2018-03-02_REPORT - C1981019 (2)

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Colowyo Coal Company 2017 Annual Reclamation and Hydrology Report Figure 8-1 Post -Mining Channel Reconstruction Certification Volume 1, Section 4.05.4 of the approved permit specifies that this certification statement must be prepared annually for each completed permanent channel segment, and that this statement shall be included in the appropriate Annual Reclamation Report. On November 8th, 2017, I inspected the following ditches: • East Taylor Ditch, Station 57+35 to 65+93 • Buckskin Draw Ditch, Station 12+70 to 35+00 I inspected the channel width, length, alignment, channel slope and rip rap sizing for this channel. The channel design is described in Volume 2C, Exhibit 7-14I for the East Taylor Ditch and Volume 2C, Exhibit 7-14M for the Buckskin Draw Ditch. The following table is a summary of the design requirements for the listed channel segments, and the stationing this certification pertains to. See Figure 8-2 and Figure 8-3 for slope profiles of the ditches listed above. The listed segments have been completed in accordance with the design requirements and dimensions. The channel widths and depths meet the minimum requirements specified in the above table. Rip rap size and placement is acceptable. Channel profiles are within specified slope percentages. The upper portion of the Buckskin Draw Ditch asbuilt slope is greater than specified, however once the lower section between station 0+00 —12+70 is completed, the overall grade of the Buckskin Draw Ditch will match design criteria. The East Taylor and Buckskin Draw Ditches are constructed to Post -mining topography requirements. Page 53 Average Bottom Minimum Side RipRap Ditch Inspection Approximate Permit Slope Width Depth Slope DSO Name Date Stationing Description (%) (Feet) (Feet) (H:V) (Inches) Buckskin Draw 11/8/2017 Exh. 17-M 4 12 1 3 Ditch 35+00 Ve g' East Taylor 11/8/2017 +35 - Exh. 17-1 10.7 12 4 3 18 Ditch 6 65+93 See Figure 8-2 and Figure 8-3 for slope profiles of the ditches listed above. The listed segments have been completed in accordance with the design requirements and dimensions. The channel widths and depths meet the minimum requirements specified in the above table. Rip rap size and placement is acceptable. Channel profiles are within specified slope percentages. The upper portion of the Buckskin Draw Ditch asbuilt slope is greater than specified, however once the lower section between station 0+00 —12+70 is completed, the overall grade of the Buckskin Draw Ditch will match design criteria. The East Taylor and Buckskin Draw Ditches are constructed to Post -mining topography requirements. Page 53