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<br />. <br /> <br />two instream flow water rights in the Soda Creek basin located downstream of Echo <br />Mountain and above its confluence with Clear Creek. The rights are located on Little <br />Bear Creek and Soda Creek and are each decreed for 1.0 cfs. Figure 1 displays the <br />, location of the two instream flow water rights in relation to the Echo Mountain wells and <br />Clear Creek. <br /> <br />CWCB is concerned that injury could occur to their rights during low flow periods 1. <br />Although Echo Mountain plans to fully augment their expected stream depletions, part of <br />the planned replacement sources are directly tributary to Clear Creek, not Soda or Little <br />Bear Creeks. <br /> <br />3.0 POTENTIAL INJURY <br /> <br />The wells that serve Echo Mountain are deep fractured rock wells developed in the <br />Precambrian Biotite Gneiss (Martin and Wood Water Consultants, Inc.). While these <br />wells are considered tributary to Clear Creek, the stream depletions will be lagged due to <br />the depth and distance of the wells from the streams. <br /> <br />. <br /> <br />Calculations of lagged depletions were completed by Martin and Wood Water <br />Consultants, Inc., using the traditional SED-accepted Glover Method. Although this <br />method was not developed for fractured-rock conditions, it is widely accepted and <br />represents the current standard of care for calculating stream depletions. The Martin <br />and Wood analysis assumed an average transmissivity value of 131.7 gallons per day <br />per foot and a specific yield of 5 percent. These assumptions, combined with the <br />projected pumping volumes at the Park indicate that depletions may not accrue to area <br />streams for as long as four years. However, for purposes of Echo Mountain's proposed <br />SWSP and plan for augmentation, the Applicant assumes that stream depletions will <br />begin to accrue at the time pumping begins (December 2005). Due to lagged <br />depletions, the calculated annual stream depletions are divided by twelve to determine <br />monthly replacement requirements. Thus, an annual diversion of 35 AF would result in a <br /> <br />Water availability projections by the CWCS predict that average streamflows in both <br />. creeks potentially drop below 1.0 cfs during the period November through March. <br /> <br />. <br /> <br />4 <br />