A proposed wave park on Perth's Swan River that would be one of the biggest ever built in Australia has sparked the ire of local residents, who say the surrounding environment will be irreversibly damaged and the foreshore should remain accessible to all.

The planned 2.4-hectare park, on the Canning Highway in the well-heeled southern suburb of Alfred Cove, would produce waves up to 2.1 metres high in an open-water lagoon in Tompkins Park, set back slightly from the river.

Wave Park Group said the attraction would cost between $26 million and $30 million and take in 4.4ha of land and water.

It would operate from 6am until 9pm and could cater for 84 people an hour, and the proponents expect it would be visited by 50,000 people a year.

But Alfred Cove Action Group spokesman David Maynier said the area was too small for the wave park, and there were bushland and marine reserves that would be damaged.

"The Swan River foreshore is one of Perth's very few priceless world-class iconic assets, and if you're going to start developing it and putting up great big fee for entry operations there, that's totally incompatible with how the Swan River foreshore should be used," he said.

"It should be as public open space, free access for all people, for ever and absolutely not used by local councils for revenue raising."

He said it was right next to the Alfred Cove nature reserve and overlooked the Swan estuary marine park, which he feared would be damaged.

"You don't have to study this, we know, it's absolutely certain, that they will be compromised and adversely affected by this development," he said.

'No evidence' of environmental harm

But Wave Park Group chief executive Andrew Ross said there was no evidence the park would cause environmental damage.

"If this proposal was to impact the environment, to have any significant impact, it just simply wouldn't go ahead," he said.

"There's terms 'environmental disaster' and various other things (are) being thrown around, which are very emotive, but there's actually nothing that supports those conclusions.

Mr Ross said he wanted the project to follow the usual statutory planning process, to establish if it was environmentally viable, and a council lease offer was the first step in that process.

He said as part of the planning approvals process, which was only commenced if the council agreed to grant a conditional lease, the Department of Parks and Wildlife would review the proposal.

The Melville council is seeking feedback on the project.

The same company wants to open parks in Sydney Olympic Park and near Melbourne Airport.