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<br />-~~-~-- <br /> <br />MAYNES.BRADFORD&SHPS <br />....1 . I: <br />. . <br />. I I <br /> <br />Opinipn Sl&le~ lIIat With I\lll compact c1evelC'pment in the San Juan River. !be 300.000 AP would ~ <br />only ljo allailable 33% of Ihe time. If &he 57,100 A:f depletion is limited to a rlet annual deplctiOn1 <br />if the aoo.ooolAF it nOl SlOred and the 300.000 AP stora~ (031 is notlulainable due to known <br />lIIater~veIOPlllellt. lhat fact should be stated as part of the itemS ill the RPA. <br /> <br />The IJw now leSt in lhe RPA b specified to ~ur in 1996/1997,tbis may nOI be ponible due to <br />nll.tun/I hydro1tgic condition.. By forcing the lest to ~.Qr in the wimer 1996-97, &he Service is <br />takii.n 'controllof te.5t flow re,imes frolD tho Sll/I JUll/IlUP biology committee and may <br />de' lllIIy ltffectlhe Dngolnr research on the San Juan. The lanlll.lge should be: changed 10 <br />"pre~ bly the vAnIer of 1996-97" rather than spctifically require the lett in 1996-97. <br /> <br />The Ii erature cited tolies bC8vily on studies (ecom the Colorado and Green rivers. The best dala <br />on SQ Juan Rlver habitat and fish communilY is in the annual reports compiled for the Seven <br />Year . esearcb Project. includinf; the Integration Report that was presented in August. 1995. <br />Other iterature rl!ar Is imponant to the physical process of spawnini habitat formation is in <br />Halve ct. aI. 199:J. ^ Phy.ical Process-bioJojlical Response Model for Spawning Habitat <br />FD tioD forthc. Endangued Colorado Squawfish. Ri vers: 4; I 14-131. <br /> <br />ID:303-247-SS27 <br /> <br />F~_B 01' 96 <br /> <br />15:43 No.DI9 P.04 <br />.",,,,,,,...r-.,:f F.ro <br /> <br /> <br />S~l c Comments: <br /> <br />'.8' ,bottom ~ 2Dd para: This section implies that water depletions WeTe the ml\ior l'e8son <br />0( the line and Dstin, of the Colorad" ~quawf1sh AIld razorback rocker. There is no Nseareh <br />Ihat I thllt water depletiDn was !he lIIIIjor factor for decline. Many other (actors have been <br />cited re~h~rs 8lI reMons for decline includmg habitat frAgmenlatiDn due to construction of <br />large . stem r12crvoirs, change in flow resimc. introduclion oC non.nlltive fishes and fish <br />erallic. tion prl?8nims. The USFWS In a memo dated Pebrulll)' 11. 1992 states tbat one of the <br />ps reasolls for decUne is blDckage of migration (Memorandum from Region 6 Regional <br />Direct r USFWS to RegiDnaJ DIrector Bureau of Reclamaticn). The emphasis of the section <br />shoul stale that there are Dther factors thaI have contributini to the decline including those that <br />ere n] direclly related to Water development. <br /> <br />Pllp ,3rd para;: The diversion structures mentioned should be cited 8S potential blocks 10 . <br />rub grations. Tho Hogback diversion is similar in conslnu:tion to Cudei diversion. It has been <br />docu~nted milt Colorado squawfish can pass Cudel dl \(.ulon (Miller 199.5). To dare no <br />intcnstre studies of .iUlcr fbb colleClions or fish tracking have been conducted In the area of <br />these 41versions similar 10 the stndies conducted in !be downstream reacbes of the river. Until <br />the&e *ruclUres are clemonstrated as "effective" blocks thcy should be referred 10 1$ "potential" <br />blocksl i <br />. I <br />Pale ~l, 3rd ~.ra.: The citations for cobble movement and cobble cleaning mechanisms should <br />includ~ B di&<:tSiOn of Harvey et aJ. 1993. ThaI study has shown that cobble cleaning can occur <br />at a wipe ran, of flows depending on local hydraulic gradients. The studies cited lU'C dlIted end <br />the nerer res h on Colorado squawfish habitat shC'uld be used. The mechAllislUS as dm:ribc:d <br />on pa~ j I Shiluld be updllled with currcnt lCIUn:h. <br /> <br />Pale f' IsI rljll para.: The statement thl[ the dillersious llre "effective" blocks should be <br />chq d \0 "pqtenlial" blocks. <br />! <br />. . <br /> <br />~ <br /> <br />2 <br />