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sufficient amounts of water to fulfill the consumptive use water demands required by each <br /> of the different vegetation types. <br /> Based on the vegetation types and the consumptive use rates described on Table 7-4 there <br /> is approximately 1,299 acre feet of water evapotranspired within the study area. <br /> Evaporation from the ponds were not included in this total . Excess irrigation water flows <br /> overland and contributes to the streamflow of Calamity and Tuttle Draws. The streamflow <br /> from Calamity and Tuttle Draws in turn contributes to the flow of the San Miguel River two <br /> and one half miles downstream of mining and the proposed mining disturbance. <br /> The total volume of water that could be evapotranspired from the vegetation study is <br /> assumed to be under ideal conditions. in reality the evapotranspiration rates are <br /> slightly less. In many areas shallow soils and rock ledges restrict rooting depths and <br /> inhibit maximum plant growth, thereby reducing ET rates. <br /> Aquifer Characteristics of the Nucla and Nucla East Mining Areas. Eleven aquifer tests <br /> have been conducted within the Nucla leasehold, the proposed Nucla East mining area and <br /> the immediate vicinity. A wide variety of aquifer testing and analysis techniques have <br /> been employed because of the range of well yields and aquifer types. Aquifer testing <br /> techniques include constant discharge tests (Theis, 1935; Neuman, 1975; and Cooper and <br /> Jacob, 1946); slug injection and withdrawal tests (Cooper et al., 1967, and Papadopulos et <br /> al., 1973); modified slug tests (McWhorter, 1982); and specific capacity tests. Analysis <br /> techniques primarily involve matching the drawdown of recovery data plots against <br /> theoretical type curves or tangent lines defining the slope of the data. With the <br /> modified slug tests, data analyses included either type curve matching or analytical <br /> solutions. <br /> The results of the pumping or slug tests performed on each well are presented in Table <br /> 7-5. Statistical summaries of each aquifer are contained on Table 7-6. The specific test <br /> data and graphs for all aquifer tests conducted to date are presented in Appendix 7-2. <br /> Data analysis problems were encountered with four of the aquifer tests. The modified slug <br /> test data plots for Wells GW-N9 and GW-N15 did not match well with any of the theoretical <br /> type curves. This is apparently a reflection of aquifer conditions (fracturing, recharge <br /> boundaries or perched layers) causing violations of some of the more critical assumptions <br /> inherent with the analysis technique. The data plots are presented; however, the <br /> analytical solution was employed in each case to calculate the transmissivity. The <br /> 7-21 Revised 04/11/88 <br />