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Home My WebLink About20112625.tiff • Exhibit N Drainage Report See the attached drainage report. • • 2011-2625 DRAINAGE REPORT FOR BERNHARDT COMPRESSOR STATION dcp Midstream DCP Midstream, LP 370 17`h Street Denver, CO 80202 June 2011 CI ENERCON Excellence—Every project. Every day. dtpoREfd FF4s(<\ Submitted By: CefiN Anubhav Gaur - Technical Specialist =__ o •.,•• •„: �SS/ONA��\\�i'° _ _3.)I Reviewed By: hh ^ Professional Engineer: Pat Brunette, P.E. Registration Number: 39164 State: CO Suraj Balan - Project Engineer • dCri DRAINAGE REPORT � ar BERNHARDT COMPRESSOR STATION • Midstream. 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 • CI ENERCON E R C O N (405) 722-7693 2 clap DRAINAGE REPORT BERNHARDT 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 Bernhardt 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 160-acre (ac) parcel of vacant land located in the southwest quarter of Section 30 and the northwest quarter of Section 31 , Township 5 North, Range 66 West, approximately eight (8) miles southwest of the town of Greeley, Colorado. The site is located east of the intersection of Weld County Road 25 and Weld County Road 52. The location is shown in Figure 1 . According to the Federal Emergency Management Agency (FEMA), the Flood Insurance Rate Map (FIRM) is not printed for the site. r sfr a ' : J . - / '#a 1 ' 1 V ' .• i - 1 t ' "3_i 1* / l I, •�' 1 •...,,k...r .aa w • t' ' ' , 1 'iLANDVOIAG[ ammositi y y '' 57:_ " ;.,rn.,• :C',is r{::. ti�i Ei Siill J 1.i4 . 0 • N a IN Willlir,1 , , "if • a : * \ r --, . ,:rratorpitimr___. , , • _. , , , 4 ilii\, ,_ CD 7 ..., eits, _ - , .. .egtitio.: ...Lt..: ..., _ arc .trieraitimeni, ). , Pr111453t'- pre Ms tar , ri 'tor As i a °Pa 0 ali At , . irol;/1>r 01aM*ztsAmoroso. ►Ira l iniArii iiaz. lg lift- - ` _, -g , aj 1 mg: ‘..,2.. . ,j . s, atttly.tirill A Nris --. - lc „_ riordreRiaist . 1 ( y . S t_.�.._ NO . -i tc0 .. .r :- .44.11711 044 [ ..`� � � E . �,,..,,:. er, �� j ' . . ��' , 1 a sue- „it IS li 1 cb„ t#Priii-d-, -- -4 = -/_' :4-:% i.‘Illf-fe pl/A ' lel \ r I . St II/ „ it - L t' fie' .�-S : , ( r A . ; 'sev r if f} ti �Q -a, N 1: 0 N-) op -1- ; ..-rt*e : 1.1 '‘. cs,i ‘,5 • .,(,- ,,lisc ,_ :ii. .. ...4:.; , , pri .,, . s _ ,/ 1 ,„ , i . -- ..., ,, wri,w.„."-,:,,,iiii,• ! �`y .. v"J... 1 ... , ---II I i-i ce ; iti i .it 1 r 4 . r Pi la . i iiit its ; 1 1 t IvI N 11 : 'I i i .e, i' 1, 1 _ " .- 1 •44 • s ..._i . , of • Figure 1 — Site Location CI ENERC0N E R C O N (405) 722-7693 3 dC DRAINAGE REPORT BERNHARDT COMPRESSOR STATION • Midstream. 3.0 Site Layout The general site layout is provided in Figure 2. Figure 2 also shows the general storm water drainage pattern and the proposed storm water detention basin location. ( ..L. - - r \ ., ►�.�►�w ♦ Detention \r. Y i I -- 1 Basin a" III II —1 _ r. Mil 'TVmum' • L_, ► _ aril • Iii I. 1 I ' • ' ■ M 1 . 0\7 Figure 2 — Proposed rainfall-runoff Flow Pattern • ID ENERCON E R C O N (405) 722-7693 4 dC DRAINAGE REPORT BERNHARDT COMPRESSOR STATION Midstream. 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 3. 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. 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 3 : 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 this project site has been divided into four (4) watersheds EOB1 , EOB2, EOB3, and EOB4 as shown in the Existing Onsite Drainage Map (Attachment A). Sub-basins EOB 1 and EOB2 represent the proposed compressor station site. Sub-basin EOB3 represents the proposed access road. Sub-basin EOB4 indicates the proposed detention basin area. The existing topography indicates there is a high point (hill) at the northwest corner of the proposed development, which will divert any offsite flows draining to the site from north-northwest direction. Under the proposed conditions, the site has been subdivided into four (4) watersheds POB 1 , POB2, POB3, and POB4 as shown in 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 POB4. Runoff from sub-basin POB 1 is carried to the proposed detention basin via proposed gravel swale and an 18- inch Corrugated Metal Pipe (CMP). The runoff from sub-basin POB2 will flow to the proposed detention basin via gravel lined swale. • The runoff from sub-basin POB3 is bypassed to flow as in existing conditions. ENERCON E R C O N (405) 722-7693 5 Cl DRAINAGE REPORT BERNHARDT COMPRESSOR STATION • Midstream. 6.0 Design Inputs Rainfall Depth As shown in Figure 3, 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. latratailleallagi my � r K ��f ♦qI ! .! s M!tr�it iii%f !s'iJi'i irA' Irt�Las , , rril�► l•I iilifiri ritlagli• r��rlat1 t1/��TA! �. w •ta sa�...r- s��r �apiF'ii ��iiraci� �"1ll t�ral. G. . ...,.. •� . . , . .� ■ r..�•urrrr r�a� I. •.� r•rr sa r"I r iar�rrrrr.rtrr.rrrrrrrr. r��• .. L N a e•�/�s. rlr. a........................................ ........... rrrrrrr � � itlSrr *C.�j� t�I��r�l�iY� /iv � ��-, g`� �rri r t r.� t{ atl=1 �� •.1 } .*f. r.l IN ` + arlr/ rd•a,i;�rr'�:��..•r71r�1{•••�+iIQ7 rpr��I•+t1�� .�,t�r( teaut � ��'��' • WiRr-. •• � � � '�r u� r �r►i �� . r�r� ice. 1 re � � �r'� �■ ■�a�.d. t=rrt�::r�ifr�.iis.�'w.�. ��^i i��e/�Ii e � s�•q��rrr�wt�a. l�a. •C• rrr •r.;: �� .y /�., l'I 61 Eat �n�nfistl. tr.■ Rkiia1l.-a.rif/ ��.-,...• ►�•i rrJ��. III litatiffiggraii;N:inaladapStliz":0;;;Ael rr ■ r� r�dRa - a • r��"ir kae .[SsN� ;: ��! r • " a- . yoga.,.■.rirur...r tic. 7.�ii 4`.�.', Rainfall / .; Bernhardt s-�_ .. d9 .u ,.� n"0H.,4: :'r.'.♦?"� Distribution 4 Compressor - :7 It: LAO iilisZre• I' . F,.., I-li T, ,,.. I Station Vo V 1 MI T,-Ii,• I:, , .. _, 4-, I s�'� , i i "'Hit. II 4.9%,-0 . '' i L pi' III I % • • Ing • lik46O ' V 401 III t Eike/ 4 ,! . ,�a0344 O<PM ‘—J Figure 3 — 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 4.30 Table 1 - Rainfall Depths for 24-hour storm • O ENERCON E R C O N (405) 722-7693 6 cJc DRAINAGE REPORT P BERNHARDT COMPRESSOR STATION 'ID Midstream. KS •0r Ttjr 1 it i " -� -� -• �' ,1 1. 2. 3 ncli---- - - r• /....-Y r i ea a1' i _ Bernhardt t1► t 1r� �. • �ly� rf.�y� , ) ,,� , COrnpre5sor r • 1 1 1 - �1* . . r :,h .. , '' Station _es • ••• �; ld \` -�� i i� 1 • - 1 - - ` sae" C • �"'�1° • 1 .y II t: --• . , . t is 1 1 lifirAir- 32 :IL' ' • 1 4 , > l• t s It --- - � j,'� `.;, , \Y,`' at i �, % sat at -J_-- —1-- ^----j. \♦ 1 1 • v 1 Y 1� . 1 r wviltS• 1 11 N• }'ice. ,:.,_ `Th/ t; 'J� t� 1 I L* I a i -II sfr r i e4' r 412 rY 71 F— I ^y. it C0I.0RAD0 ...r 4 , r fN M a r�mar+ �0 • � ____ AOPWrW.s or ivr M�vncsrt•noN w i Moe se he MINS Of 441114:14 Doe•.•.o..-••.•.See IlEltiess•et Leis be • , Figure 4 — 5-Year, 24-Hour Rainfall K. IN b7 101 _ 1M rtart iae - � ;► 1+ .L• s > cif `f� • - ` -_ 1 1 +a t- its 1 wt�»a •1' s .l" ...�cii-- - i• .3 -ohil , Ewa .. r �1 f--n. , 1 rnhardt ` * . ;.;.. . ( f � Ir• C fir:. �' �cL 14; Compressor 1 fTT�`ea ' 4. — -1 F•1 m- t ' li 1,.17 `• �c` `.;, ,, , = --- - _� jirseir ..;;;4:?•••tilt ••'" 14 . I le 1 I I. ' • ,� ' 1� alt • :; tf : ' I I— — ' • 1 . I • ( YAM 1 Al I Alp" • Vasil r r r rat • ralracu ter' I� • - COLORADO , 77.4 • -... • • I- •-• f 1...� a a �•',t""•�"""-"' 141041V1044.4 0• loom x••.111401•1441011.(_-r�{_- �r '`fir not emus►r•..r w¶ThThS d YI.ICJI rat=V w►.M O.r tat ---'C— - -- -- —,ps .03 -- '6) `1 i • Figure 5 — 100-Year, 24-Hour Rainfall O E N E R C O N (405) 722-7693 7 id DRAINAGE REPORT BERNHARDT COMPRESSOR STATION 0 Midstream. Soil Type The NRCS Web Soil Survey (Reference 5) was used to determine the hydrologic soil group for the site. The soil map shown in Figure 6 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 Pan (Bernhard Compressor Station) e St Y i 511100 51 11 5t4 . 51 00 St 11 51 ..1 511700 51 .11 51 ;al 51 011 51510(; 10 2i 5' I r + _' � Soil Ratings § / •1 el A ;` li, Di B " L .f Ill BID 'Ng inC s L.1 CA)as D wa: • Not rated or not available . § il H 3 i )1 ` 1. Drainage Area � ' `'1 i Rough Outline • . i i lk ) . 10 71.17 /y� /y .y� 40 T1-?.' 51 IX 51 1 51 •11 5! 1 51 1. 51 11 51 00 51 1 11 51 a 11 51•1.11 St ix W&al. 15500 1p on Mile 5 f 11-)vie A M Enlist, f9 3 N Pews A 0 50 100 200 300 a Fees 0 700 900 1200 1900 OSailNatural Resouloes Web Soil Survey 5/1542011 Conservat on Service National Cooperative Sod Survey Page 1 of 4 Figure 6 — 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. • CI ENERCON E R C O N (405) 722-7693 8 dC DRAINAGE REPORT BERNHARDT COMPRESSOR STATION 0 Midstream. Impervious cover corresponds to a CN of 98. Curve Number of 88 was used for gravel lined 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. Access Road 11al 18' CMR` (undergro • . Gravel le GYP I _ • p . • • :5 L.F.....„) Approx ttrtt.(. caw\ • 2.74% Bottom Wtd ' • E Depth 1.0' I.E. = 47 ` 4 Jude Slope 2H:1V. ►k e•� ,:'; , • Tope = 3.7 /° ��.. •• ,t '11 5-Year Storm Outfall /' ` t:1.� L B,�H PE Pipe I.E. = 4876' ��, v`'at / �`/hi 1 Year Storm Outfall ` '� .� I 12' Pipe, I.E. = 4876.80' �� _ — 4. ''i. i 1 ri Em ency Spillway, Irtatt_��` �� i• ////�i�1 !�O1, w = 0' I.E. 4879.50'p Cha el - / , i`�� (� L�im'• A I; i N4 I Mat . to Existi Grade with II _��l.L��..a. Co ae •. ,: • \ , sio• : • not toe et 3H:1 V t �� Fence , tillgthi;1111111 r 11/4 .� `� *s. .Ps > ,Gravel Swale Approx 250 L.F.,Bottom Width 4' IIIPI �; � =TDepth 1', Side Slope 2H:1V 1l� n s'a � ' 'i _ __ _ Slope = 0.50 % �'r• • 111 .4i ► 0319 e -l_ Mai t..,.., �1 ► x •► L_ .�. Apt •, �`��i �• 'r. ♦IIIIIIIill • 1 , ►� Bottq�mp ,th- ► t Side Stppe ' ' :1 • ...am , •' Slope 2.• 1 : .gia...i.,,i ! 4, I III ":-.- , 1 )4• • 4:9 Ili 1,1 ! lirli , " _ , : :4, .i, Grave Swale Approx 264 L.F.,Bottom Width 4' Depth 1', Side Slope 2H:1V Slope = 1.33 % Figure 7 — Impervious Cover • i1 ENERCON E R C O N (405) 722-7693 9 Cle DRAINAGE REPORT P BERNHARDT COMPRESSOR STATION Midstream. • Access tit I 18' • ( . . • • Gravel ' :lo T : I I . . . , L F. ..-----) Approx1 = - .F. • 2.74% Ii " Bottom • i 1' , . Depth 1.0' I.E. = 4 ( I I ide Slope 211:1 I*; .'• ' I •.r clops3.7 % eKM 5- ear Storm Outtall ,, ,` ‹ :�`'; ' i L 8 H E Pipe I.E. = 4876' .: f j \ l ; 1 Year Storm OutfaN / .' �` `/N',I ' i ''�/ j 1? Pipe, I.E. =4876.80' ,J ' 'Its �� -. ...` A* 1 ! , 1% / 111J11 Al l Em envy SplUway �_., � .�-.`_ � I •f�ll ' " w = 0' I.E. 4879.50' . 1 �� !1iJ1 ,I, I • I bEx� Gradewith• � , el. . . notb 311:1V 1\ w $k TFence �.,hh '4 , : Le .. .. .f.1 11 r r_ Gravel Bottom Wldlh 4' / nl;1 Approx 250 L // �� i Ili Depth 1', Side Slope 2H:1V r,�■-, ,i_ .. Slope = 0.50 % Pe rit`i'+'_miial\� ,es • / . ...A :� ,.� 1 Site i • • :1 is si I " allar.III �� Slope 2. 1 :MI r- 1 h. L„, 4I . • 9 ikt.. ,., Al i A 4009. • Al 4999. .. . . . ., Grave/Swale Approx 284 L.F.,Bottom WIdth 4' Depth 1', Side Slope 2H:1V Slope = 1.33% Figure 8 — Open Ground Cover As described below sub-basin POB 1 has an area of 0.68 ac comprising the northern portion of the site. The open ground cover area for sub-basin POB 1 is approximately 0. 14 ac and is shown in Figure 8. The remaining drainage area of 0.54 ac (0.68 ac - 0. 14 ac) for sub-basin POB 1 is gravel. CNimpervious. * Areaimpervious + CNope * Areame + CNgravei * Areagravel Drainage Area CNpOBI = (88 * 0.54 ac + 69 * 0. 14 ac) / 0.68 ac = 84.09 = 84 As described below sub-basin POB2 has an area of 2.61 ac. The impervious cover area for sub- basin POB2 is approximately 0. 16 ac and is shown in Figure 7. The open ground cover area for sub-basin POB2 is approximately 0. 14 ac and is shown in Figure 8. The remaining drainage area of 2.31 ac (2.61 ac - 0. 16 ac — 0. 14 ac) for sub-basin POB2 is gravel. • OENERC0N (405) 722-7693 10 DRAINAGE REPORT cha� BERNHARDT COMPRESSOR STATION • Midstream. The composite CN value for sub-basin POB2 is determined as follows: CNPOB2 =(98 * 0.16 ac+ 88 * 2.31 ac+ 69 * 0.14 ac)/2.61 ac = 87.6= 88 Sub-basin POB3 has an area of 0.15 ac which comprises of access road and area between access road and the detention basin. The open ground cover area for sub-basin POB3 is approximately 0.08 ac and is shown in Figure 8. The remaining drainage area of 0.07 ac (0.15 ac - 0.08 ac) for sub-basin POB3 is gravel lined access road. The composite CN value for sub-basin POB3 is determined as follows: CNPOB3 = (88 * 0.07 ac + 69 * 0.08 ac) /0.15 ac = 77.9 = 78 The access road is proposed to be gravel lined. Therefore, CN of 88 was used for sub-basin POB3. Sub-basins EOBI, EOB2, EOB3, EOB4, and POB4 represent open ground cover corresponding to CN of 69. 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 POB4 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. • ENERCON E R C O N (405) 722-7693 11 DRAINAGE REPORT �� BERNHARDT COMPRESSOR STATION • Midstream. 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 EOBI 0.95 100 0.0211 356 0.0211 - - EOB2 2.32 100 0.0482 210 0.0482 - - EO83 0.07 50 0.1000 200 0.1000 - - EOB4 0.26 156 0.096 - - Total 3.60 Proposed Conditions POBI 0.68 100 0.0300 275 0.0370 190 0.0370 POB2 2.61 100 0.0275 315 0.0255 750 0.0275 POB3 0.07 50 0.0700 200 0.070 - - POB4 0.26 - - - - - - Total 3.62 Table 2—Length & Slope Inputs for Tc Determination • • ENERCON E R C O N (405) 722-7693 12 dcp DRAINAGE REPORT Midstream. BERNHARDT COMPRESSOR STATION • Storage Volume The storage area at each elevation was determined using the AutoCAD 5 ft and I ft interval contours. The storage areas were then used to determine the storage volume. The storage areas are shown in Figure 9. The storage volume is presented in Table 3. 4880' / \ \ I\ // y 1 4875' / / / \ I LN \\% / i / / / \I It I Figure 9—Storage Area Elevation Area Volume(ac-ft) (ft) (ac) Incrementala Cumulative" 4875 0.07 0 0 4876 0.08 0.075 0.075 4877 0.10 0.090 0.165 4878 0.12 0.110 0.275 4879 0.14 0.130 0.405 4880 0.16 0.150 0.555 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 c1 p' DRAINAGE REPORT M d am_ BERNHARDT 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 CMP 0.010 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 4880 ft and a 6 ft embankment width. The detention basin has three outlets which involve pipes for 5-year and 100-year runoff and an emergency spillway. An 8-inch High Density Polyethylene (HDPE) pipe has been proposed to discharge 5-year rainfall-runoff The invert for 8-inch HDPE pipe is at elevation 4876 ft. A 12-inch HDPE pipe is proposed to discharge 100-year rainfall-runoff. The invert for 12-inch HDPE pipe is at elevation 4876.80 ft. A concrete spillway (emergency spillway) is located at elevation 4879.5 ft near the southeast end of the detention basin. The detention basin calculations are shown in Appendix B. The hydraulic calculations for swales and pipes are shown in Appendix C. Runoff from sub-basin POB3 is not staged at the proposed detention basin. The 100-year rainfall-runoff from sub-basin POB3 is 0.33 cfs and 0.48 cfs for existing and proposed conditions respectively. The increase in runoff from sub-basin POB3 due to change in land cover and grading is 0.15 cfs (0.48 cfs — 0.33 cfs). To account for this bypass flow, the 100-year outflow from the detention basin is designed not to exceed existing conditions runoff from sub-basins EOB1, EOB2, EOB4, in addition to 0.15 cfs. Therefore, the maximum allowed runoff from detention basin during 100-year rain event shall be 7.82 cfs (2.07 cfs+ 5.05 cfs + 0.55 cfs + 0.15 cfs). The HydroCAD results (Appendix B) indicate the total discharge from the detention basin during the 100-year rain event is 6.25 cfs which is less than the maximum allowed flow of 7.82cfs. The results also indicate that all storm frequency events are maintained below the • detention basin embankment crest elevation. ENERCON E R C O N (405) 722-7693 14 DRAINAGE REPORT -�� BERNHARDT COMPRESSOR STATION • Midstream. Peak Flow (cfs) Drainage Area Sub Basin 5-Year 100-Year Storm Storm Existing Conditions EOB I 0.40 2.07 EOB2 0.97 5.05 EOB3 0.06 0.33 EOB4 0.11 0.55 Total 1.54 8.00 Proposed Conditions POB1 1.03 2.69 POB2 4.95 11.57 POB3 0.15 0.48 POB4 0.16 0.79 Total 6.29 15.53 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 swales were analyzed using FlowMaster software. The runoff • from sub-basin POB1 will drain to the proposed gravel swale just north of the proposed development and then cross the access road via 18-inch CMP. A catch basin has been proposed on the north end of proposed access road to connect the 18-inch CMP to the detention basin. The runoff from sub-basin POB2 will drain to detention basin via a proposed gravel swale which encompasses the site to the east, south and to the west. 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@ 3.70 °° 2.69 0.037 0.54 4.32 slope Swale POB2 @ 1.33 % 11.57 0.133 0.68 3.90 slope Swale POB2@ 2.41 % 11.57 0.0241 0.57 4.75 slope 18-inch CMP (POB1) 2.69 0.0274 0.55 4.60 Table 6—FlowMaster Analysis Results • ENERCON E R C O N (405) 722-7693 15 dir DRAINAGE REPORT Midstream. BERNHARDT COMPRESSOR STATION • Water Quality Capture Volume(WQCV) 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. 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 * (3.62 ac) * (lft/12 inch) = 0.079 ac-ft 0.075 OK As mentioned earlier, the invert elevation for the 8-inch HDPE Pipe is 4876 ft. Therefore, there is one (1) foot of water quality storage available. Table 3 indicates that for the first one foot of • the detention basin, the available volume is 0.075 ac-ft. The WQCV is approximately equal to 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.nres.usda.gov/. 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 16 Bernhardt Compressor Station HydroCAD Existing Condition Appendix A • 1S 2S 3S EOB1 EOB2 EOB3 <4S> EOB4 Proposed Detention Pond Area • (Subcat) Reach -on. Link Drainage Diagram for CS#1_Exisitng Conditions Prepared by{enter your company name here} 5/25/2011 HydroCAD®8.00 s/n 004197 ®2006 HydroCAD Software Solutions LLC Page 1 of 24 Bernhardt Compressor Station HydroCAD Existing Condition Appendix A CS#1_Exisitng Conditions • Prepared by {enter your company name here} Page 2 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 Area Listing (all nodes) Area (acres) CN Description (subcats) 0.260 69 (4S) 3.420 69 Pasture/grassland/range, Fair, HSG B (1S,2S,3S) 3.680 • • Page 2 of 24 Bernhardt Compressor Station HydroCAD Existing Condition Appendix A CS#1_Exisitng Conditions Type 1124-hr5-year Rainfall=2.35" • Prepared by {enter your company name here} Page 3 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 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 1S: EOB1 Runoff Area=0.950 ac Runoff Depth=0.35" Flow Length=456' Slope=0.0211 '/' Tc=10.0 min CN=69 Runoff=0.40 cfs 0.028 af Subcatchment 25: EOB2 Runoff Area=2.320 ac Runoff Depth=0.35" Flow Length=310' Slope=0.0482'/' Tc=10.0 min CN=69 Runoff=0.97 cfs 0.069 af Subcatchment 3S: EOB3 Runoff Area=0.150 ac Runoff Depth=0.35" Flow Length=250' Slope=0.1000 '/' Tc=10.0 min CN=69 Runoff=0.06 cfs 0.004 of Subcatchment 4S: EOB4 Proposed Detention Pond Area Runoff Area=0.260 ac Runoff Depth=0.35" Flow Length=156' Slope=0.0960'/' Tc=10.6 min CN=69 Runoff=0.11 cfs 0.008 of Total Runoff Area = 3.680 ac Runoff Volume= 0.109 of Average Runoff Depth = 0.35" 100.00% Pervious Area= 3.680 ac 0.00% Impervious Area= 0.000 ac • • Page 3 of 24 Bernhardt Compressor Station HydroCAD Existing Condition Appendix A CS#1_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 5/25/2011 Subcatchment 1S: EOB1 Runoff = 0.40 cfs @ 12.05 hrs, Volume= 0.028 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 0.950 69 Pasture/grassland/range, Fair, HSG B 0.950 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 100 0.0211 0.99 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.60" 5.8 356 0.0211 1.02 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 7.5 456 Total, Increased to minimum Tc = 10.0 min Subcatchment 1S: EOB1 Hydrograph 0.44. •Runoff` • 0.42 10.40 cfs 038 Type II 24Lhr 5�year 0.36 Rainfall=2.35" 0.34- 0.32_ :Runoff Area=0.950 ac 0.3 0.28- - - • Runoff Volume=0.02$ of D. 6.26 024 Runoff Depth=0.35" 0:22 Flow Length=456' 0.18 LL0.16 Slope=0.021,1 /' • 0.14 0.12 0.0_thin' 0.08: CN-=69 0.06= 0.045 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 86 68 70 72 Time (hours) • Page 4 of 24 Bernhardt Compressor Station HydroCAD Existing Condition Appendix A CS#1_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 5/25/2011 Subcatchment 2S: EOB2 Runoff = 0.97 cfs @ 12.05 hrs, Volume= 0.069 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 2.320 69 Pasture/grassland/range, Fair, HSG B 2.320 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (f/sec) (cfs) 1.2 100 0.0482 1.38 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.60" 2.3 210 0.0482 1.54 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 3.5 310 Total, Increased to minimum Tc= 10.0 min Subcatchment 2S: EOB2 Hydrograph • 1- 0,97 cfs I ■Runoff` Type Ill 24-hr 5-year Rainfall=2.35" Runoff Area=2.320 ac Runoff Volume=0.069 af Runoff'Depth=0.35" LL Flow Length=3110' Slope=0.0482 Y' Tc=10.0 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 5 of 24 Bernhardt Compressor Station HydroCAD Existing Condition Appendix A CS#1_Exisitng 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 5/25/2011 Subcatchment 3S: EOB3 Runoff = 0.06 cfs @ 12.05 hrs, Volume= 0.004 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 0.150 69 Pasture/grassland/range, Fair, HSG B 0.150 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (f/ft) (ft/sec) (cfs) 1.5 200 0.1000 2.21 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 4.2 50 0.1000 0.20 Sheet Flow, Grass: Short n= 0.150 P2= 1.60" 5.7 250 Total, Increased to minimum Tc = 10.0 min Subcatchment 3S: EOB3 Hydrograph 0.07-1/ • 10.06 cfs •Runoff 0.065- 6.66- Type 24-hr 5tyear 6.655= Rainfall=2.35" 6.657 Runoff Area=0.150 ac 0045- Runoff Volune=0:0'04 at Runoff Depth=0.35 0.035- 0.037 Flo* Length=250' 6.625 Sio'pe=0.1000 /' 6.62 ! Tc=10.0 minty 0.0,5 CN=65 0.01 0.005 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 62 64 66 68 70 72 Time (hours) • Page 6 of 24 Bernhardt Compressor Station HydroCAD Existing Condition Appendix A • CS#1_Exisitng Conditions Type 1124-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 5/25/2011 Subcatchment 4S: EOB4 Proposed Detention Pond Area Runoff = 0.11 cfs @ 12.05 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) 10.6 156 0.0960 0.25 Sheet Flow, Grass: Short n= 0.150 P2= 1.60" Subcatchment 4S: EOB4 Proposed Detention Pond Area Hydrograph 0.115- ■Runoff 0 11 i 0.11 cfs 0.105: Type II 24-hr 5-year, • 6.695 6.69 Rainfall=2.35" 6.665 Runoff Area=0.260 ec 0.66 6.675 Runoff Volume=,0;0',0$ of 0.07 ?0.065 Runoff Depth=0.35" 0.06 00.055 Flow'L'eilgth=156' 0.05 0.045: S lope=0.096;0 0.04' 0.035 Tc=10.6 tin 0.025= CN=69 0.02= 0.015 0.01 0.005- 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 7 of 24 Bernhardt Compressor Station HydroCAD Existing Condition Appendix A • CS#1_Exisitng Conditions Type II 24-hr 100-year Rainfall=4.30" Prepared by {enter your company name here} Page 8 HydroCAD®8.00 s/n 004197 C12006 HydroCAD Software Solutions LLC 5/25/2011 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 1S: EOB1 Runoff Area=0.950ac Runoff Depth=1.47" Flow Length=456' Slope=0.0211 'P Tc=10.0 min CN=69 Runoff=2.07 cfs 0.116 af Subcatchment 2S: EOB2 Runoff Area=2.320 ac Runoff Depth=1.47" Flow Length=310' Slope=0.0482 '/' Tc=10.0 min CN=69 Runoff=5.05 cfs 0.283 af Subcatchment 3S: EOB3 Runoff Area=0.150 ac Runoff Depth=1.47" Flow Length=250' Slope=0.1000'/' Tc=10.0 min CN=69 Runoff=0.33 cfs 0.018 af Subcatchment 4S: EOB4 Proposed Detention Pond Area Runoff Area=0.260 ac Runoff Depth=1.47" Flow Length=156' Slope=0.0960 'P Tc=10.6 min CN=69 Runoff=0.55 cfs 0.032 af Total Runoff Area= 3.680 ac Runoff Volume = 0.449 af Average Runoff Depth = 1.47" 100.00% Pervious Area = 3.680 ac 0.00% Impervious Area=0.000 ac • • Page 8 of 24 Bernhardt Compressor Station HydroCAD Existing Condition Appendix A • CS#1_Exisitng Conditions Type 11 24-hr 100-year Rainfall=4.30" Prepared by{enter your company name here} Page 9 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 Subcatchment 1S: EOB1 Runoff = 2.07 cfs @ 12.02 hrs, Volume= 0.116 af, Depth= 1.47" 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=4.30" Area (ac) CN Description 0.950 69 Pasture/grassland/range, Fair, HSG B 0.950 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (f/sec) (cfs) 1.7 100 0.0211 0.99 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.60" 5.8 356 0.0211 1.02 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 7.5 456 Total, Increased to minimum Tc = 10.0 min Subcatchment 1S: EOB1 Hydrograph / • 12.07 cfs it Runoff 2- Type II 24-hr 100-year Rainfall=4.30" Runoff Area=0.950 ac Runoff Volume=0.116 af Runoff Depth=1.47" LL Flow Length- 466!, Slope=9.021',1 Tc:10.0 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 9 of 24 Bernhardt Compressor Station HydroCAD Existing Condition Appendix A CS#1_Exisitng Conditions Type II 24-hr 100-year Rainfall=4.30" • Prepared by(enter your company name here} Page 10 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 Subcatchment 2S: EOB2 Runoff = 5.05 cfs @ 12.02 hrs, Volume= 0.283 af, Depth= 1.47" 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=4.30" Area (ac) CN Description 2.320 69 Pasture/grassland/range, Fair, HSG B 2.320 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.2 100 0.0482 1.38 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.60" 2.3 210 0.0482 1.54 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 3.5 310 Total, Increased to minimum Tc = 10.0 min Subcatchment 2S: EOB2 Hydrograph ■Runoff • 5.05 cfs 5- Type II 24-hr 100-year Rainfall=4.30" 4- Runoff Area=2.320 ac Runoff Volume0.2',83 af 0 3- Runoff Depth=1.47" LL Flow'Length=31'0' 2- Slope=4.4482 ,/' Tc=10.0 ruin CN=69 17 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 24 Bernhardt Compressor Station HydroCAD Existing Condition Appendix A CS#1_Exisitng Conditions Type II 24-hr 100-year Rainfall=4.30" • Prepared by {enter your company name here} Page 11 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 Subcatchment 3S: EOB3 Runoff = 0.33 cfs @ 12.02 hrs, Volume= 0.018 af, Depth= 1.47" 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=4.30" Area (ac) CN Description 0.150 69 Pasture/grassland/range, Fair, HSG B 0.150 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.5 200 0.1000 2.21 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 4.2 50 0.1000 0.20 Sheet Flow, Grass: Short n= 0.150 P2= 1.60" 5.7 250 Total, Increased to minimum Tc = 10.0 min Subcatchment 3S: EOB3 Hydrograph 036• ■Runoff`0 34 10.33 cfs 0.321 Type II 24-hr 100-year 0.3= Rainfall=4.30" 0.28= 0.262 Runoff Area=0.150 00 0.24 0.22- Runoff Volume=0.0',18 at 0.2° Runoff Depth=1.47" c 0.16 Flow Lelhgth=25'0' 14 Slope=0.100'0 -'I' o 0., Tc=10.0 min 0.06 0.06 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 11 of 24 Bernhardt Compressor Station HydroCAD Existing Condition Appendix A CS#1_Exisitng Conditions Type 1124-hr 100-year Rainfall=4.30" • Prepared by {enter your company name here} Page 12 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 Subcatchment 4S: EOB4 Proposed Detention Pond Area Runoff = 0.55 cfs @ 12.03 hrs, Volume= 0.032 af, Depth= 1.47" 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=4.30" Area (ac) CN Description 0.260 69 0.260 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.6 156 0.0960 0.25 Sheet Flow, Grass: Short n= 0.150 P2= 1.60" Subcatchment 4S: EOB4 Proposed Detention Pond Area Hydrograph 0.s/ ■Runoff 0.55 cfs °.55_ • Type I.I 24-hr 100,-y,ear • 0.5= Rainfall=4.30" 0.45- Runoff Area=0.260 ac 0.4= • Runoff Valutme=0.032 af °35, Runoff'Depth=1.47' °.3j Flow Length=156' °.25- _ Slope=0.096,0 ',1/! Tcr10.6 min 0.15 CN=69 0.051 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 12 of 24 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B • 1S 3S POB1 POB2 (4s) Detention Pond (POB4) POB3 Bernhardt Compressor Station Detention Pond • 4ubca) Reach on. Link Drainage Diagram for CS#1 Proposed Conditions Prepared by{enter your company name here} 5/25/2011 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC Page 1 of 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B CS#1 Proposed Conditions • Prepared by {enter your company name here} Page 2 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 Area Listing (all nodes) Area (acres) CN Description (subcats) 0.260 69 (5S) 0.150 78 Urban industrial, 72% imp, HSG B (4S) 0.680 84 Urban industrial, 72% imp, HSG B (1S) 2.610 88 (3S) 3.700 • • Page 2 of 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B CS#1 Proposed Conditions Type 1124-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 5/25/2011 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 1S: POB1 Runoff Area=0.680 ac Runoff Depth=1.00" Flow Length=565' Tc=10.0 min CN=84 Runoff=1.03 cfs 0.057 of Subcatchment 3S: POB2 Runoff Area=2.610 ac Runoff Depth=1.25" Flow Length=1,165' Tc=10.0 min CN=88 Runoff=4.95 cfs 0.273 af Subcatchment 4S: POB3 Runoff Area=0.150 ac Runoff Depth=0.69" Flow Length=200' Slope=0.0700'/' Tc=10.0 min CN=78 Runoff=0.15 cfs 0.009 af Subcatchment 5S: Detention Pond (POB4) Runoff Area=0.260 ac Runoff Depth=0.35" Flow Length=11 Tc=0.0 min CN=69 Runoff=0.16 cfs 0.008 af Pond 2P: Bernhardt Compressor Station DPeak Elev=4,876.85' Storage=0.150 af Inflow=6.01 cfs 0.337 af Primary=1.22 cfs 0.262 af Secondary=0.00 cfs 0.000 af Outflow=1.22 cfs 0.262 af Total Runoff Area = 3.700 ac Runoff Volume= 0.346 af Average Runoff Depth = 1.12" 83.85% Pervious Area = 3.102 ac 16.15% Impervious Area =0.598 ac • • Page 3 of 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B CS#1 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 5/25/2011 Subcatchment 1S: POB1 Runoff = 1.03 cfs @ 12.02 hrs, Volume= 0.057 af, Depth= 1.00" 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 0.680 84 Urban industrial, 72% imp, HSG B 0.190 Pervious Area 0.490 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (fUsec) (cfs) 1.5 100 0.0300 1.14 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.60" 0.4 190 0.0370 8.06 56.40 TrapNee/Rect Channel Flow, Bot.W=5.00' D=1.00' Z= 2.0'1 Top.W=9.00' n= 0.029 1.2 275 0.0370 3.90 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.1 565 Total, Increased to minimum Tc = 10.0 min • Subcatchment 1S: POB1 Hydrograph / ■Runoff 1.03 cfs 1 Type Ii 24-hr 5-year Rainfall=2.35" Runoff Area=0.680 ac Runoff Volume0,Q57 at Runoff De'pth,=1.007 LL Flow Lehgth=565' Tc=10.0 min CNr84 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 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B CS#1 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 5/25/2011 Subcatchment 3S: POB2 Runoff = 4.95 cfs @ 12.02 hrs, Volume= 0.273 af, Depth= 1.25" 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 2.610 88 2.610 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (f/ft) (ft/sec) (cfs) 1.5 100 0.0275 1.10 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.60" 2.0 315 0.0255 2.57 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 1.8 750 0.0275 6.95 48.62 Trap/Vee/Rect Channel Flow, Bot.W=5.00' D=1.00' Z= 2.0 '/' Top.W=9.00' n= 0.029 5.3 1,165 Total, Increased to minimum Tc= 10.0 min Subcatchment 3S: POB2 • Hydrograph •Runoff - 4.95 cfs 5- Type IF 24-hr 5-year Rainfall=2.35" Runoff Area=2.610 ac Runoff Volume=0.273 af 3 ' Runoff Depth=1.25" o Flow Length=1,165' 2- Tc=I0.0 min CN=88 j 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 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B CS#1 Proposed 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 5/25/2011 Subcatchment 4S: POB3 Runoff = 0.15 cfs @ 12.03 hrs, Volume= 0.009 af, Depth= 0.69" 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 0.150 78 Urban industrial, 72% imp, HSG B 0.042 Pervious Area 0.108 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.8 200 0.0700 4.26 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.8 200 Total, Increased to minimum Tc= 10.0 min Subcatchment 4S: POB3 Hydrograph •Runoff • 0.16 10.15 cfs I 0.15 Type II 24-hr 5-year 0.14 .13=i Rainfall=2.35" 0.12 Runoff Area=0.150 ac 0.11E Runoff Volume=0:009 of 6.69 Runoff.Depth=0.69" • 008= Flow Length=200' LL 0.07; 0.06_ Slope=0.0700 y+ 0.05' Tc=10.0 min 0.04 •0.03 CN=78 0.02- 0.01- 0 ... .. .r . ...( 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 5254 56 58 60 62 64 66 68 70 7 r. .. .r..•,. �....�. ...�.. r..r 2 Time (hours) • Page 6 of 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B CS#1 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 5/25/2011 Subcatchment 5S: Detention Pond (POB4) [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) (fUsec) (cfs) 0.0 1 12.69 Lake or Reservoir, Mean Depth= 5.00' Subcatchment 5S: Detention Pond (POB4) Hydrograph 0.18 ■Runoff') 0.17, 10.16 cfs 0.16 Type II 24-hr 5-year 0.15 Rainfall=2.35" 0.14 0.13 'iRunoff Area=0.260 ac 0.,20.111 Runoff.Volume=0.008 af 1 0.1; Runoff Depth:0.35" • 0.09= u.• 0.06= Flow Length=1' 0.07; Tc=0:0 min 0.06- C N=69 0.05= 0.04- 0.03� 0.02 0.01 0 2 4 8 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 84 66 68 70 72 Time (hours) • Page 7 of 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B CS#1 Proposed Conditions Type 1124-hr 5-year Rainfall=2.35" • Prepared by {enter your company name here} Page 8 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 Pond 2P: Bernhardt Compressor Station Detention Pond Inflow Area = 3.550 ac, Inflow Depth = 1.14" for 5-year event Inflow = 6.01 cfs @ 12.02 hrs, Volume= 0.337 af Outflow = 1.22 cfs @ 12.29 hrs, Volume= 0.262 af, Atten= 80%, Lag= 16.3 min Primary = 1.22 cfs @ 12.29 hrs, Volume= 0.262 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=4,876.85' @ 12.29 hrs Surf.Area= 0.097 ac Storage= 0.150 af Plug-Flow detention time= 199.8 min calculated for 0.262 af(78% of inflow) Center-of-Mass det. time= 111.1 min ( 944.5- 833.3 ) Volume Invert Avail.Storage Storage Description #1 4,875.00' 0.555 af Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 4,875.00 0.070 0.000 0.000 4,876.00 0.080 0.075 0.075 4,877.00 0.100 0.090 0.165 4,878.00 0.120 0.110 0.275 • 4,879.00 0.140 0.130 0.405 4,880.00 0.160 0.150 0.555 Device Routing Invert Outlet Devices #1 Primary 4,876.00' 8.0"Vert. Orifice/Grate C= 0.600 #2 Primary 4,876.80' 12.0"Vert. Orifice/Grate C= 0.600 #3 Secondary 4,879.50' 5.0' long x 0.50' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 0.5' Crest Height rimary OutFlow Max=1.22 cfs @ 12.29 hrs HW=4,876.85' (Free Discharge) 1=Orifice/Grate (Orifice Controls 1.21 cfs @ 3.46 fps) 2=Orifice/Grate (Orifice Controls 0.01 cfs @ 0.75 fps) $econdary OutFlow Max=0.00 cfs @ 1.00 hrs HW=4,875.00' (Free Discharge) 3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) • Page 8 of 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B CS#1 Proposed Conditions Type II 24-hr 5-year Rainfall=2.35" • Prepared by{enter your company name here} Page 9 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 Pond 2P: Bernhardt Compressor Station Detention Pond Hydrograph ■Inflow 6.01 cfs ❑outflow Inflow area=3.550 ac :Primary Secondary 6 Peak Elev=4,876.85' Storage=0.150 of 5 4- L" u u. 3 2- 1.22 cfs 1 0.00 cfs 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 68 68 70 72 • Time (hours) • Page 9 of 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B CS#1 Proposed Conditions Type II 24-hr 100-year Rainfall=4.30" • Prepared by {enter your company name here} Page 10 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 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 1S: POB1 Runoff Area=0.680 ac Runoff Depth=2.64" Flow Length=565' Tc=10.0 min CN=84 Runoff=2.69 cfs 0.149 af Subcatchment 3S: POB2 Runoff Area=2.610 ac Runoff Depth=3.01" Flow Length=1,165' Tc=10.0 min CN=88 Runoff=11.57 cfs 0.654 af Subcatchment 4S: POB3 Runoff Area=0.150 ac Runoff Depth=2.13" Flow Length=200' Slope=0.0700 Tc=10.0 min CN=78 Runoff=0.48 cfs 0.027 of Subcatchment 55: Detention Pond (POB4) Runoff Area=0.260 ac Runoff Depth=1.47" Flow Length=1' Tc=0.0 min CN=69 Runoff=0.79 cfs 0.032 of Pond 2P: Bernhardt Compressor Station Peak Elev=4,878.35' Storage=0.318 of Inflow=14.39 cfs 0.836 af Primary=6.26 cfs 0.761 af Secondary=0.00 cfs 0.000 of Outflow=6.26 cfs 0.761 af Total Runoff Area = 3.700 ac Runoff Volume= 0.862 of Average Runoff Depth = 2.80" 83.85% Pervious Area = 3.102 ac 16.15% Impervious Area = 0.598 ac • • Page 10 of 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B CS#1 Proposed Conditions Type II 24-hr 100-year Rainfall=4.30" • Prepared by {enter your company name here} Page 11 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 Subcatchment 1S: POB1 Runoff = 2.69 cfs @ 12.01 hrs, Volume= 0.149 af, Depth= 2.64" 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=4.30" Area (ac) CN Description 0.680 84 Urban industrial, 72% imp, HSG B 0.190 Pervious Area 0.490 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (fUft) (ft/sec) (cfs) 1.5 100 0.0300 1.14 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.60" 0.4 190 0.0370 8.06 56.40 TrapNee/Rect Channel Flow, Bot.W=5.00' D=1.00' Z= 2.0 '/' Top.W=9.00' n= 0.029 1.2 275 0.0370 3.90 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.1 565 Total, Increased to minimum Tc= 10.0 min • Subcatchment 1S: POB1 Hydrograph 3l •Runoff 2.69 cfsl Type II 24-hr 100-year Rainfall=4.30" Runoff Area,0.680 ac 2- Runoff Volume*0',1',49 at 41 RunoffDepth=2.64" LL - Flow Length=565' Tc=10.0 min CN=84 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 11 of 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B • CS#1 Proposed Conditions Type II 24-hr 100-year Rainfall=4.30" Prepared by {enter your company name here} Page 12 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 Subcatchment 3S: POB2 Runoff = 11.57 cfs @ 12.01 hrs, Volume= 0.654 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=4.30" Area (ac) CN Description 2.610 88 2.610 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.5 100 0.0275 1.10 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.60" 2.0 315 0.0255 2.57 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 1.8 750 0.0275 6.95 48.62 TrapNee/Rect Channel Flow, Bot.W=5.00' D=1.00' Z= 2.0 '1 Top.W=9.00' n= 0.029 5.3 1,165 Total, Increased to minimum Tc= 10.0 min Subcatchment 3S: POB2 • Hydrograph / I ■Runoff 122. [11.57 cfs „ Type II 24-hr 100-year 10 Rairyfall=4.30" 9 Runoff Area=2.610 ao 6- Runoff Volume=0,654 at g 7 Runoff Depth=3.01" g 67 Flow'Len9th=1,165' 5- Tc=10.0 min CNF8a 2 0- ........n...,,...,..•.,..•.,...„... 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 12 of 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B • CS#1 Proposed Conditions Type II 24-hr 100-year Rainfall=4.30" Prepared by {enter your company name here} Page 13 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 Subcatchment 4S: POB3 Runoff = 0.48 cfs @ 12.02 hrs, Volume= 0.027 af, Depth= 2.13" 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=4.30" Area (ac) CN Description 0.150 78 Urban industrial, 72% imp, HSG B 0.042 Pervious Area 0.108 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (fUsec) (cfs) 0.8 200 0.0700 4.26 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.8 200 Total, Increased to minimum Tc= 10.0 min Subcatchment 4S: POB3 Hydrograph •Runoff • o.52 0.48 cfs Type II 24-hr 100-year 0.45- Rainfall=4.30" °`' Runoff Area=0.150 ac 0.35- Runoff Volume=0:0'27 af 0.3- Runoff'Depth=2..13" o 0.25- Flow•Lehgth=200' 0.21 Slope=0.Q700 'P 0.15 Tc=10.0 min 0.,3 CN=78 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 13 of 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B CS#1 Proposed Conditions Type II 24-hr 100-year Rainfall=4.30" • Prepared by {enter your company name here} Page 14 HydroCAD®8.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 Subcatchment 5S: Detention Pond (POB4) [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff = 0.79 cfs @ 11.90 hrs, Volume= 0.032 af, Depth= 1.47" 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=4.30" Area (ac) CN Description 0.260 69 0.260 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (fUft) (ft/sec) (cfs) 0.0 1 12.69 Lake or Reservoir, Mean Depth= 5.00' Subcatchment 5S: Detention Pond (POB4) Hydrograph 1 0.85: ■Runoff 0.79 cfs I 0.75 Type II 24-hr 100-year 0.7 Rainfall=4.30" 0.65 Runoff Area=0.260 ac 0.6 0.55 Runoff Volume=0.032 af 05 Runoff Depth=1.47" 0.45 LL Flow Length=1' 0.35 0.3 Tc=0.0 min 0.251 CN=69 0.21 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 14 of 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B CS#1 Proposed Conditions Type 1124-hr 100-year Rainfall=4.30" • Prepared by {enter your company name here} Page 15 HydroCAD®6.00 s/n 004197 ©2006 HydroCAD Software Solutions LLC 5/25/2011 Pond 2P: Bernhardt Compressor Station Detention Pond Inflow Area = 3.550 ac, Inflow Depth = 2.82" for 100-year event Inflow = 14.39 cfs @ 12.01 hrs, Volume= 0.836 of Outflow = 6.26 cfs @ 12.16 hrs, Volume= 0.761 af, Atten= 56%, Lag= 8.9 min Primary = 6.26 cfs @ 12.16 hrs, Volume= 0.761 af Secondary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 4,878.35' @ 12.16 hrs Surf.Area= 0.127 ac Storage= 0.318 of Plug-Flow detention time= 112.7 min calculated for 0.760 of(91% of inflow) Center-of-Mass det. time= 66.8 min ( 874.9 - 808.2 ) Volume Invert Avail.Storage Storage Description #1 4,875.00' 0.555 of Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 4,875.00 0.070 0.000 0.000 4,876.00 0.080 0.075 0.075 4,877.00 0.100 0.090 0.165 4,878.00 0.120 0.110 0.275 S 4,879.00 0.140 0.130 0.405 4,880.00 0.160 0.150 0.555 Device Routing Invert Outlet Devices #1 Primary 4,876.00' 8.0"Vert. Orifice/Grate C= 0.600 #2 Primary 4,876.80' 12.0" Vert. Orifice/Grate C= 0.600 #3 Secondary 4,879.50' 5.0' long x 0.50' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 0.5' Crest Height Primary OutFlow Max=6.25 cfs @ 12.16 hrs HW=4,878.35' (Free Discharge) t1=Orifice/Grate (Orifice Controls 2.38 cfs @ 6.83 fps) 2=Orifice/Grate (Orifice Controls 3.87 cfs @ 4.92 fps) Secondary OutFlow Max=0.00 cfs @ 1.00 hrs HW=4,875.00' (Free Discharge) 3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) • Page 15 of 17 Bernhardt Compressor Station HydroCAD Proposed Condition Appendix B CS#1 Proposed Conditions Type II 24-hr 100-year Rainfall=4. 30" • Prepared by {enter your company name here} Page 16 HydroCAD® 8.00 s/n 004197 © 2006 HydroCAD Software Solutions LLC 5/25/2011 Pond 2P : Bernhardt Compressor Station Detention Pond Hydrograph I 1 i I 1 I I I 1 • � i . . • I I , I I I I _ , _ I I. . 1 , i 1 I ■ Inflow 711/// 1 4.39pir cfs 1 I 1 I I I 1 1 El Outflow ` r I I I I I Inflow Area--3.'550 ac ■ Primary 16- I I , , _. , _ I _ i _ �_ _I _ I _ �. Secondary 1 I I I I 1 1 I I I I 15- I I- - I- -I I I I I I 1 Peak Elev=4, 878 . 35' 14: I I I I I I I 1 I I I I 1 ; I II 1 13 - ; - c � - �- -� - H - -H- , - , , ; ; -! ; ' Storage--0 . 318 of I I I I I I I I I I I I 1 1 12- - 7 - r - T 1 1 r 1 I i I I I f r -- 'T I r I I . I I I I I I I I I I I I I I I 1 I I I I I I I I I I I 11 I " J _ F- _ 1. - 1` _I - - I- -I ' _1 - /_ -1 - i H -1- --1 - i- - 1- _i - -1 -- F 1 4 II I I I I I I I I I 1 1 I I 1 I I I I I I I I I 1 I I 1 I 1 10 ' - '1 _ 1- - J- - 1" -1 - i I- -.i. -1 - J- 1- -1 - I- _I _ - - 1._ ..1 - -1 - ,_ -I.- I I I I I I I I I I I 1 I I I 1 I 1 1 I I I I I I 1 1 1 I I I a 9- F ?F rf 1 I IL : 1 1 L I I 1 L 1 1 I I I J _I _ 1. _ l_ _I _ 1 _ l_ _ I_ _ _ 1 I i 1 I I I 1 I I I 1 I I 1 III I I I I I I II I I I I .= 8 6.26 cfs L , _J _ ! _ L _1 -! I _ _1 -. 1 _ _J _ I _ I _ I _1 _ 1 _ L. !_ .! - I _ t_ .1 _ -1 _ !. I_. J _ 1 I I I I I II I I I I I I I I I I I I 0 i I I I I I I I I 1 : III I I 1 I I 1 I I 1 I I II I I I 1 7 .i I. _ _ _ _I . ' - _ I_ _I I _ -1 ._ _I _ .I _ I_ _' _ _ ._ I.. _ L_ _I _ _I �. _ _ _I _ u. 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Time (hours) III Page 17 of 17 Bernhardt Compressor station FlowMaster Analysis Appendix C • Trapezoidal Channel- P081 Swale Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.029 Channel Slope 0.03700 ft/ft Left Side Slope 0.50 ft/ft(H:V) Right Side Slope 0.05 ft/ft(H:V) Bottom Width 1.00 ft Discharge 2.69 fr/s Results Normal Depth 0.54 ft Flow Area 0.62 ft' Wetted Perimeter 2.15 ft Top Width 1.30 ft Critical Depth 0.58 ft Critical Slope 0.03085 ft/ft Velocity 4.32 ft/s • Velocity Head 0.29 ft Specific Energy 0.83 ft Froude Number 1.10 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 Downstream Velocity Infinity fus Upstream Velocity Infinity ft/s Normal Depth 0.54 ft Critical Depth 0.58 ft Channel Slope 0.03700 ft/ft Critical Slope 0.03085 ft/ft • Bentley Systems,Inc. Haestad Methods Solution Center Bentley FlowMaster [08.01.068.00] 6/20/2011 2:13:00 AM 27 Slemons Company Drive Suite 200 W Watertown,CT 06796 USA +1.203.765.1666 Page 1 of 1 Page 1 of 5 Bernhardt Compressor station FlowMaster Analysis Appendix C • Trapezoidal Channel- POB2 Swale O 1.33% Slope Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.029 Channel Slope 0.01330 ftft Left Side Slope 0.50 ft/ft(H:V) Right Side Slope 0.50 ft/ft(H:V) Bottom Wdth 4.00 ft Discharge 11.57 ft3/s Results Normal Depth 0.68 ft Flow Area 2.97 ft2 Wetted Perimeter 5.53 ft Top Wdth 4.68 ft Critical Depth 0.62 ft Critical Slope 0.01804 ft/ft Velocity 3.90 ft/s • Velocity Head 0.24 ft Specific Energy 0.92 ft Froude Number 0.86 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 fUs Upstream Velocity Infinity ft/s Normal Depth 0.68 ft Critical Depth 0.62 ft Channel Slope 0.01330 f ft Critical Slope 0.01804 ft/ft • Bentley Systems,Inc. Haestad Methods Solution Center Bentley FlowMaster [06.01.066.00] 5/20/2011 1:22:42 AM 27 Siemons Company Drive Suite 200 W Watertown,CT 06796 USA •1-203-766-1666 Page 1 of 1 Page 2 of 5 Bernhardt Compressor station FlowMaster Analysis Appendix C • Trapezoidal Channel- POB2 Swale @ 2.41% Slope Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.029 Channel Slope 0.02410 ft/ft Left Side Slope 0.50 ft/ft(H:V) Right Side Slope 0.50 ft/ft(H:V) Bottom Wdth 4.00 ft Discharge 11.57 ft/s Results Normal Depth 0.57 ft Flow Area 2.44 ft2 Wetted Perimeter 5.27 ft Top Wdth 4.57 ft Critical Depth 0.62 ft Critical Slope 0.01804 ft/ft Velocity 4.75 ft/s • Velocity Head 0.35 ft Specific Energy 0.92 ft Froude Number 1.15 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 Downstream Velocity Infinity ft/s Upstream Velocity Infinity fus Normal Depth 0.57 ft Critical Depth 0.62 ft Channel Slope 0.02410 ft/ft Critical Slope 0.01804 ft/ft • Bentley Systems,Inc. Haestad Methods Solution Center Bentley FlowMaster [08.01.066.00] 5/20/2011 1:23:00 AM 27 Siemons Company Drive Suite 200 W Watertown,CT 06795 USA +1-203-766-1666 Page 1 of 1 Page 3 of 5 Bernhardt Compressor station FlowMaster Analysis Appendix C • Circular Pipe - 24 inch CMP Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.024 Channel Slope 0.02740 ft/ft Diameter 1.50 ft Discharge 2.69 ft'/s Results Normal Depth 0.55 ft Flow Area 0.59 ft' Wetted Perimeter 1.95 ft Top Width 1.44 ft Critical Depth 0.62 ft Percent Full 36.6 % Critical Slope 0.01725 ft/ft Velocity 4.60 fUs Velocity Head 0.33 ft • Specific Energy 0.88 ft Froude Number 1.27 Maximum Discharge 10.13 ft'/s Discharge Full 9.42 ft'/s Slope Full 0.00224 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 36.58 % Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s • Bentley Systems,Inc. Haestad Methods Solution Center Bentley FlowMaster [08.01.066.00] 6/20/2011 2:13:44 AM 27 Siemons Company Drive Suite 200 W Watertown,C706795 USA N-203-766-1666 Page 1 of 2 Page 4 of 5 Bernhardt Compressor station FlowMaster Analysis Appendix C • Circular Pipe - 24 inch CMP GVF Output Data Normal Depth 0.55 ft Critical Depth 0.62 ft Channel Slope 0.02740 ft/ft Critical Slope 0.01725 ft/ft • • Bentley Systems,Inc. Haestad Methods Solution Center Bentley FlowMaster ]08.01.066.00] 6/20/2011 2:13:44 AM 27 Siemens Company Drive Suite 200 W Watertown,CT 06796 USA •t-20J-755-1666 Page 2 of 2 Page 5 of 5 • File contains CD with digital copies of Application materials • Please See Original File • Hello