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Chavers Mining Resources Substitute Water Supply Plan 2023 Page 3 of 8 <br /> August 29, 2023 <br /> and 7.69 acre-feet for the period of August 1, 2023 through December 31, 2023, as shown on attached <br /> Table 3. <br /> Concrete Production <br /> As mentioned above, the water used for concrete production will be provided by the alluvial well (permit <br /> no. 80120-F). Assuming 30 gallons of water/cubic yard and 154,000 cubic yards of concrete production <br /> during the period of this SWSP, the estimated water used for concrete production is 14.18 acre-feet per <br /> year and 6.28 for the period of August 1, 2023 through December 31, 2023, as shown on attached Table 3. <br /> Total Consumptive Use: Evaporative and Operational Depletions <br /> Total consumptive use includes evaporative losses of 48.68 acre-feet, 19.12 acre-feet of water lost with <br /> the mined product, 1.25 acre-feet of water used for dust control, and 14.18 acre-feet of water used for <br /> concrete production. Total consumptive use per year is 83.23 acre-feet. <br /> Total consumptive use for the period of August 1, 2023 through December 31, 2023 includes evaporative <br /> losses 18.47 acre-feet, 7.69 acre-feet of water lost with the mined product, 0.52 acre-feet of water used <br /> for dust control, and 6.28 acre-feet of water used for concrete production. Total consumptive use <br /> through December 31, 2023 is 32.96 acre-feet. <br /> Lagged Depletions <br /> The IDS AWAS stream depletion model was used to determine the lagged depletions from evaporation, <br /> operational losses, and the alluvial well to the South Platte River. The model parameters used are shown <br /> in Table A below. <br /> Table A. IDS AWAS Model Parameters <br /> Boundary Distance from Transmissivity Specific Distance from <br /> Well Name Condition boundary to stream (gpd/ft) Yield well to stream <br /> ft ft <br /> Aggregate Mining Alluvial Aquifer 7,500 85,000 0.2 575 <br /> Aggregate Processing Alluvial Aquifer 7,500 85,000 0.2 1,275 <br /> Concrete Production Alluvial Aquifer 7,500 85,000 0.2 1,045 <br /> Annual lagged depletions are as follows: 59.88 acre-feet associated with the evaporation from the pump <br /> basin and dewatering trench and water lost with mined aggregate, 9.69 acre-feet associated with the <br /> evaporation from the wash pond and dust control, and 14.30 acre-feet associated with the water pumped <br /> from the alluvial well for concrete production. The total lagged depletions per year equal 83.87 <br /> acre-feet as shown on attached Table 4. <br /> Lagged depletions for the period of August 1, 2023 through December 31, 2023 are as follows: 25.53 <br /> acre-feet associated with the evaporation from the pump basin and dewatering trench and water lost <br /> with mined aggregate ("Aggregate Mining"), 4.57 acre-feet associated with the evaporation from the <br /> wash pond and dust control ("Aggregate Processing"), and 6.56 acre-feet associated with the water <br /> pumped from the alluvial well for concrete production ("Concrete Production") as shown on attached <br /> Table 4. The total lagged depletions for the period of August 1, 2023 through December 31, 2023 <br /> equal 36.66 acre-feet as shown on attached Table 4. <br /> Dewatering <br /> Dewatering at this site will produce delayed depletions to the stream system. As long as the pit is <br /> continuously dewatered at a relatively constant rate, the water returned to the stream system should be <br /> adequate to offset the depletions attributable to the dewatering operation. Dewatering operations must <br />