43 CFR 418.22 - Future adjustments to Lahontan Reservoir storage targets.
(a) The Lahontan Reservoir storage targets must be adjusted to accommodate changes in water demand in the Carson Division. Using the information reported by the District by March 1 of each year on eligible land expected to be irrigated and end-of-year data on eligible land actually irrigated (§ 418.9(b)), the Bureau will determine if the Lahontan Reservoir storage targets need to be changed. If no change is needed, the storage targets currently in effect will remain in effect.
(1) Only the actual water demand reported for full water years (100 percent water supply) will be considered. Targets will not be changed based on water demand reported for less than full water years.
(2) All changes in storage targets must start on October 1 of any year. If information provided by March 1 and other available information indicates that the Lahontan Reservoir storage targets must be changed, the new set of storage targets must be applied starting October 1 of the same year and remain in effect until changed according to this section.
(b) All changes to storage targets will be made according to the table in this section. The table of storage targets has been developed to provide a consistent Project water supply over a range of demands.
(1) A storage target adjustment must be made in increments of thousands of acre-feet for the change as indicated in the column listing Carson Division Demand and the complete set of monthly targets must be applied.
(2) If the change in reported water demand is above or below the values in the table of storage targets, the adjustment to the storage targets can be calculated. The calculated adjustment is the number that would appear in the column Target Adjustment in the table. The calculated Target Adjustment is then added or subtracted to the base storage target for each month. Target Adjustments must be made in whole increments of 1,000 acre-feet and calculated values will be rounded to the nearest 1,000 acre-feet.
(i) For demands greater than those set forth on the table, the formula for the Target Adjustment is: Target Adjustment = 0.00208 (Demand in acre-feet - 271,000 acre-feet). For example, if water demand increased to 292,635 acre-feet per year, the Target Adjustment calculation would be = 0.00208 × (292,535−271,000). The result would be a Target Adjustment of 45 or 45,000 acre-feet. This would be added to the base monthly storage target values so, the January-May target would be 219,000 acre-feet, June would be 235,000 acre-feet, and so on.
(ii) For demands less than those set forth on the table, the formula for the Target Adjustment is: Target Adjustment = 0.00174 (Demand in acre-feet - 271,000 acre-feet). For example, if water demand decreased to 248,011 acre-feet per year, the Target Adjustment calculation would be = 0.00174 × (248,011−271,000). The result would be a Target Adjustment of −40 or −40,000 acre-feet. This would be subtracted from the base monthly storage target values so, the January-May target would be 134,000 acre-feet, June would be 150,000 acre-feet, and so on.View or download PDF View or download PDF