ANTIOCH -- The ability to draw water from the Delta without state permits has been a liquid asset for this city for nearly a century.

Antioch leaders made sure Tuesday night to keep it that way.

The City Council agreed to an extension of its 1968 agreement with the state's Department of Water Resources allowing Antioch to draw water from the San Joaquin River 208 days a year for the next 15 years.

"This preserves and projects Antioch's rights as far as our water," Councilman Tony Tiscareno said. "We're hoping that we're able to preserve this for a lifetime, but this is a start."

Antioch has rights dating back to before 1914 to pump without the need for a state permit.

The amended terms come after five years of negotiations, and call for the state to pay one-third of Antioch's costs to purchase substitute water when its normal supply is not usable because of increased salinity.

The once-fresh water has become saltier over time as state and federal agencies moved water from the region to the San Joaquin Valley and Southern California.

Antioch is guaranteed water quality at or below 250 milligrams of salt per liter.

The amendment also sets when salinity readings are taken to two hours after daily high tide. It also expands the measured volume of substitute water to include Antioch's expanded boundaries and sphere of influence areas.

Those elements are "more favorable to (Antioch) financially," Councilman Gary Agopian said.

Additionally, the new agreement would wipe out all prior claims by both sides.

Antioch's approval is independent of Gov. Jerry Brown's plan to build a pair of tunnels to move water from the Delta to Southern California, meaning the city is not obligated to support the Bay Delta Conservation Plan, said Ron Bernal, the city's public works director.

"We should have the right to speak out, and we will," Councilman Gary Agopian said.

The Department of Water Resources hasn't finalized the agreement yet.

For updates, check back to ContraCostaTimes.com.

Contact Paul Burgarino at 925-779-7164. Follow him at Twitter.com/paulburgarino.