Altona beach users are angry Hobsons Bay council has placed rocks over a popular swimming spot known as Flemings Pool.
The council told Star Weekly it had undertaken drainage works and placed the rocks to protect the seawall from erosion.
It plans to build a viewing area and new access ramp to the beach.
One local resident posted on Facebook that the council had “ruined Kokomo”, a reference to the Beach Boys’ tune.
“I’m really hoping Flemings Pool is not finished ’cause there is literally no sand, all rocks are covering it,” the post said. “I hope the rocks that have been left there will be taken away!!!”
Hobsons Bay mayor Sandra Wilson said the current state of Flemings Pool was temporary.
“Works on site are being carried out to repair damage that occurred during the 2014 storms,” she said.
“Several stop-gap measures over the past three years have delayed the inevitable and now major works need to happen to ensure Flemings Pool can be enjoyed for many years to come.
“We have plans to deliver these works over the next 18 months.”
Historian Peter Weaver, who grew up 100 metres from Flemings Pool, said that in the 1970s there was a two-metre drop from the seawall to the beach.
“The council in the ’70s got advice from Japanese hydrologists to help with the sand movement and they built large stone groynes to stop the tides flushing the sand away,” he said.
“I envisage and hope [that] after a few storms, the beach will return better and bigger than before – although they may have to take away some of the rocks.”