After steady growth for the past five years, the number of new indoor waterpark resorts in the U.S. and Canada is expected to decline this year, according to a new report. The study by David Sangree of Cleveland-based Hotel & Leisure Advisors projects 18 openings this year—13 new waterpark resorts and five expansions of existing properties. Last year, 21 hotels with indoor waterparks opened or expanded.

Two of the ’09 openings will be waterpark destination resorts, which Sangree defines as resorts with more than 30,000 square feet of indoor waterpark space. One of them, a new Great Wolf Lodge in Concord, NC, will have 402 guestrooms and 81,000 square feet of waterpark. The other opening will be Valley of the Springs Resort, a 156-room hotel with 40,000 square feet of waterpark space in French Lick, IN.

Despite the slowdown in development, Sangree says the industry is still performing well. Great Wolf Resorts, the largest indoor waterpark resort operator with 11 properties, reported higher occupancy (68.6 percent) and average rate ($256.37) for the third quarter of 2008 compared to a year earlier. (The company will report fourth-quarter results on Feb. 25). Sangree says Great Wolf and other indoor waterpark operators are doing well because more consumers are vacationing closer to home. On a negative note, however, three resorts went into bankruptcy in 2008.

Sangree says he’s tracking 300 proposals for new indoor waterpark resorts or additions to existing properties. “With the current challenges in the financing market, we project a slowdown in growth in 2010 but potential for increased growth in 2011 and beyond as lending opportunities increase,” he said.

This segment of the industry has grown to 132 properties in the U.S. and Canada, nearly double the number in business in 2004 (64). The roster of resorts includes 46 waterpark destination resorts.