Diversions at Derby Dam.

§ 418.18 Diversions at Derby Dam. (a) Diversions of Truckee River water at Derby Dam must be managed to maintain minimum terminal flow to Lahontan Reservoir or the Carson River except where this part specifically permits diversions. (b) Diversions to the Truckee Canal must be managed to achieve an average terminal flow of 20 cfs or less during times when diversions to Lahontan Reservoir are not allowed (the flows must be averaged over the total time diversions are not allowed in that calendar year; i.e., if flows are not allowed in July and August and then are allowed in September then not allowed in October and November, the average flow will be averaged over the four months of July, August, October, and November). (c) The Bureau will work cooperatively with the District on monitoring the flows at the USGS gage on the Truckee Canal near Hazen to determine if and when flows are in excess of those needed in accord with this part and bringing the flows back into compliance when excessive. (d) Increases in canal diversions which would reduce Truckee River flows below Derby Dam by more than 20 percent in a 24-hour period will not be allowed when Truckee River flow, as measured by the gauge below Derby Dam, is less than or equal to 100 cfs. (e) Diversions to the Truckee Canal will be coordinated with releases from Stampede Reservoir and other reservoirs, in cooperation with the Federal Water Master, to minimize fluctuations in the Truckee River below Derby Dam in order to meet annual flow regimes established by the United States Fish and Wildlife Service for listed species in the lower Truckee River.