Laserfiche WebLink
C <br /> Page 2 <br /> The Suety Spoil Pile is in a floodplain which is subject to debris flows. —A <br /> 100 year clean water diversion ditch intercepts water and transports it around <br /> the pile. This ditch is designed to handle clean water, not debris flows which <br /> are common occurrences in Coal Basin. The final grading plan for this pile <br /> must consider this potential debris flow hazard. <br /> A bank supporting the old coal waste pile is being undercut by Dutch Creek in <br /> the area south of the maintenance buildings. MCR is on notice to correct the <br /> undercutting problem. They are proposing to armor the bank and straighten the <br /> stream channel. Forest Hydrologist Greg Kuyumjian stated that straightening <br /> the channel would only result in accelerating the bank cutting directly down <br /> stream. He suggested that a comprehensive design plan be done before any <br /> channel changes are attempted. He also stated that Army Corp of Engineers <br /> (COE) approval would be required if fill was placed in the stream and more than <br /> likely COE would require a site specific design plan. <br /> The combination of manmade alterations of the Dutch Creek channel and <br /> floodplain and the impacts from the 1977 Flood have created a levee separating <br /> the stream from most of the development in the Dutch Creek floodplain. The <br /> stream is now higher then most of the development. A flood event could send <br /> the flood waters through the base area. This situation needs further study to <br /> determine how the floodplain can be restored. This is especially critical <br /> because of the problem of with the undercutting bank. Flood waters that would <br /> be contained by the levee in the present channel could accelerate the bank's <br /> undercutting. <br /> Both the recent MLRD and OSM inspections noted the undercutting of the spillway <br /> where Dutch Creek enters Coal Creek. In the same area the old coal waste <br /> pile's retaining structures are failing. Correcting these problems by <br /> temporary treatment measures will not solve the long term problem caused by the <br /> alteration and encroachment of the floodplains and channels of Dutch and Coal <br /> Creeks. This situation needs a long term and hopefully a permanent solution. <br /> Priority Setting <br /> Salvage operations are dictating both the timing and where the reclamation can <br /> take place. The salvage company has another 4 years to complete its' work. <br /> This makes setting priorities and completing the reclamation work very <br /> difficult. A reclamation plan should be developed that systematically <br /> schedules the work for the next 4 to 5 years. This plan should weigh the cost <br /> of delaying reclamation because of salvage opportunities against the value of <br /> systematic and timely completion of the reclamation. <br /> MCR and MLRD have set the priorities for this summer's work. Besides sealing <br /> the portals, MCR plans to reclaim the Mines 4 and 5 and the Suety and old waste <br /> coal spoil pile this summer. MCR is planning to start at Mine 5, reclaiming <br /> the portal and road. We agree that the portal and the road above the portal <br /> which accesses ventilation fans should be reclaimed. However, the road to Mine <br /> 5 does not rank as a Forest Service priority for reclamation for the following <br /> reasons: <br /> Access to the Mine 5 portal will still be needed until the portal site and <br /> road above it are satisfactorily reclaimed. Also the abandoned strip mine <br /> spoils accessed by the road above the portal needs to be reclaimed. <br /> Most of Mine 5 Road's cut and fill slopes are stable to the point that they <br /> are not a major source of sediment to Coal Creek nor it's tributaries. <br />