Laserfiche WebLink
• minimize erosion and prevent additional contributions of sediment by limiting flow velocities and <br />tractive forces that cause excessive erosion. All temporary diversions will be removed and <br />reclaimed after mining has been completed. Culverts presented in the Surface Water Control Plans <br />for both mining areas have been designed to feature adequate freeboard and ouffall protection <br />(riprap) to minimize erosion. <br />Surface Water Quantity. The sediment pond, diversions and culverts have been planned and <br />located to control all drainage into, through and out of New Horizon 2 mining area, and to insure <br />that changes in surface water quantity are minimized. <br />Postmining topographies are planned to approximate the original premining contours (see Section <br />2.05.4(2)(c), Backfilling and Grading). Replaced topsoil material will exhibit infiltration rates similar <br />to premining soils. Reclamation techniques used in the topsoiled areas (disking, ripping, mulching, <br />etc.), in combination with reestablished watershed topographies will minimize excessive rates and <br />volumes of runoff. <br />Stream Buffer Zones. A section on stream buffer zones in the New Horizon 2 mining area can be <br />found in Section 2.05.6(3), Protection of the Hydrologic Balance. A drainage ditch (diversion) which <br />routes runoff from disturbed areas to Pond 007 was constructed immediately outside the stream <br />buffer zone along Calamity Draw. Excess excavation material was spread on the ground surface <br />within the stream buffer zone. The operations plan for this ditch construction calls for no <br />disturbance to the main channel of Calamity Draw, no excavation within the 100 foot buffer zone <br />and a resultant ditch that can convey the runoff from a 10-year, 24-hour storm. Any impacts to the <br />. Calamity Draw stream buffer zone from the spreading of excess excavation materials was very <br />minimal and will be mitigated by the reclamation plan. The ditch will be reclaimed and the ground <br />surface reshaped to its original contour. The plan calls for reseeding with an irrigated <br />pasture/poorly drained phase seed mix (generally similar to the predisturbance swale/vegetation <br />type). Finally, topsoil disking activities will overlap adjacent non-disturbed native vegetation to <br />hasten reinvasion of the native plants. <br />Water Rights <br />The surface and ground water rights adjacent to the New Horizon mining area are listed in Peabody <br />Attachment 16-1. The water rights inventory boundary includes all water rights within a two mile <br />radiusoftheNewHorizonMine. PeabodyAttachment16-l describes the ground and surface water <br />rights in detail. <br />Alternative Water Supplies <br />Peabody Attachment 16-1 lists the water rights and sources WFC has available to utilize as <br />alternate water supplies to mitigate pit inflow drawdown and sediment pond storage, and industrial <br />water use impacts to surface water right holders. The principal alternative water supplies are the <br />114.5 acre foot consumptive use credit of Colorado Cooperative Company (CCC) water, 18 acre <br />feet of pit inflow water during the non-irrigation season and the absolute storage right in 001 pond <br />(at the New Horizon 1 reclaimed mine area) of 4 acre feet. No mitigation of any ground water <br />• (REVISED 2-00) 2.05.6(3)(b)(v) - 3 <br />