SAN DIEGO -- San Diego County has an unlimited supply of water -- seawater, that is.

But if the county were to have an earthquake or terrorist attack and is cut off from its normal water supplies, the Pacific Ocean could become the county's primary water source.

However, the only way to make ocean water drinkable is through desalination, which is the process of filtering seawater into drinking water.

A new report from the California Department of Water Resources said in the event of an emergency or a severe drought, mobile desalination units could be temporarily deployed to provide residents with water.

"I think this is the only reliable source of water for which you don't have to depend on it coming from another place," said Dr. Gil Dhawan of Applied Membranes, Inc.

Dhawan's company has been building desal units since the 1980s.

San Diego County imports most of its water from the Colorado River and Northern California. However, if those waterways are damaged it could take weeks to reconnected.

In the meantime, small desalination units could produce enough drinking water for up to 300 families a day.

10News' Joe Little asked Dhawan, "Your technology could theoretically save people's lives?"

Dhawan replied, "Absolutely."

A desal unit would be placed next to the ocean or a lake and it would be able to pump clean water within minutes.

Dhawan's desal systems have been used in more than 50 countries.

"They can be from residential size to millions of gallons a day," said Dhawan.

Many of Dhawan's desal units are only temporary.

Larger, permanent desalination plants, like the Poseidon plant recently approved for Carlsbad, require permits and millions of dollars.

Poseidon will eventually produce 50 million gallons of drinking water out of the ocean every day.

But in an emergency situation the government could temporarily deploy units similar to those produced by Applied Membranes for a fraction of the cost and tap into an unlimited supply of water.

"It makes all the sense to use it and not depend on other sources," said Dhawan.

The state report said if California's drought situation worsens, mobile desalination units could be deployed throughout the state.

The units could be installed permanently but would first require a number of permits.