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<br />Revised 1/za/ao <br />Section 7a5.19(c) Continued <br />Observations were made during the digging of the backhce pits, including <br />depth of soil and root zone; type of alluvial material; and water inflow <br />to the pit. No soil mottling or other evidence of periodic ground water <br />fluctuations into the root zone was observed. With the acception of a <br />few isolated sand and gravel deposits, the channel fill is predaninately <br />tight, sticky clay. The clayey alluvium in the study area was found to <br />be nearly i~ermeable, because when the digging exposed a gravel layer, <br />the water level in the pit suddenly rose several feet. This indicates <br />• that while the gravel deposits aze saturated and transmit confined water <br />when excavated, the impermeable clay surrounding the gravel effectively <br />prevents these deposits from transnitting water to or from the overlying <br />stream and root zone. 4his fact is also documented bl' the transact Hell <br />water levels and the low water table shown on Table 105, Hydrographs of <br />Transact Wells in EclananPazk Drainage 1979; Figure 44, Hydrographs of <br />1979 Transact Wells in the Eclanan Park Drainage; and the Eclanan Park <br />Stream Channel Crass Sections (Map 51), and the lack of base flow to the <br />strewn in the summer months from ground water wntribution. As docu- <br />mented in Figure 44, Hydrographs of 1979 Transact Wells in the Eclmian <br />Park Drainage, the water table under the ephermal stream is lowered <br />substantially by underflow drainage in simr.~er, and does not provide <br />water to the strewn or root zone. Therfore, ground water availability <br />. in the study area is not sufficient for subirrigation. <br />795-9(z) <br />