2017-02-14_HYDROLOGY - M1982155 - Laserfiche WebLink

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Mr. Jared Dains, P.E. February 9, 2017 Page 2 of 5 In accordance with the letter dated April 30, 2010 (see attached) from the Colorado Division of Reclamation, Mining, and Safety ("DRMS"), all sand and gravel mining operators must comply with the requirements of the Colorado Reclamation Act and the Mineral Rules and Regulations for the protection of water resources. The April 30, 2010 letter from DBMS requires that you provide information to DRMS to demonstrate you can replace long term injurious stream depletions that result from mining related exposure of ground water. In accordance with approach nos. 1 and 3, you have indicated that a bond has been obtained for $432,522 through the Division of Reclamation, Mining, and Safety ("DRMS") to assure that depletions from ground water evaporation do not occur in the unforeseen event, or events, that would lead to the abandonment of the Pit. DEPLETIONS According to the submittal, the only consumptive uses of water are from dust control, which you have estimated to be approximately 3.5 acre-feet per year, and evaporation from the ground water pond. Based on the NOAA Technical Report NWS -33, gross annual evaporation at the location of the ground water pond is approximately 46.0 inches (3.83 acre-feet per surface acre), which results in a net evaporative depletions of 0.58 acre-feet per year for the ground water pond (based on a pond surface area of 0.2 acres). The total of 3.5 acre-feet per year for dust control would be withdrawn from well permit no. 59834-F and piped approximately one mile to the storage tank and/or ground water pond. The water withdrawn from the ground water pond will be less than or equal to water delivery so Schmidt does not anticipate appropriating additional ground water within the pit itself other than water lost to evaporation. The timing of depletions to Rock Creek attributable to pumping from the sump well no. 59834-F were calculated using the Integrated Decision Support System AWAS program utilizing the following lagging parameters: distance to stream = 390 feet, transmissivity = 30,000 gallons per foot per day, aquifer width = 3,500 feet and specific yield = 0.2. Due to the location of the sump and the lagging parameters used, the steady-state lagged stream depletions were determined to be 3.49 acre- feet/year as shown in Table No. 3. The ground water pond is not located within the defined alluvium aquifer; therefore, for the purpose of this SWSP, the Applicant assumed steady-state conditions where the depletions accrue to the stream uniformly through the year. The total steady- state depletions covered by this SWSP are 4.07 acre-feet/year as shown on the attached Table 3. The SWSP does not allow for use of storm water that may collect in on-site pits. Storm water collected on site will be administered in accordance with this office's February 11, 2016 Administrative Statement Regarding the Management of Storm Water Detention Facilities and Post-Wildland Fire Facilities in Colorado. REPLACEMENTS Replacement water will be supplied by historical consumptive use credits from 20 shares of the Fountain Mutual Irrigation Company (FMIC) to Fountain Creek at FMIC's augmentation station located on Spring Creek in Colorado Springs. Replacement credits for the Fountain Mutual shares have averaged 0.7 acre-feet per share per year, representing a portion of farm headgate delivery. These share percentages have been confirmed in previous court cases, most recently by the Division 2 Water Court in case no. 07CW51. You have estimated that the 20 shares would yield 14 acre-feet per year of replacement water, which is sufficient to cover the estimated depletions from the consumptive uses mentioned above. For purposes of this SWSP, historical consumptive use credit