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<br />. ,.....~~ <br />J ~ <br />- <br />- <br />- <br />- <br />- <br />- <br /> <br /> <br />'HW.' riB' - <br />. ,." ~ <br />~ - <<>; <br />"" ".. <br />^ ~ -._ ""...;;_' ,.,....., AI <br /> <br />. <br /> <br />. <br />Mclaughlin Water Engineers, Ltd. <br /> <br />iifjJ'1lJ \::1':~~:tC'i--:i:',;-~~"f~- <br /> <br />2420 Alcott Street Denver, Colorado 80211 (303) 458-5550 <br /> <br />November 15, 1988 <br /> <br />Mr. Mike Woika <br />Utilities Manager <br />City of Englewood <br />3400 S. Elati <br />Englewood, Colorado 80110 <br /> <br />~(.'./., <br />"'.1.f&8 <br /> <br />RONALO C. hkLAUCHUN <br />HAJJIORD E. ElICKSON <br />JX)lIC;US T. SOVERN <br />WIlUAM C. TAGGART <br />RALPH l. TOlEN <br />WIL.UAM R. ICENDAll <br />GENE A. IRJIUtEl.l <br />MlOfAEL E. MERCER <br />JOHN M. PFl.Jt.t1M <br />MIOIAEl R. CALuzzr <br />IlONALOE_DVOItAI:. <br />SCOTI E. U!HMAN <br />KENNET'HO. ZlElAJtT <br />MAlty ANNE 8USH <br />HAROlD ROOliRTS <br />JACk w. STEINMEYER <br />l.U.NDERt, UlMY <br /> <br />RE: Review ot Wright Water Engineers "Preliminary Design" Plan view of Union Avenue Dam <br />Boating Bypass Structure as it pertains to the Raw Water Intake of the City of Englewood. <br /> <br />Mr. Woika: <br /> <br />You requested that we review the referenced "Preliminary Design' as it pertains to the raw water <br />intake. This letter makes no comment as to matters of whitewater function, safety or flood stability <br />ofthe bypass. <br /> <br />1. No water surface profiles are given which illustrate the profile anywhere along the bypass or <br />upstream of the intake. In our opinion, these should have been shown in earlier conceptual <br />design phases and greatly detailed in preliminary design. Therefore, we don't believe this is <br />really a preliminary design but an initial conceptual drawing with no apparent hydraulics <br />completed. <br /> <br />2. You asked if the concept with the raised tailwater caused by the whitewater bypass would <br />affect t.1je radial gate performa.'lce and the sediment f1ushi'lg capacity L'l the upstream intake <br />channel. Since there are no water surface profiles given, we cannot give a defmitive answer <br />to the question. We can observe that the invert of the downstream whitewater bypass chute <br />is 85 with a general crest elevation of 87. Since the upstream water surface above the gate is <br />.<'typically held at 89.1 to 89.5 (which is adjustable by the operator), it appears to us that, within <br />a normal flow range, the gate would open slightly wider to pass the same flow. Flushingwould <br />..thus be assured, so long as the upstream water and sediment flow split above the whitewater <br />bypass entrance doesn't result in a heavier concentration of sediment (see item 5). We have <br />some concern that at high flows the tailwater could rise high enough to decrease the flows and <br />velocity through the intake channe~ resulting in sedimentation in the intake channel. We <br /> <br />ASPEN <br />(303) 925--1920 <br /> <br />TULSA <br />(918)66+-27"1 <br /> <br />Ul.KE DILLON <br />(303) 468-2141 <br /> <br />II 111 _~,,.~..,, J!Ly:_~t",,~,; ".4'--;/_'::, <br />CCMPLEiE INGINEIIUNC SBMCES IN, WATEIlIUQfI'S AND ItIIOURCIS WATBR TUAJMENT ANI) DI5T1UIlU1'1ON ....,;.a DIlAINACE IUtICAllON KlUNTAINS STClAM DRAINAGE AND FLOOD CCll'o"lltOl <br />WASTIlWATIR au.&CT1ON. TUA1WENT AND REUSE IUE PlOTI!Cl1ON WATIlIASiD lliClEATlOII SP&ClALTY Hl'DRAWCS RATE STUDIES AND Lmll11ES ECONOMICS <br />