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area, divert water from Fish, Middle, and Trout Creeks to facilitate farming of forage crops such as grass, hay and alfalfa. The ditches are utilized primarily during the growing season. Water rights records from the State Engineer's Office were reviewed to determine current surface water usage in the area. These records (1984) indicate that the primary use for water from Fish Creek outside of any permitted mine area is for irrigation. There are several domestic water users along the Fish Creek drainage, but these are all upstream from the Foidel Creek Mine. Foidel Creek water is used solely for irrigation purposes at Eckman Park. There are no surface water rights along the reach of Middle Creek downstream from its confluence with Foidel Creek. Water use along Trout Creek is also principally agricultural. Probable Hydrologic Consequences of the Foidel Creek Mine A. Ground Water The proposed Foidel Creek Mine may impact the quantity and quality of ground water during and after mining. Possible ground water impacts are: 1) Depletion of ground water from rock and alluvial aquifers; 2) Depletion of spring flows; 3) Depletion of water well yields; 4) Degradation of water quality in bedrock and alluvial aquifers; 5) Degradation of water quality through surface discharges of aquifers (springs and base flow to streams), and 6) Degradation of surface water quality through pumpage of lower quality water from the mine. These potential impacts are discussed by aquifer in the following paragraphs. Aquifers not discussed will not be impacted by the proposed Foidel Creek mine. During mining, the applicant has predicted a dewatering of the Wadge coal-overburden aquifer and the dewatering of three fault zones due to drawdowns of ground water into the mine workings. The applicant used two mathematical models to obtain a projected combined mine inflow rate and drawdown cone with the Wadge coal-overburden aquifer. These two models were the GROUND WATER model, a finite difference, two dimensional, digital model, and a Line-Sink model. The GROUND WATER model was developed by Colorado State University to predict steady-state dewatering of an aquifer, while the Line-Sink model presented in McWhorter and Sunada (1977) was used to predict the additional inflows resulting from the dewatering of two fault zones. The resulting discharge rates and extent of the drawdowns from the two models were added together to obtain a total maximum predicted mine inflow of 310 gallons -40-