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into the surrounding adjacent areas. Every year TMI submits to the Division their Annual <br /> Reclamation Report(ARR)revising Appendix W of the permit. Each ARR includes a map showing <br /> actual post-mining topography from the previous year. <br /> Reestablished and constructed drainages are delineated on Map 1, included in the SL21 bond <br /> release application. TMI has spared no effort and expense in constructing reestablished drainages <br /> effectively controlling erosion and downstream sediment deposition. Various sediment control <br /> materials and methods and sediment reducing measures have been implemented on reestablished <br /> drainages. Drainages at Trapper Mine are trapezoidal in shape with a bottom width of 20 feet, <br /> grass lined with regularly spaced check dams. Rock check structures dissipate the energy of <br /> flowing water within channels. Debris and sediment deposition occurs upstream of structures <br /> allowing vegetation to establish behind structures, further stabilizing the channels. This <br /> configuration results in shallow flow depths for the design storm and low flow velocities. Rock <br /> Channel slopes are generally 10 percent. Detailed engineering criteria regarding drainage <br /> reconstruction practices can be found in TMI's permit Appendix Q Section XXXVII. <br /> — ' .3i:- y!j. —'���11• '.'t1cl�+` c -fit\ ,'. � <br /> Photo l: Topsoil grading operations. <br /> Permit Number <br /> C1981010 <br /> Prepared by: R.Reilley,MS,GISP <br /> SL21 <br /> Page 8 of 15 <br />