Laserfiche WebLink
<br />/. <br /> <br />generated by the release of water through the river bypass tubes. Elevation 3,370 feet is <br />the lowest elevation at which water can be released from Lake Powell. Between <br />elevations 3,490 feet and 3,370 feet, there is four million acre-feet of storage. The <br />Operating Criteria do not reference these elevations at Lake Powell. Previous river <br />simulation modeling of the Colorado River system performed by Reclamation showed no <br />occurrences of Lake Powell reaching 3,490 feet in the next 50 years when subject to the <br />most severe droughts of the 20th cenhIry. However, since the current five-year drought is <br />worse than any of the 20th century droughts, there is now some risk that Lake Powell <br />could reach minimum power pool (elevation 3,490 feet) under a scenario of continued <br />drought in combination with the continuation of the minimum release objective from <br />Lake Powell. The Department will continue to address the issue of low reservoir storage <br />at Lake Powell in the Annual Operating Plan consultation process. In addition, see <br />response to Comments No. 34 and 38. <br /> <br />Comment No. 40 - (Letter No. 19): Over the past 10 years, the Upper Basin has delivered <br />more than 100 million acre-feet of water to the Lower Basin, which now in combination <br />with drought conditions has prejudiced the interests of the Upper Basin. <br /> <br />Response: During the past 10-year period (water years 1995-2004), over 100 million <br />acre-feet has flowed past Lee Ferry. The majority of this flow occurred during the five- <br />year period of 1995 through 1999 which was a period with above average flow on the <br />Colorado River. In July 1999, Lake Powell storage was 97 percent of capacity. During <br />the five-year period of 1995 to 1999,59.5 million acre-feet flowed past Lee Ferry, with <br />reservoirs throughout the Upper Colorado River Basin, including Lake Powell, releasing <br />excess water because they were full. Release of this water froth Lake Powell was <br />necessary because of the physical storage limitation of Lake Powell and dam safety <br />considerations. During the past five years, the objective in the operation of Lake Powell <br />has been to release 8.23 million acre-feet per year, consistent with the Operating Criteria. <br />It should also be noted that during the late 1990s, flood control releases were taking place <br />from Lake Mead in the Lower Basin resulting in a significant volume of water, <br />approximately 5 million acre-feet, being released from Lake Mead in excess of Lower <br />Basin demands. In addition, see response to Comment No. 34. <br /> <br />Comment No. 41 - (Letter No. 19): The existing Operating Criteria need clarification <br />that the minimal objective release of 8.23 million acre-feet stated in the Operating <br />Criteria is an "operating target" which is subject to revision in the Annual Operating Plan <br />process. <br /> <br />Response: See response to Comment No. 34. <br /> <br />Comment No. 42 - (Letter No. 19): The Friends of Lake Powell strongly endorse the <br />Annual Operating Plan process. Furthermore, we believe that operation of the Colorado <br />River reservoirs can be optimized with each Basin sharing more equitably in the burden <br />of drought. This would be best accomplished by maintaining, as equally as practicable, <br /> <br />25 <br /> <br />