Updating the Hoover Dam documents, 1978 / Milton N. Nathanson.

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108 UPDATING THE HOOVER DAM DOCUMENTS Upper Colorado River Basin Fund (Colorado River Storage Project) but were not subject to reimbursement by the Boulder Canyon Project as was the case for deficiencies in firm energy as determined pursuant to the 1962 filling criteria. The foregoing was done in accordance with the principles set forth in the document entitled "Operation of Lake Mead Below Elevation 1123 by Reason of Resumption of Storage Operations at Lake Powell," approved by the Secretary of the Interior on May 11, 1964. The text thereof follows: OPERATION OF LAKE MEAD BELOW ELEVATION 1123 BY REASON OF RESUMPTION OF STORAGE OPERATIONS AT LAKE POWELL The "General Principles to Govern, and Operating Criteria for, Glen Canyon Reservoir (Lake Powell) and Lake Mead during the Lake Powell Filling Period (27 F.R. 6851, July 19, 1962)," herein referred to as the "Filling Criteria," provide that until Lake Powell attains minimum power operation level (about elevation 3490) any water stored in Lake Powell is to be available to maintain Lake Mead at elevation 1123 (rated head at Hoover Powerplant). In order to resume filling operations at Lake Powell under runoff conditions which would necessitate drawing Lake Mead below elevation 1123, the Hoover allottees must be maintained in the same position that they would have been in had Lake Powell storage not been resumed. By so doing, water in Lake Mead may be drawn down below elevation 1123 consistent with the objectives of the Filling Criteria. The following conditions will therefore be observed effective upon announcement by the Secretary of the Interior: 1. Outflow from Lake Powell will be reduced to not less than 1,000 ftVs. 2. Under no circumstances will Lake Mead be drawn below a minimum power operation level of elevation 1083 as a result of storage of water in Lake Powell. Any storage in Lake Powell will be used to avoid drawing Lake Mead below elevation 1083. 3. In addition to the allowances for deficiencies in firm energy generation determined pursuant to the Filling Criteria, the United States will replace deficiencies in Hoover Powerplant capacity and energy available to the Hoover allottees which result from the lowering of Lake Mead below elevation 1123 by reason of storage of water in Lake Powell. The United States will also relieve the allottees of cost of extraordinary maintenance of the Hoover turbines and generators resulting from such lowering. Costs incurred by reason of this paragraph will be charged to the Upper Colorado River Basin Fund and will not be subject to reimbursement from the separate fund identified in Section 5 of the Act of December 21, 1928, or otherwise charged against the Boulder Canyon Project. 4. Until Lake Mead is returned to elevation 1123 and subject to condition 2 above, Lake Powell will be permitted to exceed minimum power operating level only to the extent inflow exceeds turbine capacity, or as required to assure operation at not less than minimum power operating level. 5. When actual runoff through the month of June becomes known, early in July, the likelihood of attaining minimum power operating at Lake Powell in calendar year 1964 will be reasonably deter-minable. A decision will be made at that time whether to continue storage at Lake Powell or to release water stored therein in order to raise the elevation of Lake Mead. In arriving at that decision, consideration will be given to a comparison of estimated costs to the Colorado River Storage Project and the decision will be made after consultation with appropriate interests of the Upper and Lower Colorado River Basins. Releases from Lake Powell were held down to approximately 1,000 ftVs most of the time from March 13, 1963, the date of partial closure, to January 30, 1964. From that date to March 26, 1964, releases were increased to about 4,000 ftVs and again increased at that time to meet the requirements of 1.0 maf/yr in Principle 7 of the criteria and to maintain minimum Lake Mead active content at 14.5 maf (elevation 1123). Releases were again restricted to a minimum of 1,000 ftVs on May 12, 1964, by order of the Secretary at which time Lake Mead was slightly above rated power head elevation. Minimum power operating level (6.1 maf at elevation 3490) was achieved in Lake Powell on August 16, 1964, and the releases increased thereafter holding Lake Powell close to minimum operating level. Energy generation began September 4, 1964.