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<br />. <br /> <br />Chapman Gulch <br />South Fork <br />Main stem <br />Sawyer Creek <br /> <br />3 c.f.s. <br />6 e,f.s. <br />12 c.f.s. <br />o e.f.s. <br /> <br />(""8 <br />;;) - <br /> <br />Due to the unprecedented operating conditions of the system and the <br />high fluctuations of the native flows, it was impractical to maintain <br />the required bypasses at a constant rate. About 1,300 acre-feet were <br />bypassed that could have been diverted had this ideal condition been <br />attained. A t no time, on a mean daily basis, were the bypasses less <br />than those set as the requirements. The bypass requirements are based <br />on the operating principles (appended to this report) and each stream <br />bypass is proportional to its natural contribution on an average basis. <br />The minimum required bypass at the collection system controlled until <br />about July 8 when it became necessary to pass more than the minimum at <br />the collection system in order to meet the streamflow requirement of <br />the Fryingpan River below Norrie, 100 c.f.s., in July. Diversions were <br />stopped on July 20 when the streamflow below Norrie became too low to <br />allow any diversions and still meet the minimum streamflow requirements. <br /> <br />. <br /> <br />Exhibi t 4, in four parts, shows graphically the undepleted and residual <br />flows at various points below the collection system. Exhibit 4A, 4B, <br />and 4C show the gaged flow below Chapman Gulch, South Fork, and frying- <br />pan diversions, respectively. Sawyer Creek diversions were subtracted <br />from the Chapman Gulch undepleted flow as Sawyer Creek would normally <br />enter Chapman Gulch below the gage. Exhibit 4D shows the flows of the <br />fryingpan River at Norrie, Colo., with and without fryingpan-Arkansas <br />project diversions. The hydrographs demonstrate that the fish flow <br />criteria were met. <br /> <br />The 1972 operating plan predicted a project diversion of 34,000 acre- <br />feet under most probable conditions. The actual diversion was 32,000 <br />acre-feet as measured at the East Portal of the Charles H. Boustead <br />Tunnel. The maximum mean daily import was 555 c.f.s. on June 7; the <br />maximum instantaneous imports that day were 711 c.f.s. While the <br />seasonal snowmelt runoff period at the collection system was near nor- <br />mal, the pattern of runoff was quite out of the ordinary. The runoff <br />started late, and high temperatures and warm rains caused a much great- <br />er percentage of runoff to occur in late May and throughout June than <br />is usual. <br /> <br /> <br />. <br /> <br />8 <br /> <br />