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I I I I I I I I I I I I, I I I I I I I OJ2972 BIOLOGICAL OPINION Proposed Action Reclamation actions involving projects in the planning or implementation phase or that are mitigation for past projects may require additional section 7 consultation to address site-specific issues. Other activities not expressly included in the following description of the proposed action are not covered under this consultation, such as, but not limited to, changes in criteria for developing Annual Operating Plans or for declaring water surpluses (beyond the parameters in the description of the proposed action, below), new water contracts, new power production or transmission facilities, and changes in flood control regulations by the Army Corps of Engineers. Actions 1. Flood control Flood control operations have the first priority on the LCR as mandated by the Boulder Canyon Project Act. Section 7 of the Flood Control Act of 1944 established that the Secretary of War (now the Army Corps of Engineers [COE]) will prescribe regulations for flood control for projects authorized by that Act. The COE is responsible for developing the flood control operation plan for Hoover Dam and Lake Mead as indicated in 43 CFR 208.11. The plan is the result of a coordinated effort by the COE and Reclamation, but the COE is responsible for providing the flood control regulations and has authority for fmal approval. Any deviations from the flood control operating instructions must be authorized by the COE. The Secretary is responsible for operating Hoover Dam in accordance with these regulations; therefore, Reclamation has only limited discretion in managing Lake Mead elevations for flood control. Flood control regulations promulgated by the COE for Lake Mead were established to deal with two distinct types of flooding: rain and snowmelt. Snowmelt constitutes about 70 percent of the annual runoff of the Colorado River into Lake Mead. Lake Mead's uppermost 1.5 maf of storage capacity, between elevations 1219.6 and 1229.0 mean sea level (msl), is allocated exclusively to control floods from rain events. Within this capacity allocation, 1.218 maf of flood storage is above elevation 1221.4, which is the top of the raised spillway gates. Flood control regulations specify that once flood releases exceed 40,000 cubic feet per second (cfs), the releases shall be maintained at the highest rate until the reservoir drops to elevation 1221.4. Releases may then be gradually reduced to 40,000 cfs until the prescribed seasonal storage space is available. The flood control regulations set forth two primary criteria to deal with snowmelt: 1) preparatory reservoir space requirements, and 2) application of runoff forecasts to determine releases. In preparation for the coming year's season of snow accumulation and associated runoff, progressive expansion of total Colorado River system reservoir space is required during the latter 10