As California enters another period of drought, experts say the dry spell could make an already difficult housing market even worse. … Some housing experts say about 20,000 homes need to be built in San Diego every year. Building more houses requires more water. … [Dr. Norm Miller, a Real Estate Professor at USD] believes San Diego already has enough water to build that many new homes. But he thinks the State and Federal Governments need to make housing a priority over other water users, like agriculture.