Updating the Hoover Dam documents, 1978 / Milton N. Nathanson.

page VI-70

VI-70 UPDATING THE HOOVER DAM DOCUMENTS COLORADO RIVER STORAGE PROJECT G5 We wish to make it clear, as was done at the Boulder City meeting, that our expression of concern over the inclusion of evaporation from storage project units was cited, not only to call attention to that specific problem, but also to indicate that the upper basin had objections to the proposed "general principles" of January 1960. At Boulder City we did not wish to leave the impression that we were agreeing to the "general principles" by our silence. Likewise, by this reply to your August 26 letter, which is concerned with the evaporation question exclusively, we do not intend to imply that we have no other objections to the proposed "general principles" of January 1960. Evaporation from upper basin reservoirs should not be included in the reconstructed inflow to Lake Moad that is used in computing the so-called "basic firm" energy and deficiencies in Hoover powerplant generation. It is a well-documented fact that long-time holdover storage of water in the upper basin is mandatory if the upper basin is to be able to develop the consumptive use of water that has been apportioned to it. There is no doubt in anyone's mind that the negotiators of the pertinent compacts and other documents constituting the "law of the river" recognized this condition and contemplated the storage of water upstream from Lee Ferry. The evaporation from storage units is to be regarded as a diminution of water supply associated with the necessity to store water for consumptive-use purposes in the upper basin. In a sense it is a necessary cost of doing business similar to the cost of snow removal being a necessity cost of providing public transportation. The situation with respect to upper basin reservoirs is no different from that with respect to lower basin reservoirs. Those reservoirs evaporate water, too, and diminish the water supply. There is no more reason to include evaporation from upper basin storage units in reconstructing the inflow to Lake Mead for the computation of "basic firm" energy than there is for including the water consumptively used by the upper basin participating projects of Public Law 485, or by all of the upstream projects and reservoirs. You would agree that to include these latter mentioned items would be nothing snort of ridiculous. In other words, there is no more reason to reconstruct the inflow to partially virgin-flow conditions for the benefit of Hoover powerplants than there is to reconstruct it to absolute virgin-flow conditions. If upper basin evaporation is to be included in the theoretical Lake Mead inflow, the salvage of water due to the reduction of river losses resulting from the operation of the storage units and additional consumptive-uses in the upper basin should also be considered. This salvage would be substantial during the initial filling period under the proposed general principles. It should be apparent that our objections to the inclusion of evaporation in the reconstructed inflow are aimed at the principle involved rather than at the amount of water or the magnitude of the additional deficiency in computed Hoover power generation. By the inclusion of evaporation in the inflow. Glen Canyon is forced to pay a penalty for power not generated at Hoover and is also required under the proposed criteria to furnish water during the filling period that is evaporated from the lower basin reservoirs. We fail to see the equity in penalizing the upper basin for exercising a right that belongs to it, the right to store water necessary for its development. It certainly must