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Home My WebLink About20112673.tiff • Exhibit N Drainage Report See the attached drainage report. • • aoli &73 • DRAINAGE REPORT FOR GODFREY BOTTOMS COMPRESSOR STATION dcp Midstream, DCP Midstream, LP 370 17th Street Denver, CO 80202 • July 2011 ENERCON r . Excellence—Every project Every day. 00/0/.4% ....� edit, Submitted By: /j164 `. . A •ail:' �t, \�� Anubhav Gaur- Technical Specialist =c�Ss,pNAL ei?11\ Reviewed By: c ,t^ ,n� Professional Engineer: Pat Brunette, P.E. V V Registration Number: 39164 State: CO Suraj Balan-Project Engineer • sapDRAINAGE REPORT Midstream. GODFREY BOTTOMS COMPRESSOR STATION • TABLE OF CONTENTS 1.0 Purpose 2.0 Site location 3.0 Site Layout 4.0 Methodology 5.0 Watershed Delineation 6.0 Design Inputs 7.0 Calculation 8.0 References Appendices: Appendix A HydroCAD Existing Condition Appendix B HydroCAD Proposed Condition • Appendix C FlowMaster Analysis Attachments: Attachment A: Existing Onsite Basin Map Attachment B: Proposed Onsite Basin Map Attachment C: Grading Plan Attachment D: Erosion Control Plan Attachment E: Erosion Control Details • CO ENERCON E R C O N (405) 722-7693 2 dcp DRAINAGE REPORT GODFREY BOTTOMS COMPRESSOR STATION Midstream. • 1.0 Purpose The purpose of this Detailed Drainage Report (Report) is to establish overall storm water drainage patterns, constraints and details for a proposed Godfrey Bottoms Compressor Station (site). It includes an analysis of onsite and offsite hydrology, and calculations to substantiate onsite and offsite hydraulic design. 2.0 Site Location The site is located on an approximately 150-acre (ac) parcel of vacant land located in the northeast quarter of Section 10, Township 4 North, Range 66 West, approximately six (6) miles southwest of the town of Greeley, Colorado. The site is located west of the intersection of Weld County Road 33 and Weld County Road 64. The location is shown in Figure 1. According to the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM) Community Panel Number 0822660750C, Weld County, Colorado, dated September 28, 1982. The site is located within a Flood Zone "X". Zone"X" is described as an area outside the 0.2% annual chance flood plain. FEMA Map showing the approximate site location is shown in Figure 2. • • ENERCON E R C O N (405) 722-7693 3 DRAINAGE REPORT cp GODFREY BOTTOMS COMPRESSOR STATION • Midstream,. 1 + -7%\r`.. ; • * ~ Lr �ll��,•��►+h+►sf..Fwt . av P. I '. 'i.•ti �� _ � i -:. • •''. � .. It, _� �.. t � , ••� ill 4. yr w� NIP e fr.4. �_ fy'!A n K J , - • am . Li., " � •;•-• '#' �'GREEtEY, r , ,A • a A `� _ 1. Its I .. - 4.:41 {.I -e-^ ...N.: . - Ire l .. a in :.* -4 I - , } ( �1. ". ....2__ �w, / SITE R ! �. - � .� ._ • r. :;. . . . _. T w -GIs, }ia + i ' . % nit r . r • • ' --�' I .... i .trx'M , t i i V. 4. ...M•- ., :. •tom ..... y . c, {i '< i-11 I .. -r' ;ate .4-141 fJ/ - y •Y= t A !._. 1, � � ' �° OK Figure 1 — Site Location • .,r:; �� I 1 f _ _ AMR0JI:MAtI )Ul: E< D :ix,f[I- . II _ ._ I • G••rI S wax PX I j - - -._- - - r '- _. - i . �a"'E'i V6- - _ - - N 1 Saes►NN r'its MUM • J / L=__�ir__JL_-_ - -^ fir FIRM iC 1 11000 PISORANCE RATE MAP 1� Q`T i) ■ 'G WELD COUNTY, �' ! zCNrE C II Ir COLORADO ', I I QNLICORPORATRD AIWA Project1`— ►1NEE7S0of N175 w...,........ ...,•.-.... Site `: li -- - J' rI C31011,011111 PAIR NO R ►/ r - 080186 07$0 C II YAP REVISED: nRT' f SfPEfYREk7d 1982,cli/ 1 f••.r Irr.ti rr•.r..•.:Won J I .w annoy••w0►••• ammo 2• 1•wq M e ,o <N.p•• ,•:' I 1 h.Yen Fe •haw wt.*Ma Y!•Smiler h .4 I tea*•II••h,.Me . N• _-. ih Y+rwl•.••.M•4wr•l y•Went 1.•wd••.•w• f'••Q.!'1•'tl1 Tom•CMt•OW I[1Y Y000 My Went M[M•00. • Figure 2 — FEMA Map • r3 ENERCON E R C O N (405) 722-7693 4 ticdlcia DRAINAGE REPORT GODFREY BOTTOMS COMPRESSOR STATION • Midstream. 3.0 Site Layout The general site layout is provided in Figure 3. Figure 3 also shows the general storm water drainage pattern and the proposed storm water detention basin location. U I Detention • a Basin band ! 111, �a - a... - C Figure 3 — Proposed rainfall-runoff Flow Pattern 4.0 Methodology The overall hydrology of the site and hydraulics of the storm water drainage system was analyzed using HydroCAD (Reference 1) and FlowMaster (Reference 2) software. HydroCAD utilizes Natural Resources Conservation Service (NRCS) Soil Conservation Service (SCS) TR- 20 methodology to compute runoff. The results are presented in Appendix A — HydroCAD Existing Condition, Appendix B - HydroCAD Proposed Condition, and Appendix C — FlowMaster Analysis. The limits of drainage remained the same as the existing condition. However, there were minor shifts in sub-basin boundaries to accommodate the grading. The rainfall-runoff analysis is performed within HydroCAD software using the NRCS SCS methodology. The standard SCS 24-hour storm is used to identify the rainfall events. The SCS Type II rainfall distribution is the distribution applicable to Weld County, Colorado as shown in Figure 4. The SCS unit hydrograph method is used to transform rainfall to runoff. The SCS curve number method is used to account for precipitation losses during the storm event. Storage- Induction method was used within HydroCAD for reach and pond routing. • ENERCON E R C O N (405) 722-7693 5 emP dC DRAINAGE REPORT GODFREY BOTTOMS COMPRESSOR STATION • Midstream_ Site parameters (e.g., elevations, distances, areas, etc.) are determined using AutoCAD (Reference 3) software and the existing/proposed site contours. The increase in runoff due to site development will be staged at the detention basin. The proposed conditions runoff staged at the detention basin will be released at a controlled rate so as to not exceed the existing conditions runoff rate. The detention basin is designed to have adequate storage to provide extreme flood control for up to a 100 Year, 24 Hour storm event runoff from the proposed site. The proposed embankment will be an earthen embankment structure. The embankment slopes are 4: 1 (horizontal: vertical). The erosion control plan and details are shown in Erosion Control Plan and Detail Sheets (Attachments D & E) respectively. 5.0 Watershed Delineation The historic onsite drainage pattern for the project site is generally to the northeast. The rainfall- runoff is conveyed as sheet flow and shallow concentrated flow across the site. Under the existing condition, drainage areas for the project site have been divided into two (2) sub-basins EOB 1 and EOB2 as shown in the Existing Onsite Drainage Map (Attachment A). Sub-basin EOB 1 represents the proposed compressor station site. Sub-basin EOB2 represents the proposed detention basin area. There is an additional offsite area (EOB3) which was analyzed for hydraulic design of the proposed culvert across the proposed access road at the intersection of Weld County Road 33 . Sub-basin EOB3 indicates the area west of the Weld County Road 33. This area (EOB3) will drain across the proposed access road via a 30-inch Reinforced Concrete Pipe (RCP). • Under the proposed conditions, drainage areas for the project site have been subdivided into two (2) sub-basins POB1 , and POB2 as shown in the Proposed Onsite Drainage Map (Attachment B). A detention basin is proposed at the northeast corner of the proposed development; this is represented by sub-basin POB2. Sub-basin POB 1 represents the proposed compressor station site. Runoff from sub-basins POB 1 is conveyed to detention basin via gravel lined swale, a 24- inch High Density Polyethylene (HDPE) pipe, and a 24-inch RCP pipe. • 10 ENERCON E R C O N (405) 722-7693 6 ditu.75- DRAINAGE REPORT GODFREY BOTTOMS COMPRESSOR STATION III Midstream. 6.0 Design Inputs Rainfall Depth As shown in Figure 4, the SCS Type II distribution is applicable to Weld County, Colorado. The HydroCAD software incorporates the SCS Type II distribution. However, in order to fully describe the rainfall event, the 24-hour total rainfall depth is needed. The National Oceanic Atmospheric Administration (NOAA) Atlas 2 (Reference 4) provides rainfall frequency maps for various events. The total rainfall depths for various frequencies are provided in Table 1 and are based on the location of the site as shown in Figures 4 and 5. At„, eminrial_ .... i Mar IA t `'ice' , 1, tta 14 /tl�„ i. t sta f--S, in re. . 4ifranr . :It e t r. . .- . 1/4 hirroa �.: � A� .'il,.i�.i•�•jtj �4i1•+�� . '�.•r `tom r�.rr -� �. -- :- U�Z�'��:.f�1�2•�. FIB/� �aI". y r �'� `r S�i•K" ' mot♦ ♦.� If• ilaillanEUMIL , _.) 122.,; -, , i . • a ...rte tik EC.:AL 4 ,. :a,....... , . : � - J4 ir, ,,,..........I, Et_ r. . _. .., .--,...;.:,;,:t;;;,,-...tv in • I Rainfall t --/ �. Godfrey Bottoms Distribution Compressor Station ' I Type I NM Type IA i '• ---- �� NM Type II �� r y - 4.y `I A TypeIII ,T III 11 1 III L �, ; '. t--- Figure 4 — SCS Rainfall Distributions The rainfall intensity affecting the Site has been referenced from NOAA Atlas 2. The rainfall depths with the proposed site location for 5-year and 100-year for 24-hour events are shown in Table 1 . Rainfall Depths Storm Event for a 24-hour storm (inch) 5-year 2.35 100-year 4.40 Table 1 - Rainfall Depths for 24-hour storm • OENERC0N (405) 722-7693 7 dC DRAINAGE REPORT GODFREY BOTTOMS COMPRESSOR STATION Midstream. • W. . - -- -- - 1a 10f KM 10Q �._.ere 1T---4 11142 " t. 441 1 2 :\a 1. - :) pe_ie.., -,"••--i . � 2. > > inc -- 7 it.- 1 . -it::v -11; Goofrey Bottoms ' . Compressor • :A. '.y -. 1- Y•"�"'t-�•l�.' ice. \ �\ r it 4 Station t \ 1 +�.- - -- --- --+ -r- 1 as SON al • la I SIN . pant r NOS • NISI le s‘ --- • ' - --r - t. 4 ' - --1 ---ik 1 . • • _ _,, .. ,.._ , , , ,, ' L___._ t • , ' • • '' • 1 • t tq .\ F 1 :I 1-,i .1i . 7w� 1 1.---.\ l b I I �' �`� tt • i 3 1 �:.Q • • 1 ' � 1i Or M N r Li II CIS sa COLORADO .o..eta&1.—. Iq,.V w $ 1 MOM w.r-ersIA 0r -FZ :-• -illaiwillani ISIIBIO If0/tlh.4l C(VII 3440 rLLC11T414011S —L. ...r SOS ire.Veils.re o..r.•r. T(1004011./CM ...-w ri a+.w-r.w/..•, 10a— la 10T )O. RH �a1 --- ICJ to ` • Figure 5 — 5-Year, 24-Hour Rainfall a __ __a_ 1M IM _ t _ WI 104 t 40 .. _ -sr I ar . kLriviriti_ - ---. - -I.-- I , 1 ,., , 11 ;11 t �� ' 4,40 ' h - _ 1 ---i I. , far iti ta [ jv Y' + iiek 1 ;�r ► "'" �� _�� r; 7 ;Godfrey Bottoms 11 ipielt_1 - r �� `� . -9 iCompressor L : ) sit �-- -'* • ._\„' ,_ 1 . ,, 'o`er_ et') 1 i ' ( rw7 �i Trl A c't' • f .mss. 1 r ✓•! j,u*m �' • s �• 1• - N 1 r � Ifs :t1% nb , - - - r..., eat T �t�i mritRaest. • _ ,-• i 4' .- i r 1---- -44" --1." is irsit Ills . I` , k ` �, .� -:alt . 1 - - ; I% ` • ) 1S ''re f T.., , , 1 voit , 4 w...r 1 t � t 1 f' ' k4 1 71 -_ .•,_ _±.- . ,A-4;\-- ._�_ ��'^�• : -..• /JI�� __� 1_ ' ___-..r++ale 1 a 1 • 7 A 1 IONS CMS • f • COLORADO .rir.nr t r..• fen T1 • I • ass ..r-.../...- r.r... .......r.r .w�.rr. SON. Of 100 A?1M�LfIT flON -- --- -- en �I....:Y••• ` , w Tatty Of Ni 1401 101 -_- -SP Ni..-_ _- 10S _ - 5 Figure 6 — 100-Year, 24-Hour Rainfall O ENERCON E R C O N (405) 722-7693 8 'JeepDRAINAGE REPORT GODFREY BOTTOMS COMPRESSOR STATION Midstream. • Soil T e va The NRCS Web Soil Survey (Reference 5) was used to determine the hydrologic soil group for the site. The soil map shown in Figure 7 identifies that the area of concern has a hydrologic soil group of B. The hydrologic soil group is used for the SCS curve number method. Hydrologic Sod Group—Weld County. Colorado- Southern Part :: r . a a 'We .OW .. •. 1.1 ..." 520700 a:.. 52'4X0 527, . !u2I!017 0 20 7 40 :J Soil Ratings eM. O A/D a MI B BID O C O CID § O D ' Drainage Area Not rated or not available Rough Outline ft j ill s • : _ . atir I . ngr i 40 1947 ...• • •. .• •• 4 5w" •,tl0 S..:a. 5-a:.. 521.r. _r!0Q meoSu1a 14500 a c>M13onAhot 05-.11')sheet Wren c N 3 50 10C :00 �0 2• /IA ree 3 400 10C , :: LISD‘ Natural Resources Web Soil Survey 6/2912011 Conservation Service National Cooperative Sod Survey Page 1 of 4 Figure 7 — NRCS Soils Map Curve Number The NRCS Technical Release No. 55 (TR-55) identifies the SCS curve numbers (CN) for the various cover conditions and hydrologic soil group. Currently, the site is vacant pastureland. Under developed conditions, there are three (3) types of cover to consider. There are impervious areas (e.g., parking lot, buildings, etc.), gravel lined areas, and open ground cover areas adjacent to the impervious/gravel areas that are bare or maintain short growth vegetation. • F3 E N E R C O N (405) 722-7693 9 dC DRAINAGE REPORT GODFREY BOTTOMS COMPRESSOR STATION Midstream. • corresponds to a CN of 98. Curve Number of 88 was used for gravel lined Impervious cover areas; which corresponds to urban industrial area. The open ground cover is categorized as fair condition with 50% to 75% ground cover corresponding to a CN of 69 for soil type B. 1 ar lensa ENa Gut nip Pal It- -a- *vs limmai Ob Operig I •s4a =Me Om Oat Cow* Wet Pta It scan kelleira-. 41W Is Fbr w•SIEamf.7' / a1' w 0S•OW One Revd MIS PrCOEW Aran+ a t aniola1LF. C . Cre OM 41t 47L. N\11C► v Sin*s Oad�wY 11.313.104 d10'• s Del; hIIV MMAai+Q ) tit les et M a1 dorm dqN 47q MbMq.Mt7M . Aga Nlf, Ps•lir% MI/.O Y 11�jr0 ws ere 47t tun 1 Mk M ata III 4717' �� 0� ■w o.7' ai MI:--i WOE Aawsw aslraMaM i 1 1 .�. 1E •am1C avw�s PwU Mai OW bids-- l O _____ __ ladAr0ISI - srwa t Ouldir.asar. \I Oa la Os Sta a MbMwftly Ift �� On•OX% • \ b ! . , / aM OMMO.w ism ase ors u7' MapitIV MIN•OM• Figure 8 — Impervious Cover • OENERC0N (405) 722-7693 10 dC DRAINAGE REPORT GODFREY BOTTOMS COMPRESSOR STATION • Midstream, / AIIo I >r JS Wan r . EM Is OS CSPr ARb ar its Saw Is CS tTY OS,ICalien't00wr ntaGalI / Cs, x1aE Per IE satin Enerr Y WS tans W•PIEon71 47 1 W a .7,f- past• ! _ f Crane PS Is / S�i Ole xro ale(..J r4 p • San LP p Sten PM -�-Slie 77pa1!Owo eraMCP ors obi la lm OS SS • it .•01130' d71r Mn"• sous, el p1.pp.7tri . OS SLY. tii\\ 7Tlrlw b I�rpnbNw/rf► ow llp•!DS 1 ISM dal r` O=1tapaa M Film .eMi. air A)" 5, ' I it PO „LucCi" - O,f *nil: _im l�� I - . �at a�odba l ygy 1 Q 1" I _ . 1 1 ...,. aw,to Nadi MR) r w_,er . I _ RRatt tbibbq.0.0 L 1-Er f..-1 i..r \ L , 14 ins Ms • Ss Ss Din Mpsatty sa•on% Figure 9 — Open Ground Cover As described below sub-basin POB 1 has an area of 3.40 ac comprising the proposed compressor station site. The impervious cover area for sub-basin POB 1 is approximately 0. 17 ac and is shown in Figure 8. The open ground cover area for sub-basin POB 1 is approximately 0.26 ac and is shown in Figure 9. The remaining drainage area of 2.97 ac (3 .40 ac - 0. 17 ac — 0.26 ac) for sub-basin POB1 is gravel. CNimperviou * Areaimnervious + CNpoen * Areaopen + CN Qravel * AreaQravel Drainage Area CNPOB1 = (88 * 2.97 ac + 69 * 0.26 ac + 98 * 0. 17 ac) / 3 .40 ac = 87.05 = 87 Sub-basins EOB2 and POB2 represent proposed detention basin area for existing and proposed conditions respectively; corresponding to CN value of 69. Sub-basin EOB 1 and EOB3 represents open ground cover corresponding to CN of 69. • O ENERCON E R C O N (405) 722-7693 11 _/�-.-I�- DRAINAGE REPORT �■ GODFREY BOTTOMS COMPRESSOR STATION • Midstream. Design Length and Slope for Time of Concentration HydroCAD utilizes SCS TR-55 method to determine the time of concentration (Tc). The SCS TR-55 method consists of categorizing portions of the hydraulic length into overland flow, shallow concentrated flow, or channel flow. The travel time for each segment of flow is summed to result in the time of concentration. Weld County Drainage Manual (Reference 6) recommends minimum Tc value of 10 minutes for non-urban watersheds. The time of concentration is estimated using initial sheet flow and channelized flow within the ditches. HydroCAD model is set to use Tc value of 10 minutes; if the estimated Tc values is less than 10 minutes (Appendix A and B). As indicated above, sub-basin POB2 represents the detention basin area; therefore Tc value of 0 min. is used in the runoff analysis to indicate instantaneous runoff. The sheet flow and channelized flow characteristics (length and slope) are determined using the grading plan (Attachment C) for the site. The initial overland, sheet, and channel flow lengths used in HydroCAD are summarized below in Table 2. The initial overland flow length of 100 feet(ft)was used for each sub-basin except sub-basin EOB3. Shallow Sheet Flow Concentrated Channel Flow Sub- Area Flow Basin (ac) Length Slope Length Slope Length Slope (ft) (ft/ft) (ft) (ft/ft) (ft) (ft/ft) • Existing Conditions EOB1 3.30 100 0.0027 455 0.0027 EOB2 0.26 100 0.0027 115 0.0027 - - Total 3.56 Offsite Basin (Access Road Culvert) EOB3 129.50 300 0.0027 5370 0.0027 - - Total 129.50 Proposed Conditions POBI 3.40 100 0.0027 275 0.0027 190 0.0027 POB2 0.26 - - - - - - Total 3.66 Table 2—Length & Slope Inputs for Tc Determination • ENERCON E R C O N (405) 722-7693 12 . DRAINAGE REPORT �■ GODFREY BOTTOMS COMPRESSOR STATION • Midstream. Storage Volume The storage area at each elevation was determined using the AutoCAD 5 ft and 1 ft interval contours. The storage areas were then used to determine the storage volume. The storage areas are shown in Figure 10. The storage volume is presented in Table 3. 4718' y1 4713' Figure 10—Storage Area Elevation Area Volume(ac-ft) (ft) (ac) Incremental' Cumulative" 4713 0.07 0 0 4714 0.10 0.085 0.085 4715 0.12 0.11 0.195 4716 0.15 0.135 0.33 4717 0.18 0.165 0.495 4718 0.21 0.195 0.69 Table 3—Storage Volume a) Incremental=(Area X +Area Y) /2 • b) Cumulative= Incremental X +Incremental O ENERCON E R C O N (405) 722-7693 13 ci cp DRAINAGE REPORT Midstream. GODFREY BOTTOMS COMPRESSOR STATION • Manning's Roughness Manning's roughness coefficients used in hydraulic analysis utilizing FlowMaster are listed below in Table 4. Material Manning's Roughness Coefficient Gravel 0.029 HDPE 0.010 RCP 0.013 Table 4—Manning's Roughness Coefficient Source: Chow Book(Reference 7) 7.0 Calculation Hydraulic and Hydrologic Calculations The overall hydrology of the existing and proposed site conditions were analyzed using HydroCAD software. The existing condition results are presented in Appendix A. The proposed condition results are presented in Appendix B. Resultant rates of runoff for the 5-year and 100- year frequency storms are summarized in Table 5- Runoff Summary. The proposed conditions will increase the peak storm water runoff. The increase in runoff due to change in land cover will be staged at the detention basin. The proposed conditions runoff detained at the detention basin will be released at a controlled rate so as to not exceed the existing conditions runoff rate. • The proposed storm water drainage structures (i.e. swales, storm drain pipe, and detention basin) have been designed to have adequate capacity to convey discharges from up to a 100-year, 24 hour storm frequency. The hydraulic capacity of the proposed drainage system was assessed using the FlowMaster software. The proposed detention basin is 5 ft deep with a crest elevation at 4718 ft and a 4 ft embankment width. The detention basin has a 24-inch HDPE standpipe with opening for 5-year and 100-year runoff and an emergency spillway. A 12-inch opening is proposed at an elevation of 4714.55 ft to discharge the rainfall-runoff from 5-year rain event. The top of 24-inch standpipe is at elevation 4715.75 ft. The standpipe is open at top to discharge 100-year rainfall-runoff. A concrete spillway (emergency spillway) is located at elevation 4717.75 ft along the north boundary of detention basin. The detention basin calculations are shown in Appendix B. The hydraulic calculations for swales and pipes are shown in Appendix C. The hydraulic calculations for the detention basin (Appendix B) indicates that the total discharge from the detention basin during 100-year rain event is 5.80 cfs which is less than the existing condition runoff of 7.71 cfs. Similarly for 5-year rain event, the total discharge from the detention basin is 1.02 cfs which is less than the existing condition runoff of 1.47 cfs. • ENERCON E R C O N (405) 722-7693 14 dcp DRAINAGE REPORT Midstream. GODFREY BOTTOMS COMPRESSOR STATION • Peak Flow (cfs) Drainage Area Sub Basin 5-Year 100-Year Storm Storm Existing Conditions EOB1 1.19 6.81 EOB2 0.28 0.90 Total 1.47 7.71 Offsite Basin (Access Road Culvert) EOB3 I 5.30 I 27.10 Proposed Conditions POB1 6.11 15.12 POB2 0.16 0.82 Total 6.27 15.94 Table 5—Runoff Summary Note Composite hydrograph presents peak flow at the design outlet point. Individual drainage areas represent unrouted peak flows. The flows within the proposed swale and pipes were analyzed using FlowMaster software. The runoff from sub-basin POB 1 will drain via the proposed gravel and 24-inch HDPE Pipe. Catch basins have been proposed to connect the 24-inch HDPE to the detention basin. Please refer to • the Proposed Onsite Drainage Map (Attachment B) for catch basin and pipe location. The results from the FlowMaster analysis are shown in Table 6. 100-Year Runoff Slope Depth of Flow Velocity (cfs) (ft/ft) (ft) (ft/sec) Swale POB1 15.12 0.0027 1.41 2.45 24-inch RCP (POB1) 15.12 0.005 1.55 5.79 24-inch HDPE (POB1) 15.12 0.005 1.26 7.22 30-inch RCP(Access 27,10 0.004 2.17 5.99 Road EOB3) Table 6—FlowMaster Analysis Results • ENERCON E R C O N (405) 722-7693 15 dDRAINAGE REPORT C r GODFREY BOTTOMS COMPRESSOR STATION Midstream. • Water Quality Capture Volume(WOCV) Calculation As indicated in the Weld County Drainage Manual, the required WQCV can be estimated using following equation: WQCV= a(0.91 I3- 1.19 12 + 0.78 I) (Reference 6; Equation 3-1,Page 930) Where: WQCV = Water Quality Capture Volume (watershed inches) a=Coefficient corresponding to WQCV drain time I = Imperviousness (%) As indicated in the Drainage Manual (Reference 6), the value of coefficient "a" ranges from 0.8 to 1.0 depending on drain time. The value of coefficient"a" chosen was 0.80 corresponding to 12 hour drain time. The Drainage Manual indicates a percentage imperviousness value of 80 for light industrial facilities. Therefore, the value of I was chosen to be 0.80. The transformed basin areas will consist of sub-basins POB1 and POB2. Therefore water quality drainage area will be 3.56 ac(3.40 ac +0.26 ac) WQCV =0.80 (0.91 * 0.803- 1.19 * 0.802+ 0.78 * 0.80) =0.80 (0.46592-0.7616 +0.624)watershed inches =0.262656 * (3.56 ac) * Oft/12 inch) • =0.078 ac-ft<0.1825 OK As mentioned earlier, the invert elevation for the 12-inch pipe opening is 4714.55 ft. Therefore, there is one and half foot of water quality storage available. Table 3 indicates that the available volume for the detention basin. Therefore, the available storage volume for first one-half foot will be 0.1825 ac-ft (0.085 ac-ft + ((0.085 ac-ft + 0.11 ac-ft) / 2)). The WQCV is less than the available volume. 8.0 References 1) HydroCAD 8.0, HydroCAD Software Solutions LLC, P.O. Box 477, Chocorua, NH 03817. 2) FlowMaster 3.1, Service Pack 3, Open Channel Design & Analysis, Haestad Methods, Inc., 37 Brookside Road, Waterbury, CT 06708-149. 3) Autodesk, AutoCAD Lite Desktop Software, 2006. 4) U.S. Department of Commerce, National Oceanic and Atmospheric Administration, and National Weather Service's NOAA Atlas 2 Precipitation- Frequency Atlas of the western United States, Volume- III Colorado, prepared by J.F. Miller, R.H. Fredrick, and R.J.Tracey, 1973 5) United States department of Agriculture, Natural Resource Conservation Service, Soil Data Mart http://soildatamart.nrcs.usda.gov/. • ENERCON E R C O N (405) 722-7693 16 d �"'� DRAINAGE REPORT C�--+ GODFREY BOTTOMS COMPRESSOR STATION • Midstream. 6) Urban Drainage and Flood Control District's, Denver Colorado — "Urban Storm Drainage Criteria Manual", Volumes 1,2, and 3;, June 2001 Revised April 2008. 7) Chow, V.T., "Open Channel Hydraulics," McGraw-Hill, New York, 1959. END OF REPORT • • E N E R C O N (405)722-7693 17 Godfrey Bottoms Compressor Station HydroCAD Existing Conditions Appendix A • <EOB> <EOB2> EOB1 EOB2 Proposed Detention Pond Area • <EOB3 EOB3 Offsite Basin (Access Road Culvert) ID Subcat Reach on• Link Drainage Diagram for CS#2_Exisitng Conditions Prepared by{enter your company name here} 7/19/2011 HydroCAD®8.00 sin 004197 ©2006 HydroCAD Software Solutions LLC Page 1 of 10 Godfrey Bottoms Compressor Station HydroCAD Existing Conditions Appendix A • CS#2_Exisitng Conditions Prepared by {enter your company name here} Page 2 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Area Listing (all nodes) Area (acres) CN Description (subcats) 129.500 69 50-75% Grass cover, Fair, HSG B (EOB3) 3.300 69 Pasture/grassland/range, Fair, HSG B (EOB1) 0.260 79 Pasture/grassland/range, Fair, HSG C (EOB2) 133.060 • • Page 2 of 10 Godfrey Bottoms Compressor Station HydroCAD Existing Conditions Appendix A • CS#2_Exisitng Conditions Type II 24-hr 5-year Rainfall=2.35" Prepared by{enter your company name here} Page 3 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment EOB1: EOB1 Runoff Area=3.300 ac Runoff Depth=0.35" Flow Length=555' Slope=0.0027 T Tc=12.9 min CN=69 Runoff=1.19 cfs 0.097 af Subcatchment EOB2: EOB2 Proposed Detention Pond Area Runoff Area=0.260 ac Runoff Depth=0.74" Flow Length=215' Slope=0.0027'/' Tc=10.0 min CN=79 Runoff=0.28 cfs 0.016 af Subcatchment EOB3: EO83 Offsite Basin (Access Road CuRunoff Area=129.500 ac Runoff Depth=0.35" Flow Length=5,670' Slope=0.0027 'P Tc=320.4 min CN=69 Runoff=5.30 cfs 3.825 af Total Runoff Area = 133.060 ac Runoff Volume = 3.938 of Average Runoff Depth =0.36" 100.00% Pervious Area = 133.060 ac 0.00% Impervious Area= 0.000 ac • • Page 3 of 10 Godfrey Bottoms Compressor Station HydroCAD Existing Conditions Appendix A • CS#2_Exisitng Conditions Type II 24-hr 5-year Rainfall=2.35" Prepared by{enter your company name here} Page 4 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Subcatchment EOB1: EOB1 Runoff = 1.19 cfs @ 12.08 hrs, Volume= 0.097 af, Depth= 0.35" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 5-year Rainfall=2.35" Area (ac) CN Description 3.300 69 Pasture/grassland/range, Fair, HSG B 3.300 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (fUft) (fUsec) (cfs) 3.8 100 0.0027 0.44 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.60" 9.1 455 0.0027 0.84 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 12.9 555 Total Subcatchment EOB1: EO61 Hydrograph •Runoff 1.19 cfs Type II 24-hr 5-year Rainfall=2.35" 1- Runoff Area=3.300 ac Runoff Volume=0.097 af Runoff Depth=0.35" E Flow Length=555' Slope=0.0027 '/' Tc=12.9 min CN=69 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) • Page 4 of 10 Godfrey Bottoms Compressor Station HydroCAD Existing Conditions Appendix A • CS#2_Exisitng Conditions Type II 24-hr 5-year Rainfall=2.35" Prepared by {enter your company name here} Page 5 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Subcatchment EOB2: EOB2 Proposed Detention Pond Area Runoff = 0.28 cfs @ 12.03 hrs, Volume= 0.016 af, Depth= 0.74" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 5-year Rainfall=2.35" Area (ac) CN Description 0.260 79 Pasture/grassland/range, Fair, HSG C 0.260 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.8 100 0.0027 0.44 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.60" 2.3 115 0.0027 0.84 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 6.1 215 Total, Increased to minimum Tc= 10.0 min Subcament EOB2: EOB2 Proposed Detention Pond Area Hydrograph / ■Runoff • 0.3= 1 0.28 cfs 0.28i Type II 24-hr 5-year 0.26= Rainfall=2.35" 0.24= 0.22' Runoff Area=0.260 ac 0,2? Runoff Volume=0.016 af 0,6= Runoff Depth=0.74" LL 0.14- Flow Length=215' 0.12' Slope=0.0027 'I' Tc=10.0 min 0.08= 0.06 CN=79 0.04= 0.02= 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) • Page 5 of 10 Godfrey Bottoms Compressor Station HydroCAD Existing Conditions Appendix A • CS#2_Exisitng Conditions Type II 24-hr 5-year Rainfall=2.35" Prepared by{enter your company name here} Page 6 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Subcatchment EOB3: EOB3 Offsite Basin (Access Road Culvert) Runoff = 5.30 cfs @ 16.75 hrs, Volume= 3.825 af, Depth= 0.35" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 5-year Rainfall=2.35" Area (ac) CN Description 129.500 69 50-75% Grass cover, Fair, HSG B 129.500 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 74.3 300 0.0027 0.07 Sheet Flow, Grass: Short n= 0.150 P2= 1.60" 246.1 5,370 0.0027 0.36 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 320.4 5,670 Total Subcatchment EOB3: EOB3 Offsite Basin (Access Road Culvert) Hydrograph / •Runoff • 15.30 cfs 1 Type II 24-hr 5-year 5- Rainfall=2.35" Runoff Area=129.500 ac 4- Runoff Volume=3.825 af 3- Runoff Depth=0.35" LL Flow Length=5,670' 2- Slope=0.0027 '/' Tc=320.4 min CN=69 1- 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) • Page 6 of 10 Godfrey Bottoms Compressor Station HydroCAD Existing Conditions Appendix A • CS#2_Exisitng Conditions Type II 24-hr 100-year Rainfall=4.40" Prepared by {enter your company name here} Page 7 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment EOB1: EOB1 Runoff Area=3.300 ac Runoff Depth=1.53" Flow Length=555' Slope=0.0027 'P Tc=12.9 min CN=69 Runoff=6.81 cfs 0.422 af Subcatchment EOB2: EOB2 Proposed Detention Pond Area Runoff Area=0.260 ac Runoff Depth=2.29" Flow Length=215' Slope=0.0027'/' Tc=10.0 min CN=79 Runoff=0.90 cfs 0.050 af Subcatchment EOB3: EOB3 Offsite Basin (Access Road CuRunoff Area=129.500 ac Runoff Depth=1.53" Flow Length=5,670' Slope=0.0027 'P Tc=320.4 min CN=69 Runoff=27.10 cfs 16.550 af Total Runoff Area= 133.060 ac Runoff Volume= 17.022 af Average Runoff Depth = 1.54" 100.00% Pervious Area = 133.060 ac 0.00% Impervious Area= 0.000 ac • • Page 7 of 10 Godfrey Bottoms Compressor Station HydroCAD Existing Conditions Appendix A • CS#2_Exisitng Conditions Type II 24-hr 100-year Rainfall=4.40" Prepared by{enter your company name here} Page 8 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Subcatchment EOB1: EO61 Runoff = 6.81 cfs @ 12.06 hrs, Volume= 0.422 af, Depth= 1.53" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-year Rainfall=4.40" Area (ac) CN Description 3.300 69 Pasture/grassland/range, Fair, HSG B 3.300 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.8 100 0.0027 0.44 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.60" 9.1 455 0.0027 0.84 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 12.9 555 Total Subcatchment EOB1: EOB1 Hydrograph • / 6.81 cfs I ■Runoff Type II 24-hr 100-year 6- Rainfall=4.40" Runoff Area-3.300 ac 5= Runoff Volume=0.422 af 4- Runoff Depth=1.53" rz Flow Length=555' 3- Slope=0.0027 '/' 2 Tc=12.9 min CN=69 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 38 38 40 42 44 46 48 50 52 54 56 58 60 82 64 66 68 70 72 Time (hours) • Page 8 of 10 Godfrey Bottoms Compressor Station HydroCAD Existing Conditions Appendix A CS#2_Exisitng Conditions Type II 24-hr 100-year Rainfall=4.40" • Prepared by{enter your company name here} Page 9 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Subcatchment EOB2: EOB2 Proposed Detention Pond Area Runoff = 0.90 cfs @ 12.02 hrs, Volume= 0.050 af, Depth= 2.29" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-year Rainfall=4.40" Area (ac) CN Description 0.260 79 Pasture/grassland/range, Fair, HSG C 0.260 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (f/sec) (cfs) 3.8 100 0.0027 0.44 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.60" 2.3 115 0.0027 0.84 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 6.1 215 Total, Increased to minimum Tc = 10.0 min Subcatchment EOB2: EOB2 Proposed Detention Pond Area Hydrograph • 0.90 cfs Type II 24-hr 100-year Rainfall=4.40" Runoff Area=0.260 ac Runoff Volume=0.050 af Runoff Depth=2.29" 2 Flow Length=215' u. Slope=0.0027 '/' Tc=10.0 min CN=79 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) • Page 9 of 10 Godfrey Bottoms Compressor Station HydroCAD Existing Conditions Appendix A CS#2_Exisitng Conditions Type II 24-hr 100-year Rainfall=4.40" • Prepared by{enter your company name here} Page 10 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Subcatchment EOB3: EOB3 Offsite Basin (Access Road Culvert) Runoff = 27.10 cfs @ 16.05 hrs, Volume= 16.550 af, Depth= 1.53" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-year Rainfall=4.40" Area (ac) CN Description 129.500 69 50-75% Grass cover, Fair, HSG B 129.500 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 74.3 300 0.0027 0.07 Sheet Flow, Grass: Short n= 0.150 P2= 1.60" 246.1 5,370 0.0027 0.36 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 320.4 5,670 Total Subcatchment EOB3: EOB3 Offsite Basin (Access Road Culvert) Hydrograph • 30./ ■Runoff 28 127.10 cfs l 26 Type II 24-hr 100-year 24 Rainfall=4.40" 22 Runoff Area=129.500 ac 20 Runoff Volume=16.550 af ;6 Runoff Depth=1.53" 14 Flow Length=5,670' LL 12 Slope=0.0027 '/' 10 Tc=320.4 min 6 CN=69 6 4 2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 5052 54 56 58 60 62 64 66 68 70 72 Time (hours) • Page 10 of 10 Godfrey Bottoms Compressor Station HydroCAD Proposed Conditions Appendix B • POB• POB1 • POB2 A Detention Pond (POB2) Godfrey Bottoms Compressor Station Detention Pond • 4ubc) Reach on. Link Drainage Diagram for CS#2 Proposed Conditions / Prepared by{enter your company name here} 7/19/2011 HydroCAD®8.00 s/n 004197 O2006 HydroCAD Software Solutions LLC Page 1 of 12 Godfrey Bottoms Compressor Station HydroCAD Proposed Conditions Appendix B • CS#2 Proposed Conditions Prepared by {enter your company name here} Page 2 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Area Listing (all nodes) Area (acres) CN Description (subcats) 0.260 69 (POB2) 3.400 87 Urban industrial, 72% imp, HSG B (POB1) 3.660 • • Page 2 of 12 Godfrey Bottoms Compressor Station HydroCAD Proposed Conditions Appendix B • CS#2 Proposed Conditions Type II 24-hr 5-year Rainfall=2.35" Prepared by(enter your company name here} Page 3 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment POB1: POB1 Runoff Area=3.400 ac Runoff Depth=1.19" Flow Length=565' Slope=0.0027 '/' Tc=10.0 min CN=87 Runoff=6.11 cfs 0.336 af Subcatchment POB2: Detention Pond (POB2) Runoff Area=0.260 ac Runoff Depth=0.35" Flow Length=1' Tc=0.0 min CN=69 Runoff=0.16 cfs 0.008 af Pond 2P: Godfrey Bottoms Compressor StPeak Elev=4,714.76' Storage=0.167 af Inflow=6.14 cfs 0.344 af Primary=1.02 cfs 0.201 af Secondary=0.00 cfs 0.000 af Outflow=1.02 cfs 0.201 af Total Runoff Area= 3.660 ac Runoff Volume= 0.344 af Average Runoff Depth = 1.13" 33.11% Pervious Area= 1.212 ac 66.89% Impervious Area = 2.448 ac • • Page 3 of 12 Godfrey Bottoms Compressor Station HydroCAD Proposed Conditions Appendix B • CS#2 Proposed Conditions Type II 24-hr 5-year Rainfall=2.35" Prepared by {enter your company name here} Page 4 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Subcatchment POB1: POB1 Runoff = 6.11 cfs @ 12.02 hrs, Volume= 0.336 af, Depth= 1.19" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 5-year Rainfall=2.35" Area (ac) CN Description 3.400 87 Urban industrial, 72% imp, HSG B 0.952 Pervious Area 2.448 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.7 100 0.0027 0.46 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.75" 1.5 190 0.0027 2.12 12.69 TrapNee/Rect Channel Flow, Bot.W=4.00' D=1.00' Z= 2.0'/' Top.W=8.00' n= 0.029 4.3 275 0.0027 1.05 Shallow Concentrated Flow, Paved Kv= 20.3 fps 9.5 565 Total, Increased to minimum Tc = 10.0 min • Subcatchment POB1: POB1 Hydrograph •Runoff 6.11 cfs 6 Type II 24-hr 5-year Rainfall=2.35" 5- Runoff Area=3.400 ac Runoff Volume=0.336 af 42. Runoff Depth=1.19" 2 Flow Length=565' u. 3 Slope=0.0027 '/' 2 Tc=10.0 min CN=87 0 2 4 6 8 1012 ,4 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) • Page 4 of 12 Godfrey Bottoms Compressor Station HydroCAD Proposed Conditions Appendix B CS#2 Proposed Conditions Type II 24-hr 5-year Rainfall=2.35" • Prepared by{enter your company name here} Page 5 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Subcatchment POB2: Detention Pond (POB2) [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff = 0.16 cfs @ 11.91 hrs, Volume= 0.008 af, Depth= 0.35" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 5-year Rainfall=2.35" Area (ac) CN Description 0.260 69 0.260 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.0 1 12.69 Lake or Reservoir, Mean Depth= 5.00' Subcatchment POB2: Detention Pond (POB2) Hydrograph 0.18 / •Runoff 0,17= 10.16 cfs 0.16u. Type II 24-hr 5-year Rainfall=2.35" 0.14= 0.13 Runoff Area=0.260 ac 012, Runoff Volume=0.008 af °•i= Runoff Depth=0.35" Jr! 0.08 Flow Length=1' 0.0Th Tc=0.0 min aosi 0.05- CN=69 0.04 0.03? 0.02= 0.01 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) • Page 5 of 12 Godfrey Bottoms Compressor Station HydroCAD Proposed Conditions Appendix B • CS#2 Proposed Conditions Type 1124-hr 5-year Rainfall=2.35" Prepared by {enter your company name here} Page 6 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Pond 2P: Godfrey Bottoms Compressor Station Detention Pond Inflow Area = 3.660 ac, Inflow Depth = 1.13" for 5-year event Inflow = 6.14 cfs @ 12.02 hrs, Volume= 0.344 af Outflow = 1.02 cfs @ 12.35 hrs, Volume= 0.201 af, Atten= 83%, Lag= 20.3 min Primary = 1.02 cfs @ 12.35 hrs, Volume= 0.201 af Secondary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 4,714.76' @ 12.35 hrs Surf.Area= 0.115 ac Storage= 0.167 af Plug-Flow detention time= 234.3 min calculated for 0.201 af(58% of inflow) Center-of-Mass det. time= 116.9 min ( 951.6- 834.7 ) Volume Invert Avail.Storage Storage Description #1 4,713.00' 0.690 af Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 4,713.00 0.070 0.000 0.000 4,714.00 0.100 0.085 0.085 4,715.00 0.120 0.110 0.195 • 4,716.00 0.150 0.135 0.330 4,717.00 0.180 0.165 0.495 4,718.00 0.210 0.195 0.690 Device Routing Invert Outlet Devices #1 Primary 4,714.55' 12.0" Horiz. 12 Inch Pipe opening Limited to weir flow C= 0.500 #2 Primary 4,715.75' 24.0" Vert. 24 Inch Dia Pipe C= 0.600 #3 Secondary 4,717.75' 5.0' long x 0.25' rise Overflow Flume 2 End Contraction(s) 0.5' Crest Height Primary OutFlow Max=1.02 cfs @ 12.35 hrs HW=4,714.76' (Free Discharge) '1=12 Inch Pipe opening (Weir Controls 1.02 cfs @ 1.51 fps) 2=24 Inch Dia Pipe ( Controls 0.00 cfs) $econdary OutFlow Max=0.00 cfs @ 1.00 hrs HW=4,713.00' (Free Discharge) 3=Overflow Flume ( Controls 0.00 cfs) • Page 6 of 12 Godfrey Bottoms Compressor Station HydroCAD Proposed Conditions Appendix B CS#2 Proposed Conditions Type II 24-hr 5-year Rainfall=2. 35" • Prepared by {enter your company name here} Page 7 HydroCAD® 8.00 s/n 004197 © 2006 HydroCAD Software Solutions LLC 7/19/2011 Pond 2P : Godfrey Bottoms Compressor Station Detention Pond Hydrograph ■ 6. 14 cfs Inflow Outflow Inflow Area=3 . 660 ac O Primary Secondary 6 Peak Elev=4, 714. 76' Storage=0 . 167 of 5 y 4 U 0 3 2 1 fl7 rf 1 .02 cfs 0.00 CfS ;/ 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 • Time (hours) • Page 7 of 12 Godfrey Bottoms Compressor Station HydroCAD Proposed Conditions Appendix B • CS#2 Proposed Conditions Type II 24-hr 100-year Rainfall=4.40" Prepared by {enter your company name here} Page 8 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Time span=1.00-72.00 hrs, dt=0.05 hrs, 1421 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment PO81: POB1 Runoff Area=3.400 ac Runoff Depth=3.01" Flow Length=565' Slope=0.0027 'P Tc=10.0 min CN=87 Runoff=15.12 cfs 0.852 af Subcatchment POB2: Detention Pond (POB2) Runoff Area=0.260 ac Runoff Depth=1.53" Flow Length=1' Tc=0.0 min CN=69 Runoff=0.82 cfs 0.033 af Pond 2P: Godfrey Bottoms Compressor Speak Elev=4,716.28' Storage=0.373 af Inflow=15.26 cfs 0.885 af Primary=5.80 cfs 0.742 af Secondary=0.00 cfs 0.000 af 0utflow=5.80 cfs 0.742 af Total Runoff Area= 3.660 ac Runoff Volume= 0.885 af Average Runoff Depth = 2.90" 33.11% Pervious Area= 1.212 ac 66.89% Impervious Area = 2.448 ac • • Page 8of12 Godfrey Bottoms Compressor Station HydroCAD Proposed Conditions Appendix B • CS#2 Proposed Conditions Type II 24-hr 100-year Rainfall=4.40" Prepared by {enter your company name here} Page 9 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Subcatchment P081: POB1 Runoff = 15.12 cfs @ 12.01 hrs, Volume= 0.852 af, Depth= 3.01" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-year Rainfall=4.40" Area (ac) CN Description 3.400 87 Urban industrial, 72% imp, HSG B 0.952 Pervious Area 2.448 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (f/ft) (ft/sec) (cfs) 3.7 100 0.0027 0.46 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.75" 1.5 190 0.0027 2.12 12.69 TrapNee/Rect Channel Flow, Bot.W=4.00' D=1.00' Z= 2.0'/' Top.W=8.00' n= 0.029 4.3 275 0.0027 1.05 Shallow Concentrated Flow, Paved Kv= 20.3 fps 9.5 565 Total, Increased to minimum Tc = 10.0 min • Subcatchment POB1: POB1 Hydrograph •Runoff 16 115.12 cfs 15 Type II 24-hr 100-year t313 Rainfall=4.40" 12 Runoff Area=3.400 ac Runoff Volume=0.852 af 10 9 Runoff Depth=3.01" LL 8 Flow Length=565' 6 Slope=0.0027 '/' 5 Tc=10.0 min 4 CN=87 3 2 1 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 5052 54 56 58 60 62 64 66 68 70 72 Time (hours) • Page 9 of 12 Godfrey Bottoms Compressor Station HydroCAD Proposed Conditions Appendix B • CS#2 Proposed Conditions Type II 24-hr 100-year Rainfall=4.40" Prepared by{enter your company name here} Page 10 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Subcatchment POB2: Detention Pond (POB2) [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff = 0.82 cfs @ 11.90 hrs, Volume= 0.033 af, Depth= 1.53" Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-72.00 hrs, dt= 0:05 hrs Type II 24-hr 100-year Rainfall=4.40" Area (ac) CN Description 0.260 69 0.260 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (fUft) (fUsec) (cfs) 0.0 1 12.69 Lake or Reservoir, Mean Depth= 5.00' Subcatchment POB2: Detention Pond (POB2) Hydrograph 0.9. / •Runoff • 0.85= 10.82 cfs 0.8. Type II 24-hr 100-year 0.75: Rainfall=4.40" 0.7- 0.65: Runoff Area=0.260 ac 06' Runoff Volume=0.033 af 0.55 0.5 - Runoff Depth=1.53" 2 °o4 Flow Length=1'- 0.35 Tc=0.0 min 03' CN=69 0.25. 0.2= 0.15- 0.1 0.05.. 0- 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) • Page 10 of 12 Godfrey Bottoms Compressor Station HydroCAD Proposed Conditions Appendix B CS#2 Proposed Conditions Type II 24-hr 100-year Rainfall=4.40" • Prepared by{enter your company name here) Page 11 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 7/19/2011 Pond 2P: Godfrey Bottoms Compressor Station Detention Pond Inflow Area = 3.660 ac, Inflow Depth = 2.90" for 100-year event Inflow = 15.26 cfs @ 12.01 hrs, Volume= 0.885 af Outflow = 5.80 cfs @ 12.17 hrs, Volume= 0.742 af, Allen= 62%, Lag= 9.8 min Primary = 5.80 cfs @ 12.17 hrs, Volume= 0.742 af Secondary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev=4,716.28' @ 12.17 hrs Surf.Area= 0.158 ac Storage= 0.373 af Plug-Flow detention time= 130.4 min calculated for 0.742 af(84% of inflow) Center-of-Mass det. time= 58.4 min ( 866.6-808.2 ) Volume Invert Avail.Storage Storage Description #1 4,713.00' 0.690 af Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 4,713.00 0.070 0.000 0.000 4,714.00 0.100 0.085 0.085 4,715.00 0.120 0.110 0.195 4,716.00 0.150 0.135 0.330 • 4,717.00 0.180 0.165 0.495 4,718.00 0.210 0.195 0.690 Device Routing Invert Outlet Devices #1 Primary 4,714.55' 12.0" Horiz. 12 Inch Pipe opening Limited to weir flow C= 0.500 #2 Primary 4,715.75' 24.0"Vert. 24 Inch Dia Pipe C= 0.600 #3 Secondary 4,717.75' 5.0' long x 0.25' rise Overflow Flume 2 End Contraction(s) 0.5' Crest Height Primary OutFlow Max=5.73 cfs @ 12.17 hrs HW=4,716.27' (Free Discharge) t1=12 Inch Pipe opening (Orifice Controls 4.13 cfs @ 5.26 fps) 2=24 Inch Dia Pipe (Orifice Controls 1.60 cfs @ 2.46 fps) Secondary OutFlow Max=0.00 cfs @ 1.00 hrs HW=4,713.00' (Free Discharge) 3=Overflow Flume ( Controls 0.00 cfs) • Page 11 of 12 Godfrey Bottoms Compressor Station HydroCAD Proposed Conditions Appendix B CS#2 Proposed Conditions Type II 24-hr 100-year Rainfall=4. 40" • Prepared by {enter your company name here} Page 12 HydroCAD® 8.00 s/n 004197 © 2006 HydroCAD Software Solutions LLC 7/19/2011 Pond 2P : Godfrey Bottoms Compressor Station Detention Pond Hydrograph ■ Inflow 15.26 cfs ❑ outflow r : . .. II Primary Inflow Area=3.660 ac 17= Secondary I 16- - Peak Elev=4,716 .28' 15; I I I , I I 14 , - , 1 . 1 . 1 Storage=0. 373 of I I I 1 I I 1 13- - Y - r - r 1 -I I -I - ` - t- -1- -1 - • II I 1 i i I I 1 I 1 1 I 11 I I I 1 1 1 t 1 I I I 1 I , I I I I I I I 11 ; 1 I I I I I I I ^ 10^ , N _o 9 = cRnrf 5.80 cfs - I I- r -I - ~ -I - 1 I + 6- / I I , I I . 1t III + I I I 4' 3; .., 0.00 cfs /%//// 0 I R$I 7I .l . �. .1• 1. 7 2 4 6 81 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 • Time (hours) • Page 12 of 12 Godfrey Bottoms Compressor Station FlowMaster Analysis Appendix C • Trapezoidal Channel- P0B1 Swale Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.029 Channel Slope 0.00270 ft/ft Left Side Slope 0.50 ft/ft(H:V) Right Side Slope 0.05 ft/ft(H:V) Bottom Wdth 4.00 ft Discharge 15.12 ft'/s Results Normal Depth 1.41 ft Flow Area 6.17 ft2 Wetted Perimeter 6.98 ft Top Wdth 4.77 ft Critical Depth 0.75 ft Critical Slope 0.01878 ft/ft Velocity 2.45 ft/s • Velocity Head 0.09 ft Specific Energy 1.50 ft Froude Number 0.38 Flow Type Subcritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity fl/s Normal Depth 1.41 ft Critical Depth 0.75 ft Channel Slope 0.00270 ft/ft Critical Slope 0.01878 ft/ft Bentley Systems,Inc. Bursted Methods Solution Center Bentley FlowMaster (08.01.066.00] 7/1/2011 4:67:34 AM 27 Siemens Company Drive Suite 200 W Watertown,CT 06796 USA +1-203-766-1666 Page 1 of 1 Page 1 of 7 Godfrey Bottoms Compressor Station FlowMaster Analysis Appendix C • Circular Pipe - 24 inch RCP (P081) Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.013 Channel Slope 0.00500 ftftt Diameter 2.00 ft Discharge 15.12 ft2ls Results Normal Depth 1.55 ft Flow Area 2.61 ft2 Wetted Perimeter 4.30 ft Top Width 1.67 ft Critical Depth 1.40 ft Percent Full 77.4 % Critical Slope 0.00635 ft/ft Velocity 5.79 fUs Velocity Head 0.52 ft • Specific Energy 2.07 ft Froude Number 0.82 Maximum Discharge 17.21 fN/s Discharge Full 16.00 iris Slope Full 0.00447 fUft Flow Type SubCritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Average End Depth Over Rise 0.00 % Normal Depth Over Rise 77.44 % Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s • Bentley Systems,Inc. Haestad Methods Solution Center Bentley FlowMaster [08.01.066.00] 7/19/2011 4:25:14 PM 27 Siemens Company Drive Suite 200 W Watertown,CT 06796 USA +1-203-755-1666 Page 1 of 2 Page 2of7 Godfrey Bottoms Compressor Station FlowMaster Analysis Appendix C • Circular Pipe - 24 inch RCP (P081) GVF Output Data Normal Depth 1.55 ft Critical Depth 1.40 ft Channel Slope 0.00500 ft/ft Critical Slope 0.00635 ft/ft • • Bentley Systems,Inc. Hamster!Methods Solution Center Bentley FlowMaster [08.01.066.00] 7/19/2011 4:25:14 PM 27 Siemons Company Drive Suite 200 W Watertown,CT 06795 USA +1.203-766-1666 Page 2 of 2 Page 3of7 Godfrey Bottoms Compressor Station FlowMaster Analysis Appendix C • Circular Pipe - 24 inch HDPE (POB 1) Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.010 Channel Slope 0.00500 Mt Diameter 2.00 ft Discharge 15.12 fN/s Results Normal Depth 1.26 ft Flow Area 2.09 ft' Wetted Perimeter 3.68 ft Top Wdth 1.93 ft Critical Depth 1.40 ft Percent Full 63.2 % Critical Slope 0.00376 ft/ft Velocity 7.22 fUs Velocity Head 0.81 ft • Specific Energy 2.07 ft Froude Number 1.22 Maximum Discharge 22.37 ft'/s Discharge Full 20.79 ft'/s Slope Full 0.00264 ft/ft Flow Type SuperCritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Average End Depth Over Rise 0.00 % Normal Depth Over Rise 63.24 % Downstream Velocity Infinity We Upstream Velocity Infinity fUs • Bentley Systems,Inc. Haeetad Methods Solution Center Bentley FlowMaster [08.01.066.00] 7119/2011 4:24:25 PM 27 Siemons Company Drive Suite 200 W Watertown,CT 06796 USA +1.203-766-1666 Page 1 of 2 Page 4 of 7 Godfrey Bottoms Compressor Station FlowMaster Analysis Appendix C • Circular Pipe - 24 inch HDPE (POB1) GVF Output Data Normal Depth 1.26 ft Critical Depth 1.40 ft Channel Slope 0.00500 ft/ft Critical Slope 0.00376 ft/ft • • Bentley Systems,Inc. Haestad Methods Solution Center 7/19/2011 4:24:26 PM 27 Siemons Company Bentley FlowMaster [08.01.066.00] Drive Suite 200 W Watertown,CT 06796 USA +1-203-766-1666 Page 2 of 2 Page 5of7 Godfrey Bottoms Compressor Station FlowMaster Analysis Appendix C • Circular Pipe - 30 inch RCP Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.013 Channel Slope 0.00400 ft/ft Diameter 2.50 ft Discharge 27.10 ft'/s Results Normal Depth 2.17 ft Flow Area 4.52 ft' Wetted Perimeter 5.99 ft Top Wdth 1.70 ft Critical Depth 1.78 ft Percent Full 86.7 % Critical Slope 0.00600 ft/ft Velocity 5.99 ft/s Velocity Head 0.56 ft • Specific Energy 2.73 ft Froude Number 0.65 Maximum Discharge 27.90 ft'/s Discharge Full 25.94 fP/s Slope Full 0.00437 Nft Flow Type SubCritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Average End Depth Over Rise 0.00 % Normal Depth Over Rise 86.70 % Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s • Bentley Systems,Inc. !tainted Methods Solution Center 27 Siemons Company Bentley FlowMaster (08.01.066.00] 7/1/2011 6:54:23 AM Drive Suite 200 W Watertown,CT 0679b USA .1-203-755-1666 Page 1 of 2 Page 6 of 7 Godfrey Bottoms Compressor Station FlowMaster Analysis Appendix C • Circular Pipe - 30 inch RCP GVF Output Data Normal Depth 2.17 ft Critical Depth 1.78 ft Channel Slope 0.00400 fUft Critical Slope 0.00600 ft/ft • • Bentley Systems,Inc. limited Methods Solution Center 27 Siemons Company Bentley FlowMaster [08.01.066.00] 7/1/2011 4:64:23 AM Drive Suite 200 W Watertown,CT 06796 USA t1-203-766-1666 Page 2 of 2 Page 7of7 • File contains CD with digital copy of Application materials • Please See Original File • Hello