Regarding the lock and dam decommissioning:
Has any consideration been given to turning the facility (partially) into a low-head hydroelectric generation facility? The costs for repairs might be better spent by rolling them into the cost of upgrading the facility to provide for electricity generation. Revenues from the electricity thus generated could then be used to offset further operation and maintenance costs of the facility -- maintaining the locks and the considerable utility of the upstream pool for continued public benefit.
Stephen V. Geddes, Aiken