There's another drought plaguing California these days: Gas supplies are running dry, driving prices up, reports CBS News' Danielle Nottingham.

Many industry analysts agree higher prices are the result of low supplies at California's refineries, but there's sharp disagreement about why those supplies are low.

"What we're looking at is a system where inventories have been kept really, really low by four oil refineries that control 78 percent of the market. And by keeping inventories low, they keep gas prices artificially high, and with it, their profits are artificially high," Consumer Watchdog President Jamie Court said.

His organization sent a letter to California Attorney General Kamala Harris Monday with evidence it says confirms that oil refineries have been shipping gas to Central and South America instead of keeping it for California.

"That's happening at a time when our well is supposed to be dry," Court said. "It's clearly gouging. It's clearly profiteering."

Or is it?

AAA said one reason California has low gas supplies is because of a shortage of special ingredients needed to make its fuel.

"We use a specialized blend to reduce pollution. It can't be gotten from other states," AAA spokesperson Marie Montgomery said.

Another potential reason for the price spike is disruptions at some of the state's refineries -- one plant has been offline since February after an explosion. But Consumer Watchdog contends that's not enough to explain the state's explosive price increases.

"Our crude costs are half of what they were the last time gasoline was this high in price. All that's really left is 'ka-ching,' 'ka-ching' in the coffers of the oil refiners," Court said.

While California's gas prices are spiking, prices in other states, like Michigan, Illinois and Wisconsin are actually on the decline. In Indiana, drivers are paying 13 cents less per gallon than they were a week ago.

If you're a California driver waiting to fill your tank-- don't. Industry analysts say the refinery shortages keeping prices high won't be shored-up anytime soon, resulting in higher prices in the days, and perhaps weeks, ahead.