That thing you thought would never happen in a region with 11 operational breweries and four more in the pipes? It’s happening: Central Oregon is running low on beer.

Don’t panic. You don’t have to switch to water or drive to Portland. But some favorite brands and styles may be hard to come by in the next couple of weeks.

To some degree, demand for beer goes up every summer. In March, breweries ramp up production so there’s enough supply to slake the hot-weather thirst.

This summer, however, was off the charts.

“It’s one of the busiest summers we’ve ever had,” says Tonya Cornett, brewmaster for Bend Brewing Company.

Some of the mighty thirst might be thanks to an increase in tourism.

“We … used to see a couple of international visitors a month,” Cornett says, “now it’s several a week.”

Others say the shortage points to still-growing interest in craft beer.

Paul Gatza, of the Brewers Association, a national trade group for craft brewers, says that when the recession began in 2008, many small breweries had recently expanded. Then the economy tanked, the credit supply dried up and breweries delayed plans to grow. Thirst, however, didn’t stop rising.

“Now it’s time for the next round of expansions,” Gatza says, “and there’s some catch-up to be done.”

Still, Gatza admits he doesn’t know of any other regions where more than one or two breweries are facing shortages.

Cascade Lakes Brewing, in Redmond, finished an equipment upgrade early this year. This summer, seasonal styles ran out faster than anticipated and President Chris Justema says he’s considering another expansion in early 2012.

Jimmy Seifrit became brewmaster of 10 Barrel Brewing in January. When he arrived, the Bend company was producing 60 to 80 barrels (each holding 31 gallons) of beer per week. Now it produces 110 to 130 barrels a week, which still isn’t enough.

“We turn down thousands and thousands of beer sales a week,” Seifrit says, mostly to people seeking kegs. “We would love to be able to sell more, we just don’t have enough beer.”

Stop by 10 Barrel’s jam-packed pub on Galveston Avenue and you’ll likely find that a couple of varieties on the menu have been tapped out.

Boneyard Brewing planned to start canning its beer this summer, says Tony Lawrence, co-founder and brewmaster. The company even has a new canning line ready to go. Trouble is, there’s not enough beer to fill the cans.

For now, Boneyard primarily sells kegs to bars and restaurants.

“We don’t seem to be able to fill our purchase orders for distributors,” Lawrence says. He estimates that Boneyard is only managing to provide about two out of every three kegs ordered.

Visitors to the brewery’s taproom on Lake Place in Bend can walk in and pay to fill a growler. But certain styles, especially the RPM IPA, are frequently sold out.

The company just purchased three new fermentation tanks this summer, which increased capacity by 75 percent. And Lawrence is already looking to buy three more tanks.

Even Bend’s largest brewer is scrambling to keep up, says Mark Hegedus, director of sales and marketing for Deschutes Brewery.

Since the recession took hold in 2008, the brewery’s draught business at restaurants and bars remained flat. Until this spring, that is, when it skyrocketed.

“We had a forecast going into the year that we would experience about a 12 percent increase in our business,” Hegedus says. “For the last five or six months, we’ve been trending in the 25 percent range, which is almost double the growth rate that we thought. It’s been a really crazy year.”

Brewers say seemingly insatiable demand is a good problem to have, especially in this economy. But it’s stressful nonetheless.

“I’ve been in this industry for 15 years now,” says 10 Barrel’s Seifrit, “and I’ve never seen anything like it.”

Sounds like Seifrit could use a cold one, wherever he finds it.