A Lake Macquarie water ski club displaced by a power generator and governmental fears an earthquake could trigger a huge coal ash dam collapse wants access re-instated to the lagoon.

In 2019, a Origin Energy report into the possible consequences of an earthquake near its Eraring Power Station site prompted the New South Wales government's sudden closure of Lake Macquarie's Myuna Bay Sport and Recreation Centre overnight.

At the time, Origin Energy said the risk of its massive ash dam failing in the event of an earthquake was so high the centre should be moved.

The decision to close the centre was made in the middle of an international water skiing event on Whiteheads Lagoon.

It followed a 2002 earthquake risk assessment for Lake Macquarie compiled by Geoscience Australia analysts that identified whole suburbs at risk from the ash dam in the event of a quake.

For decades, the Myuna Bay centre attracted more than 20,000 children each year from across New South Wales for its school camps.

Water skiing struggling

The president of the Myuna Bay Water Ski Club Peter Atkinson still remembers the day it closed like it were yesterday.

"Everybody was just in shock, it was like 'are you serious?' I have never experienced anything like it," he said.

In July last year, the state government announced plans for a new site one kilometre away, offering a range of specialist programs and activities, including water sports.

But Mr Atkinson said Whiteheads Lagoon, at the old site, is unrivalled in terms of its suitability.

"Without Myuna Bay the sport is struggling in New South Wales."

Mr Atkinson said the new site would not be appropriate and has called on the government to have access re-instated at the lagoon.

"[The new site] is not closed off and so you have got fishing boats, speed boats, wakeboard boats. So it won't be suitable for us," he said.

Mr Atkinson said any risk to club members would be minor and was a risk that they would be willing to take.

"We are all adults and we don't ski in adverse conditions. We are not there at night time and we are only there for two hours at a time each during the day," he said.

Lake Macquarie MP Greg Piper backed the club.

"I agree with them that Whiteheads Lagoon is probably second to none, certainly in our region, and probably in Australia," he said.

Origin Energy said the Office of Sport continued to progress regulatory approval for the new Myuna Bay Sport and Recreation Centre.

The Office of Sport was approached for comment.