The reheating of Baywave's pools is expected to begin in less than a week.
The bore system at the Mount Maunganui pools was shut down after it was unable to maintain consistent water temperatures for all pools.
Bay Venues project manager Justine Brennan said investigation into the bore issue had now been completed and work to implement the remediation plan will begin today.
The plan will involve re-casing the reinjection bore and partially re-casing the production bore.
Problems with the bore system, which provides heating to the pools at Baywave, were identified on May 13.
Brennan said the decision to immediately shut down the bore system was made to avoid damage to the plant and water temperatures had been slowing dropping since then.
"Re-casing the bores will involve inserting a new pipe of a smaller diameter inside the existing casing and then concreting this pipe into place," she said.
"This is expected to take three days, and the concrete will then need a four-day curing period."
Bay Venues hoped to switch the bore back on and start the heating process via a heat exchanger on May 29.
"The pools will then take at least 48 hours to reheat to normal temperatures," Brennan said.
The lap pool and wave pool will remain open for use and Brennan said swimmers were encouraged to bring their wetsuits to combat the cooler temperatures.
Brennan said the lap pool temperature was currently 23 degrees and was not expected to drop much further.
"The rate of temperature decrease in the lap pool has slowed significantly indicating that it may be levelling off as it approaches the ambient air temperature, although this will be dependent on the weather over the coming days," she said.