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Ms. Joanna Williams <br />October 31, 2007 <br />Page 3 <br />the amount of gross evaporation. Overall, the unit net evaporation rate was calculated to be 2.86 <br />feet per year (Table 1). <br />Ground water will be exposed in a rinse water lagoon and dewatering pond with a total <br />maximum exposed surface area of 2 acres. Correspondingly, the annual net evaporation for <br />these 2 acres will be 5.72 acre-feet (Table 1). The monthly net evaporation for the period of this <br />plan is shown in Table 2. <br />Operational Losses <br />The moisture content of the annual aggregate production of sand and gravel is determined <br />to be 4 percent by weight. We anticipate that the slung wall liner will be approved by May 31, <br />2008, at which time 120°i Estates Partners will no longer need to replace operational losses. <br />Therefore, the total volume of water lost in the production of sand and gravel is 1.77 acre-feet <br />for the remainder of 2007 and 3.89 acre-feet for 2008 (Table 2). Note that the amount of water <br />lost in production of sand and gravel has been updated since the last SWSP renewal request to <br />reflect the actual production on site from the period of January 2007 through June 2007. <br />All water used for dust suppression on <br />remainder of 2007 and 2.60 acre-feet in 2008, <br />(permit number 64401). The dust suppression <br />conservative. <br />the site, approximately 0.30 acre-feet for the <br />shall come from the Laramie-Fox Hills well <br />use was extended into December 2008 to be <br />Total Losses <br />The total consumptive use from the mining operation, including annual evaporative and <br />operational losses, equals 2.13 acre-feet for the remainder of 2007 and 9.25 acre-feet for 2008. <br />There is no consumptive use after October 2008 as there will be no further mining at the site <br />after September 2008. To be conservative, evaporative losses were included through October <br />2008. <br />MINING STREAM DEPLETIONS <br />The SDF method was used in all the prior substitute water- supply plans but the Glover <br />methodology, as incorporated in the AWAS program, was used to compute the lagged depletions <br />for this renewal request. The hydrogeoiogical.. parameters were obtained from the GIS files <br />developed by the IDS Group which includes harmonic transmissivity. The following <br />hydrogeological parameters were used in the AWAS program. <br />Location X - Dist to River W - Boundary Harmonic <br /> (feet) Dist (feet) Transmissivity <br /> (gpd/ft) <br />Gravel Pit 2,295 3,836 63,000 <br />Henderson Water Ski 1,808 5,300 61,600 <br />Lake <br />Martin and Wood Water Consultants, Inc.