WSP03375 - Laserfiche WebLink

Home Browse Search

..: Chapter 2 CONCEPT EVALUATION 2.1 Concept of Redistribution of Excess Water Redistribution of required excess water releases forms the cornerstone for increasing operational flexibility and control under full reservoir conditions. Key to the process of formulating AOPs that provide for the redistribution of excess water is the annual quantification of excess water, the planned scheduled releases thereof, and provisions in the AOP, consistent with "The Law of the River", that establish a high level of assurance that the system's conservation storage would be preserved under such operations. The preservation of water conservation can be assured so long as river operations can be modified at any particular time dur ing the year to provide the same reservoir vacant flood control storage space on January I of the following year that would have occurred under a minimum flood control requirement operation. Thus, the monitoring and periodic assessment of the potential for system recovery to that which would have occurred under a minimum flood control operation become essential and required elements for any recommended process for formulating and revising an AOP involving the redistribution of excess water. 2.2 General Considerations Inasmuch as the Colorado River Basin is an arid to semi- arid water-short basin, a fundamental premise of annual operating plans for Colorado River reservoirs is to maximize, consistent with "The Law of the River", system conservation storage. Under full or near full conservation storage conditions, a higher degree of day-to-day river management and more frequent re-evaluations of annual operating plans are required to ensure that mandatory flood control releases in excess of water needs can be effectively routed through the system. The Secretary of the Interior's operations for flood control are governed by the Corps of Engineers' Hoover Dam Flood Control Regulations. The regulations, established pursuant to the Flood Control Act of 1944, have evolved with time. When there were no major Upper Basin storage facilities and when the average annual water supply far exceeded downstream demands, inflexible mandatory criteria reserved 9.5 million acre-feet of vacant system storage space on April I of each year. Now, a more flexible concept enhances all project purposes while providing a degree of flood protection equivalent to that provided under the -7-