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Mr. Andy Rodriguez, P.E. Page 3 of 5 <br />April 21, 2011 <br />to the stream system that result from the past dewatering at the site. The depletions from past <br />dewatering at the site during the period of this plan total 354.21 acre-feet. <br />The depletions from evaporation, water removed in the mined product, dust suppression, <br />concrete batching and dewatering were lagged to Saint Wain Creek using a Glover analysis. The <br />following parameters were used in the model to lag operational and evaporative losses: <br />transmissivity (T) = 72,300 gallons per day per foot, specific yield (SY) = 0.2, the distance from <br />the exposed ground water to the creek (X) = 5,409 feet, and the location from the parallel <br />impermeable boundary to the creek (W) = 10,000 feet. The attached Table 2 provides a monthly <br />schedule of total lagged depletions to the river system, shown to be 55.75 acre-feet for this plan <br />period. <br />Replacements <br />The proposed replacement sources are net accretion credits at the river that occur due <br />to the dewatering operation at the site (cell D). These accretions are applied to this plan against <br />the evaporation and operational depletions at the site. Dewatering accretions were lagged using <br />a Glover analysis with the above parameters and a distance from the dewatering trench to the <br />creek (X) of 4,507 feet. A monthly breakdown of depletions and replacements is shown in the <br />attached Table 4. <br />Conditions of Approval <br />I approve the proposed substitute water supply plan in accordance with Section 37-90- <br />137(11), C.R.S., subject to the following conditions: <br />1. This SWSP shall be valid for the period of January 1, 2011 through December 31, 2011, <br />unless otherwise revoked, modified, or superseded by decree. If this plan will not be <br />made absolute by a water court action by the plan's expiration date, a renewal <br />request must be submitted to this office with the statutory fee (currently $257) by <br />November 15. 2011. <br />2. Well permit no. 61716-F was obtained for the current use and exposed pond surface <br />area of the gravel pit in accordance with §37-90-137(2) and (11), C.R.S. <br />3. The total surface area of the groundwater exposed at the Shores Pit must not exceed 4.6 <br />acres during the approval period of this SWSP resulting in an annual evaporative loss of <br />12.32 acre-feet. <br />4. The annual amount of water used at the operation shall not exceed 3.33 acre-feet for dust <br />control, 20.59 acre-feet of water lost with the product (700,000 tons) and the amount used <br />for concrete batching shall not exceed 10.43 acre-feet used in the production of 85,000 <br />cubic yards of concrete. <br />5. Total consumption at the Shores Pit must not exceed the aforementioned amounts <br />unless an amendment is made to this plan. <br />6. Approval of this plan is for the purposes as stated herein. Any additional uses of this <br />water must first be approved by this office.