SANDUSKY, Ohio -- An expansion planned for an indoor water park that opened nearly two years ago will make it the nation's biggest, its operators said.

Kalahari Resorts said it plans to double the size of its water park, making it bigger than the company's water park in Wisconsin Dells, Wis.

The project is expected to be completed by December.

It will include two surfing rides, a wave pool, slides, a swim up bar and a children's play area.