2019-12-18_REVISION - C1981019 (13)

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2. Performance of the reconstructed topography. Symptoms of failure or instabilities such as slumping or exposed highwalls were examined; 3. Hillslope design/function with regard to erosion; 4. Swales and depressions with regard to numbers of features and effect on post-mining land use; 5. Blending of regraded land to undisturbed areas; 6. The functioning of drainages with regard to knickpoints,blending at disturbance boundaries and channel erosion; 7. Erosional features; and 8. Drainage control for the reclaimed area, including upslope diversions. Colowyo AUSiR)1UUfW IIKQSUW U SU-KffUIQmFFRLSI�BkRule 2.05.4. Colowyo was granted a variance for contemporaneous reclamation for the East Pit, West Pit and the South Taylor Pit due to the nature of multi-seam mining. Backfilling and rough grading commenced once a steady-state condition was reached in each of the pits. The approved backfilling and grading plan for the Colowyo Mine is found in Volume 1 (East and West Pit), Volume 12 (South Taylor), and Volume 15 (Collom) of the PAP. Maps 19, 19A and 19B show the approved post-mining topography, Maps 29 and 29A, and 29B show the backfilling and grading schedule. The pre-mining and post-mining cross-sections are shown on Maps 20, 20A and 20B, and the permanent drainage channel profiles are shown on Maps 33, 33A, 33B, and 33C. Map 1 of the SL-17 application show cross-section area for the 0.4 acres being requested of the South Collection Ditch, including approved post-mining topography alongside the constructed topography. The approved drainage reestablishment consisted of the design and construction of permanent post mining drainage channels. The post-mine channel locations are shown on Maps 41, 4 1 A and 4 1 B of the Colowyo PAP. The South Collection Ditch construction designs can be found in Exhibit 7 of the Colowyo PAP. Phase II Bond Release Proposed Decision and Findings of Compliance December 18,2019 Partial Phase I,II and III Bond Release SL-17 Page 5