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<br /> <br />In a natural situation, cottunwootl trees are best adapted to a moist <br />situation. Their roots ar•e able to withstand inundation for- are <br />extended period in addition to withstanding drought conditions. They <br />et•e a h!ar•dy and opportunistic tree which can adapt to var•ying <br />conditions. <br />C. MinYncl <br />The value! of the sand to be used for construction purposes has been <br />well documented. Over- 2!D test holes and pits have been dug in the fast <br />year-. The sand mater•fal is suitable fur pipe bedding, structural fill, <br />drain nra t:erial, concrete, masonry mortar, and asphalt. fa mining <br />open^atiurt will result in a net lower•in of Sc feet of the Coal Creek <br />channel. Mining will occ ur• n the Creek bottom in a regular fashion, <br />so that over- 8!DX of the cottonwood trees can be preserved. Refer- to <br />the MLRD Regular Operations application for a complete descriptYOn or" <br />the mining oper•at ion. <br />D. Gr•ouncSwat er <br />During t:he testing of the material, the gr•oundwat er• elevations were <br />noted in the holes. These etevet ions are graphically portrayed in the <br />eccompan_v ing sheets showing five different Creek cross Qa~*+•~ns in the <br />low er• haLf of the mYnYng er•ea. The testing was d6ne during May of 1987 l~ <br />and ear•iy June of 1988. During May one could expect the groundwater- to l <br />be at itla highest Level. During the course of a year-, the groundwater <br />will vary in elevatian depending on the amount of precipitation. <br />During the pet•iod of !august tht•ough January, one could expect e 4 to 6 <br />foot drop in the_gruundwat er• table.. In order- to survive, the routs of <br />the cottonwood trees will be wYthin this range of fluctuation of the <br />groundwater- tnbie. <br />The bores and excavations also indicate that the elevation of the <br />groundwater- vat•ies from place to place along the Creek bottunt. This <br />phenomena may result from different amounts of groundwater coming down <br />from the si d__e fi_i 11.s and from clay layers in the sand deposit actYng as /~ 1- <br />dams to ~t he groundwater flow. Ib yV i~v~ ~rwi U/~.tJ TF bIX <br />In the mining at•ea itself the groundwater- table will drop 12 feet;efter <br />nri Wing has passed through an area. ince the groundwat er• rlrrors the <br />contour of the land, the groundwater will begin to rise out of th~~ <br />mining area and reattain its n~r•mal eievatYOn. Th 1s infornratlon is <br />graphically noted on the cross sections. We predict that the <br />groundwater will rise back to its normal elevation approximately 4!DB to <br />500 feet from the edge of the mining. <br />V!, oW ~~~ <br /> <br /> <br />