SACRAMENTO  (AP) — California’s drought is beginning to dry up the water supplies for some state parks, including some of the system’s most popular places.

Restrooms with flush toilets have been closed at D.L. Bliss State Park at Lake Tahoe, the Hearst Castle Visitor Center and Hearst San Simeon State Park, replaced with portable toilets. The showers at D.L. Bliss, San Simeon and Portola Redwoods State Park also are shut down.

Each park relies on a local water supply, and in some cases, that’s a creek or spring. D.L. Bliss, which gets more than 12,000 campers a year, relies on a spring that dropped noticeably just before the Fourth of July weekend.

What water remains at the affected parks is being reserved for potable water at individual campsites and for firefighting, California Department of Parks and Recreation spokeswoman Vicky Waters told The Associated Press on Friday.

Some of the closures, such as at D.L. Bliss, are coming at the height of camping season. She said campers who have reservations are being notified through automated phone calls and will be allowed to cancel without penalty.

“We’re really trying to minimize the impact to our visitors because we know how important it is ... but we’re in this situation across the state,” Waters said.

The Hearst Castle Visitor Center receives 660,000 visitors a year, while the nearby San Simeon campground receives 83,000.

Waters said many parks, especially those in remote areas, have limited control over their water supplies. She said the department has taken steps to reduce consumption at all its parks and is monitoring the water supplies throughout the system.

At D.L. Bliss, popular for its sandy beach, crystal clear water and proximity to Tahoe’s Emerald Bay, it is the first time the park has ever had to close bathrooms or showers because of a lack of water, District Superintendent Marilyn Linkem said.

She was notified July 2, just ahead of the holiday weekend, that the amount of water coming in from the spring that supplies the park was not keeping up with the demand. That prompted the closure of the showers and flush toilets in a park that typically swarms with families throughout summer.

Some visitors were upset, she said, but others understood because they’re already aware of the severity of the state’s drought.

If the spring runs completely dry, she said the park is considering trucking in water to maintain potable sources at the campsites through Labor Day weekend. Meanwhile, the portable toilets are costing $1,200 a week, according to the state parks department.

Linkem said the park staff realizes the inconvenience to campers who made reservations months ago expecting flush toilets and showers.

“It’s hard for us, too. We’re used to providing quality customer services,” she said. “We’re doing the best we can.”