Best Indoor Water Parks - Top Ten in the USA

1. Kalahari Resort's Waterpark - Sandusky, Ohio
America's Largest Indoor Waterpark offers something for everyone! Stand up surf or boogie board 365 days a year on one of two FlowRiders® where 50,000 gallons of water each minute flow under you to create a five-foot ocean-like wave! Catch some rays under the Texlon transparent roof while enjoying the 12,000 sq. ft. wavepool! Experience the thrill of the Swahili Swirl 60' diameter bowl raft ride, Zip Coaster uphill water rollercoaster waterslide, Cheetah Race 4 lane mat slides, Rippling Rhino and Victoria Falls raft rides, lazy river, indoor/outdoor spas, swim up bar and MUCH more! 
Kalahari Resort's Waterpark - Wisconsin Dells
One of Wisconsin Dells' mega waterpark resorts, the original Kalahari features a cavernous indoor water park that includes all kinds of watery diversions such as one of the industry's first indoor water coasters. And there are plenty of other things to do, including a 10-screen movie theater, a day spa, fitness center, arcade, and a host of daily kids activities such as karaoke, scavenger hunts, and live animal encounters.

Great Wolf Lodge's 3 Waterparks - Wisconsin Dells
Giving new meaning to the term “year-round family resort,” Great Wolf Lodge defies the weather outside with an indoor waterpark experience that has young and old soaking in the fun! Whether it's 10 degrees below or raining cats and dogs, it's always a balmy 84 degrees inside the resort's mammoth, 100,000 square-foot indoor waterpark. Its three indoor waterparks, Bear Track Landing, Spirit Island and Treehouse Island put the emphasis on fun with 19 waterslides, six pools and a four-story treehouse waterfort. The state-of-the-art facility utilizes nearly 300,000 gallons of water that is splashed, sprayed, waved and played in by both kids and parents alike.

Avalanche Bay Indoor Waterpark - Boyne Falls, Michigan
Quench your thirst for BIG family fun at Avalanche Bay, Michigan's LARGEST indoor waterpark and voted BEST by the readers of The Detroit News! This 88,000 square foot aquatic playground offers a complete sensory experience for all ages. Austrian streetscapes, avalanche rumblings and Boyne memorabilia is incorporated into an elaborate and expansive series of falls, tubes, waves and pools. It is phenomenal. The interior detailing will is executed to a level never before seen in any waterpark in the nation.
Chula Vista Resort's Lost Rios Indoor Waterpark - Wisconsin Dells
Lost Rios Indoor Waterpark has something for everyone. Race each other on the Matador Mat Racers or hang out in Mount Montezuma's giant rain forest. You may get sprayed while floating along Rio Rapido action river, but you can have tons of dry fun in the new huge mega arcade, Pesos O' Plenty. And if you get hungry, you won't even have to leave the waterpark. Crash Landings snack bar has all kinds of tempting treats including, pizza, burgers and wraps. Don't be afraid to get lost in all the fun at Lost Rios Indoor Waterpark.
Great Wolf Lodge - Sandusky, Ohio 
Originally the Great Bear Lodge this was Ohio's original indoor waterpark and it also remains one of the best kept with great fun inside.

Great Wolf Lodge's Indoor Waterpark - Scotrun, Pennsylvania
Splash Lagoon - Erie, Pennsylvania
Located just 90 miles north of Pittsburgh in Erie, Pennsylvania, the Splash Lagoon resort complex includes Splash Lagoon Indoor Water Park, Laser Tag Arena and Arcade, and several hotel properties connected to the water park. The indoor water park features the latest and greatest rides in the water park industry, set in a South Sea Island atmosphere with palm trees, tropical plants, and flowers.
Water Park of America - Bloomington, Minnesota
Adjacent to the Mall of America and soaring 90 feet above the Twin Cities' skyline, Water Park of America entertains both the young and young at heart. Surf on Minnesota's only Flow Rider Surf Simulator, catch a wave in the Lake Superior wave pool or challenge your fears in America's longest indoor family raft ride at ten stories tall and over a mile long! The Water Park of America offers a spa, two restaurants, 5,800 sq ft arcade, cafe, wireless internet and much more await you.
KeyLime Cove's Indoor Waterpark - Gurnee, Illinois
KeyLime Cove Water Resort is so much fun, the rest of the world's water is jealous! The first thing you’ll notice about KeyLime Cove's massive 65,000 square foot indoor waterpark is what's missing – the long lines and giant crowds you'll find at most other waterparks. KeyLime Cove indoor waterpark paradise, located less than 1 hour from downtown Chicago, is exclusively for our favorite people – guests of KeyLime Cove Water Resort. You can't buy a ticket for our waterpark. That's because admission to our indoor water park is completely free when you stay with us. Unlimited splashtastic rides and unlimited splash-tacular fun is what you'll find at KeyLime Cove Water Resort.