It's been promoted as a water playground for western Sydney but the premium season ticket price for Wet'n'Wild in Prospect has left many locals high and dry.

The water park, which is set to open in December, recently began selling its "gold season pass" online for $124.99.

The pass allows one person unlimited entry to Wet'n'Wild Sydney from December through to the end of April, when the park will close for winter.

However there is no discount for children and even gold season pass holders will have to pay extra for parking, locker rental, food and the two pay-per-ride attractions in the park.

READ MORE: Thousands register for jobs at Wet'n'Wild Sydney

Quakers Hill mother-of-three Eleanor Harrison said the price was "outrageous" and would be out of reach for many young families like hers.

"I had been counting down to the opening but at these prices there's no way we'll be going," she said.

"We drive past the site all the time and my kids ask, 'is it December yet?'

"I think it's crazy to ask so much money for something that is only going to be open five months of the year."

media_camera Wet, wild and too expensive

A question about the price posed on the Blacktown Advocate's Facebook page last week prompted a social media backlash, with hundreds of people declaring it too expensive.

Yet, Wet'n'Wild Sydney general manager Chris Warhurst said on Monday that "plenty" of local families had been among the "thousands of people" to already purchase the pass.

"The gold season pass is good value, especially when you consider it allows for unlimited entry to the park," he said.

"There are going to be certain price points that appeal to certain people and thousands of people have already purchased the gold season passes.

"It has almost got to the point where we are going to have to cut them off because they have been so popular."

Mr Warhurst said a full list of ticket prices, including the cost of single entry tickets, would be released on the Wet'n'Wild website this week.

On social media, many people responded it would be more affordable to head to the Gold Coast, with unlimited access to Movie World, Sea World and Wet'n'Wild Gold Coast priced at $100.

Others said they would be taking their families to Jamberoo Action Park, south of Wollongong, where a season pass costs just $90.