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Mr, Richard T. Raines Page 2 December 2, 2004 The source of replacement water for this combined plan will be from 5.75 Taylor and GiII Ditch shares. The shares will be diverted into a recharge pit located on the Home Office site. The evaporation losses values fisted in the Table B for the Home Office Pit includes the evaporation losses from the recharge pond. In 2004 the 5.75 Taylor and Gitl Ditch shares were diverted into the recharge pond for lagged replacement water. The 5.75 shares will be diverted in the recharge pond again in 2005 and 2006 to provide replacement water for this combined plan. The 5.75 shares were historically used to irrigate 104.5 acres of pasture grass, all of which have been taken out of production. The historic consumptive use of the 5.75 shares was determined to be 122.8 acre-feet. The 5.75 shares will be diverted into the recharge pit each irrigation season. The return flow obligations from the Taylor and Gill Ditch will be maintained by the recharge plan. It should be noted that the only consumptive use at the North Taft Hill Expansion Site and the Overland Ponds Site is the evaporation from exposed ground water. The mined material from the North Taft Hill Expansion Site and the Overland Ponds Site will be conveyed to the existing facilities at the Home Office Pit for processing. Therefore the 14.7 acre-feet associated with mining of up to 500,000 tons of aggregate per year and 2 acre-feet per year of water used for dust control listed in Table B for the Home Office Pit will in fact be from the North Taft Hill Expansion Site and the Overland Ponds Site. According to the information provided mining will occur at the North Taft Hill Expansion Site through the end of January 2005. This site will be continuously dewatered until the end of January 2005. After January 2005 the lake will be allowed to fill, as the mining operation will begin at the nearby Overland Pond Site. The timing of the lagged depletions from the dewatering operations was determined through a stream depletion model for the North Taft Hill Expansion Site. The model addresses the lagged depletions after the dewatering stops by accounting for the net accretion credits at the river that occur due to the dewatering operation at the Overland Ponds Site. These accretions are applied to this plan against depletions from the North Taft Hill Expansion Site and the Home Office Pit. Based on the information provided the dewatering rate at the North Taft Hill Expansion Site and the Overland Ponds Site was assumed to be 1,200 gallons per minute. During the Water Year 2006, a lease from the Tri-Districts will make additional replacements for two months with insufficient recharge credits. The point of replacement will be Chambers Reservoir, which can only deliver water during the warm months of the year. Therefore since the months with insufficient credits are February and April, the water commissioner will operate an exchange of water from the North Poudre Reservoir No. 6 with Water Supply and Storage Company's transmountain water stored in Chambers Reservoir. The total amount of water required including 7.8 percent transit losses will be 13.3 acre-feet. A monthly breakdown of the real time stream depletions from the mining operation as well as the real time replacements made by lagged timing of the historic consumptive use credit is shown in the attached Table 1. I hereby approve this substitute water supply plan, in accordance with Section 37-90- 137(11}, C.R.S., subject fo the following conditions: 1. This plan shall be valid through October 31, 2005 unless otherwise revoked or modified. This plan will be extended until October 31, 2006, if a lease for 13.3 acre-feet from the Tri-Districts for Water Year 2006 is provided to the State Engineer's Office by October 31, 2005.