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Peter Foster and Jonah Howe, Wright Water Engineers Page 5 of 14 <br /> Re: Gunnison West Gravel Pit SWSP <br /> December 8, 2025 <br /> Dewatering <br /> Dewatering is proposed to occur continuously during the term of this SWSP, therefore, <br /> depletions from dewatering are assumed to be offset by the dewatering discharge to the <br /> stream. In the event dewatering will cease and the mined area is allowed to refill during the <br /> term of this SWSP, the Applicant will develop a stage-volume relationship for the actively <br /> mined area and these depletions will be added to the total depletions from the mining <br /> operation and included on accounting provided to the Division Engineer and Water <br /> Commissioner. An example pit filling accounting sheet is included as Table 5. <br /> Replacement <br /> Replacement Water <br /> The proposed source of replacement water for this pit during the irrigation season (April <br /> through October) is a portion of the Applicant's interests in the Seventy-Five Ditch (WDID <br /> 5900668). The Seventy-Five Ditch diverts water from the Gunnison River and was decreed in <br /> Civil Action No. 1325 (Priority No. 1) for 14 cubic feet per second ("cfs") to irrigate 560 <br /> acres, providing a duty of water of 1 cfs per 40 acres of land. <br /> United owns thirty-one percent (31%) of the senior water right in the Seventy-Five Ditch, or <br /> 4.33 cfs, which is proposed to be used as a replacement water source in this SWSP. Based on <br /> United's pro-rata ownership of the Seventy-Five Ditch, the 4.33 cfs could irrigate up to 173 <br /> acres. The StateCU model with the Upper Gunnison High Elevation Calibration Coefficient <br /> was used to determine the historical consumptive use (HCU) for lands irrigated under the <br /> Seventy-Five Ditch, Priority No. 1. In addition, based on the decreed duty of water of 1 cfs <br /> per 40 acres of land, the Applicant has determined the historical consumptive use for the <br /> lands under the Seventy-Five Ditch as 1.7 acre-feet/acre, as shown on attached Table 3. <br /> Based on the average depth to groundwater of approximately five (5) feet below the ground <br /> surface, the historical consumptive use for subirrigation was reduced by fifteen percent <br /> (15%), resulting in an adjusted historical consumptive use value of 1.5 acre-feet per acre. <br />