The shutdown of the Phillips 66 refinery complex in Wilmington and Carson next year will force California to make up for the loss by importing more gasoline by ocean tanker, which is expected to raise prices to motorists at the pump.

—The closure will leave California with eight gasoline refineries, down from 11 five years ago.

California for decades produced enough gasoline to supply almost all of its own needs, but the era of self-sufficiency is coming quickly to an end.

The Phillips 66 refinery complex in Wilmington and Carson now produces 1.3 billion gallons of gasoline annually, which will leave a huge gap to be filled after its planned closure late next year. With no pipelines into the state, and no plans to add new refineries, California will need to make up for the deficit by imports via ocean tanker — in what analysts say will be a costly endeavor, and one with inherent risks of supply disruptions.