2024-04-08_PERMIT FILE - M2024015

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EXHIBIT G Water Information Introduction The Sweet Valley Pit mining site is I located in the Northeast 1/4 of Section 30, Township 4 North, Range 66 West of the 6th Principal Meridian, in Weld County, Colorado. The proposed mining site is located adjacent to WCR 42 on the north side, WCR 25.5 on the west side, and CO Hwy 60 on the east side. WCR 40 is approximately 2,630 feet to the south of the permit boundary. Access to the site will be located on the south side of the permit boundary and approximately 1,311 feet west of CO Hwy 60 and 1,285 feet east of WCR 25.5. The dominant land use surrounding the property is agricultural. The operation will consist of sand and gravel production and will not impact the South Platte River in the form of depletions due to a slurry wall that will be installed prior to mining below exposed groundwater. Mining of the Sweet Valley Pit site will last for approximately 11 years and 8 months. Once reclamation is complete, the water storage reservoirs will be called the Sweet Valley Reservoir Complex with a total of two reservoirs. The north reservoir will have a water surface area of 32.42 acres and the south reservoir will have a water surface area of 40.10 acres. The depth to groundwater ranges from 13 to 18 feet seasonally within the permit boundary (measured in Existing MW, and MW-1 through MW-3, See the attached piezometer measurements table). The site will be mined down to a depth of 49 to 68 feet thus exposing groundwater to the atmosphere. This exposed groundwater, along with the operational losses associated with the extraction of sand and gravel deposits, will impact the South Platte alluvial aquifer. These impacts will cause river depletions that must be augmented. Groundwater will be exposed during the mining once the mining depths reach an elevation of approximately 4749 feet on the south side of the property and an elevation of approximately 4739 feet on the north side. To enable dry mining at the Sweet Valley Pit mining site, there will be dewatering trenches around the bottom of the mining slope. These dewatering trenches will change in length throughout mining. The maximum length will occur when the north or south cell is completely mined, concurrently with reclamation since the mining slope is the same as the reclaimed slope. The maximum size of dewatering trench will be 0.75 acres of exposed surface area. The water will flow from the dewatering ditch to a small pond at the end of the dewatering ditch from which the water will be pumped where it will either be used for processing and dust control water or where it will be discharged to eventually reach the South Platte River. As mining progresses, the dewatering trenches will shift to account for additional groundwater being exposed. The gravel pit will have slurry wall liners for Phase 1 and Phase 2 constructed prior to exposing groundwater. Water Requirements Water use at the Sweet Valley Pit mining site will include evaporation from exposed groundwater, dust control of haul roads and stockpiles, water for the wash plant (i.e. wash screen for concrete rock and sand) and water retained in material removed from the site. IN Central Colorado Water Conservancy District ' JaT Consulting,Inc. Sweet Valley Pit DRMS 112 Permit Application