The 25 metre indoor pool at the Mandurah Aquatic and Recreation Centre has been closed down since late May after storm water damaged the ceiling.
The initial findings of an investigation indicate the damage is due to a break in a section of the roof structure, likely initiated by excessive loading from a storm.
According to a City of Mandurah spokesperson, the damage hasn't impacted the safety of any other roof structure in the centre.
Measures have been put in place to secure the damaged area. In the coming weeks a temporary wall will be erected between the two indoor pools in preparation for the repair work.
Related: MARC closes 25m pool
The findings of the investigation are now undergoing an independent peer review to ensure due diligence is carried out.
The comprehensive peer review is expected within the next three weeks, and should provide the City with information to make a decision on how to progress with the repairs and a timeline to achieve this.
"We acknowledge this investigation has taken sometime, and it is still ongoing," City of Mandurah chief executive Mark Newman said.
"This is due to the need for specialist technical analysis and extensive scientific testing of the roof materials. It's a complicated project which relies on the advice of a number of third-party engineering experts.
"We understand the current uncertainty regarding a timeframe for reopening is disappointing, however, until we receive all the information we need to make a decision, the timeline for repairs is unknown."
While this process continues, alternative programming has been put in place at the MARC to help the community stay connected, fit and healthy.
To find out more visit, the MARC website.