43 CFR 418.24 - Precautionary drawdown and spills from Lahontan Reservoir.
(a) Even though flood control is not a specifically authorized purpose of the Project, at the request of the District and in consultation with other interested parties and the approval of the Bureau, precautionary drawdown of Lahontan Reservoir may be made to limit potential flood damage along the Carson River. The Bureau will develop criteria for precautionary drawdown in consultation with the District and other interested parties.
(1) The drawdown must be scheduled sufficiently in advance and at such a rate of flow in order to divert as much water as possible into the Project irrigation system for delivery to eligible land or storage in reregulating reservoirs for later use on eligible land.
(2) During periods of precautionary drawdown, or when water is spilled from Lahontan Reservoir, Project diversions will be determined by comparison with other years' data and normalized by comparison of differences in climatological data. The Bureau will estimate the normalization in consultation with the District and other interested parties.
(3) Spills from Lahontan Reservoir and precautionary drawdown of the reservoir to create space for storing flood waters from the Carson River Basin that are in excess of the normalized diversions will not be used in calculating Project diversions.
(4) Water captured in Project facilities as a result of a precautionary drawdown or spill will not be counted as storage in Lahontan Reservoir for the purpose of calculating Truckee River Diversions. Such water will not be counted as diversions to the Project unless such water is beneficially applied as described in (a)(5) of this section.
(5) Water from precautionary drawdowns or spills that is captured in Project facilities must be used to the maximum extent possible, and counted as deliveries to eligible lands in the year of the drawdown. If all the drawdown water captured in Project facilities cannot be used in the year of capture for delivery to eligible lands, then that water must be delivered to eligible lands in subsequent years to the maximum extent possible and counted against the water users' annual allocation.
(b) If a precautionary drawdown in one month results in a failure to meet the Lahontan Reservoir storage objective for that month, the storage objective in subsequent months will be reduced by one-half of the difference between that month's storage objective and actual end-of-month storage. The Bureau is not liable for any damage or water shortage resulting from a precautionary drawdown.