_GENERAL DOCUMENTS - C1981017 (250)

Home Browse Search

Memo to Dave Bucknam Dutch Creek Flume Recommendations page 4 in extremely coarse material entering the flood flow. This material in turn can be mobilized as abnormally large sized bed load. The debris flow threat is twofold. First, the abnormally high snow pack and pending rapid melt represent the possible causal relationship which may trigger debris flow activity on Dutch Creek or in the upper reaches of Coal Creek. If a debris flow is initiated it will continue until it naturally terminates. Mine improvements will probably not significantly effect the occurrence, distribution or length of debris flows. Coarse debris spawned by previous debris flows on Dutch Creek probably contributed to the damage sustained by the flume. The 9 foot diameter pipe recently placed in the flume will be damaged, if not obliterated, by a debris flow. Second, coarse debris eroded from the old debris flow levees, or spawned by a new flow, could plug or seriously damage the pipe and the deteriorating flume. Caution Regarding Worker's Safety Both Dutch Creek and Coal Creek represent high gradient and high-energy channels. As such they represent extremely hazardous threats to the safety of the manpower performing emergency response tasks. In no event should heavy equipment enter the flume or channels during high flow. Particularly in light of the unpredictable secondary threat of debris flow occurrence. Bogue excavation's backhoe should be stationed immediately to the north of the up gradient inlet end of the 9' pipe, in order to remove bed load gravel which accumulates at that point. If it appears that the Dutch Creek flume and pipe are in threat of overtopping the equipment and operators should withdraw to a safe location. Implications for Permanent Reclamation In my opinion, based upon the past two days occurrences, the Dutch Creek flume and pipe are inappropriate components of a permanent reclamation plan for the Coal Basin mines. If we had not intervened and cleaned the blockage during the last few days the flume/pipe would have jammed with debris, overtopped and probably been seriously damaged.