_INSPECTION - C1981019 (57) - Laserfiche WebLink

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Colowyo C-1981-019 18 August 2009 Pg 4/9 Hydrologic Balance (cont.): - The entire length of the South Collection ditch was walked on the inspection. The South Collection Ditch runs from the beginning of the Section 16 Perimeter Ditch and drains into the Prospect Pond. The ditch is a little more than 11,000 feet long and is located in undisturbed ground 500 feet to more than 2000 feet from the disturbed (and reclaimed) areas of the mine. The ditch has areas that are grass-lined, areas that have various sizes of riprap and areas that are down to the native bedrock, depending on the slope of the ditch section. Several areas of the ditch are very steep and rocky. The entire length of the ditch appeared to be stable and there was no apparent down-cutting in the areas with riprap or native and no erosion in the ditch bottom where it was grass-lined. In many areas the outslopes of the ditch are butting against native areas, which are dominated by the tall mountain shrubs. The other areas, where Colowyo constructed the ditch, are all well vegetated and stable, with no erosional problems noted. The area where the ditch intercepts the drainage to the Prospect Pond has some erosion that will need to be reclaimed when the ditch is pulled. At this point the erosion does not appear to be any worse than it was in the past years. The Division will continue to monitor this area. *See the pictures at the end of this inspection report for the area where the South Collection Ditch intercepts the Prospect drainage*. - There is a small, unnamed perimeter ditch to the north of the Prospect Pond (that basically intersects the East Collection Ditch at its beginning) that was walked. This ditch is approximately 1,800 feet and collects the remaining runoff from the north side of the Prospect watershed, all north of the Prospect Ditch. The majority of the area has not been backfilled or regraded. The ditch is a grass-lined ditch. The ditch and both inslopes and outslopes were well vegetated and stable and no erosional problems were noted. - The East Side Collection ditch was walked in its entirety on the inspection. The majority of the ditch is along the reclaimed East Pit in the Gulch A watershed. All but one very small triangle at the top of the watershed has been reclaimed. The ditch is approximately 7,000 feet long and is predominately a grass-lined ditch. It dumps into the Gulch A drainage and ultimately into the Gulch A Pond. The length of the ditch was well vegetated and stable and no erosional problems were noted on either the ditch bottom or the inslopes or outslope of the ditch. The area where the ditch dumps into the Gulch A drainage was also stable, with no problems noted. There are several small springs that begin at the level of the ditch. None of the springs really have any flow, just enough to make the immediate area wet and muddy. *See the pictures at the end of this inspection report for one of the springs and the area where the East Side Collection Ditch intercepts the Gulch A drainage*. - The entire length of the Streeter South Side Ditch was walked on the inspection. The ditch is approximately 4,700 feet long and it flows along the disturbed boundary of the Gulch A and Streeter watersheds, across the Streeter fill and empties into the final 1,000 feet of the Streeter Gulch Ditch (along the north side of the Streeter Fill). The majority of the area flowing to the Streeter South Side Ditch has been reclaimed. The ditch is a grass-lined ditch. It was well vegetated and stable and no erosional problems were noted in the bottom of the ditch or on the outslopes or inslopes of the ditch.