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, It 4220 It . , the east side of the Continental Divide in the Arkansas River Basin is not as high as its adjacent west slope. The drainage area above the gage on Halfmoon Creek near Malta, elevation 9830, has averaged 16.7 inches annually. The average annual yield for the 23.6 square miles above this station is 21,080 acre-feet. The average annual discharge for the period 1928 through 1965 at the Arkansas River at Granite gate with all transmountain diversions taken out, was 219,400 acre-feet. Drainage area above that gage is 427 square miles. Floods in the Fryingpan River Basin, such as the one which occurred in the spring of 1957, are often the result of heavy rain on an abnormally heavy snowpack. In that particular year the snowmelt was late in starting, the Fryingpan River peaked much higher and later than usual, and there was an internal rain on the snowpack. On June 30, 1957, the Fryingpan River at Norrie peaked at 1,780 cubic feet per second (ft3/s), and the North Fork of the Fryingpan River near Norrie peaked at 1,140 ft3/s. The Fryingpan River at Norrie normally ranges from 15 ft3/s to 40 ft3/s during December. The recorded low there was 8.0 ft3/s in December 1962, but may have been less during periods of no record. The native flow of Lake Fork as measured at the gage 1,000 feet upstream from original Sugar Loaf Reservoir has averaged 25,400 acre-feet annually. The flows have ranged from winter average of about 4 ft3/s to a June average of about 180 ft3/s. The Busk-Ivanhoe transmountain diversions from the Fryingpan River to Lake Fork have averaged about 5,000 acre-feet annually. These transmountain diversions and the native flows were to some extent regulated by the original 17,416 acre-foot capacity Sugar Loaf Reservoir which was owned and operated by the CF&I Steel Corporation. The outflow from this reservoir is esti- mated to have ranged from 1 to 500 ft3/s. The historic end-of- month water surface elevations are shown in Figure II-53. As a feature of the Fryingpan-Arkansas Project, Turquoise Lake was created by construction of a new and larger Sugar Loaf Dam (completed in 1968), providing a storage capacity of 120,490 acre-feet and inundating the original CF&I Sugar Loaf Reservoir. Under Bureau of Reclamation operation the outlet structures have the capability of discharging as much as 1,120 ft3/s to Lake Fork and 500 ft3/s to the Mt. Elbert Conduit. Under normal operation, minimum bypass flows to Lake Fork of 10 ft3/s May 111-32