Rapid growth in Park City and the Snyderville Basin is soaking up the region's water and quickly tapping resources unable to keep up with the development boom.

And conservation efforts and above-average runoff may not be enough to shore up the resort community's water supply, a U.S. Bureau of Reclamation study has found.

"When they start running short because they run out of water, that would trigger the county to stop allowing new building permits," said Eric Millis, assistant director of the Utah Division of Water Resources. "It would limit growth."

Residents got their first peek at the water predictions Tuesday night as bureau officials unveiled their preliminary recommendations to stave off a water shortage. By 2030, the bureau expects a 7,000-acre-foot shortfall in usable water. By 2050, that shortage is predicted to jump to 13,000 acre feet.

The area is already stretching the limits of its water supply with a demand for 9,800 acre feet a year and a supply capacity of about 14,000 acre feet. By 2050, that demand will have tripled, but the resources will remain stagnant, with a majority of the basin's water flowing from groundwater mined from tunnels.

The projected water deficit is also a conservative estimate, Millis said, because it assumes the region will meet the state's goal of cutting per capita water demand by 25 percent by the year 2050.

"Conservation does a huge amount to help. But it doesn't do it all," he said.

The bureau's report notes that without a concerted conservation effort it will be difficult to justify any investments in new water projects. According to the report, major infrastructure and importation projects are going to be needed to keep the Snyderville Basin's water supply fully stocked.

The bureau's report, which began in 2003 and is to be completed this September, includes eight alternatives to funnel and retain new water sources in the basin.

Chief among those are two options to route water either from the Weber River via the Weber Provo Canal or to funnel water from Rockport Reservoir.

"Between those two alternatives, if they each bring up the amount of water they think they're capable of bringing, you end up meeting the future water needs," said Larry Anderson, director of the Utah Division of Water Resources.

Other ideas include importing water from Provo River, creating additional surface water storage and reusing water for agricultural purposes.