Nearly six decades ago, shortly after becoming governor, Pat Brown persuaded the Legislature and voters to approve one of the nation’s largest public works projects, the State Water Plan. New reservoirs in Northern California, including the nation’s highest dam at Oroville on the Feather River, would capture runoff from snowfall in the Sierra, and a miles-long aqueduct would carry water southward to San Joaquin Valley farms and fast-growing Southern California cities.