Shawn Jenkins, a developer who had two projects caught up in the delays, said he was accustomed to piles of paperwork and reams of red tape in getting projects approved. But he was not prepared to have the water district hold up the projects he was planning. He changed the projects’ landscaping, to make it less water dependent, as the board pondered their fate.

Image An East Bay Utility District sign along I-880 in Oakland thanks customers for conserving water. Credit... Jim Wilson/The New York Times

“I think this is a warning for everyone,” Mr. Jenkins said.

Also in Riverside County, a superior court judge recently stopped a 1,500-home development project, citing, among others things, a failure to provide substantial evidence of adequate water supply.

In San Luis Obispo County, north of Los Angeles, the City of Pismo Beach was recently denied the right to annex unincorporated land to build a large multipurpose project because, “the city didn’t have enough water to adequately serve the development,” said Paul Hood, the executive officer of the commission that approves the annexations and incorporations of cities.

In agriculturally rich Kern County, north of Los Angeles, at least three developers scrapped plans recently to apply for permits, realizing water was going to be an issue. An official from the county’s planning department said the developers were the first ever in the county to be stymied by water concerns. Large-scale housing developments in Santa Barbara and San Luis Obispo Counties have met a similar fate, officials in those counties said.

Throughout the state, other projects have been suspended or are being revised to accommodate water shortages, and water authorities and cities have increasingly begun to consider holding off on “will-serve” letters  promises to developers to provide water  for new projects.

“The water in our state is not sufficient to add more demand,” said Lester Snow, the director of the California Department of Water Resources. “And that now means that some large development can’t go forward. If we don’t make changes with water, we are going to have a major economic problem in this state.”

The words “crisis” and “water” have gone together in this state since the 49ers traded flecks of gold for food. But several factors have combined to make the current water crisis more acute than those of recent years.