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<br />Actual Operations Under Criteria. Water Year 1993 <br /> <br />Water year 1993 signaled the end of six years of drought <br />within the basin. Basinwide precipitation during 1993 was <br />well above average. The high precipitation also translated <br />into a well above average snowpack. At the beginning of the <br />runoff season (April 1, 1993) basinwide snowpack was <br />approximately 140 percent of average and above normal <br />precipitation was received throughout most of the runoff <br />season. <br /> <br />A weather pattern of southerly storms developed during the <br />snow accumulation season. As a result, the northern portion <br />of the basin had average to slightly above average snowpack <br />levels, and the central and southern portion of the basin had <br />well above average snowpack levels. These factors combined <br />to produce a near average runoff in the Green River, a 20 <br />percent exceedance runoff (values exceeded 20 percent of <br />the time) in the Gunnison and San Juan Basins, and a 25 <br />percent exceedance inflow (values exceeded 25 percent of <br />the time) into Lake Powell. <br /> <br />Even though snowpacks in the Gunnison and San Juan <br />basins were very high in water year 1993, only minor <br />flooding occurred because temperatures fluctuated and <br />adequate time was available to evacuate Blue Mesa and <br />Navajo reservoirs as necessary. Minor flooding also <br />occurred in the Jensen, Utah area on the Green River just <br />downstream of its confluence with the Yampa River. <br /> <br />Unregulated inflow into Lake Powell in water year 1993 was <br />17,210 million cubic meters (13,950,000 acre-feet), 116 <br />percent of the loog term average. This inflow was enough <br />to eliminate much of the storage deficit that had <br />accumulated over the 6 previous drought years in Colorado <br />River reservoirs. In water year 1993, Colorado River <br />reservoirs gained 8.81 billion cubic meters (7.14 million acre- <br />feet) of storage. It is now estimated that 2 normal flow <br />years would completely fill the system. During 1993, all <br />deliveries of water to meet obligations pursuant to "The Law <br />of the River" were maintained. <br /> <br />During water year 1993, Mexico received a total delivery of <br />approximately 6.23 billion cubic meters (5.05 million aere- <br />feet) at the Northerly International Boundary (NIB). <br />Approximately 5.53 billion cubic meters (4.48 million acre- <br />feet of the NIB deliveries will be the product of flood control <br />releases from Painted Rock Dam on the Gila River. The <br />Gila River confluence with the Colorado River is between <br />Laguna Dam and Morelos Dam. The remaining volume <br />delivered at NIB will be Colorado River water. Of that <br />volume, approximately 535.3 million cubic meters (434,000 <br />aere-feet) will have been released through Laguna Dam. <br />The remaining 169.0 million cubic meters (137,000 acre-feet) <br />will have been discharged through Siphon Drop and Pilot <br />Knob Powerplants on the All-American Canal. <br /> <br />2 <br />