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David Heintz <br /> April 10, 2020 <br /> Page 2 of 5 <br /> DEPLETIONS <br /> During this plan year, the maximum exposed surface area will total 16.7 acres within the Active Pit <br /> and 12 acres at the Wash Pond Site. The former Unused Wash Pond (0.5 acres) was previously filled <br /> in, and it is expected that lagged depletions from the Unused Wash Pond will continue to accrue <br /> during this plan year. Additionally, during the April 1, 2020 through March 31, 2021 plan year, the <br /> site excavations will expose an additional 12 acres of ground water at the Wash Pond Site, <br /> consisting of two 5-acre silt ponds and one 2-acre fresh water pond (see Figure 1). In accordance <br /> with the conditions of permit #45995-F, all exposed groundwater Including new proposed silt and <br /> fresh water ponds at the wash site must be located at least 600 feet from any existing well. <br /> Water losses in the mined material at the Active Pit have been estimated to be 5.30 acre-feet, <br /> based on a projected 360,000 tons of mined material and a 2% moisture content. The moisture <br /> content is less than wet mining (4% loss) due to the fact that the pit is dewatered. <br /> Water losses from washing the material at the Wash Pond Site have been estimated to be 5.30 <br /> acre-feet, based on an additional loss of water of 2% by weight of the total mined material. <br /> A Glover analysis was utilized to determine lagged depletions to the stream from the consumptive <br /> use of ground water described above. The Glover analysis utilized the following parameters: <br /> Active Wash <br /> Pit Pond <br /> Specific Yield 0.2 0.2 <br /> Distance to the Stream, X (ft) 864 11400 <br /> Distance to No-Flow Boundary, W (ft) 4,121 2,650 <br /> Transmissivity (gpd/ft) 80,000 80,000 <br /> Based on these parameters, modeling was prepared for the exposed surface area from April 2019 <br /> through March 2020 as shown in Table 1. The lagged depletion analysis uses the previously used <br /> approach to account for all lagged depletions prior to March 2016. According to the analyses, 60.13 <br /> acre-feet of lagged depletions will occur during this plan year. This total is made up of 59.59 <br /> acre-feet of depletions due to the Active Pit, 0.20 acre-feet of depletions due to past use of the <br /> Unused Wash Pond and 0.33 acre-feet of depletions from the Sanitary Well (see Table 3). <br /> The total calculated depletion for this plan is 88.99 acre-feet. <br /> REPLACEMENTS <br /> The source of replacement water is Colorado Springs Utilities (CSU) for the period from April <br /> through November 2020 and the Arkansas Groundwater Users Association (AGUA) for the period <br /> from December 2020 through March 2021. If replacement water is released from an upstream <br /> source, the Applicant will need to account for transit losses as required by the Division Engineer or <br /> Water Commissioner. <br /> The lease of 115 acre-feet with CSU will provide sufficient replacement water for the calculated <br /> depletions of 66.24 acre-feet at the Rich Pit from April through November of the plan year. The <br />