2011-10-31_REVISION - M1976009HR (7)

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Grading Reclamation Plan Stream Corridor Area: Grading of the 6,762 square feet of disturbed land beyond the original affected land boundary primarily involved rehabilitation of the stream channel. Although a good deal of rock also spilled on to the east bank of the stream, those damages were quite superficial and primarily affected woody, streamside vegetation. In only a few places was the surface soil disturbed (perhaps 300 square feet) with the remainder still in good to excellent condition. When the rocks were cleaned up they were lifted vertically by a backhoe with a claw on the bucket, thereby avoiding any more than superficial damage to the soil. The stream channel was cleaned of spill rock as well as the sizeable volume of older rocks that had slid down the original steep slope above this area since the landslide estimated at about 150 to 250 years old. When that was completed it left a stream channel that was considerably cleaner than the channel downstream from this area, but not as clean as the stream channel upstream from this area. It was reasoned that because of its location and geological history it would be better to put some rock back into the bed to simulate the channel downstream. Because the stream course in this area flows across the remains of an old landslide there is an elevation drop across this area that is greater than is normally seen along the stream. Leaving the channel as clean as the channel upstream would encourage some rapid headward erosion as the channel attempts to smooth its profile. Therefore, rock in the 12" to 18" size was replaced in the channel as that is the range of larger rock sizes downstream. In the process of rehabilitating this area it was found that the material under the natural stream channel seems to contain a sizeable amount of larger rock that came down in the landslide. Very minor water flows after the rehabilitation work was completed simply sank into the slide debris rather than flowing over it. This water would seep out and form shallow puddles in the channel on the downstream side of the old landslide. This type of behavior is typical of landslides into streams because the slide debris is quite porous and remains porous for a long time after the slide until all the spaces between the larger stones in the debris can fill with fine sediment. Even then, slide debris can be significant sub - surface reservoirs for water. Care was taken throughout the rehabilitation to not disturb these characteristics of the stream channel Rehabilitation of Access Lands: As described in the Mining Plan (Exhibit D), a debris filled meander was discovered on the west side of the stream and within the original affected land boundary. Access to clean the stream channel and east bank was across this area, but at the time it was not known there was up to 30 or 35 feet of landslide debris beside the stream. It was thought to be sloping bedrock covered by several feet of talus and spill rock. What resulted after the rehabilitation was done, was a wide bench where the old meander had been. This is backed by about a 25 to 35 foot high wall of rock that formed the west bank of the stream before the landslide filled this area with debris. Menzer Quarry Corrective Action Amendment Exhibit E October 2011 Page 2