescr't tlon 2,000 83 13RU H,POOR,D 6,000 84 LA3,FAIR,D 1,300 W PAVEMENT_ 9,300 86 Weighted Average Tc Length Slope Velocity Oapacity Description rr�ir #eet ftffE ftfsec cfs 0A 25 0,0200 1,0 Sheet Flour, Segment ID: Srnooth surfaces n= 0-011 P = 8.19- 0. 0 0.0 00 2A Shallow Concentrated Flow, Segment ID: Grassed Waterway Kv= 15.0 fps 0.6 45 Total Subcat hment 2 : FLOWS TO 1NIETLA D Runoff - 1.89 cfs @ 12.00 hfs, Volume- 0_120 a# Runoff by SCS TR- 0 methcd, UH=SOS, Time Span-- 10,00-20,00 hrs, dt= 0.10 hrs TYPE III 24-SIR Rajnfal1= .19' Areas ON DeSGTi tiara 7,200 91 GRAVEL,D $,7E10 69 IAVV ,D,P00R 18,600 83 WOODS D POOR 87,600 87 Weighted Average Tc Length Slope Velocity Capacity Description min fee# f Mt f Us-ec cfs 2,3 25 0,05W 0.2 Sheet Flaw, Segment ID: Grass: Short n= 0.150 132= 3,10" 0.5 50 0.1000 1.6 Shallow Concentrated Flow, Segment 10: Woodland k v= 5,0 fps 2A 75 Total ............ WOW ac III C I)MfnageDlagramfor 117201-SEVEN HIUS-1a-YEAR PAEDEVELOPMEN v. Preperad by MHF Design COnsuUAts, Enc_ iE IM)D9 "MCAEND 6.00 sfn a01710 4�)1 2=►PPIrad Miorcorr OI-f GY"k !3 117201-SEVEN HI LLB I0 YEAR P RE DEVELOPMENT TYPE 1H24-HR R+ kQ#3O" Prepared by MHF Design Consultants, Inc. Page H droCwM&00 Qn DO4710 0 1986-2001A Bd Vicrocamputer S ms 10/]] OO1 me span=1a0- .00 m% m=a1Oi1O1pdnS Runoff by SCS T 20 method, UH=SCE TYPE 11124-HR Rai m 6 S Read tng by Stor-Ind+ s method . Pond rouVrtg by Stor- nd rnethad Subcatchment IS. FLOWS TO BOUNDARY .EAST THEE min C N=86 Area=9,300�f Runoff-- 0, cfs 0-048« Subcatchmem 2S. FLOWS TO WETLAND Tc=2 3 min CN=7 Ate=R60 0 @ Rumft 3-16 da 0-20 O m Runoff Area 1.077 ac Volume= 0.248 af Average Depth -216 117 01-SEVEN# HILLS- IO EAR P EDEVELOPMENT r PE/if 4-HR Rainfall=4_ 0" Prepared by MHF Design GonsuAants, Inc. Page 2 jydroCAEO 6.O0 sJn 01710 Q 1986-2001 Applied Mlqmfomputer Systerns 14f11f2 1 Sulocaktchment IS: FLOWS TO BOUNDARY - EAST Runoff - 0,72 cfs @ 11.98 hrs, Volume= 0,048 of Runoff by SOS TR- 0 method, U H=SC S, Time Span= 10.00-20.00 hrs, dtm 0.10 hrs TYPE III 24-HR Rainfall=4.50" Area (sq CN Description 2,000 83 BRU H,POOR,D 6,000 B4 LAWN,FAIR,D 1300 98 PAVEMENT 9,800 86 Weighted Average Tc Length Slope Velocity Capacity Description mirk feet ftlf# t ec ofs 0A 25 O OO 1.0 Sheet Flow, Segment ID: Smooth surfaces daces n 0,011 P2= 3.10" 0-2 20 0,0200 2A Shaftw Goncentrated Flow, Segment ID: -Grassed Watervvay Kv= 1b,0fps 0,6 45 Total Subcatchment : FLOWS TO WETLAND Runoff 3,16 cfs @ 1 _00 hrs, Volume= 0.200 of Runoff' by SC S TR-20 method, U H=SCS, Time Span= 10.00-20_00 hfs, dt= 0,10 hrs TYPE III 24-HR Rairofal1-4.50" A $ N Descri fiorl 8,100 98 PAVEMENT 7,200 91 GRAVEL,D 8700 89 LAWNPR OR 18,600 83 V31OODS] D POOR 37,600 87 Weighted Average Tc Length Slope Velocity Capacity DescfiptiOn rnln feet fdit) (fUse cf 23 25 0.0500 0.2 Sheet Flow, Segment ID: Grass: Short n= 0, 160 P2= 3.10" 0_5 60 0.1001) 1.6 Shallow Concentrated Flow, Segment ta: Woodland Kv= 5.0 fps 2.8 76 Total 9e :On I Drrainage magram for 1W201-SEVEN HlLi�S-100-YEAR FRL5QF-VELOPMENT Prepared by MHF Design Consul s, 6nc. I0l1 rt1200 - RWrorACkO 6.00 an p4}l710 919M2001 Applfstk Moromrr'PLfW rbtBWS 117201-SEVEN HILLS- 1 00-YEA PREDEVELOPMENT TYPE I!! 4-HR Rainfall=6-40" Prepared by MHF Design Consultants, tnc. Page 1 W dm AD 6.00 sin 001710 C 1986-2001 Hqd microcomputer Sygems 10111/29 Time span=10.00- 0.00 hrsr dtTO.10 hrs, 101 points Runoff by SCS TR- 0 method, U H=SCS, TYPE €II 24-HR Rainfaii;--6_40" Reach routing by for-Ind+Trans method - Pond rouUng by for-Ind method Subcatchment 1S: FLEWS TO BOUNDARY-EAST T 0.6 ruin CN=86 Area=9,300 sf Runafl= 1.11 cfs 0.075 of Subcatchment 2S: FLOWS TO WETLAND Tc=2.8 miry C{+1=87 Afea�37,600 sf Runof€=4_89 cfs 6_ 10 of Runoff Area= 1.077 ac Volume 0.385 akf Average DeiAh 4.29" 117201 EVEN HILLS- I00 YEAR P EDEVELOPMENT TYPE ill 4-HR Rainfall= .40" Prepared by MHF Design Consultants, Inc. Page 2 H cfro A 8.00 sfn 001710 0 1086-2001 Appiled Wrocom tFter erra 1011112001 Sttbcatchment 1S: FLOWS TO BOUNDARY - EAST Runoff - 1_'11 ors @ 11,98 hrs, Volume-- 0.075 of Runoff by SCS TR- O method, UH= D , Time Span= 10.0D- 0.00 hrs, dt= 0_10 hrs TYPE 11124-HR Rainfall=6.40° A s CN Description 2,000 83 BRUSHPOOR,D 6,000 84 LAVti N,FAIR,D 1,300 98 PAVEMENT 9,300 86 Weighted Average Tc Length Slope Velcdty Capacity Description min feet Wft 1`tlsec cfs 0,4 25 0,0200 1'0 Street Flow, Segment ID- Smooth surfaces n= 0.01 1 P = 3.10" o.2 20 0,0200 2.1 Shallow Concentrated Flow, Segment ID: Grassed Waterway Iv= 15.0!Ps 0.6 45 Total Subcatchment : FLOWS TO WETLAND Runoff - 4A9 cfs @ 12.00 hrs, Volurnemm 0,310 at Runoff by SCS T - 0 mel:hod, UH=SC S, Tine Sparc= 10.00-20,00 hrs, dt= 0,10 hrs TYPE III 4-HR Rainfall=6AU' Area (sf) CN Description 3,100 98 PAVEMENT 7,200 91 GRAVEL,D 8,700 89 L.AW E,D,PG0R 18,600 83 W0 QD ,D P0DR 37,E 87 Weighted Average Tc Length Slapa 1lalocIty Capaoity Description min feet f#!ft ftlsec s .3 26 0,0600 0.2 Sheet Flow, Segment 1D: Grass' Short n=0.150 P = 3. 19' 0.5 50 0.1000 1 A Shallow Concentrated Flow, Segment 10: oodand Kv= 5.0 fps 2.8 75 Total -year Storm ` t f 2BC} 4L1 � f1�F EDra[rtago DFA(yrarrtfor IInal-SEVEN tiILLS-2-YEAR POSTPEVnOPMEN REV _y P(epared by MHF Design CoMuttanks. Irec- �4f�2J�0a� HydM AE]�D 6-W e n COI 714 j�j96 -2{?af Applied M[cracompu[or 51Oams 117 Q1-SEVEN HILLS- YEAR P0STDEVE L.OPMEN REV Type 1H 4-hr Rainf]1101 2 ' Prepared by MHl4 Design Consultants, Inc, i f Page 1 H dm Ann s no Fin 001710 01 86- 01 Applied icr�com �t�r S stems Time$pan--10.00-20= hrs, dt=0.'k0 hrs, 101 POInts Runoff by SOS Tf - 0 method, UH=SC , Type 111 4-hr Rainfall=3.19' Reach routing by for-tnd+Trans method - Pored roufang by for-1nd method Subcatchment 1S: FLOWS TO O1 To---O.5 min CH=93 Area=i0,000 sf RunofER 3.5$as 0,040 of Subcatchment S: ROOF TKO,I min CN=98 Afea=3,400 sf Runoff= 0.22 as 0,015 of Subcatchment 3S: FLOWS TO WETLAND Ti-,�6 miry N;=82 Ptiree=34,$00 s!' Runa#l= 1.30 cfs 0.E189 of Subcatchment 4S: BOUNDARY-EAST T0,6 min CN=83 Afea=9,8Q0 sf Runoff--0.39 cfs 0.06 of :each IR. 12"HDPE B-1 TO DEFrENDERIDETENT16N SYSTEM 100W= 0.53 cfs G.w of Length=40.V Marl=3.5 fps Capadt-3.86 cfs OuViow--0.58 cfs O.039 of Reach 2F - 6" ROOF DRAIN inflow= 0. 2 cfs 0.015 of i Length= 0.0' Max Vel=3.6 fP Capacity^0.86 cfs Outflow=0.21 cfs 0.015 of Reach 3R: SUMMATION AT WETLAND inflow= 1,82 cfs 0.143 of Length= 100,9 Maxvet--0.5 fps Capacity+=440.46 cfs Outflow-- 1-54 cfs 0-143 of Pond 1 P. UNDEROROUND DETENTION SYSTEM Peak Storage=388 cf inf ow=0,79 cfs 0.055 of Primary= G.47 cfs 0.054 of Outflow=0.47 cfs 4.054 of Ruinof'F Area= 1.32T ac 11olunie= 0.170 of Average Depth 1.54„ 117 01 EVEN HILLS. 2-YEAR POSTD VELOPMEN REV Type J 112 4-hr Rain faD=3, 10 Prepared by MHF Design Consultants, Inc. Page H dmCAD0 6.00 qfn 001710 0 1986-2001 Applied 1 W02l 001 u hcatchment IS. FLOWS TO CB-1 Runoff - 0.58 cfs @ 11.97 hrs, Volume- O-W of Runoff by SGS T -20 method, UH=SD , Time Span;-- 10,00- 0.00 hrs, dt= 0.10 hrs Type III 4-hr Rainfa11=3.19" Area(sf ) Cat Description 7,100 98 PAVEMENT 2,900 80 LANDS APP D GOOD 10,000 93 Weighted Average Tc Length Slope Velocity Capacity Description miry itfft ftke-c cfs 9.3 25 O.0 00 1-5 She4al Flow, Segment ID; Smooth surfaces n-z 0,011 P2= 3.1U' 0.2 50 0,06 4.5 Sha i'low Concentrated Flow, Segment ID: Paved # v= 0_3 fps.. 0.5 75 Total Subcatchment 2S: ROOF Runoff mm 0,22 cfs @ 11.96 hrs, Vo3ume= 9_015 of Runoff by SD S TRy 0 method, UH=SDS, Tirne Span= 10,00�-20-00 hrs, dt= 0,10 hrs Type#1# 24-hr Rainfall=3.1Y" Area (sn GN Description 3,400 95 ROOF Tc Length Slope Velocity Capacity Description (min) (feet} (Wft) O' sec} (cfs) 0A 15 0.2500 2.5 Sheet Flow, Segment ID: Smooth surfaces n= 0_911 P ;--- .19' ubcatchment 3 . FLOWS TO WETLAND Runoff = 1.39 cfs @ 1 .00 hrs, Volume= O.099 of Runoff by SCS TIC- O method, UH=SDS, Time Span= 10.00- 0_OD hrs, dt= 0,10 hrs Type III 24-hr Rai nfall=3.1 0" Area sf DES Description 0 0 12,400 80 LAN S APE,D, OOD 2 200 33 WOQD ,D,PQOR 34,6W 82 Weighted Avexage i I i 1 17201-SEVEN HILLS- -YEAR POSTI]E ELOPMEN REV Type 1�1 4-hr Raarrfal1=3.10' prepared # + +1HF esi r o s I ants, Inc. Page F� d o l7 B_ sa'rx{3017 198fr20G HO Miarocom L tef sterns 10f4 1 001 Tc Length slope Velocity Capacity Description (min) (feet) (ftlft) {ftLsec} (ON 2.3 25 0.0600 0.2 Sheet Plow, Segment ID: Grass: Short r�= 0,150 P2= 3.10,' o,3 25 0.1000 1.6 Shallow Concentrated Flow, Segment ID: Woodtand Kv= 5.0 fps 2.6 50 Total Subcatchment 4S: BOUNDARY - EASE` Runc#f - 0_ 9 cfs @ 11.98 hrs, Volume= 0.0 6 of Runoff by SOS TR-20 method, UH=SOS, Tree Span= 10.00- 0-00 hrs, dt= 0,10 hrs Type III 24-hr Rainfall=3.19' Areas _QN Descri t'san 2,000 83 BRU H.D,POOR 6,600 80 LAN DSOAPE,D,GOOD 1,300 88 PAVEMENT ,800 83 Weighted Average Tc Length Slope Vetocity Capacity Descrlptlon rn}rt feet ftlft ftfsec cfs 0-4 25 0,0200 1.0 Street Flow, Segment Il]: Smooth surfaces n=0.011 P2= 3-19' 0,2 20 0-0200 2.1 Shal bw ConcentratedFlow, Segment ID: Grassed Waterway } v= 15.0� s 0.6 45 Total Reach 'IR: 12"HDPE B-1 TO DEFE BEFUDETENTION SYSTEM Inflow 0.58 cfs Q 11,97 hre, Voiurne 0,040 of oufflow 0.58 cfs @ 11.98 hrs, Volume 0-039 af, Atten;: 0%, Lag= 0-3 min Routing by Stor-Ind+Trans method, Time Spar= 10-00-20.00 hrs, eft= 0,10 hrs Max. Velocify= 3.5 fps. Min. Travel Time=0.2 min Avg- Velocity = 1_5 fps, Avg. Travel Ttrrre= 0-8 min Peale Depth= 0.2U Capacity at bank full= 3.86 cfs 12.0" Dlarneter Pipe n= 0-012 Len th=40,0' Slope- 0,0100 T Reach 2R. 6" ROOF DRAIN Inflow 0,22 efs 0 11.96 hrs, Volume;-- 0,015 of Outflow 0,21 cfs @ 11,96 hrs, Volume= 0.015 af, Atten= I%, Lague 0.1 ruin Rooting by tor-Ind+Tra ns method, Time Pa ?T-- 10-00- 0.00 he's, dt- 0.10 Firs Max. Velocity= 3.6 fps, Min. Travel Time- 0.1 rnin Avg_ Velocity= 1.5 fps, Avg, Tfavel Time= 0.2 rain 117 01-SEVEN MILLS- -YEAR POS'TOEVELOPMEN REIN Type Jf! 4-hr-Ra&afaff= .10" Prepared by MHF Design Consultants, Inc. Page 4 Lj dmCAD@ 6.00 sin 001710 0 1986- 001 8pplled €Nicroxm r S sterns 1=212001 Peak[Depth= 0.17' Capacity at bank full= 0.86 cfs 6.0" Diameter Pipe n= 0_012 Length= 20.0' Slope=0.0200 7' Reach R: SUMMATION AT WETLAND Inflow - 1.82 cfs @ 12_01 hrs, Volume= 0,143 at Outflow - 1.54 cfs 12.13 hrs, Volume 0,143 af, Men= 16%, Lag= 7.q min Routing by Stor-lnd+Trans method, Time$parr= 10,00-20.00 hrs, pit= 0_10 hrs Max_ Velcc4= 0.5 fps, Ain_Tavel Time= 3.7 snit} Avg.Velocity= 0.2 fps, Avg. `F avel Time= 7.8 rain Peak Depth= 0,03' Capacity at bank full;-- 440,46 cfs 100,W x 1. ' deep channel, n= 0.035 Length=10W Slope= 0.0140 ? Side Slope value= 10.0 T Pond IP. UNDERGROUND DETENTION SYSTEM Inflow 039 cfs @ 11-97 hrs, Volume= 0.055 of outflow - 0.47 cfs @ 12.11 Ears, Volume= 0,054 af, Men=41%, Lag= 8.2 rain Primary = 0_47 cfs @ 12.11 hrs, Volume= 0,054 a€ Routing by Star-1nd method.Time Span;-- 9€3.0Q-20.00 ht's, dt= 0.10 hrs Peak Elev= 1,1 U Storage= 388 0f Plug-Flow detention time--- 12_9 rnin calculated for 0.054 of(08"A of inflow) Elevafion Oum'store (feet'} (cubic-feet) 0.00 0 .00 1,059 4.00 1,071 Primary OutF low {Fme Discharge) L1R0rificefrate .2=0rifice[Grate # Routing Invert Outlet Devices 1 Primary 0.00, 3.0"pert. Orifice/Grate C= 0.600 2 Primary U0' 3.0"Vert. Orifice/Grate 0= 0.$04 i POST-DEVELOPMENT: 1 -Year Storm i i I i $C i f LI arartwe a alagramn for i I nO-E +E t4 HELLS-40-YFJPLR FOSTar-V�LOPMEN REV Prepared by MHF gn ComuftarftS, €nc- IM2f2QOl HydroCAD@ 6.00 5fn 001710 9D11143$,2001 Appliod M3crwmmpLrt9rsyaiNms 117201-SEVEN HI LL R I YEAR POSTDIEVELOPMEN REV Type !II 4-hr Rainfa#=4. 0" Prepared by MHl✓ Design Consultants, Inc. . Page I HydroCAD&6.00 sJn 001710 0 1986-2001 Appiied Wicrocorn uter§ystems 10l0 12001 Tame spar=10.00-20,00 hrs, cii=l�_10 his, 101 points Runoff by SCS TR-20 method, UH= , Type 111 24-hr Rainfall=4.50" Reach routng by Stor-Ind+Trans method - pond roufing by for-Ind method ulocatchntent 1B: FLOWS TO 8-1 TG=0.5 min CN=93 Area=10.000 sf Runoff= G,80 cfs 0.061 of ubca#ctrment 2S: ROO>r T(,,---O,I m1ri CN=98 Area=3,400 sf Run =0.32 s G.022 of Suhcatchment 3S. FLOWS TO WETLAND 72,6 min CN=82 Area=34,600 sf Fturroi'1=2,61 cfs 0.159 a1= ubcatch ent : BOUNDARY-EAST To=0,6 miry CN=83 Area=9,800 sf Runoff--0.69 cfs 0.047 of Reach 1R. 1 Z'HDPE B-1 TO DEFENDERIDETENT16N SYSTEM Inflow=0.89 cfs 0.061 of Length=40H Ntax Val=4,0 fps Capacity- 3,86 ifs Outflow--0.89 cfs 0.0ro1 of Reach 2R: 6" ROOF DRAIN lniflow= 0.32 cfs 0.022 of Length=20.0` 11flax Vtl=4.0 fps Oapacli<y=0.86 cfs Outflow= 0.31 cfs 0.022 of Reach 3R. SUMMATION AT WETLAND inflow--3.09 cfs 0.242 of Length= 'I00_(' Coax Vet=0.6 fps Capacity=440.46 cfs Out€{ow=2_6G dr, 0.241 af Pond 1 P: UNDERGROUND DETENTION SYSTEM Peak Storage=077 cf tnflow= 1-20 cfs 0.083 of Primary 0-63 cft 0.083 of Outflow= 0.63 cfs 0_083 of Runoff Area= 1.327 ac Volume=0.289 at Average Depth = 2.62" 117 01-SEVEN MILLS- ID-FEAR POSTDEVELOPMEN REV Type III 4-hr Rainfall=4. 0" Prepared by MHF Design Consultants, Inc. Page LL)LdroGAIDD 6,00 sln 001718 01 -2001 Applied ir,=gMputer ystem _ 1010212 Subcatchment IS. FLOWS TO D8-1 Runoff = 0,89 rfs c@ 11.97 hrs, Vole.me= 0.061 of Runoff by SCS TR-20 method, UH=SC S, Time Span= 10,00-20.00 hrs, dt= 0,10 hrs Type III 24-hr Rainfall�4.50" Areas I�escri #ion 7,100 98 PAVEMENT 2 90G 80 LANDSCAPE, GOOD 10,000 93 Weighted Average To Length Slope Velocity Capacity Description in feet ftlft ftlsec cfs 0.3 25 0.0500 1.5 Sheet Flow, Segment ID: Smooth surfaces rr- 0.0'11 P2= 3.10" 02 s0 0,0500 4.5 Shallow Concentrated Flow, Segment ID: Paved Kv= 20.3 f s 0.5 75 Total Subcatchment S: ROOF Runoff - 0_32 cfs @ 11,96 hrs, Volume= 0.022 of Runoff by SCS TR- 0 method, UH=SCS, Time Sparc= 10.00-20.00 hrSr dt= 0.10 hrs Type Ili 4-hr Rain ail=4.50" Areas Cif Description 3,400 98 ROOF Tc Length Slope Velocity Capacity Description (min) met ftlff ftfsec cfs 0A 15 0_ 500 2.5 �S+heet Flow, Segment ID: rry� ++�� +��y Smooth surfaces V k� P2= 3. 9 0" Subcatchrrtent 3S. FLOWS TO WETLAND Runoff - 2,51 cts @ 12,00 hrs, Volume- 0.159 of RurofF by SCS TR-20 method, UH= CS, Time Span= 10.00-20.00 hT-s, dt= 0.10 hrs Type III 24-hr Rainfall 4.50" Area N Description 0 0 12,400 80 t..AN€]SDAPE.D, ODD 2200 83 WOODS D POOR 34,600 82 Weighted Average 117 01- EVEN HILLS- 10-YEAR POSTDEVELOPMEN REV Type III 4-hr Rainfal1=4 0" Prepared by M HF Design Consultants, Ino. Page 3 F dro A 6-00 s1n 001710 *19M-2001 Applied Microcomputer S st 1010212001 Tc Length Slope Velo4-,4 Capacity Description (min) {feet} {f#1f#} {tt}sec) {cfs) .S 25 0.0500 0-2 Sheet Flow, Segment ID: Grass: Short n= 0.150 P2= 3.19' 0.3 20 0,1000 1.6 Shallow Concentrated Flaw, Segment ID: Woodland Kv= 5.0 fps m 2.6 80 Total Suhcatchment 4 ; BOUNDARY - EAST Runoff - 0.69 cfs @ 11.98 hrs, Volume= 0, 47 of Runoff by SCS TIC-20 method, UHmm5 5, Time Spar= 10_ -20.00 hi-s, d;-- 0,10 hrs Type III 24-hr rainfall=4.60" Area (sn ON Descri f on 2,000 83 I3RUSH,D,P00R 6,500 80 LANDSCAPE D, OOD 1.300 98 PAVEMENT ,800 83 Weighted Average Tc Length ~Mope Velocity Capacity Description mint feet ft/ft f fseo 40 0.4 25 0,0200 1.0 Sheet Flow, Segment ID' Smooth sutfaces €-- 0.011 P2mm 3,10" 0,2 20 0.0200 2.1 Shallow Concentrated Flow, egment ID: Grassed Waterway Kv= 15.0 fps T 0,6 45 Total Reach IR. I2"HDPE C B-'I TO DEFENDEWDETENTION SYSTEM Inflow 0.89 cfs a 11,97 hrs, Volume-- 0,061 of Outflow - 0,89 cfs @ 11.98 hrs, Volume- 0.051 af, Atten=0%. Lag=0.3 min Routing by Stor-Ind*Trams method, Time Sparc= "I0.00-20.00 hrs, dt- 0.10 hrs Marx. Velocity=4.0 fps, Mitt_ Travel T€me= 0. min Avg. Velocity = 1.7 fps, Avg. Travel Time- 0_4 min Peak Depth= 0.33 Capacity at bank fall= 3_86 cfs 12.0" Diameter Pipe n= 0.012 Length- 40.0' Slope= 0.0100'1' Reach 2R: F ROOF }RAIN Inflow - 0_32 cfs @ 11.96 hrs. Volume= 0,02.2 of oufflow 0.31 cfs @ 11.96 hrs, Volume= 0.022 a'af, Atten= I%, Lag= 0.0 min Routing by Star-]nd+Trans method, Time Sparc= 10_00- 0.00 hrs, dt= 0.10 hrs Max, Velocity= 4.0 fps, Mir€_Travel Tifne= 0.1 min Avg. Velocity = 1.7 fps. Avg. Travel Time= 0_2 min 117201-SEVEN HILLS- 10 YEAR POSTOEVELOPMEN REV Type 11i 4-hr Rainfall=4_ 0" Prepared by MHF Design Consultants, Inc. Page 4 HOrnCAM 6.00 sfn 001710 0 1986-2001 AppiiedMicrommputeri stems 40f021 Q1 Peak Depth= 0.21` Capacity at bank fell= 0.86 cfs 6.0° Diameter P1pe n= 0.012 Length= 20.0' Slope= 0_020D T Reach 3R. SUMMATION AT VVETLAND Inf cw = 109 cfs C 12.00 tars, Volume= 0.242 of Outflow 2,60 cfs @ 1 .10 hrs, Volumez- 0.241 af, Atben= 161%, Lag;;; 5_8 min Routing by Stor-ind+Trans method, Time Span= 10.00-20.00 hl's, dt= 0.10 hrs Max_Ve€ocity= 0.6 fps, Min. Travel Time= 3.0 min Avg. Velocity= 0.2 fps, Avg. Travel Time= 7.2 min Peak Depth= 0.06 Capacity at bank fuli=440.46 ofs 100.00, x 1.00` deep channel, n= 0.035 Length= 1;00.9 Slope- 0,0100 T Side Slope Z-value= 10.0 T Pond IP: UNDERGROUND DETENTION SYSTEM Inflow = 1, 0 s 11.97 hrs, Volume= 0.083 of Outflow = 0_ 3 cfs @ 12.13 hrs, Volume= 0.083 at, Atten= 47° , Lag= 9A rein Primafiy T 0.63 cfs a 12,13 hrs, Volume= 0.083 of Flouting by for-lnd method, Time Spar= 10.00-20.00 hrs, dt- 0,10 Ears Peak Elev= 1.9Z Storage= 677 cf Plug-Flow detenfion time= 13.4 min calculated for 0.082 at ( 8% of inflow) Elevation Cum.Store feet Mbic-feet 0.00 0 3,00 1,059 4,00 1,071 rimary OutF#ow (Free Discharge) 1=0ri€€celrate F0riftce1G rate # Routing invert Outlet Devices 1 Primary 0.00° 3.0"Vert. orifice/Grate C= 0.600 Primary 0.W 3,0"Vert. Orifice/Grate = 0.600 i i i POST-DEVFLM 1 -yeah" Stir i 117 i}b LR,3 ch Ura3oago Diagram for 417201-SEVEN HILLS-fflo-YEAR FOSTDEVELOPPrfENT Prepared by MBF€]eOgn Corsuttmts, kno. jOfa212UU7 ^� HydraCAEFO B_U) sdn DIM 710 D 19B&2U41 Applled Mior4Gamputw Sysl&ms 117 01-S EVEN HILLS- 100-YEAR. POSTOEVELOPMENT TYPE 11; 24-HR Rain WI-z6.40" Prepared by MHF Design Consultants, Inc, Page 1 HyftGAEO 6.00 C101 710 C 1386-200 1 Applied Microcomputer S+sterns 1010 12t Time span=10.00-20.00 hrs, dt=0.10 hts, 101 poOts Runoff by SCS TR-20 method, UHy OS, TYPE III 24-HR Rainfall=6_40" Reach routing by tor-Ind+Trans method - Pond routing by Stor-ind method Subcafchment IS: FLOWS TO CBA Tc--0.6 art GN=93 Area=10,000 sf Runoff= 1.31 ds 0,090 of Subca#ch nt 2S: ROOF Tc-0-1 ruin Cif=98 Area=3,400 sf Runoff=0.45 cfs 0.032 of Subcafcli ment 3S: FLOWS TO WETLAND T 2.6 rdn CN=82 Area=34,6 0 sf Runo f=4_10 cfs 0.259 of Subcatchmgnt 4 : BOLINUARY-EAST Tc=0,6 rein CW83 Area=9,800�f Runoff-- 1,11 cfs 0.075 of Reach IR: 12"HDPE C9-1 TO DEFER 05WDETENTION SYSTEM [nfCow- 1,31 cfs 0_090 of Length=40.V flax Vel=4.4 fps Gapadty=3.86 cfs Ouftw� 1,30 cfs 0,090 of Reach 2R: W' ROOF DRAIN €nfix+= 0,46 as 0_0 2 of Length--20V Max Vel-4.4 fps Caparity=0.85 cfs Qutf€ow� 0,48 cfs 0.032 of Reach 3R: SUMMATION AT WETLAND Inflow=4.84 cfa 0.380 of Length•- 100.0` Maxej=0-7 fps Capacity=440.46 cfs Outflow=4.11 cfs 0.378 of Pond 1P. UNDERGROUND DETENTION SYSTEM Peak Storage— 1,074 cf lnflow-- 1.75 cfs 0.121 of Primary=0.97 ds 0.121 of Outflow=0.97 cfs 0.121 of Runoff Area= 1.327 ac Rotuma`=0.465 of Average Depth= 4.1X" 117201 EVEN HILLS. I00-YEAR POSTDE ELOPMENT TYPE fl124-HR Rainfaff=6.40" Prepared by MHF Design Consultants, Inc. Page 2 dro A 6.00 sfn 0 17i 986- 40 3 A ied h E r rorr� Ater S sterns 1 1L 001 Subcatcttment 1S: FLOWS TO B-1 1: un ff = 1.31 c% @ 11.97 hrs, Volume= 0.09D of Runoff by SC S TR-20 method, U H-.;-SC S, TirneSpan;-- 10_00-20.00 hra, dt= 0_10 hrs TYPE III 4-Flit Rainfall 6A(T Area (so CN Description 7,100 98 PAVEMENT 900 80 t-ANQSOAPE D,OOOD 10,000 93 Weighted Average Tc Length Slope Velocity Capacity Description {rrtin� {feed (ftlf#} (#tlsec} �cfs} _ 0.3 25 0.0500 1.6 Sheet Flow,Segment ID-. molath surfaces n= 0.011 P2= 3,IU' 0.2 50 4.0Sw 4.5 Shallow Concentrated Flow, Segment ID: Paved l v= 20.3 fps 4.5 75 Total Subcatchment S: ROOF Runoff — 0,45 cfs @ 11.96 hrs, Volume= 0.032 of Runoff by SCS TR- 0 method, U H=;SCS, Time Span 10.00-20.00 hrs, dt= 0.10 his TYPE III 24-HR Rajnfai1�6.40" Areas N Descr€ fior 3,400 98 ROOF Tc Length Shope Velocity Oapac€ty Description {rnirll (feet) (ft ) Msec) (ofs) 0.1 15 0,2500 2.5 Sheet Flow,Segment lD: rrrcc�M surfaces n= 0.011 P2= 3,1Ur Subcatchment 3S: FLOWS TO WETLAND Ruttoff 4.10 cfs 12,00 hrs, Volume= 0,2 9 of Runoff by SOS TR-20 method, U H;--SCS, Tire Span= 10.00-20.00 hrs, dt= 0,10 hrs TYPE III 4-HR Rainfall^6.40" Area Cis! Descrf lon 0 0 12,400 80 1ANDS APE,D,OOOD 22,200 88 WOODS D POR 34,6 82 Weighted Average 117 01-SEVEN Hill LLS- 100-YEAS PO TDE ELOPMENT TYPr! If/ 24-HF?Rainfa#=6.4W Prepared by MHF Desrgn Gonsul ants, Inc. Page 3 Hydro A _ ,OD_. €r 001710 0 19 -2001 Applied Mrh mcgmputer Systems ICV02/2001 Te Length Slope Velocity Capacity Description (rain) (feet) (ffi t)(ftlsec em s), .,,,..,. 2.3 25 0.0500 0.2 Sheet Flow, Segment ID; Grass= Short n= 0.150 P2= 3.10" 0.3 25 CA000 1.6 Shadow Concentrated Flow, Segment Ili: Woodland Kv= 5.0 fps _ 2.6 64 Total Sub catchment 4S: BOUNDARY - EAST Runoff - 1.11 cfs @ 11.98 hrs, Volume;-- G.G75 of Runoff by SOS TR-20 method, UH=S S, Time Span= 10.00-20,00 hrs, dt= 0-10 hrs TYPE III 24-HR # ainfall=6.40" Area (s#) ON Description} 2,000 83 BRU5H,D,PQ0R 8,500 80 LAND APE,D,GOOD 1,300 98 PAVEMENT 9,SW 83 Weighted Average Te Length Slope Velocity Capacity Description (min) {feet) (fit) (ft#sec) {cfs) 0.4 25 0,0200 1.4 Sheet Flow, Segment ID: Smooth surfaces n= 0.01'1 P2= 3-10" U 20 0.0200 2A Shallow Concentrated Flow, Segment ID: rassed Water ay Kv-- 15.0 fps 4.8 45, -Total Reach 1R: 1 "HDPE CB-1 TO DEFENDEWDETE TION SYSTEM Inflow = 1-31 cfs @ 11,97 hrs, Volume= 0.090 of Outflow 1.30 cfs as 11-97 hrs, Volume= 0,090 af, Atten= 0°lo, Lag=0.2 Min Routinag by for-lnd+Frans method, Time Span= 10.00- 0,00 hrs, dt= 0,10 hrs Max- Velocity= 4.4 fps, Min.Travel Time-- 0.2 min Avg. Velocity= 1.9 fps, Avg. Travel Time- 0.4 miry Peak Depih= 0.40' Capacity at batik full= 3.86 efs 12,0" Diameter Pipe n= 0-012 Length= 40.Y Slope= 0.0100 7 Reach 2R: 6" ROOF DRAIN Inflow - 0.45 cfe @ 11,96 he's, Volume- 0.032 of Outflow 0.45 cfs 14.55 hrs, Volume= 0.032 af, Atten= 1%, Lag= 4,O min Rouling byStar-Ind+Trans method, Time Span= 10. -20.00 hrs, pit= 0,10 hrs Max. Velocity=4.4 fps, Mini Travel Time= 0.1 minx Avg. Velocity = 1-9 fps, Avg. Travel Time-0-2 min 117 01 EVE HILLS- 100`FEAR POSTDEVELOPMENT TYPE If/ 4-rt-afFR Rafrrfad=8,40" Prepared by MHF Design Consultants, Inc. Page 4 H drO ADS 6.00 sin DO1710 10 2001 Applied Microcom steals 10�62l 001 Peak Depth; 0,26' Capacity at bank full= 0.86 cfs 6,0" Diameter Pipe n= 0.012 Length- 20.0' Slope= 0_0 00 T Reach 3 R. SUMMATION AT WETLAND Inflow 4,84 cfs @ 12.00 hrs, Volume 0-380 of Outflow - 4.11 cfs @ 1 _05 hrs, Volume= 0.378 af, Afters= 15%, Lague 4.8 rein Routing by for Ir +Trafks method, Time Span= 10,00- 0. firs, dt= 0,10 hrs Max, Velocity= 0.7 fps, Rhin. Travel ` jme= 2.5 mio Avg. Velocity =0.3 fpz, Avg. Travel Time 6.5 man [peak Depth= 0.06 Capacity at banks full=440.46 cfs 100.00' x 1.00' deep channel, n= 0.035 Length;;-- 10D.9 Slope- 0.01 00 'r Side Slope Z-value= 10.0'P Pond I P: UNDERGROUND DETENTION SYSTEM Inflow = 1,75 cfs @ 11.97 hrs, Volume= 6.1 1 of Outflow - 0_97 efs @ 12. 11 hrs, Volume= 6.121 at, Men= 45%, Lag= 8.2 min Primary - 0.97 ofs t 12,11 hers, Volum 0.121 of Routing by tar-Ind method, Time Span= 10.00-20.00 hrs, df-- 0.10 hrs Peak Bev=4.29 Storage= 1,074 cf Plug-Flaw detention Irye= 14.6 rain cal fated for 0.119 at (980A of inflow) Revation um.6tuy-e feet cubic-!q t 0.00 0 8,00 1,059 4.60 1,071 Primary Outflow (Free Discharge) L1=0rifice/Grate 2:;--Orifioe/Grate # Routing Invert Outlet Devices 1 Primary 0,00' 3.0" Vert. 00cerGrate C=; 0.600 Ptirnaa'y 0.00' 3.0" eTL 0rl#fCe1Grate = 0_600