OCR Text |
Show Spring Runoff raising Lake Powell feet with a water year total for 1978 of 8.2 million acre-feet. acre-feet. Lake Powell should remain above elevation 3,660 feet through the summer months and then drop slowly during the fall and winter. Prior to the 1979 spring runoff, the lake should be about elevation 3,658 feet with an active content of 18.9 million acre-feet. Runoff of the Colorado River and its tributaries above Lake Powell during the April through July period is forecast at 11.0 million acre-feet, or 141 percent of normal, the Bureau of Reclamation announced. This forecast is based on the May 1 and June 1 water content of 41 snow courses within the watershed area of the Upper Colorado River Basin and presumes that precipitation during the remainder of the runoff season will be normal. Runoff flows, which usually reach their peak by early June, will probably peak in mid June or later because of the cold spring weather throughout the Upper Colorado River Basin. Lake Powell should rise from its present elevation, 40 feet, about 26 feet to elevation 3,666 above mean sea level by July. This would be about 9 feet lower than the all time high reached in 1975. This year's above average runoff will not fully recover the drop resulting from the 1976-77 driest year of record. Releases from Glen Canyon Dam from June through September 1978 will be 3.4 million acre- |