Five appointed state regulators can do an enormous amount to help salmon and the state’s most-altered water system on Dec. 12. Or they can guarantee that water lawyers will stay busy for decades to come. The State Water Resources Control Board’s five members – including one added Thursday – are scheduled to vote on implementing the Bay-Delta Plan’s Substitute Environmental Document. If unchanged, the SED will require 40 to 50 percent of the Stanislaus, Tuolumne and Merced rivers to flow unimpaired to the Delta, for the sake of salmon. It would also require vast amounts of water be left in cold storage behind the region’s three dams to help salmon in an ever-warming environment.