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Inouye Pit SWSP Page 3 of 7 <br /> March 24, 2022 <br /> anticipates the liner construction beginning in April, no dewatering is anticipated to occur during the SWSP <br /> period. <br /> Total Consumptive Use <br /> The total consumptive use from evaporation is 44.4 acre-feet and the total operational consumptive use is <br /> 35.5 acre-feet. The total consumptive use at this site from evaporation, dust suppression, water lost in <br /> mined product, and slurry wall construction is estimated at 79.9 acre-feet for the SWSP period. <br /> Lagged Depletions <br /> The IDS AWAS stream depletion model was used to determine the lagged depletions from dewatering, <br /> evaporation and operational losses to the South Platte River. The aquifer characteristics used in the model <br /> for the gravel pit are: <br /> • Transmissivity (T) = 140,000 gallons per day per foot, <br /> • Specific yield (SY) = 0.2, <br /> • The location of the parallel impermeable boundary (W) = 5,001 feet from the stream, <br /> • The distance from the centroid of the gravel pit site to the stream (X) _ <br /> o 3,582 feet for evaporation, and <br /> 0 1,763 feet for operational losses. <br /> The total lagged depletions are equal to 38.6 acre-feet for evaporation and 37.4 acre-feet for operational <br /> losses, or 76.0 acre-feet total for the SWSP period, as shown in Table 4 (attached). Depletions from this <br /> operation will accrue to the South Platte River in the SW'/a of Section 31, Township 2 North, Range 66 West, <br /> 6th P.M. <br /> Dewatering and Recharge Depletions/Accretions <br /> Upon construction of the slurry wall, no dewatering depletions will occur during the SWSP period. <br /> Previously, the mining operation was continuously dewatered to the South Platte River as shown in Table 3 <br /> (attached). Additionally, depletions due to evaporation from and credits due to the recharge pond were <br /> accounted for in the previous SWSP; however recharge has since ceased and therefore only lagged <br /> dewatering depletions and recharge accretions from the previous SWSP period are considered in this <br /> renewal. The quantity of water pumped at the site for dewatering and recharge purposes was lagged to <br /> the South Platte River using the IDS AWAS stream depletion model using the Glover analysis and the <br /> following aquifer parameters: <br /> • The distance to the river (X) = 3,582 feet for dewatering and (X) = 2,587 feet for recharge, <br /> • The aquifer width (W) = 5,001 feet, <br /> • Transmissivity (T) = 140,000 gpd/ft, and <br /> • Specific yield (S) = 0.2. <br /> The net replacement requirement, which is the total lagged accretions minus the total lagged depletions <br /> from past dewatering and recharge activities, is 9.3 acre-feet for this SWSP period. Therefore the total <br /> replacement requirement is 85.3 acre-feet. <br /> Replacements <br /> The Applicant proposes to provide replacement for this pit using fully consumable water leased from the <br /> Central Colorado Water Conservancy District ("CCWCD"). A copy of the lease agreement with CCWCD for <br /> 97.75 acre-feet for April 2022 through March 2023 was provided to this office with the SWSP request and <br /> is attached to this letter. The leased water will be water made available to CCWCD from Aurora and <br />