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• u~ ~ <br />Basin-wide contouring of~water levels in n any year produces <br />a map that indicates the direction of regional ground-water flow <br />`-~-:~z). The regional flow in the Raton Basin is from west to <br />east. However, little ground water discharges on the east side of the <br />basin because much of the water in the system is intercepted by stream <br />valleys. In these valleys, ground water flowing through permeable <br />layers and along fractures and faults discharges as springs where <br />water-yielding rocks are exposed, or flows into alluvium where the <br />alluvium overlies the rocks. Deflections of ground-water level contours <br />around stream valleys in figure 7.3-2 are caused by these local flow <br />systems. <br />Water level fluctuations in wells from year to year show an <br />aquifer's response to seasonal and annual variations in the availability <br />• of water. Graphs of ground-water fluctuations in wells penetrating the <br />Poison Canyon-Cuchara aquifer, Trinidad-Vermejo-Raton aquifers, and <br />alluvium are shown in figure 7.3-3. The Poison Canyon-Cuchara well is <br />143 feet deep; the Trinidad-Vermejo-Raton wells, 62 feet deep; and the <br />alluvium well, 26 feet deep. The Poison Canyon-Cuchara aquifer is <br />confined; the other aquifers, unconfined. Annual fluctuations in water <br />levels are greatest in the shallow, unconfined aquifers because these <br />rocks receive water primarily by downward drainage from the surface, <br />and are, thus, affected more by precipitation cycles. These wells may <br />go dry during prolonged drought. Since the intake of water to confined <br />aquifers is controlled primarily by the thickness of the overlaying <br />confining layer and the ability of the aquifer and confining layer to <br />transmit water, water levels in wells penetrating deep confined <br />. aquifers respond less to precipitation cycles and usually fluctuate <br />less than in unconfined aquifers. <br />59 <br />