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Show April-July Runoff for Colorado t Predicted at 9.2 Million Ac. Ft. f Heavy early winter snow-fcacks snow-fcacks over the Colorado River watershed indicat that the 1970 April-July Colorado River snowmelt runoff could be 9.2 million acre-feet, or 111 percent of normal, the Bureau of Reclamation announced an-nounced today. The predicted runoff is based ba-sed on measured precipitation precipita-tion for October, November, and December of 1969- The forecast assumes that normal nor-mal precipitation will occur druing the coming 7 months. Usually the most sigmti-cant sigmti-cant amounts of precipitation contributing to runoff occur during the winter and early spring. This year's forcast of 9.2 million acrefeet compares with 8.2 million acre-feet of measured runoff in AprU through July 1969 and the longtime average runoff at 8 3 million acre-feet of those snowmelt months. About two-thirds two-thirds of the total annual flow of the Colorado River occurs in the heavy . runoL month of April though July. About 950,000 acre-feet of runoff is (expected to occur above Flaming Gorge Dam on the Green River, 730,000 acre-feet above tuia Blue Me-sa Me-sa Dam on the Gunni , son, River and 880,000 acre - feet above Navajo I m on the San Juan River. U'ha remainder will come from fr-om the main stem from generally gen-erally unregulated tributaries. Although a seasonal rise in water levels will occur at Flaming Gorge, Blue Mesa, and Navajo eReservoir, th Major portion of the 9.2 million acre - feet will flow into Lake Powell Pow-ell behind Glen Canyon Dam. Based on the present forecast, fore-cast, Lake Powell should rise to about elevation 3,609 feet, with a usable content of 13.1 million acre-feet by the end of the summer. Lake Mtead on Jan. 1 was at elevation 1,152 feet above ab-ove mean sea level, or about 12 fee't higher than a year ago. It contains 16.8 million acre-feet of available" storage, stor-age, or 61 per cent of its capacity. ca-pacity. The reservoir Level is now 69 feet below the top of the raised spillway gates at Hoover Dam. The lake is expected to rise slowly about ab-out 3 feet by next year at ; this time. Levels of tj,e . ervoir after then pend on the amount of ' ! j off received from the f shed. . 'J . 1 . rf |