2014-04-16_INSPECTION - C1981010

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Apri19, 2014 C- 1981 - 010 /Trapper Mine JLE B -10 was walked. The portion of the channel that runs through Parcel A -B -10 was walked in August of 2013 during the Phase I bond release inspection for the SL 14 bond release application. At that time, is appeared few check dams had been constructed and the center channel of the drainage was deeply incised. Significant upgrades and repairs have occurred in this channel. The reclaimed slopes of the parcel surrounding the lower (northern) reaches of the channel are steep making the channel a fairly deep "V" shape. At observation point MP I, a recently placed check dam was observed. Smaller rocks were used to construct the majority of the check dams within this drainage. At observation point MP 1, it was noted the face and toe of the check dam was larger and extended down slope at a greater distance than most of the check dams observed in No Name drainage. There seemed to be less of a formation of the incised center channel between check dams of this type of construction. At observation point MP2, the channel runs through a very narrow section of the reclaimed parcel. It appears the side slopes of this channel have been knocked and graded down. The side slopes of the channel are steep and were estimated to be at a 1:1 horizontal to vertical ratio. The check dams installed in this portion of the channel have larger rocks used to construct the dams. Several dams do not extend very far into the side slopes of the drainage, at these locations a potential for side cutting around the check dam exists. At observation point MP3, the slope of channel is not as steep and the overall channel is not as "V ", at this point the small center channel begins for form. Given recently backfilled areas are located above this channel, the potential for elevated sediment load over the next few years exists, and the small basins upstream of each check dam has already filled with sediment for many of the check dams observed. It may be beneficial to clean behind these check dams to allow for additional sediment capacity over the new few years to help slow the flow through this channel and limit the deep incisions at the bottom of the channel. Repairs of check dams and slope failures could also occur at that time. The eastern branch of Middle Pyeatt that runs through the Phase III bond release area is a well vegetated channel with a very gentle slope. This channel appears stable and the small center channel is not very deep. A portion of the East Pyeatt reconstructed channel was walked. We began near the where the channel goes under the life of mine road east of topsoil stockpile A92 -2. The portion of the channel observed runs through parcel F- AB-05. At the south end of this parcel the channel splits into three branches and runs through parcels, F- AB -01, 02, 03, 04, 05 and 06. We walked a portion of the eastern most branch of this channel. Significant repair work has been done in the northern /lower reaches of the channel we walked. The side slopes of the channel appear to have been graded to a slope and additional check dams have been installed and existing check dams appear to have been repaired. The channel below the fork and the eastern most fork of the channel was actively flowing at the time of the inspection. Similar to the Middle Pyeatt reconstructed drainage, the channel below the fork is fairly deep with the steep reclaimed slopes /undisturbed slopes above the channel making the channel a deep "V" shape. Many of the check dams appear to be made up of small rock and the face of the dam extends further down the channel than previous check dams. The dams appear to be handling the flow at this time. Sediment above the dams have filled the majority of the small basins above the dams. Between some of the check dams the center channel has formed with steeper side slopes and some vertical cutting. Oak Gulch reconstructed drainage, was walked. There is a steep drainage with very steep reclaimed slopes above the channel. Significant erosion was observed in this channel in October of 2012. Trapper has conducted significant repair work in this channel. Many new check dams have been constructed and many of the existing Number of Partial Inspection this Fiscal Year: 7 Number of Complete Inspections this Fiscal Year: 3 Page 4 of 22