SACRAMENTO, Calif. (AP) – A California water board has adopted a contentious plan to revive dwindling salmon populations by boosting flows through a Central California river and its tributaries. The State Water Resources Control Board adopted the plan on Wednesday over the opposition of water districts serving the state’s agricultural heartland. The board voted to study a last-minute agreement among several key water agencies to voluntarily curtail their water usage and pay into a fund for habitat improvements. The agreement was reached after Gov. Jerry Brown and his successor, Gavin Newsom, asked water users to find an agreement that could support salmon populations without a strict state mandate. However, it lacked support from water agencies that rely on two of the three affected tributaries to the Lower San Joaquin River.