2011-08-23_PERMIT FILE - M2009024

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Mr. Pete Foster Page 2 of 4 August 22, 2011 Depletions The uses of water for the Simmons Pit during this approval period are expected to consist of 0.83 acre -foot of gross evaporation from a water surface area not to exceed 0.22 acres (surface water diverted into the two wash pits, no groundwater exposure), 3.53 acre -feet of water lost in product, and 2.95 acre -feet for dust suppression. Under Colorado statutory law, ET credit can be utilized to offset the exposure of ground water only for streambed reservoirs and gravel pit ponds. You indicated that the two ponds are off-channel ponds therefore, the gross evaporation from the two ponds is being replacedl under this SWSP. The annual gross unit evaporation rate for Mancos, Colorado is 45 inches (3.75 feet). Based on a combined surface area of 0.22 acres, the calculated maximum annual depletions from evaporation is 0.83 acre -feet per year. Total consumptive use from the pit operation is expected to be 7.30 acre -feet with the total out -of- priority depletions being 4.58 acre -feet (See attached Table 2) occurring when the Carpenter and Mitchell Ditch is diverting and 2.72 acre -feet of uses occurring when there is no call. Replacement Water The mining operation is located on lands historically irrigated by the Carpenter and Mitchell Ditch. Simmons owns 2 cfs out of 2.33 cfs decreed to the M -13 water right (Case No. CA -1993) from Chicken Creek, a tributary to Mancos River. This water historically irrigated 85 acres and provides 0.99 AF /acre of historical consumptive use based on water physically available when in priority. The area to be mined is 28.1 acres of the northern part of the Simmons property and will be accomplished in phases. For this plan period, 18 acres in the northwest portion of the property (See Figure 1) will be dried -up and mined, and the consumptive use credits (17.78 acre -feet) will be used as the replacement source (See Table 3). Two wash ponds will be located within this 18 acre area. Water from M -13 water rights associated with the 18 acres (historical consumptive use, transit loss of 10 %, and groundwater return flow obligations) will be delivered to the ponds. Each pond has an estimated volume of 0.31 acre -feet (total of 0.62 acre - feet). There is also a stock pond located nearby within the property. When the volume of the wash ponds is not enough to contain the historical return flow volume, the additional water can be discharged into the dry pot and /or the stock pond in order to replicate the historical return flow pattern. The groundwater return flow obligation will lag back to the stream system at the same rate that had historically occurred under irrigation where the reining now occurs. Water placed into the ponds is expected to infiltrate quickly due to gravely nature of the soils. The surface return flow obligation of the dry- up area will be delivered to the stream via a surface drainage that runs through the property to Mud Creek, a tributary to Mancos River, or allowed to remain in Chicken Creek as needed for water administration as determined by the Colorado Division of Water Resources. Return flow and replacement requirements are shown on attached Table 4. Given that water shortages in the ditch typically start in July, material washing will most likely occur in April, May, and June or during the non - irrigation months of November through March. The wash plant can be mobilized to the site at times when water supply is available and removed from the site during water shortages. If there is a water shortage and the M -13 priority is called out, the facility will simply not wash material during the call period. In addition, water for dust control can be hauled from offsite. Conditions of Approval I hereby approve the proposed substitute water supply plan in accordance with Section 37 -90- 137(11), C.R.S., subject to the following conditions: