OCR Text |
Show Colorado River Run-off High The reservoir is 19 feet below the top of the raised spillway gates at Hoover Dam. At present, it contains 23.2 million acre-feet of available storage or 89 percent of its capacity. Based on the present forecast, Lake Mead is expected to increase four feet to about elevation 1,206 feet above mean sea level by the end of September. Runoff of the Colorado River and its tributaries above Lake Powell during the April through July period . is forecast at 11.5 million acre-feet, or 144 percent of normal, Bureau of Reclamation Regional Director Bill Plummer announced today. The forecast is based on the March 1 water content of 55 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. nor-mal. Snow pack distribution is heavier in the southern part of the Basin (up to 165 percent of normal) while it is only normal in the north. Lake Powell should rise from its present elevation, 3,629 feet, about 57 feet to elevation 3,686 above mean sea level by the end of July. This would be about 11 feet higher than the all time high reached in 1975. Ruleases from Glen Canyon Dam from April to September 1979 will be 4.5 million acre-feet acre-feet with a water year total for 1979 of 8.2 million acre-feet. acre-feet. Lake Powell should remain above elevation 3,680 feet through the summer months and then drop slowly during the fall and winter. Due to the record amount of snow in the San Juan Mountains, Navajo Lake, which is on the San Juan River, should receive 165 percent of normal runoff. The present ' release of 630 cfs will be increased to between 2500 and 4000 cfs after the middle of March to provide space so that the high flows can be stored in Navajo Lake and flood-damage flood-damage reduced when the snow in the mountains melts in May and June. Lake Mead's present elevation is 1,202 feet above mean sea level, or about 14 feet higher than a year ago. |