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designed channel. Additionally, the as-built channel has a fork at the upper end, where the <br />channel design is straight. The as-built channel profile is between 6 and 40 feet lower than the <br />design profile due to changes in the post-mining topography and the resulting change in the <br />channel's alignment. Overall, the grades of the as-built channel approximate those of the <br />designed channel. The channel was stable overall, but there was some erosion entering and <br />exiting Stock Tank T-27 and the surge ponds, which was repaired during the inspection. The <br />lower portion of the channel, below stock tank T-27, was well vegetated and stable with very <br />little erosion. <br />PM-2B: The as-built channel location deviates from the design location, including its intercept <br />locations with channels PM-2, PM-2C, and PM-21). The as-built channel profile for channel <br />PM-2B is between 25 and 60 lower than the design profile due to changes in the post-mining <br />topography and channel location. Based on the changes, the as-built channel is slightly steeper. <br />The channel was stable overall and was well vegetated, with only minor erosional features <br />observed in the channel. There was some erosion at the inlets and outfalls of each of the two <br />surge ponds. <br />PM-2C: The as-built channel is much shorter and deviates from the designed channel. As stated <br />in the discussion of channel PM-2B above, channel PM-2C intercepts channel PM-2B <br />approximately 250 feet farther east than the design shows. There is also an unnamed channel to <br />the north of channel PM-2C that does not have an approved permanent, post-mining channel <br />design. The Division is currently reviewing a technical revision (TR-73) that will include the <br />designs for this and two other unnamed channels (along PM-2B) that lack approved designs. <br />The channel appeared to be well vegetated and stable and there did not appear to be any <br />erosional problems related with channel PM-2C. <br />PM-21): The as-built channel location deviates from the designed location below stock tank T- <br />26, where it intercepts PM-2B and -2C, as described above, but generally follows the designed <br />location above the stock tank. The majority of the channel was stable and vegetated, although <br />the lower approximately 50 feet of the channel, where it intercepts channel PM-2B, exhibited <br />down-cutting in the channel approximately five feet deep. There was also some side-cutting on <br />the east side of the channel below stock tank T-26. The down-cutting in the lower 50 feet of the <br />channel, at the intercept point with channel PM-2B, will need to be repaired. Given the extent of <br />the erosion, this area will be excluded from the areas proposed for Phase I release in the SL-3 <br />decision. <br />PM-2E: The as-built channel location is approximately 25 feet west of the design location, <br />primarily due to the change in location of channel PM-2D. The as-built channel PM-2E <br />generally follows the designed flow path. The as-built channel profile is less than four feet lower <br />than the designed channel profile and maintains an identical grade. The channel had a fair <br />amount of vegetation growing in the riprap and there were no visible signs of erosion. <br />PM-3: The as-built channel location was basically the same as the designed channel location but <br />the as-built channel does not meander as much in the middle portion, and it does not go up the <br />regraded slope as high as the designed channel. The channel itself was stable with very little <br />Page 13 of 22