The former owner of Leisure Island says the water park was uneconomic and rebuilding would create a double up with the Mount Hot Saltwater Pools.
Spencer (Spinner) Black took ownership of Leisure Island, which opened on Moturiki in 1981, as part payment for his shares in the Rainbow Corporation which owns Rainbow's End theme park in Manukau.
Mr Black, who lives in Morrinsville, said the popular attraction was profitable during the summer season, but had to make enough in three months to cover a year of costly maintenance and staffing.
"It was very hard work. We did okay some years but some years we struggled."
Earlier this month Mount Maunganui resident Catherine Hunt, and husband Thomas, started a petition in support of a water park being rebuilt on the island.
The couple are aiming to present 30,000 signatures of support for the pools to Tauranga City Council.
The Facebook page "Bring Back Leisure Island Pools" has also attracted more than 7200 likes and Mrs Hunt said she had received plenty of support since the Bay of Plenty Times featured the story.
While Mr Black wished the couple luck, he did not see the need for more hot pools in Mount Maunganui.
"A double up doesn't seem very intelligent to me," he said.
However, the bumper boats and hydroslide were popular with locals and tourists, he said.
He estimated the park, which closed in 1990, cost $300,000 to $400,000 to set up. "For the massive investment it wasn't worth pursuing," he said.
Rex Green, who looked after the pumps and bumper boats at Leisure Island, said the salt water also caused the erosion of stainless steel and aluminium at the park, adding to the maintenance bill.
While managing Marineland - the predecessor to Leisure Island - Mr Green lived in a flat on Moturiki.
He said the island was a special place and should be left as it was.
"I'd say, leave well enough alone. It is a spiritual place, and I say that without being a very spiritual person," he said.
Tourism Bay of Plenty chief executive Rhys Arrowsmith said undoubtedly more attractions would add to the already popular region.
"However, we are in a unique position to not become a tacky Disneyland, so any investor should focus on developing activities in harmony with our environment and ensure that a robust business plan supports which location works best for the community and visitors."
Tauranga Mayor Stuart Crosby said people's attitudes to the natural environment had changed dramatically since the 1980s.
"People view our natural environment a little bit differently than they did in the earlier years. I don't think the wider community would actually support it."
Open spaces such as Moturiki are now rare and special in Mount Maunganui, he said. "To start to put hard infrastructure on there again I think would be very challenging in today's environment."
The Tauranga City Coastal Management Plan for Moturiki states that no new structures or permanent buildings are permitted on the island.
Under the Reserves Act, an amendment to the plan would be required before the park could be rebuilt, which would involve public consultation.
Resource consent would be needed and consultation with affected parties, including the Department of Conservation, Historic Places Trust and local iwi would be required.
Despite his own reservations, Mr Crosby welcomed the Hunts' petition to the council. "We have an open door and will listen and see what they have to say," he said.