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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />1999 OPERATIONS SUMMARY AND RESERVOIR STATUS <br /> <br />Water year 1999 obsetved near normal hydrologic conditions in the basin. The distribution of <br />precipitation and snowpack accumulation through the water year, however, was quite varied. <br />Very dry and abnormally warm weather in late February and March resulted in snowpack levels <br />being very low by April 1, 1999. The final April inflow forecast issued by the National Weather <br />Service was calling for only 62 percent of average April through July unregulated inflow into <br />Lake Powell. This warm dry pattern was quickly reversed, however, as April and May were <br />cooler than average months with abundant precipitation. April was particularly wet, with <br />precipitation in the Upper Colorado River Basin more than twice average. By mid-May, basin <br />wide snowpacks had risen to levels moderately above average. The end result was a near average <br />inflow year for Lake Powell. <br /> <br />While the Upper Colorado River basin was near average as a whole in water year 1999, there was <br />a contrast between the northern and southern river basins. The Upper Green River basin <br />experienced inflow that was much above average. Alternatively, the Gunnison and San Juan <br />River basins experienced moderately below-average conditions in water year 1999. <br /> <br />Unregulated inflow into Lake Powell was 15,680 MCM (12.71 MAF) in water year 1999, <br />approximately 108 percent of average. This inflow resulted in a gain of approximately 732 MCM <br />(0.593 MAF) of storage in Lake Powell. Approximately 164 MCM (0.133 MAF) of storage was <br />gained in resetvoirs upstream of Lake Powell, approximately 900 MCM (0.729 MAF) was lost <br />in Lower Basin resetvoirs, and the total Colorado storage system lost approximately 4 MCM <br />(0.003 MAF) during water year 1999. It is estimated that with average inflow during 2000, the <br />system will remain relatively full. During 1999, all deliveries of water to meet obligations <br />pursuant to "The Law of the River" were maintained. <br /> <br />Tables 1 (a) and 1 (b) list the October 1, 1999 resetvoir vacant space, live storage, water elevation, <br />percent of capacity, change in storage, and change in water elevation during water year 1999. <br /> <br />December 1, 1999 <br /> <br />3 <br />