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<br />~OOLEY RESERVOII2 AND FULTON WII,DLIFE AREA PIT <br />EXHIBIT G WATER INFORMATION <br />This first section is a Floodplain Issues Summary on activities proposed in the S. Platte River <br />floodplain, and general standards for mining within the floodplain. The floodplain and floodway are ~ <br />shown graphically on Exhibit C-1, Pre-Mining Map, Exhibit C-2, Mining Plan Map, and Exhibit F;~, <br />Reclamation Map; The next sections address Surface Water, Groundwater Impacts, Project Water <br />Requirement, Water Quality Impact, and Figure G-1, Well Location Map and Morutoring Plan. <br />TuttleApplegate prepared the data contained in this Exhibit. <br />Floodplain Issues Summary <br />CAMAS Colorado, Inc. proposes to mine existing permitted property near ]04'~ Avenue and <br />the S. Platte River. A significant portion of the mining area is located within the S. Platte <br />River floodway and floodplain as defined by the Urban Drainage and Flood Control District <br />(UD&FCD) and the Federal Emergency Management Agency (FEMA). Generally, it is <br />accepted that the reclaimed mine pits are an advantageous use of floodplain areas, because <br />if properly planned, they can maintain or can even increase important floodplain storage and <br />conveyance capacity, provide buffering, and preclude more intensive development from the <br />floodplain. The proposed reclamation of a water storage reservoir(s), undisturbed open <br />space, and created wetlands buffer should further all of these goals. <br />The proposed improvements in the floodplain include a temporary conveyor bridge over the <br />S. Platte River with ramped approaches to the bridge, temporary overburden stockpiles, <br />mining in some areas on both sides of river within 400' of the river banks, permanent stable <br />water storage reservoir banks, and permanent created wetlands, as well as extensive <br />undisturbed areas. The temporary features are expected to have essentially the same life as <br />the mining activity, and will be removed when mining and reclamation of the site are <br />complete. The lowest chord of the conveyor bridge will be at least three feet above the i <br />effective base flood elevation (BFE, 100 year water surface elevation) as required by , <br />UD&FCD through Adams County. The bridge approach ramps will come down from the ~,o~ <br />bridge at 2% to 5% grades on each side of the river. Temporary overburden and topsoil ~~ <br />stockpiles will be placed parallel to the river and will have a maximum height of 20' and base "'~ <br />width of 100'. The stockpiles will be limited to 300' in length, with minimum 100' gaps ,~'~~ <br />between, to avoid levee type floodplain constrictions. ,/,~i~a~~~~'"' d <br />J --.~' <br />~.~% <br />~,~~~ <br />~:~~r <br />