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III. COMMENTS -COMPLIANCE (continued) <br />The top of the dam of Oak #1 pond was littered with woody debris, indicating it too may have <br />been overtopped. Oak drainage received a large flow of water as shown by grasses and cattails <br />laid flat in the drainage channel above pond #1 and below pond #2. Vegetation was flattened <br />several feet up the sides of the channel. The operator had recently rebuilt brush dams in this <br />channel near subdrainage junction 1 (400 feet south of Oak #1 pond), but they were again <br />breached. <br />In the spillway outflow channel downstream from the dam of Oak pond #2, boulder-sized riprap <br />apparently was transported by a strong current. A 100-foot length of fabric that lines this <br />channel appeared to have been ripped and carried down to the flume. The flume (NPDES 017) <br />was buried in sediment and woody vegetation debris. This debris extended 50 feet downstream <br />from the flume through flattened cattails. <br />There was no erosional downcutting in the Oak drainage channel where it is protected by <br />vegetation or rock riprap above, between, and below the ponds. There was downcutting of a <br />foot or more in an unprotected part of the channel where the gradient is steep just downstream <br />from subdrainage junction #1. Oak drainage receives runoff from a large tract of ground that <br />has been stripped in advance of the Ashmore-South pit, the current easternmost mining on <br />Trapper. The amount of stripped area is consistent with what the permit shows as being <br />approved. <br />Runoff partially covered the flume in East Pyeatt (NPDES 011) with sediment and brush. A half- <br />dozen hay bales downstream from the flume were damaged by the current in the drainage <br />channel. Trapper is working to resolve the matter with the farmer. <br />The flume in West Pyeatt (NPDES 013) needs repair on its inlet end where the concrete channel <br />has eroded leaving cone-inch gap between the channel and the flume. The gap allows water to <br />bypass the flume. <br />Runoff also was heavy in Johnson and No Name drainages. The emergency spillway at <br />Johnson #2 had discharged as shown by flattened vegetation. Strong currents had flattened <br />vegetation in the drainage channels between and immediately below the ponds and flumes in <br />Johnson and No Name. There was no erosional downcutting found in those areas, however, <br />due to the heavy vegetation cover. There was substantial erosion, though, above the second <br />pond at the head of No Name drainage where runoff downcut into a convex hillslope leaving a <br />gully 2 feet wide at the widest point, 3 feet deep, and 100 feet long. Spoils are exposed in the <br />gully. This gully has been repaired before. Repair work is planned for next spring. <br />Runoff apparently was relatively light in the drainages where the watershed is well-vegetated: <br />the Buzzards, Coyote, and West and Middle Pyeatt. <br />Pond Sediment Levels. Suspended sediment was abundant in all of the ponds in drainages <br />that received heavy runoff: Johnson Gulch, No Name, East Pyeatt, Sage, Grouse, and Oak. <br />The ponds in the latter four drainages also have pieces of woody vegetation floating on the <br />water surface. Within each drainage there was a progressive decrease in the amount of <br />suspended sediment from pond to pond in a downstream direction. The most sediment was in <br />East Pyeatt #1 which appeared to be filled with mud. All of the ponds containing large amounts <br />of suspended sediment and floating debris are downstream from active mining areas where <br />large tracts of land are have not yet been revegetated. <br />Page 6 <br />