2013-12-19_HYDROLOGY - M1982131 - Laserfiche WebLink

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Ar Mr. Jared Dains Bucklen SWSP December 19, 2013 Page 2 of this SWSP, this affidavit will be accepted for the dedication of the shares; however, if the State Engineer determines that a different affidavit or dedication process is necessary to assure proper dedication of the shares, additional information may be required prior to future SWSP approvals. Depletions Depletions from the Bucklen Pit will result from exposed groundwater evaporation and operational losses resulting from mining activity. Currently there are a total of 17.81 acres exposed at the Bucklen Pit site. The pit is presently being dewatered to allow for dry mining in Amendment Area A. The majority of the current exposed surface area consists of a large pond of 17.65 acres and the additional 0.16 acres of exposed surface area consists of the dewatering trenches. Per the WY 2012 SWSP, it was determined the site is eligible to claim a credit of 5.27 acres of groundwater as being exposed prior to 1981. The location of the pre -81 area is permanently tied to the location depicted in Figure 2. The evaporative area is therefore based only on 12.54 acres (17.81 total acres less 5.27 "pre -81" acres). Computation of evaporation under this plan was reduced during the ice covered period. You have assumed the ice covered period to occur during the months of December and January based on the average monthly temperatures of 29.4 °F for December, and 28.6 °F for January. Temperature data were obtained from the Greeley UNC weather station (053553) for the time period of 1967 through 2005. The ice covered periods may be used to reduce the amount of evaporative losses that need to be replaced; however, for the purpose of this SWSP, the Applicant shall replace the net evaporation depletions from the exposed ground water surface area that may occur during the assumed ice covered period (December and January) for any time that the pit is not completely covered by ice. Computation of the net evaporation during any time that the pit is not completely covered by ice shall be determined as the pro -rata amount of the monthly gross evaporation rate distribution amount identified in the State Engineer's General Guidelines for Substitute Supply Plans for Sand and Gravel Pits, subtracting the pro -rata amount of the effective precipitation for that period. The attached Table 1 identifies the estimated monthly depletions from evaporation. The total projected evaporative consumptive use for WY 2014 is 34.60 acre -feet. Operational losses associated with mining activities will include water removed with the mined product and water used for dust control. Approximately 200,000 tons of material is projected to be mined in WY 2014. A 2% water loss is assessed as the material will be mined in a dewatered state and will not be washed. The water removed with the mined product is therefore estimated to be 2.94 acre -feet. The Applicant has estimated 6,000 gallons of water per day will be used for dust control purposes during the months of March through October. This water lost to dust control is therefore estimated to be 4.51 acre -feet. The estimated monthly depletions due to operational losses are shown on the attached Table 2. The total projected operational consumptive use for WY 2014 is 7.45 acre -feet. According to the Applicant, dewatering commenced in Amendment Area A in the summer of 1998 and is not projected to cease until 2021. Dewatering occurs through the use of two pumps, with one pump usually running continuously, and two pumps running in high water events. The water is pumped into two settling ponds north of Amendment Area A and immediately adjacent to the Cache la Poudre River, where it is allowed to seep and discharge into the river. Historically, the volume of water pumped has not been accounted for or otherwise tracked. This SWSP approval