Last week, Bob Hunt wrote a response to a previous letter by Randy Brook with respect to the removal of Enloe Dam. He cited two enduring myths about the liability and limited ecological value of removing the dam. His statements are understandable as these are myths repeated by the PUD for many decades. And it is difficult to stay current on the significant work that has been done recently to challenge these myths.
His first statement is that the sediments accumulated above the dam contain heavy metals that pose liability for the PUD and if released would cause serious concerns downstream were the dam removed and expose the PUD to costly cleanup. Fair point! Significant progress has been made in the last few years studying and understanding the actual presence of such materials and the degree of concern for downstream toxic effects.
First, USGS conducted an extensive survey of sediment cores that describes relative concentrations of metals in sediments. The State Department of Ecology (who now retains legal authority over such matters) also recently completed a further study and refined analysis that largely corroborate those initial findings. The jury is still out as to whether or not these concentrations rise to the level of requiring substantial concern, but so far there have not been any huge alarms set off by these studies.
The second and persistent myth, largely fostered by the PUD, is that the falls just below the dam is impassible to adult salmon. In fact, adult salmon have been photographed jumping at the base of the dam for the last seven years. A recent study completed by a consultant for the Colville Confederated Tribes concluded that there are several pathways that salmon can likely use to migrate above the falls at a range of flows.
The PUD just spent $8 million on a required dam safety study on a dam that hasn’t produced a watt of energy in over 80 years. Removal of the dam would open up in excess of 300 miles of river and tributary habitat to the much diminished wild Upper Columbia steelhead and spring Chinook salmon populations. Dam removal, with full cooperation of the PUD, just might save them from extinction.