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<br />002133 <br /> <br />Operating Criteria for Glen Canyon Dam <br />In accordance with the <br />Grand Canyon Protection Act of 1992 <br /> <br />These Operating Criteria are promulgated in compliance with section 1804 of Public Law 102-575, the <br />Grand Canyon Protection Act of 1992. They are to control the operation of Glen Canyon Dam, <br />constructed under the authority of the Colorado River Storage Project Act. These Operating Criteria <br />are separate and apart from the Criteria for Coordinated Long-Range Operation of Colorado River <br />Reservoirs prepared in compliance with the Colorado River Basin Project Act of 1968. <br /> <br />1. Annual Report <br /> <br />As required in the Grand Canyon Protection Act, a report shall be prepared and submitted to Congress <br />annually that describes the operation of Glen Canyon Dam for the preceding water year and the <br />expected operation for the upcoming water year. The annual plan of operations shall include such <br />detailed rules and quantities as are required by the Operating Criteria contained herein. It shall provide <br />a detailed explanation of the expected hydrologic conditions for the Colorado River immediately <br />below Glen Canyon Dam. <br /> <br />2. Review of Criteria <br /> <br />. <br /> <br />.'- <br /> <br />The Secretary of the Interior shall review these Operating Criteria as the result of actual operating <br />experiences to determine if the Operating Criteria should be modified to better accomplish the <br />purposes of the Grand Canyon Protection Act. Such a review shall be made adeast every 5 years in <br />consultation with the appropriate Federal agencies, Governors of the Colorado River Basin States, <br />Indian Tribes, representatives of academic and scientific communities, environmental organizations, <br />the recreation industry. and contractors for the purchase of Federal power produced at Glen Canyon <br />Dam. <br /> <br />3. Specific Operational Constraints <br /> <br />The plan of operations will follow the description of the preferred altemative (Modified Low <br />Fluctuating Flow) in the Operation of Glen Canyon Dam Final Environmental Impact Statement and <br />its Record of Decision. The specific criteria are as follows: <br /> <br />Minimum Releases - 8,000 cfs between 7 a.m. and 7 p.m. 5.000 cfs at night. <br /> <br />Maximum Releases - 25,000 cfs. Several circumstances warrant exception to this restriction. These <br />are the BeachlHabitat-Building Flows and the Habitat Maintenance Flows (both described below) and <br />the release of large volumes of water to avoid spills or floodflow releases from Glen Canyon Dam. <br />These latter releases would most likely result from high snowmelt runoff into Lake Powell: if such <br />high releases above 25.000 cfs are required, they shall be made at constant daily flow rates. <br /> <br />Allowable Dailv Flow Fluctuations - 5,000 cfs/24 hours for monthly release volumes less than <br />600.000 acre feet; 6,000 cfs/24 hours for monthly release volumes of 600,000 to 800,000 acre feet; <br />and 8,000 cfs/24 hours for monthly release volumes over 8,000 acre feet. <br /> <br />Maximum Ramll Rates - 4.000 cfs/hour when increasing, and 1,500 cfs/hour when decreasing. <br /> <br />14 <br />