OCR Text |
Show PART VI STREAM MANAGEMENT Of particular importance to the Upper Basin interests is the provision that sufficient water is to be retained in storage in the Upper Basin reservoirs to assure delivery of water at Lee Ferry as required by the Colorado River Compact without impairment of Upper Basin consumptive uses. Such storage, in the amounts to be determined annually by the Secretary, constitutes the first call on the waters produced above Lee Ferry. Next, Lake Powell is to acquire the same amount of active storage as found concurrently at Lake Mead. During these two conditions the objective shall be to maintain a minimum release of water from Lake Powell of 8.23 million acre-feet per year. However, in order to meet the Compact Lee Ferry requirements of 75,000,000 acre-feet for the 10-year period ending September 30, 1972, there is recognized the need for releases greater than 8.23 million acre-feet in the years ending September 30, 1971 and 1972. This is due to the small releases at Glen Canyon Dam following closure in 1963. When Lake Powell has retained the same amount of water as found concurrently in Lake Mead, releases greater than 8.23 million acre- feet annually are to be made from Lake Powell (a) to the extent they can be applied to downstream consumptive uses, (b) to maintain equal storage in Lake Powell and Lake Mead, and (c) to avoid spilling Lake Powell. All such releases shall be through the Glen Canyon powerplant and, when necessary, adjustments in requirements (a), (b), and (c) above are permissible to avoid a bypass of water around the Glen Canyon powerplant. A disclaimer is included in the criteria as to the magnitude of the specified releases with respect to the actual requirements of the Compact. The criteria also furnishes guidelines for the operation of Lake Mead, many of which have little or no effect upon the Upper Basin. However, the principle of equal opportunity for storage in Lake Powell and Lake Mead has the effect of sharing draw down at both reservoirs in meeting out storage water for downstream consumptive uses. Thus Upper Basin interests are particularily concerned with any buildup of excessive uses or wastes in the Lower Basin. 27 |