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Mr. Richard Raines June 17, 2008 <br />Middle Poudre Combined Plan - Lafarge West, Inc. Page 5 of 9 <br />an additional lease with the LCRC to replace the monthly shortfall of 251.31 acre-feet (Table 6). <br />A copy of the lease with the LCRC was submitted to this office on January 9, 2008. Based on <br />the information received from the water commissioner, the 251.31 acre-feet were released from <br />Gray Lakes. Lafarge will divert the full farm headgate delivery of the 8.5 Box Elder Ditch shares <br />starting in April 2008. Accordingly, the monthly timing of 747.5 acre-feet (full farm headgate <br />delivery of the 8.5 shares) was used in the recharge model to determine the recharge accretion <br />credits for 2008. The lagged accretions to the Cache la Poudre River are estimated to total <br />517.53 acre-feet for this approval period (includes carry over from recharge in previous years). <br />The Three Bells site was continuously dewatered at a rate of 1,200 gallons per minute. <br />The timing of the lagged depletions from the dewatering operation was determined through a <br />stream depletion model for the Three Bells Pit. The model addresses the lagged depletions at <br />the Greeley 351h Avenue Pit, East Rigden Pit, Kyger Pit, Port of Entry Pit and Weizel Pit by <br />accounting for the net accretion credits at the river that occur due to the dewatering operation at <br />the Three Bells Pit. These accretions are applied to this plan against depletions from the <br />Greeley 35th Avenue Pit, East Rigden Pit, Kyger Pit, Port of Entry Pit and Weizel Pit. The <br />attached Appendix E summarizes the accretion credits from dewatering at the Three Bells Pit. <br />During the Water Year 2008, a lease from the LCRC will make replacements for <br />depletions not covered by the recharge program. A lease of 174.85 acre-feet of fully <br />consumable water from LCRC will make replacements from November 2007 through August <br />2008 (Table 7). A copy of the LCRC lease was submitted to this office on May 8, 2008. The <br />source of the replacement water will be from Gray Lakes, which can deliver water to Box Elder <br />Creek and from there to the Cache La Poudre River. Approximately 9.12 acre-feet of water <br />(0.25 percent per stream mile) from the Gray Lakes are estimated to be required to replace <br />transit losses. The water storage right for the Gray Lakes owned by.LCRC is not presently <br />decreed for augmentation, therefore a change of use application for the Gray Lakes water <br />storage right was filed with the Division 1 Water Court in case no. 2006CW276. A detailed <br />historical consumptive use analysis has not been provided in case no. 2006CW276. According <br />to previous information provided by TZA Water Engineers, Inc. ('TZA") in a letter dated March <br />15, 2006, LCRC water rights have historically been used to provide supplemental water to <br />irrigated lands within the Lake Canal Service area. Based upon the crop mix, irrigated acreage <br />and water available for irrigation, TZA concluded that the Lake Canal system is water short. <br />TZA also noted that a historical consumptive use of 65% is not uncommon for the use of <br />supplemental reservoir water within water short ditch systems. <br />For the purposes of this plan, you proposed to assume the consumptive use associated <br />with the Gray Lakes water is 50%. However, in the previous plan approved on January 26, <br />2007, the Applicant was advised that if a subsequent request to use Gray Lakes water for <br />replacement purposes is submitted without a detailed historical consumptive use analysis being <br />provided to substantiate a larger credit, the consumptive use credit allowed would be limited to <br />45% for the Gray Lakes water (55% assumed to be return flow). Since a detailed historical <br />consumptive use analysis of the Gray Lakes water was not provided, the consumptive <br />use credit allowed for this plan will be limited to 45%. Thus; in order to provide 174.85 <br />acre-feet of replacement water, a total of 388.6 acre-feet of Gray Lakes water must be released <br />(55% of 388.6 acre-feet or 213.7 acre-feet are the required return flow obligations). These <br />amounts do not include any required transit losses. By July 1, 2008, the Applicant is required to <br />provide updated accounting to document the monthly amount and timing of releases to maintain <br />the historical return flow obligations of the Gray Lakes water used for replacement purposes. <br />Applicant is also required to provide a copy of a revised lease for Gray Lakes water that reflects