Why Mackay Bluewater Lagoon is at risk of creating a sinkhole

Mackay council will carry out emergency repairs to reopen the Bluewater Lagoon by the next school holidays but it will then have to shut again to prevent a sinkhole.

The Bluewater Lagoon will need major relining repairs next year or else risk a sinkhole could form underneath.

It comes after the facility was shut on August 31 after significant water leaks were discovered towards the end of the 2021 winter shutdown.

Mackay Mayor Greg Williamson said the council had a two-step approach to fixing the lagoon starting with about $65,000 of temporary patches to reopen the popular swimming hole hopefully towards the end of November.

“We’ve known there have been leaks for some time,” Cr Williamson said.

“When the pool was drained, we discovered that the leaks and the cracking was more extensive than we thought.”

Cr Williamson said further investigation prompted the council to extend the shutdown with product availability issues now influencing the reopening date.

He said once it opened in time for the school holidays, the lagoon would then need to close down sooner than usual for its annual maintenance period so contractors could complete a more permanent fix to prevent the formation of sinkholes.

Repairs included resealing all the pool lining as well as replacing the plant room roofing and upgrading pipework.

“There will be an extended period for shut down next year” Cr Williamson said, adding there was no ballpark figure on how much “extensive” repairs would cost with tenders to return in the coming months.

“If we continue to lose water through leaks, what that develops under a body of concrete like that, sitting on a riverbank, could be a sinkhole.

“That’s almost what happened to the Tobruk Pool in Townsville.

“They were in danger of that whole pool sliding into the ocean.

“I’m extrapolating to the nth degree here, but that could have been an outcome.”

Cr Williamson said they would rather fix Mackay’s issues now than have the problem worsen four or five years later.

“The pool’s over 10 years old so you’ve got to expect some replacement,” he said, adding the council would dip into maintenance funds put aside in the budget every year.

Mackay Regional Council Mayor Greg Williamson at the opening of the new interactive play area at the Bluewater Lagoon in October, 2020. Picture: Zizi Averill

The prospective reopening date will be a welcome relief for Mackay’s tourism sector with council data showing between 30,000 and 50,000 people visit the Lagoon each month over the October to January period.

This was compared to between 7000 and 8500 swimmers frequenting the Mackay Aquatic Recreation Centre over the same period.

Cr Williamson said the council would continue to offer free entry to the Mackay ARC on weekends until the lagoon reopened.