2012-08-20_HYDROLOGY - M2000158 - Laserfiche WebLink

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Mr. Rick Parsons, P.E. August 17, 2012 Page 2 anticipated consumptive is 31.0 acre -feet annually of evaporation Toss from an exposed ground water surface area of 10.8 acres. Effective precipitation was taken as 70% of the average precipitation recorded at the NOAA Fort Lupton climate station. Net evaporation at this site is therefore 34.34 inches per year. The depletions were lagged to the stream using a Glover analysis and assuming a distance to the stream of 1,000 feet, distance to the impermeable boundary of 16,100 feet, transmissvity of 156,000 gpd /ft and a specific yield of 0.2. The Applicant has provided a monthly schedule of lagged actual depletions to the river system, together with a schedule of replacement requirements (see Table 2). This SWSP accounts for actual depletions determined to accrue to the steam system during this plan period. In total 31.0 acre -feet of lagged depletions are expected to hit the river annually. Replacements The proposed source of replacement for this pit is water stored in priority within Sharkey's Reservoir. This water will be pumped from the reservoir directly to the South Platte River near the same location as depletions from Sharkey's pond hits the river. Therefore, no transit losses will be applied and there will be no interviewing water rights to be injured. After the slurry wall liner leak test it was estimated that 663 acre -feet of water remained within the liner boundary. From 2008 to 2009, the District 2 Water Commissioner allowed 346.5 acre -feet of this water to be booked over during periods of free river water. Additionally, in the Fall of 2009 the remaining 316.5 acre -feet of water was booked over at a rate of 3.53 acre -feet per day for 90 days. From 2008 to 2011 a total of 236.3 acre -feet of water has been pumped out of Sharkey's Reservoir and into the South Platte River to make replacements on behalf of this SWSP. This leaves a total of 426.7 acre -feet available for augmentation purposes. It is noted that this value is an estimate based on the estimated starting storage volume, and the true amount of water remaining within the lined boundary may be less than 426.7 acre -feet. In no case will the operator be allowed to pump as an augmentation credit more than 426.7 acre -feet from within the liner boundary. If not already installed, the operator must install a Totalizing Flow Meter ( "TFM ") to accurately measure the amount of water pumped from Sharkey's Reservoir for replacement purposes by September 31, 2012. The monthly consumptive use and lagged depletions for this plan period are shown in the attached Table 2. Long Term Augmentation Requirements In accordance with the letter dated April 30, 2010 from the Colorado Division of Reclamation, Mining, and Safety ( "DRMS "), all sand and gravel mining operators were required to demonstrate to DRMS how they were in compliance with the requirements of the Colorado Reclamation Act and the Mineral Rules and Regulations for the protection of water resources by April 30, 2011. The operator's response to the DRMS letter has not been provided to this office. The final reclamation of the pit includes backfilling or lining of all exposed groundwater within the permit boundary. The operator currently has a bond through DRMS in the amount of $686,900 to cover reclamation cost. It is not known if this current bond is sufficient to cover the cost of lining or backfilling Sharkey's pond to mitigate injurious stream depletions. In order to provide additional renewals of this SWSP, the applicant must provide documentation that a bond is held, or a plan with DRMS to obtain such a bond is implemented, which is sufficient to cover the cost of lining or backfilling Sharkey's pond. Such a bond must be maintained until the Division Engineers office approves the liner as meeting the gravel pit liner criteria, or the pit is backfilled.