2010-10-21_REVISION - C1982057 - Laserfiche WebLink

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elevation in the as-built channel as compared to the designed channel due to the change in channel location. This makes for a slightly steeper as-built channel versus the designed channel in this location. The following chart shows the GPS data for post- mining channel PM-1B. GPS Height Northing Easting Z Corr. Correct Z Exh D Elev. Z Diff. Exh 20- 5.9 Station 7659.3 4468852.3 309754.5 40.620 7699.951 7700 0.049 7711 0+00 7722.8 4468784.6 309809.5 40.620 7763.400 7764 0.600 7767 2+85 7761.8 4468736.1 309850.9 40.620 7802.403 7804 1.597 7807 4+95 7844.5 4468705.1 310004.2 40.620 7885.148 7888 2.852 7891 10+08 7953.0 4468749.9 310135.3 40.620 7993.639 7996 2.361 7998 14+63 7993.3 4468779.2 310186.5 40.620 8033.872 8036 2.128 8040 16+56 - Channel PM-1 C runs on the south side of channel PM-1 in basically a northwest direction along the disturbance boundary and intercepts channel PM-1 at approximately station 4+86 (on the Division's channel profile). The channel has an as-built length of approximately 501 feet compared with a design length of approximately 376 feet. The channel design specifies a bottom width of 3 feet, an overall depth of 0.8 feet and a lining TRM. The observed channel bottom width was between 4 and 6 feet, its depth was between 3 and 5 feet and its lining was TRM. The as-built channel location is basically the same as the designed channel location with the exception that the as-built channel is approximately 125 feet longer than designed channel. The channel was very well vegetated and there were no erosional problems noted. The as-built channel profile for the lower 300 feet of the channel (where there is a design profile) is between 14 and 40 feet higher than the design. This is a result of a slight variation in the post-mining topography and the change in the alignment of the lower portion of the channel. The overall grade of the lower portion of the channel is not affected. The following chart shows the GPS data for post-mining channel PM-1C. GPS Height Northing Easting Z Corr. Correct Z Exh D Elev. Z Diff. Exh 20- 5.9 Station 7423.4 4468756.9 309421.8 40.620 7464.011 7466 1.989 7457 0+00 7445.8 4468735.5 309446.9 40.620 7486.438 7490 3.562 7472 1+09 7465.7 4468710.4 309492.9 40.620 7506.333 7508 1.667 7500 2+81 7522.4 4468709.6 309560.1 40.620 7563.016 7562 -1.016 5+01 - Channel PM-2A runs on the west side of the disturbed area basically in the middle of the Seneca II-W South area and flows basically from south to north, discharging into Pond 016A. The as-built channel is approximately 2,730 feet long compared with a designed length of approximately 2,680 feet. The channel design specifies a bottom width of 3 feet, an overall depth of 1.25 feet and a lining of either 6 inch riprap or TRM. The observed channel bottom width was between 3 and 10 feet, its depth was between 1 and 3 feet and its lining was 9-12 inch riprap and TRM (depending on the location). The as-built channel was generally between 25 to 150 feet west of the designed location but