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6. The functioning of drainages with regard to knickpoints,blending at disturbance boundaries <br /> and channel erosion; <br /> 7. Erosional features; and <br /> 8. Drainage control for the reclaimed area, including upslope diversions. <br /> Colowyo's approved reclamation plan was prepared in accordance with Rule 2.05.4. Backfilling <br /> and rough grading commences once a steady-state condition is reached in each of the pits. The <br /> approved backfilling and grading plan for the Colowyo Mine is found in Volume 1 (East and <br /> West Pit),Volume 12 (South Taylor), and Volume 15 (Collom) of the PAP. Maps 19, 19A, <br /> 19B, and 19C show the approved post-mining topography, Maps 29, 29B and 29C show the <br /> backfilling and grading schedule. The pre-mining and post-mining cross-sections are shown on <br /> Maps 20, 20A, 20B, and 20C and the permanent drainage channel profiles are shown on Maps <br /> 33, 33A, 33B, and 33C. Map 1 of the SL-18 application show cross-section area for the 44.6 <br /> acres being requested of the West Pit, including approved post-mining topography alongside the <br /> constructed topography. <br /> The approved drainage reestablishment consisted of the design and construction of permanent post <br /> mining drainage channels. The post-mine channel locations are shown on Maps 41A,41B, and 41 C <br /> of the Colowyo PAP. <br /> IV. OBSERVATIONS AND FINDINGS <br /> The following discussion of observations and findings focuses on the results of the construction of a <br /> permanent structure in support of the approved post-mining land use and drainage establishment for <br /> the portion of the West Pit as requested in the SL-18 application. <br /> The evaluation of the bond release application included the bond release inspection, an office <br /> review of the permit requirements and regulatory criteria, and review of past inspection reports. <br /> The bond release inspection was conducted on June 4,2020. Several items were reviewed by the <br /> Division during the technical evaluation of the bond release application before, during, and after <br /> the inspection, including: the post-mining topography and cross-sections of backfilled and graded <br /> areas as approved in the Colowyo PAP. <br /> During the SL-18 Bond Release inspection, participants walked the bond release request area to <br /> allow for visual assessment of compliance with pertinent requirements. Observations were made <br /> during the bond release inspection with regard to approximate original contour and stability of <br /> the reclaimed landscape. To determine compliance with Colowyo's approved approximate <br /> original contour(AOC) in the SL-18 area, elevation data provided in the SL-18 partial bond <br /> release application was compared to GPS data collected by the Division. A total of nine points <br /> were taken along the West Pit and are shown on Figure 2 of this document. Points were placed at <br /> a selected transect at approximately 400 feet intervals and along contour elevations in ArcGIS <br /> and those points were then downloaded on ArcGIS for ESRI Collector(Collector). During the <br /> bond release inspection, the Division navigated to the points using the data in Collector and a <br /> GPS data point was collected at each predetermined location along the transect. Each <br /> Proposed Decision and Findings of Compliance July 21,2020 <br /> Partial Phase I Bond Release SL-18 Page 5 <br />