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Parsons Mine SWSP June 30, 2017 Plan ID 5822 Page 3 of 10 Office of the State Engineer 1313 Sherman Street, Room 821, Denver, CO 80203 P 303.866.3581 www.water.state.co.us The Alluvial Water Accounting System (AWAS) program developed by the Integrated Decision Support (IDS) Group at Colorado State University was used to lag depletions from evaporation and operational losses at the mine site to the Cache La Poudre River. The model requires the following parameters: distance (X) from the centroid to the river, aquifer width (W), transmissivity (T), and specific yield (S). The Parsons Mine was split into four different areas, designated Areas A, B, C and D, as shown on the attached Figure 1, in order to more accurately determine the lagged depletions from the site. The aquifer parameters used for each area are listed in the table below: Aquifer Parameters – Depletion Areas Area X (ft) W (ft) T (gpd/ft) S A 2,176 9,823 85,000 0.15 B 208 9,946 85,000 0.15 C 297 10,816 85,000 0.15 D 2,636 10,810 85,000 0.15 As shown in the attached Figure 1, Phase 1A and Phase 1B are located within Area A, while Phase 1C is located within Area B. The total lagged depletions for the Parsons Mine site were determined to be 66.07 acre-feet for this plan period. This amount includes lagged depletions resulting from past consumptive use at the site that are projected to impact the river during this plan period. A monthly breakdown of lagged depletions, both by area and in total, is shown in the attached Table 1. Dewatering No ground water has been exposed so far in the mining of Phase 1A or 1C. Once ground water is exposed, all phases of the mine will be continuously dewatered for the entire plan period. As long as the site is continuously dewatered, the water returned to the stream system should be adequate to offset the depletions attributable to dewatering operations. MM is not planning to use any dewatering credits for replacement purposes of depletions at the Parsons Mine or at any other site under this SWSP. Totalizing flow meters must be installed at each discharge location and meter readings must be reported on the submitted accounting. The meter readings will be used in calculating the post-pumping depletions that must be replaced if dewatering ceases at the site. Replacements The operator proposes to provide replacement for this pit using consumptive use credits from 12 shares of Whitney Ditch owned by MM delivered directly to the river for immediate credit or delivered to a recharge pond (Parsons Mine Recharge Area, WDID 0302067) for lagged recharge accretion credits. In addition, MM proposes to use water stored in the Heaton Reservoir under case no. 2001CW193 as well as any excess fully consumable water leased from the City of Greeley available after use for replacement purposes in MM’s combined SWSP for the Iverson Mine and the 35th Avenue Pit. The decreed source for the water rights under the Whitney Ditch (WDID 0300930) is the Cache la Poudre River, and the decreed point of diversion for the Whitney Ditch is on the north side of the Cache la Poudre River in the NW¼ of the SE¼ of Section 19, T6N, R67W, 6th P.M., Weld County. During the period of this SWSP, MM will dry up a total of 130.8 acres attributed to the 12 Whiney Ditch shares, as shown on attached Figure 2. MM’s 12 shares in the Whitney Ditch Company were changed for a variety of uses including augmentation/replacement in case no. 2008CW65. Case no. 2008CW65 relied on a ditch-wide analysis of the 320 total shares in the Whitney Ditch. Based on a study period of 1950 through 1995, the Court found that the average annual gross river