(CNN) -- When the water of Lake Delton ripped through the highway and drained into the Wisconsin River this week, so did the lifeline for much of the surrounding community.



Boats sit mired in mud Tuesday after Lake Delton drained into the Wisconsin River the day before.



Lake Delton Village and Wisconsin Dells, the self-professed "waterpark capital of the world," are home to about 5,000 residents. But the area's motels, resorts and vacation homes can accommodate more than 10 times that, according to the visitors bureau.



Innkeepers, restaurateurs and other business owners were getting ready for the typically bustling tourist season this week when torrential rains sent the 267-acre lake rushing through an embankment propping up Highway A. The manmade lake sucked a 200-foot swath of highway and a half-dozen homes into the Wisconsin with it.



"I was on the water when I realized the plug had been pulled," said Steve Zowin, who was towing a capsized pontoon boat when he noticed the water level quickly diminishing. "It drained like a bathtub."  Watch a report from the lake »



Zowin and his wife, Kathy, have owned Lake Delton Watersports for almost three decades. In addition to running a marina, the couple offers parasail rides and rents boats. Personal watercraft and ski boats are their most popular wares, he said.



"My gross income will be reduced by about 75 percent, and that's huge," he said Wednesday. "It's a big step backwards for someone who's been in business for 29 years."



Zowin, 56, says that most of the tourists hail from metropolises like Chicago, Illinois; St. Paul/Minneapolis, Minnesota; and Madison and Milwaukee, Wisconsin -- all "within a gas tank of the Dells." They start trickling in on Father's Day, and tourism booms between Independence Day and mid-August, he said.



Like many business owners around Lake Delton, Zowin is seeing canceled reservations from disenchanted visitors who will be spending their summers elsewhere.



Asked whether visitors were canceling reservations at her lakeside resort, one owner who didn't want to give her name replied, "Every day, many."



Thomas Brown, who owns Port Vista, a popular burger and steak joint on the lake, said that one of his resort-owner friends has refunded $10,000 in deposits for canceled reservations. The friend has closed his resort until at least July, Brown said. iReport.com: Are you near the floods? Send photos, video



Brown, 49, who has owned the bar and restaurant for 15 years, said business hasn't been hit hard yet.



"The first couple of days has been absolutely packed because of all the people coming by to look at the lake and stopping by for a burger or steak," he said, adding that he doesn't expect business to boom for long. "I think when people see what they have to see, it's going to be not so good."



Some business owners who aren't on the lakefront are still trying to gauge what effect the drained lake will have on them.  Watch the rushing lake carry a home away »



Del-Bar is a popular seafood and steak restaurant near the lake on Wisconsin Dells Parkway. It's so popular, in fact, that actor Johnny Depp and director Michael Mann recently stopped in during filming of their upcoming movie "Public Enemies," owner Jeff Wimmer said.



Wimmer said his restaurant, which he has owned for 30 years, may be more resilient than lakefront businesses because he relies more on Wisconsin Dells locals. The 66-year-old knows that the summer brings hungry tourists; it's just too early to tell how many of them have been deterred by the dry lake bed.



"We're anticipating that it's going to affect us, but it's too early to tell right now," Wimmer said.



How long the lake will remain dry is also a question. Business owners say, some skeptically, that there are efforts afoot to refill the lake by mid-July.



Delton Oaks Resort
What are many businesses already seeing? What happened to Lake Delton? When was Lake Delton drained? What is Lake Delton? When is tourist season? How much income will be lost by local businesses?
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question: What are many businesses already seeing?, answer: canceled reservations | question: What happened to Lake Delton?, answer: ripped through the highway and drained into the Wisconsin River | question: When was Lake Delton drained?, answer: the day before. | question: What is Lake Delton?, answer: "waterpark capital of the world," | question: When is tourist season?, answer: between Independence Day and mid-August, | question: How much income will be lost by local businesses?, answer: 75 percent,