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Mr. Gregg Squire Page 3 December 21, 2000 Item 4 -Placement of stockpiles. The application showed topsoil and product stockpiles out of the floodplain where possible. However the project site does not contain sufficient area to allow tlus to happen for all stockpiles. When topsoil piles are placed in the floodplain they will be located as far as practical from the main channel of the river, located with the long axis of the pile parallel to the flood flow, and spaces will be left in between piles if the length of the pile exceeds 50 feet. The in-pit crushing and screening operations will require stockpiling of pit run and product material in the pit bottom. The pit bottoms are below grade as are the stockpiles. The pits increase the cross section area for flood waters significantly compared to flowing across the undisturbed ground. For instance if the flood depth ranges from 0.3 to 4 feet and the pit is 15 feet deep this represents an increase in cross sectional area from 3.75 to 50 times. Because of this large increase in cross sectional and the stockpiles being below grade, the stockpiles in the pits are not expected to adversely affect the flow pattern of a flood inundating the pits. Item 5 -Barriers. The barriers used in the pit design have nothing to do with flood control. These barriers are essentially buffers of the undisturbed ground around the proposed pits to protect man-made resources, wildlife habitat, primarily large cottonwoods, wetlands and aquatic habitat where possible. These non-flood control barriers are shown on the Exhibits C-1 and C-2. Item 6 -Facilities and stockpiles. The operator has proposed one facility area in the Dry Creek mining area. This facility area includes • Portable scale and house • Concrete batch plant • Asphalt plant • Concrete products manufacturing • Sand and gravel stockpiles • Office trailer • Portable shop In addition to this facility area, the operation will utilize in-pit crushing and screening equipment and a portable scale and scale house at the entrance to the active mining areas. The facilities in the Dry Creek mining area are out of the floodplain. The stockpiles in the pits are addressed in Item 4 above. Item 7 - O1F site impacts. The Grant Brothers pit is located upstream approximately 7400 feet on the south side of the river from the proposed eastern edge of the west property line to horse fence mining area. Two other gravel pits are on the north side of the river. One is across from the west end mining area and the other is slightly downstream from the first pit. All gravel pits are not mining in the active main channel of the river. Portions or all of these pits are in the 100 year floodplain. The proposed Mamm Creek Gravel Pit is not expected to impact any of these pits. The responses provided to Mr. Allen Sorenson's review comments support this conclusion.