Over decades, families have trekked up the hill at the Jamberoo Action Park to stand atop the Splash Out waterslide, the first waterslide at the region's much loved water park.

It was the first place many felt the pang of anxiety before launching down a whitewash of water, being swayed and swung around before safely splashing into a pool of water and being told to get out of the way of the next person by a diligent lifeguard.

Read more: Two men, real estate agent charged $14.7 million scam to build homes in Avondale

Park owner and founder Jim Eddy can only estimate "millions" when asked on how many people would have travelled the slide in its lifetime.

While not having the glitz and glamour of the new "whiz bang" modern slides like The Perfect Storm or the Funnel Web, Splash Out has been a family favourite for over four decades.

Alas, all good things must come to an end. Splash Out is now in its finals days. It will be disassembled over Jamberoo's winter break to make way for a new $10 million attraction, Velocity Falls, which will be built in its place.

"Splash Out was the third waterside in Australia," Mr Eddy remembered this week.

"There was one in the Gold Coast and one in Coffs Harbour and the people who built the Coffs Harbour one built ours."

In its earliest incarnation many would remember Jamberoo was a grass skiing park, a fad which seemed to come and go as quickly as it appeared across the country.

"We built the grass ski park which opened in 1980 and the drought hit us pretty hard ... we couldn't put enough water on the grass to keep the grass growing," Mr Eddy said.

"We looked around for alternatives, I saw the waterslide in Queensland and on driving back down the coast I saw the one in Coffs Harbour.

"We didn't have money to pay for building it, we had to use our own resources. We were going to go to the bank to borrow the balance to pay the building of (Splash Out) off but we just opened the slide anyway and away it went.

"It was a very successful development and probably one of the most successful we've ever had."

Since then in 1981, Jamberoo Action Park has grown immensely and is NSW's largest family owned and operated water theme park.

With the imminent closure of the ride which helped build it all, the Illawarra Mercury this week asked Mr Eddy to recreate a picture which the Mercury took for the opening of the slide. The old black and white image features Mr Eddy and friends hurtling down the new sensation. Mr Eddy jumped at the chance this week to get back on his beloved ride.

Got a news tip or story for us? Email cos@illawarramercury.com.au

"The simple design has been the essence of success of the ride," Mr Eddy said.

"It's inground, people don't have to walk up a tower and it's always landscaped so it looks good. But it's past its use-by date and what we've got planned is the biggest thing ever done in a single ride.

"It's a $10m development and it's going to give us a different perspective on the park."

So how did Mr Eddy enjoy the experience of riding Splash Out again?

"It's exactly the same as it was 40 years," he said.

"Generally people could ride the thing 15-20 times in a day if they wanted. There would be millions who have been down that slide. The gel coat has worn off the slide on at least four occasions.

"There wouldn't be a slide in Australia or one in the world that has had that number of people down it. Very few slides are 40 years old."

Over the years, Mr Eddy admits there has been the odd unauthorised ride by trespassers.

"But we've got sensors all through the park now so we tend to catch them," he said.

The attraction which will take its place is a new, state-of-the art waterslide built by Canadian water park experts ProSlide called Velocity Falls.

Adapted from an earlier proposal, this concept is themed around the region's own Fitzroy Falls and designed to blend in with the local landscape.

The ride is currently making its way to Jamberoo on 45 42-foot shipping containers which arrive in the country in March. It will involve a combination of several new waterslides and 33 new shelters for families.

"This is one ride but it's the centrepiece of the park," Mr Eddy said.

"It is a strong focal point and very valuable real estate for us, so we wanted to build something really outstanding. What we've tried to do at Jamberoo is develop the park and put a lot of attention on detail and theming of the park.

"This will be a rainforest/waterfall theme and we looked at Fitzroy Falls. A lot of the colours and the rock designs are ones you will see at that beautiful place.

"Essentially this is three different rides in the one ride and we went around the world looking at different developments to come up with this concept."

Also arriving during the off season will be a new train which will run on a network connecting the entire park. The next planned development after Velocity Falls will involve a 440 m long river connecting existing elements of the park and involving three different formations of waves.

Despite a summer of bushfires two years ago and a COVID-tainted summer, Mr Eddy said it had been a relatively strong season.

"This summer has been well above our budget and although we've had some crook weather, because people haven't been able to travel overseas or have been restricted in movement we've been flooded," he said.

"We've had some 9000 people days at the park where people have just flooded out of their homes and made their way to the park in huge numbers."

Yet he acknowledges it has been a much tougher environment for smaller operators or those interstate.

"The mind games that have gone on in trying to stay about it, be resilient and hold everything together has been hard on some people," Mr Eddy said.

"Look at what has gone on in Victoria, I feel so sorry for those businesses."

It is hoped the Velocity Falls will be ready in time for the September reopening of the park.

We depend on subscription revenue to support our journalism. If you are able, please subscribe here. If you are already a subscriber, thank you for your support.