Aquazone at Lake Mulwala is adding a new module to the original structure this weekend, effectively doubling the size of the park.

Aquazone at Lake Mulwala managing director Deb North said it was the first major change for the business since it opened four years ago.

"It will be at least double in size," she said.

"There will be a hamster wheel, volleyball court, balance beams and giant slides."

Having opened in November 2016, Ms North said the community had embraced the venture.

"We've had really good visitor numbers," Ms North said.

"We've had fabulous growth in school visits because it really suits as an adventure and bonding exercise and a great day out."

Aquazone at Lake Mulwala, which employs 40 staff, will operate until mid-April.

Users must be aged 5-plus.