(Department of Environment Conservation Officer James Maguire) said the flooding of the Murrumbidgee River is the most likely cause of the frog's resurgence and said there is really only one way to ensure the frogs do not disappear again.

"It's all about the water really," he said.

"If we can get environmental water back into these wetland systems annually or every second year, then we'd be looking pretty good to their population there.

"Also vegetation wise, we need to be managing the systems so they're well vegetated so the frogs have a good habitat to hide and lay eggs in."

Mr Maguire said monitoring of the Murrumbidgee's wetlands will be stepped up, following the discovery.