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for the Operation of Glen Canyon Dam Final Environmental Impact Statement. <br />Releases from Lake Powell in water year 1999 will continue to reflect <br />consideration of the uses and purposes identified in the 1970 Operating Criteria and <br />the 1992 Grand Canyon Protection Act, including ecological impacts to the Grand <br />Canyon. Daily and hourly releases will continue to be made according to the <br />parameters of the ROD for the Glen Canyon Dam Final Environmental Impact <br />Statement preferred alternative, as shown in the following table: <br />Table 3. Glen Canyon Dam Release Restrictions <br />Parameter (cros) Icfs) Conditions <br />Maximum flow ~'~ 708.0 25,000 <br />Minimum flow 141 .6 5,000 nighttime <br /> 226.6 8,000 7:00 am to <br /> 7:00 pm <br />Ramp rates <br />ascending 1 13.3 4,000 per hour <br />descending 42.5 1,500 per hour <br />Daily fluctuations 12~ 141.6 / 226.6 5,000 / 8,000 <br />"' To be evaluated and potentially increased as necessary and in years when delivery to the <br />Lower Basin exceeds 10,152 MCM (8.23 MAF). <br />121 Daily fluctuations limit is 141.6 cros (5,000 cfs) for months with release volumes less than <br />740 MCM (.600 MAF-, 169.9 cros (6,000 cfs) for monthly release volumes of 740 to 987 <br />MCM (.600 to .800 MAF), and 226.6 cros (8,000 cfs) for monthly volumes over 990 MCM <br />(.800 MAF-. <br />62 <br />