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b) Stormwater run-off from the highwall area can be more efficiently collected and directed from the highwall benches to the lower storm ditch network and eventually to the large sediment pond system in the north end of the affected land iftopsoil/fines is not placed on the mining benches. Sedimentation of the collection ditches will result in high maintenance demands of the storm ditch system and tendency to plug during times of high intensity events. c) The intent of the mining law is to promote site stability and impact control. This I;oal is more readily achievable if the highwall benches are not a source of sediment loads during :>torm events. The rock faces, if left in the configuration as shown in the attached drawing, will best meet these requirements without attempting to revegetate the benches. The general drainage direction of the toe-to-drain ditches located at the toe of each vertical face run will bt: to the North to facilitate the overall site drainage to the north end of the affected land into the SWMP containment area. 2) PROTECTING NEIGHBORING LAND AREAS FROM STORM FLOWS STORM WATER MANAGEMENT PLAN At the present time, the drainage from the mining area and from the large (> 100 ac) watershed area to the west of the mining area flows basically to the South along drainage of topographic control which have been operating as such for hundreds of years. The construction o.° sediment ponds along the main haul road have helped somewhat in retaining stormwater tows. although the paving of the main haul road for dust control has tended to promote somewhat higher stormflow velocities and has directed storm waters down the paved roadway onto Tunnel Drive. Historically, stormwater has crossed Tunnel Drive and Flowed into the Hydraulic Ditch which flows in an eastemly direction app. 50' South of Tunnel Drive. This storm path is considered unacceptable to the Canon City Hydraulic Ditch Company and to land owners along ",unnel Drive. This amendment proposes to eliminate all stormwater flows from crossing Tunnel Drive in the future up to and including a 100 year storm event by way of construction of retention ponds within the mine site, along and at the bottom of the existing haul road, and diverting app. 90°ro of stormwater flows away from Tunnel Drive and North to a network of sediment control and retention ponds located on Tezak Heavy Equipment Company property. A minimum of seven retention ponds with total capacity of app. 20 acre feet of storage will be constructed to attain this goal of diversion and retention of s[ormwater flows. The construction of sediment ponds, inlets and spillways will take place during 1996 ;tnd revegetation of the outslopes and disturbed areas within the SWMP area will be performed as soon as possible after construction. All construction will be in accordance with the engineered design plans submitted with this application. All construction methods will be reviev<ed and approved by a registered engineer and certified for proper installation. Revegetation of the course alluvium derived soils will entail grading to 3:1 slopes on the sediment pond outslopes, contour furrowing, and broadcast seeding of all disturbed areas with a mixture of nati~ie grasses, shrubs, and tree species found growing in [he area at the present time. A species list will be 13