Most signs point to the State Water Board approving a much-disputed river flow plan next week that will mean less water for farms and cities in the Northern San Joaquin Valley. The board, also known as the State Water Resources Control Board, is set to vote Wednesday to require irrigation districts to leave more water in the Tuolumne, Stanislaus and Merced rivers in an effort to restore salmon. Local irrigation districts and county and city leaders have promised a prolonged battle over the water board’s final plan released in July, saying it will devastate the region’s economy and won’t help the fish.