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Mamm Creek Pit 2 November 16 2000 proposed boulder placement, and that the Applicant also provide sloping specifications for stabilization of the upstream end of the renewable resource area and a gradation specification for the boulders. The "In-Stream Aggregate Extraction and Reclamation Guidance Document" provides examples of this type of installation; 3:1 slopes and well graded riprap with a D5o of 24 inches (type VH riprap) is recommended. Pit run substrate should provide a suitable bedding for the riprap, but if the substrate lacks gravel and cobble sized material, riprap bedding may have to be installed. The upstream end of the renewable resource area must be stabilized prior to each annual flood season whether mining has reached [he 150 foot barrier location or not. The flood season runs from April 1~' to September 30'h. It is further recommended that the Operator establish 3:1 slopes along the banks of the overflow channel comprising the renewable resource area. These slopes should be established concurrently with each mining pass through the renewable resource area; this topic will be further discussed in item no. 3. 3. The application states that if the renewable resource area becomes part of the main channel then the area is considered reclaimed. Although the Division recognizes that the main channel may migrate into what is currently a backwater channel during a future high-Flow even[, we cannot accept language in the application that would trigger a mandatory release of reclamation responsibility in the renewable resource area if such a channel migration occurs. Capture of the renewable resource area by the river must result in a condition of dynamic channel stability that protects upstream and downstream property and is characteristic of the pre-mining condition of the Colorado River as modified by natural causes such as high flows or flooding. If the Operator establishes 3:1 slopes in the renewable resource area concurrently with mining, it is likely that less mitigation work would be necessary if the river captures the backwater channel. If a portion of the main river channel establishes in the renewable resource area, this area would still be subject to inspection and verification that an acceptable post-mining channel is functioning. The Operator may be required to complete any bank stabilization and channel reconstruction work that may be needed. 4. The application states that if the renewable resource area becomes uneconomic to mine and is still an overflow channel (as opposed to being captured by the main channel) then the area will be reclaimed to create a backflow area using materials in the pit area. The Division requires additional detail on [his aspect of [he reclamation plan. Essentially, the Operator will be engaging in a stream channel reconstruction project. The plan should include a description and/or illustration of [he reclaimed contours, a description of [he backflow channel bottom and bank materials, particularly if backfilling is to be employed, and a description of any bank or channel stabilization measures or structures to installed. The Division's "In-Stream Aggregate Extraction and Reclamation Guidance Document" includes discussion of stream channel reconstruction and examples of structural controls. 5. The application states that in some areas replacement wetlands will be created [o replace the majority of those disturbed by mining. Tom Schreiner's memo discusses [he need [o incorporate detailed wetlands construction and reclamation plans in the application. This may not be possible