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6 RELEASE OF COLORADO RIVER WATER Senator ANDERSON. The Supreme Court thought the Congress had some power in this matter? Mr. WEINBERG. Yes, sir. Senator ANDERSON. That is a revolutionary doctrine, is it not? The Congress thought it had some power, too, when it passed the Boulder Canyon Project Act, the storage project and set out between the States the amount of water they were going to get. Just because we have water on hand in Lake Mead this year, 5 million acre-feet more than last year, does not change the obligation of the compact; does it? Mr. WEINBERG. No. Senator ANDERSON. Mr. Dominy, do you have a statement to make about the reasons for this sluicing? Was there a request for $500,000 for dredging? Mr. DOMINY. We did make a request, Mr. Chairman, to purchase a dredge, and we believe firmly that we will need a dredge in this section of the river on a permanent basis, as Glen Canyon comes into being on the river, and the days of availability of water for flushing will be at end. I think this statement which I have will indicate some of the problems. Below Imperial Dam on the lower Colorado River, a current major problem is river regulation. River regulation, as referred to here, is the maintenance of a suitable channel that will transport the sediments introduced at Imperial Dam without causing channel deterioration. This can be accomplished by the release to the channel of a certain percentage of the water flowing into Imperial Reservoir. Based on studies of sediment data collected at Imperial Dam and downstream some relationships have been established for the amount of water needed for river regulation. HISTORIC METHOD OF HANDLING SEDIMENT PROBLEM River channel surveys indicate that since the operation of the desisting basin began at Imperial Dam, there has been a slow siltuaion and aggradations of the river channel downstream and that since operation of Morelos Dam began in 1950 there has been a local upbuilding of the channel immediately below that dam. With flows below Imperial Dam ranging from 3 mill on to 10 million acre-feet annually from 1950 through calendar year 1955, regular sluicing operations and systematic river regulation were possible. In calendar year 1956, a short water year, the flow reaching the northern international boundary was approximately 1,780 million acre-feet and the sediment accumulation increased below Morelos Dam. Senator ANDERSON. Where is Morelos Dam? Mr. DOMINY. Morelos Dam is the diversion dam into the Mexican irrigation system. Senator ANDERSON. Has there been 1,780 million acre-feet of water going down to that dam? Mr. DOMINY. To that point.Epson Perfection 4870 Photo, 400 dpi, 24 bit, 6,221,824 byte