2013-11-19_HYDROLOGY - M1982155 - Laserfiche WebLink

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Jared Dains Page 2 November 18, 2013 letter from DRMS 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 groundwater 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), or 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 The total of 3.5 acre -feet per year for dust control would be withdrawn from well permit no. 59834 -F and piped approximately one mile to the storage tank. 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: X =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 stream depletions were determined to be 3.49 acre -feet. 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, thus depletions accrue to the river uniformly through the year. The total steady -state depletions covered by this plan period are 4.07 acre -feet 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 must be pumped out of any impoundment so it may enter the local drainage back to the stream within 72 hours. REPLACEMENTS Replacement water will be supplied by historic 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 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 (including the requirement to replace the gross evaporation from the storage pond). Transit losses will occur down Fountain Creek to the delivery point distance an estimated distance of 18 miles. An average transit loss of 0.25% per mile (total transit loss of 4.5 %) was estimated and assessed against the 20 shares of FMIC replacement credits, as shown in the attached Table 5. Please note that the 0.25% per mile transit loss is only an estimate and the actual transit loss shall be determined by the Fountain Creek Transit Loss Model, as outlined in conditions of approval nos. 7 and 10 of this plan. In the event that accounting shows that the FMIC shares are not yielding adequate amounts for replacements, you will seek