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DR8601-CS 860520 ",-. -- ESPEY, HUSTON & ASSOCIATES, INC. Engineering & Environmental Consultants May 20, 1986 Mr. Ed Powell, P.E. Coppell City Engineer City of Coppell P.O. Box 478 Coppell, Texas 75011 EH&:A Job No. 8237-30 RE: Drainage Channel Failure Report Dear Ed: We have attached our report on the failure of the drainage channel for your review. Our conclusions were based on the available correspondence, construc- tion plans and our on-site inspection. We thank you for all your help, which was necessary in gathering the documents needed to review this report. We appreciate this opp~rtunity to be of service and are available at your convenience to discuss our conclusions and recommendations. If desired, we would be pleased to provide final construction plans for your selected alternatives. Sincerely, ~'/M~" Bob Whaling 1 BW:ss Enclosure 333 West Campbell Road, Suite 400, 4th Floor . Richardson, Texas 75080 . (214) 669-9600 ".- --.. Espey, Huston &: Associates, Inc. (EH&:A) was authorized by the City of Coppell on May 12, 1986 to provide an independent opinion in regard to the failure of the drainage channel in the Park wood Subdivision. EH&:A has obtained and reviewed, in cooperation with the City of Coppell, available correspondence and construction plans related to the drainage channel. EH&:A has discussed the problem with the City Staff and various staff members of consultants that have been involved with design, construction and/or inspection of this drainage channel. EH&:A has made a on-site inspection to provide additional information in determining the cause of the failure. ORIGIN AL DESIGN The original typical design cross-section for the drainage channel included a 15-foot wide earthen channel with 3:1 side slopes. An 8-foot concrete pilot lining was placed in the channel bottom at an 0.10% slope beginning at the 3-span 8x5 box culvert at Parkway Boulevard and ending approximately 2,000 feet downstream. From this point, the channel was to continue with the same cross section but without the concrete lining approximately 255 feet to an unnamed tributary of Denton Creek. CHRONOLOGICAL EVENTS From the available data that was collected, we have reconstructed the events in chronological order as they relate to the channel. They are as follows: October 1983 April 1984 September 1984 Parkwood I Subdivision begins construction Drainage channel improvements are under construction Drainage channel construction approved and One Year Maintenance Bond issued Material excavated for lake downstream of the drainage channel One Year Maintenance Bond expires (exact time unknown) September 1985 .~ --.. November 1985 General Homes notifies the City of the failure of pilot channel December 1985 - Present Various meetings to discuss the problem CONCLUSIONS In our OpIniOn the failure of the drainage channel was caused by excessive velocities along the unprotected reach of the earthen channel and at the outfall. There also appears to be a small localized problem where an existing drainage pipe outfalls into the channel. The excessive velocities in the unprotected reach caused the erosion of the earthen channel along the side slopes and channel bottom. The erosion migrated upstream to the earthen channel with the concrete lining causing undermining of the concrete lining. This led to further failure of the channel. Contributing factors in order of importance are as follows: 1. The "Temporary" earthen channel without the concrete pilot lining was designed and constructed on a 3.06% grade which would cause velocities large enough to be erosive. Based on the original plans, the velocity has been calculated as follows: REACH DEPTH OF VELOCITY FLOW IN CHANNEL CHANNEL CHANNEL W/PILOT W /0 PILOT FT FT/SEC FT /SEC 1 0.9 5.2 2 1.4 7.6 3 1.7 9.5 4 2.0 11.1 5 2.3 12.6 6 2.5 13.9 Erosive velocities in this type of material with good vegetation, for slope protection, are on the order of 6 to 8 feet per second. r - ..--, 2. Although we were unable to obtain detailed information about the excavation of the lake downstream of the channel it appears that this construction lowered the outfall elevation of the channel which resulted in a steeper channel bottom grade. This increased the velocities and further increased the erosion. Based on the plan we were furnished, the outfall was deepened approximately 6.5~ feet. 3. The outfall of an existing stormsewer pipe did not begin the erosion downstream but it does appear to contribute to the erosion adjacent to its location. RECOMMENDA TIONS We believe that unless some remedial action is taken, the erosion will continue and cause further failure of the channel and appurtenances. We have developed several alternatives for rehabilitation of the drainage channel. Alternative I - No Action Left in its present state, the erosion and undermining of the pilot channel will continue and would result in possible loss and/or damage to alleys, channel, storm sewer appurtenances and private property. The erosion of the channel bottom will continue to migrate upstream until a non-erosive channel velocity is achieved. Alternative 2 - Reconstruct drainage channel at the existing channel bottom elevation. Under this alternative, the failed concrete bottom would be removed, the channel graded to a uniform cross-section and new concrete pilot and side slope protection constructed. This would also require the construction of two drop structures (approxi- mately Station 2+35 and 0+55). The side slopes would also be concrete due to the deepening of the channel. This alternative would be the most expensive. -. --.. Alternative 3 - Reconstruct drainage channel to original design elevation and extend the channel bottom grade. As shown on the attached exhibit, the failed concrete might be left in place, fill material compacted over it up to the original design grade and a new pilot channel constructed. Unlike the original design, the bottom grade would be extended to the outfall at the lake. This would require the construction of a drop structure at the outfall of the drainage channel with some concrete rip rap on the side slopes. This would restore the original design intent and provide a shallower channel for additional safety in this residential neighborhood. We believe this would be the preferred option due to cost and safety. We appreciate this opportunity to be of service and are available at your convenience to discuss our conclusions and recommendations. If desired, we would be pleased to provide final construction plans for your selected alternatives. >- 2 z >- ~ >- NO 460 455 450 445 440 ... 8 - - --- - --. ............ + O. --- --- --... -- - - """"--.. - ---~~---------- / -- "- ----- ~ ~ -- .......... - - - - " ....... - ---- " - -- -- ~ - ---- ....... ----- -- --- -- -- -- -- -- REV S ON 7 BY 6 DESIGNED BY DRAWN BY CHECKED BY SCALE DA T E 5 4 0% - - -------- 3 2 0 - - ESPE'f, HUSTON a ASSOCIATES, Engineering 8 Environmental Consultonts 333 W Campbell Rd. Richardson, Texas 75080 (214) 669- 9600 ".-, / ~ / """" / ,---------- -;- _ _ ~.Q.R~I~L_D!.S~tL<lli~E_ _ _ _ _ _ __ _ _ _ ..... .......... EXISTING CHANNEL BOTTOM .c-::::- .!CMPOR MARCH 1st .1986 ,,__ 4Ry € (APPROXIMATE ..... -- -- ~IHctv c -- - 'H4tv.A/t::- - _ IVel. -..... --..... ti) ..... ..... ,,:3 06 0" .... '0 ........ - PROFILE) I NC. ORIGINAL EXISTING GROUND LINE -----------~ \ PROPOSED DROP STRUCTURE -2 ALTERNATIVE \ \ ,---------- I / , I J .-t' NO. 3 -3 JO B SH E E T OF -4 NO NO SHEETS 460 445 455 450 440 -. 1----- ------- II I PROJECT:CITY IF aJlPEU. II I PROJ fI):8237 0RtEL CA...a.lATI~ II I DAIEl..:DRAINA6E DAtEL II I RaDi:OR WI PILOT IIlAI<StET II I EN6IteR: II I 0<. BY: II I II I--------------~-------------T-------------------------T--------------~TA-----PT[nr_11 I THIS 5PREAI>9ET CAN I PLEASE IlEFItE TIE FI1UIIINS I 5(LUTI~: A 18.81 9.42 II I DETEAIiIItE 1lE aPACITY I PARAMETERS 1lEN PRESS F8. I P 21.32 8.18 II I IF A TRAPEZOIDA.. 04NEL I I R 8.84 1.16 II I WITH (OR wITIwn A I MAIN 0RfEL: I '.84 1.16 II I TRAPEZOIDIl. PILOT DAIEl... I BOTT[JI WIDTH........... 15.8 I II I I DEPTH ................. 1.8 I II I TO VIEW CRDSS-SECTI~ I RWHESS ctEFFICIENT.. 8.845 1 ~ITY = 19.23 II I PRESS F9 1lEN TYPE fi) . I SLlJlE IF EJIlBAttOENT.... 3..: 11 MAIN 0RfEL VELOCITY = 1.93 II I I INVERT SLIJlE........... 8. .1. I PILOT DAIEL VELOCITY = 8.26 II I DATA FOR 1EC2 SR CARDS I I T(I) WIDTH MAIN CI4INNEl. = 27.. II I FOR THIS CRDSS"'SECTI~ I PILOT DAfEl.: (ALL I' 5 t<<) PILon I TOP WIDTH PILOT 0AtEl = 8.87 II I CAN BE F(lN) BEUII. I BOTT[JI WIDTH........... 8.8 I II I I DEPTH.................. .1.3 I II I I RIlJIHESS aEFFICIENT.. I. 288 I II I I SLlJlE IF EMBAN<JIENT.... 12.12: 11 II I I I II 452.4 452.2 ~2 451.6 451.6 ~ 461.4 ~ 451.2 ~ ~ I&J 461 450.8 4fiO.6 450.4 4flO .2 460 CHANNEL CROSS-SECTION / \ I \ / \ / \ / \ J \ / ~ / \ I \ / I "- 1/ "- V , o 4 28 8 12 16 20 24 STATION - PROPOSED GRADE - ~ 1---------------------------------------------------------------------------------------------------------rl I PROJECT:CITY (F CXJlPELL II I PROJ t<<l:8237 0RfEL CR..ClI.ATI~ II I . CIfMEL:DRAltAlE OAIEL II I AEOCH:otI.. WI PILOT I<<lRK9EET II I ENGlER: II I CK. BY: II I II I-------------------------------T------------------------------------T------------------~IR------py[Dy-11 I THIS SPREADStET CAN I PLEASE DEFltE TIE FIll~IN6 Sll..UTI~: A ~.. 17.49 II I IlETERMltE TIE CSlPACITY I PARAlETERS MN PRESS F8. P 27.65 8.18 II I (F A TRAPEZOIIlIl.. DAtEL I R 1.52 2. 16 II I WITH <OR WIllWTl A I MAIN aRtEL: 1.52 2.16 II I TRAPEZOIIlIl.. PILOT OIlNEL. I 1lOTT(It WIDTH........... 15. 8 II I I DEPTH ................. 2.e II I TO VIEW CROSS-SECTI~ I ROOGtIESS ctEFFICIENT.. e. 845 CSlPACITY = 64.82 II I PRESS F9 MN TYPE 6P . I SLCJlE (F EMBANOENT.... 3.. :1 MAIN aRtEL VELOCITY = 1.38 II I I INVERT SLCJlE........... e. .1. PILOT CIiMEl.. VELOCITY = 1.3'3 II I DATA FOR lEC2 6R CARDS I TtJl WIDTH MAIN DAtEL = 33.. II I FOR THIS CROSS-SECTI~ I PILOT 0RfEl.: (Ill 115 t<<l PILon T(I) WIDTH PILOT CIIltHL = 8.87 II I CAN BE FOUND BEL~. I BOTTOM WIDTH........... e.8 II I I DEPTH.................. 1.3 II I I ROOlHESS aEFFICIENT.. e.288 I II I I SLOPE (f' EMMf<JIENT.... 12. 12 : 11 II I I I II 1-------------------------------1------------------------------------I--------------------~IR------PI[OT-I I 1 THIS SPREADSlEET CAN I PlEASE DEFItE TIE FIll~IN6 I Sll..UTI~: A 72.. 25.56 II 1 IlETERMItE TIE CAPACITY I PARMTERS no PRESS F8. P 33.97 8. 18 II I (F A TRAPEZOIIlIl.. 0Rte. I R 2. 12 3. Hi II I WITH <OR WITIOJTI A I MAIN CIfMEL: 2.12 3.16 II I TRAPEZOIIlIl.. PILOT 0RtEL. I. BOTT(It WIDTH........... 15.1 II I I DEPTH ................. 3.. II I TO VIEW CROSS-SECTION I ROOGtIESS aEFFICIENT.. 0.845 CSlPACITY = 136.96 II I . PRESS F9 TlEN TYPE 6P . I SLCJlE [f' EMBAtf<MENT.... 3.. : 1 MAIN CHAttEL VELOCITY = 1.72 II I I INVERT SL(pE........... 8..1. PILOT DAtEL VELOCITY = 8.51 II I DATA FOR 1EC2 SR CARDS I T(I) WIDTH MAIN DRfEL = 3'3.. II I FOR THIS CROSS-SECTI~ I PILOT 0RtEl..: (&U 8'5 t<<l PILon T(I) WIDTH PILOT CHIMEL = 8.87 II I CAN BE FIlJID BEL~. I BOTTOM WIDTH........... 8.8 II I I DEPTH.................. 1.3 If I I ROOGtIESS CtEFFICIENT.. 8.288 II I I SLCJlE (F ~T.... 12.12: 1 II I t I II 1-------------------------------1------------------------------------I--------------------MAIA------pyCOT-11 I THIS SPREADSIEET CAN I PlEASE DEFltE TIE FIllIliING I Sll..UTH..: Al08.. 33.63 II I IlETERMItE TIE CAPACITY I PAR$lIETERS 1lEN PRESS F8. I P 40.38 8.18 II I (F A TRAPEZOIIlIl.. DRfEL I I R 2.68 4.15 II I WITH <OR WITIo.m A I MAIN OAfEL: I 2.68 4.15 II I TRAPEZOIIlIl.. PILOT CHANNEL. I BOTTOM WIDTH........... 15.. I II I I DEPTH. . . . . . . . . . . . . . . . . 4. 8 I II I TO VIEW CROSS-SECTION I ROOGtIESS COEFFICIENT.. 8.845 I CAPACITY = 238.. II I PRESS F9 1lEN TYPE 6P. I SLIJlE (F EMBANKJIIENT.... 3..:11 MAIN av:NEL VELOCITY = 2.81 II I I INVERT SLIJlE........... 0. .1. I PILOT CI4lNtEl VELOCITY = 8.61 II I DATA FOR 1EC2 GR CARDS I I T(I) WIDTH MAIN DiAtHL = 45.. II I FOR THIS CROSS-SECTI[J4 I PILOT DAtEL: (&U 0'5 NO PILon I T(I) WIDTH PILOT CHANNEL = 8.87 II I CAN BE FIlJID BELOW. I BOTT(It WIDTH........... 0.8 I II I I DEPTH.................. 0.3 I II I I Rll.&fESS aEFFICIENT.. 8.200 I II I I SL(JIE (F EMBAN<MENT.... 12. 12 : 11 II I I I II ------------------------------- ------------------------------------ ------------------------------------ ,r -- 1--------------------- I PROJECT:CITY IF CIPPEll 'I PROJ 1t):8237 I DRfEl.:DRAIfRiE CIiNEL I RBQi:ON.. WI PILOT I BIll lEER: I 0<. BY: I I I I I I I I I -----------T----------T-----------PWIr- PILOT-I THIS SPREADSIET CAN PLEASE DEFItE TIE FIllIl4IN; I Sll.UTUlh AlS1.18 41.18 I DETERMItE TIE ~ITY PARAlETERS nEN PRESS F8. I P 46.62 8.11 I IF A TRAPEZOIIlIl. DAta. I R. 3.22 5. 15 I WITH lOR WmDrn A MAIN 0A'tlEl..: I 3.22 5.15 I TRAPEZOIIlIl. PILOT ctRfEL BOTT(JI WIDTH........... 15. I I I DEP1lt ................. 5.' I I ROOIHESS ClEFFICIENT.. 1.845 I ~ITY = 371.56 I SUIlE IF EMMtOENT.... 3.18 : 11 MAIN 0A'tlEL VELOCITY = 2.28 I INVERT SUIlE........... 8.18118 I PILOT 0A'tlEL VELOCITY = 1.71 I I TIP WIDTH MAIN 0AtEl.. = 51.18 I PILOT CIWfEL: Uti 8' s It) PILon I TOP WIDTH PILOT DWfEl.. = 8.87 I OOTT(JI WIDTH........... 8.8 I I DEPTH. . . . . . . . . . . . . . . . . . 8. 3 I II RWHESS aEFFICIENT.. 1.218 I II SLOPE IF EMBAN<MENT.... 12. 12 : 11 II I I II ,-----------------------------1-------------------------------,------------------MAyR------py(QT- I , THIS SPREAD!HET CAN I PLEASE DEFINE TIE FIllIl4INB I Sll.UTI~: Al98.18 49.78 I I DETERMINE HE CAPACITY I PARMTERS TlEN PRESS Fa. I P 52.95 8.18 I IF A TRAPEZOIIlIl. CIRtEL I I . R 3.74 6.15 I WITH lOR Wmo.rn A I MAIN D4NEL: I 3.74 6.15 I TRAPEZOIIlIl. PILOT OMEI.... I BOTT(JI WIDTH........... 15. i I I I DEPTH ................. 6.1 I I TO VIEW CROSS-SECTI~ I RWHESS ClEFFICIENT.. 8.845 I CAPACITY = 537.33 I PRESS F9 TIEN TYPE 6P . I SLOPE OF EMBAN<MENT.... 3.N:1I MAIN DRtEL VELOCITY = 2.52 I I INVERT SLOPE........... 8.181N I PILOT DWfEl.. VELOCITY = e.79 I DATA FOR IECC SR CARDS I I TOP WIDTH MAIN ctRfEL = 57. N I FOR THIS CROSS-SECTI~ I PILOT 0RfEL: Uti 8's It) PILon I TOP WIDTH PILOT 0A'tlEL = 8.87 I CAN BE F(lN) BELOW. I BOTTOM WIDTH........... I. e I I I DEPTH. . . . . . . . . . . . . . . . . . e. 3 I I I RWIIfESS ctEFFICIENT.. i.2M I I I SLOPE IF EMBAN<MENT.... 12. 12 : 11 , I I 0RfEl.. CA..aLATIlJt YlRK9EET TO VIEW CROSS-SECTI~ PRESS F9 nEN TYPE 6P . DATA FOR IECC SR CARDS FOR THIS CROSS-SECTl~ CAN BE F~D BELOW. ------------------------------- ------------------------------------ ------------------------------------ ,r - -------------- --------------------- -, PROJECT :CITY IF C(JlPELl. I PROJ tII:8237 0IltfEl.. Cf.l.ctLATl~ I CIfNEL:DRAlNASE CIfNEL I ~:DN.. WID PILOT 1IlRK9ET I ENGINEER: I I 0<. BY: I I I I----------------------r--~-----------------r__-----------------~IR-----_py(OT-1 THIS SPREAD9EET ~ I PLEASE DEFItE TfE F(LLlJIINS I Sll.UTI~: A 18.. 8.. I DETERJIlItE TIE CAPOCITY I PArwETERS no PRESS F8. I P 21.32 8.. I IF A TRAPEZOIDAL OINEL J I R 0. M ERR I WITH lOR WITIOJT) A I MAIN 0RfEl.: I 0.M 8.. I TRAPEZOIDAL PILOT OINEL. I BOTTlJI WIDTH........... 15. . I I I DEPTH. .. . .... . .. . ..... 1.' I I TO VIEW CROSS-SECTllJf I RIlBtESS (;(EFFICIENT.. 8.145 I CAPOCITY = 92.87 II PRESS F9 no TYPE 6P . I SlCJlE IF EJIIBAN<IENT.... 3.. : 11 MAIN ()AIIEl VELOCITY = 5. 16 II J INVERT SlCPE........... 8.83861 I PILOT ()AIIEl VELOCITY = ERR II I I Tl:P WIDTH MAIN 0AfEL = 27.. II I PILOT OIMEL: HILL 0's NO PILon I Tl:P WIDTH PILOT CHANtEL = 8.. II I BOTTlJI WIDTH........... 8.8 I I I DEPTH.................. 1.8 I I I ROOHESS aEFFICIENT.. 8._ I I I SlIJlE IF EMBAN<MENT.... 8.. : 11 I I I I ,-----------------------------,------------------------------I------------------~IA----PIODT-I , THIS SPREADHET CAN I PLEASE DEFINE TIE FllllJlINS I sa..UTI~: A 42.. 8.. I I DETERJIlltE TIE CAPOCITY I PARAlETERS TJ.EN PRESS F8. I P 27.65 0.. I I IF A TJRlEZOIDAL D4NIEL I I R 1.52 ERR I I WITH <OR WITHOOT) A I MAIN CI4NEL: I 1.52 8.88 I I TRAPEZOIDAL PILOT 0iAtfEL. I BOTTlJI WIDTH........... 15.8 I I I I DEPTH ................. 2.8 I I I TO VIEW CROSS-SECTI~ I RIlBfESS COEFFICIENT.. 0.845 I CAPACITY = 321.59 I I PRESS F9 no TYPE 6P . I SlCPE IF EMBAN<JIENT.... 3.. : 11 MAl N CHANtEL VELOCI TY = 7. 63 I I I INVERT SlCPE........... 8.03068 I PILOT 0AfEL VELOCITY = ERR' I DATA FOR fEC2 6R CARDS I I Tl:P WIDTH MAIN CI4NEL = 33.. I I FOR THIS CROSS-SECTHIl I PILOT CIINlEL: Hti 0's NO PILon I Tl:P WIDTH PILOT CHANtEl = 0.. I I CAN BE FCUlD BELlJI. I BOTTlJI WIDTH........... 8. 8 I I I I DEPTH.................. 0.' I II I I RD.&IESS COEFFICIENT.. 0." I I I , SlCPE IF EMBAN<MENT.... 0.. : 11 I I I I I ,------------------------------1--------------------------------I----------------~----_py(OT-1 I THIS SPREADSlHT CAN I PLEASE DEFINE TfE F(LLlJIINS I SOlUTI~: A 72.. 0.88 I I DETERJIlItE TIE CAPOCITY I PARAMETERS no PRESS F8. I P 33.97 0." I I IF A TRAPEZOIDAL DRfEL I I R 2.12 ERR I I WITH (OR wmlllm A I MAIN CHANtEl: I 2.12 0." I I TRAPEZOIDAL PILOT CHANNEL. I BOTTlJI WiDTH........... 15.8 , - I I , DEPTH. . .. . . .. . . . .. . .. . 3.8 I I I TO VIEW CROSS-SECTl~ I RflJ6IfESS COEFFICIENT.. . 0.845 I CAPACITY = 686.18 I I PRESS F9 THEN TYPE 6P . I SlCPE IF aIBANQENT.... 3.. : 11 MAIN CI4lNNEL VELOCITY = 9.53 I I I INVERT SLOPE........... 0.03860 I PILOT CKlNNEL VELOCITY = ERR II I DATA FOR fEC2 GR CARDS I I Tl:P WIDTH MAIN CIRflEL = 39.. II I FOR THIS CROSS-SECTIlJ4 I PILOT DAfEL: HU 0' s NO PILon I TOP WIDTH PILOT CHAttEL = 0.. II I CAN BE FOOND BEL(J,l. I BOTTlJI WIDTH........... 0. 8 , II j I DEPTH.. . .. .. .. . .. .. .. .. 0. 0 I II I I ROOHlESS aEFFICIENT.. 0.. I II I I SlCPE IF EMBAN<MENT.... 0. 88 : 11 II I I I II DATA FOR fEC2 6R CARDS FOR THIS CROSS-SECTIlJf CAN BE FCUlD BELlIl. ~ .~ -. . ,--,-------------- ------------------------ ------------tl I . PROJECT:CITY IF ClJlPEU. II I PROJ t<<I: 8237 0AtEl. CSl.aJ..ATI ~ II 1 0AtEl. :DRAlNA6E 0AtEl. II I REACH:OIl. WIO PILOT IIJRK9ET II , ENGlER: II , ()(. BY: II 1 II I-------------------T---------------------r--------------RAIA------PICOT-II I THIS SPREADSIEET CAN I PlEASE DEFltE TJ.E F[ll(JIINS I sn..UTI~: Al88.. 8.. II I DETERMItE nE CSlPOCITY I PAAAlETERS nEN PRESS Fa. I P ~.38 8.. II I IF A TRAPEZOIM. 0RfEl I I R 2.68 ERR I' I WITH (OR WlllD.1Tl A I ~IN 0RtEL: I 2.68 0.. II I TRAPEZOIM. PILOT DAfEL. I BOTT(Jt WIDTH........... 15.8 I II I I DEPTH... . ... ... . . .. . . . ~.. I II I TO VIEW CROSS-SECTJ(~ I RO.&tESS ctEFFICIENT.. 0.145 I CAPACITY = 1283.61 II I PRESS F9 no TYPE 6P . I SLlJlE IF B8N<1ENT.... 3..: 11 ~IN 0RtEL VELOCITY = 1l.1~ II I I INVERT SLlJlE........... 0. &3868 I PILOT DAfEL VELOCITY = ERR II I DATA FOR J.EC2 SR CARDS I I TII> WIDTH ~IN 0RfEl. = 45.. II I FOR THIS CROSS-SECTI~ I PILOT CHAttEL: Uti 0' s NO PILon I TII> WIDTH PILOT 0RtEL = 8.. II I CAN BE FIJH) BEL(I,l. I BOTT(Jt WIDTH........... 0.8 I /I I I DEPTH.................. 8.8 I II I I RIl/GIf€SS lXEFFICIENT.. 0.800 I II I I SllJlE IF E~.... 8.. :11 II I I I II 1-------------------------1-----------------------------1--------------RAIN----pyCOT-" I THIS SPREADSlHT CAN I PlEASE DEFINE THE F[ll(l,lING I sn..UTJ~: IUse.. e.. II I DETERMltE TIE CAPOCITY I PARAlETERS no PRESS Fa. I P ~6. 62 8.. II I IF A TRAPEZOIM. DAfEL I I R 3.22 ERR II I WITH <OR wmom A I ~IN CIilffEL: I 3.22 8.. II I TRAPEZOIDAL PILOT 0RfR. I BOTT!Jl WIDTH........... 15.0 I II I I DEPTH ................. 5.8 I II I TO VIEW CROSS-SECTION I ROIDIESS COEFFICIENT.. 8.145 I CAPOCITY = 1888.22 II I PRESS F9 TIEN TYPE 6P . I SLlJlE IF EMBANKMENT.... 3.08: 11 MAIN CHANtEl. VELOCITY = 12. 59 II I I INVERT SLlJlE........... 0. e3060 I PILOT CHAItEL VELOCITY = ERR II I DATA FOR J.EC2 SR CARDS I I TII> WIDTH ~IN CIilffEL = 51.. II I FOR THIS CROSS-SECTION I PILOT CHAttEL: Uti 0's t<<I PILon I TII> WIDTH PILOT ()RfEL = 8.. II I CAN BE FOUND BEL(I,l. I BOTT!Jl WIDTH........... 0.8 I II I I DEPTH. . . . . . . . . . . . . . . . . . 0. 0 I II I I ROl.IGtESS COEFFICIENT.. 8." I II I I SlOPE OF EMBSN<IENT.... 0..: 11 II I I I II ,------------------------------,------------------------------I-------------------~~---lPICOT-11 I THIS SPREADSIeT CAN I PLEASE DEFINE THE FOlL(I,lING I sn..UTI()j: A198.. 0.. II I DETERMIIE THE CAPOCITY I PARAMETERS nEN PRESS Fa. I P 52.95 0.. II I IF A TRAPEZOIIlAI.. DAfEL I I R 3.74 ERR II I WITH <OR wmulTl A I ~IN CIfWNEL: I 3.74 0.08 II I TRAPEZOIDAL PILOT CHANNEl. I BOTTOM WIDTH........... 15.0 I I I I I DEPTH ................. 6.1 I II I TO VIEW CROSS-SECTION I ROlJ6HNESS COEFFICIENT.. 8.845 I CAm:ITY = 2755.34 II I PRESS F9 THEN TYPE SP . I SLOPE IF EMIm<MENT.... 3.. : 11 JllAIN (}MR VELOCITY = 13.92 II I I INVERT SLOPE........... 0.83060 I PILOT CHAtflEL VELOCITY = ERR II I DATA FOR HEC2 SR CARDS I I T[P WIDTH MAIN CHANNEL = 57.80 II I FOR THIS CROSS-SECTION I PILOT CHANNEL: (ALL 0' s NO PILOT) I TOP WIDTH PILOT CHANNEL = 0.00 II I CAN BE FOUND BELOW. I BOTTOM WIDTH........... 0.0 I II I I DEPTH. . . . . . . . . . . . . . . . . . 0. 0 I II I I ROlIGfESS ctEFFICIENT.. e.808 I II I I SLOPE IF EMBANKMENT.... 0. 00 : 11 II I I I II ------------------------------- ------------------------------------ ------------------------------------ ~ ,r II II PROJECT :CITY IF CIJlPElL. II PROJ t<<I :8237 II OAtfi.:DRAHllSE 0AIEl. II REACH:DN.. WID PILOT II OOItEER: II CK. BY: II - II II II II II II II II 0RfEL OI.Cl.l.ATI~ I<<JRI(HET ----------------------------------------------- ~ ~ ~ -oJ III CHAN NEL CROSS-SECTION 467 458 465 4M 4603 462 451 450 o 20 40 &:l STATION - PROPOSED GRADE