State water regulators are leaving their options open for how best to protect endangered fish and distribute water in the San Francisco Bay and Sacramento-San Joaquin Delta under a draft plan released Friday. The release intensifies a bruising battle between environmentalists, tribes and fishing groups on one side and cities and farmers on the other over managing the state’s main water hub, which supplies water to most Californians as well as habitat to migratory birds and endangered fish like chinook salmon. The State Water Resources Control Board detailed several alternatives in its draft plan for meeting state and federal water quality standards, including requiring minimum flows on the Sacramento and San Joaquin rivers and tributaries, settling with water districts that’ve proposed instead to limit their deliveries and pay for habitat restoration, and a combination of both.