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Coalreek - 4 - July 13, 1988 saturate this material, no aquifer (by definition) will remain. The mine plan proposes that by maintaining the peninsulas of alluvium under the cottonwoods, the trees are expected to survive because although the water table will be lowered to the level of the channel bottom, runoff supplied from the adjacent hillslopes will maintain the trees sufficiently. The ground water table in the alluvial aquifer in the area of the mine is controlled by the head of water in the upstream watershed alluvial body and rate of ground water drainage downstream. Although the ground water level will vary laterally across the valley, the water is supplied from upstream and the primary control is longitudinal. Although runoff from the hillslopes and tributaries will add to the ground water in the alluvium, the major source is upstream. The cottonwoods, which occur as a band down the valley, are a reflection of the alluvial ground water body. On page G-3, it is stated that: "Approximately 200 of the sand resource will be left in place and undisturbed. The undisturbed portion will lie on both sides of the stream channel and will provide water to the trees left in place as well as providing a path for continuous flow down the valley." Although the trees may survive, this statement says in essence that 800 of the ground water storage and transmissibility of the unconfined Coal Creek aquifer has been removed by mining on the site. The effect of this is a lowering of the ground water table which will project in both an upstream and downstream direction. The Division cannot make the finding that disturbances to the prevailing hydrologic balance of the affected land and the surrounding area and to the quality and quantity of water in surface and ground water systems both during and after the mining operation and during reclamation have been minimized based on the plan proposed and information presented in the application. The following modifications for mining the lowland area should be considered prior to Baard consideration: a. The depth of mining should be reduced. b. Sand should be maintained as the channel bottom substrate uniformly along the longitudinal profile. Reject fines from processing should be backfilled in selected excavated areas or along the channel banks. "Pockets" of excavation between tree peninsulas as noted down the longitudinal profile should be removed from excavation. Pit boundaries, if smoothed off, would allow a continuous body of alluvium down both sides of the valley. The location of fords should be considered from the perspective of their use as channel controls as well as access to processing sites. Each of these structures should be designed and described as to their stability and ability to pass design flows.