Residents are outraged by plans to erect a fence around Hunter Water land that houses the newly completed $2.6 million temporary seawall, which would restrict public access to the northern end of the beach.

Northside Boardriders' Club president Simon Jones said there were fears about loss of access to a 3km strip of beach used by surfers due to worsening erosion at the southern end of the beach.

Mr Jones said four of the five competitions hosted by the boardriders' club this year were held north of Corroba Oval.

He said if the area was fenced off, it would be impossible to hold surf competitions in Stockton.

"I'd say 90 per cent of people who surf in Stockton do so in that area," he said.

"For years it's always been tolerated that people can access the beach and if that changes they will basically be shutting people out of the only surfing spot left."

Residents are calling on Hunter Water to designate an access point to avoid people damaging a fence to gain access.

Mr Jones said he understood Hunter Water was concerned about potential damage to the old tip.

The site has been excavated enough to allow for the construction of a temporary seawall to protect the remaining landfill from erosion.

"The tip site is only one small corner of that parcel of land and we think it's best to clearly define an access area so people stay away from areas where they shouldn't be," he said.

"On any given day you will find 50 people surfing that part of the beach."

A Hunter Water spokeswoman said it was considering options to fence a section of land that contains the old garbage tip and the wastewater treatment plant for "community safety".

"The location of the fence has not yet been confirmed," she said.

"We will be engaging with the community over the coming weeks to understand, and where possible, mitigate impacts to community amenity."