Allianz Stadium could go offline for drainage works

Allianz Stadium officials have told Sydney FC to prepare for the prospect of the $828 million venue being unavailable for part of the summer if a report calls for a significant fix to drainage issues.

Less than three years after the opening of Australia's most expensive rectangular stadium build, an investigation is continuing into repeated problems with the field.

Venues NSW, who operate the ground, expect to have the outcome of that report by the end of this month.

Multiple scenarios are being worked through for the potential fix of the issue, as officials attempt to identify at which layer of the turf build the problem exists.

The most extreme scenario would be if the issue was found to exist in the stadium's underground drainage.

It could take at least six week to rebuild the profile of the drain and turf.

"The comprehensive review into the playing surface and drainage system at Allianz Stadium is expected to be finalised later this month," a Venues NSW spokesperson told AAP"As we are awaiting the results of the investigation, no decision has been made on what remediation works are required."

AAP understands that Sydney FC would most likely play matches at Leichhardt Oval if Allianz was to become unavailable.

That would create significant commercial hurdles.

The Sky Blues are already unable to use Allianz when it is required for major concerts, with two scheduled for mid-December.

The situation comes as the playing surface at the adjacent SCG, also managed by Venues NSW, was slammed after last week's AFL match between Sydney and the Western Bulldogs.

Allianz Stadium only re-opened in September 2022, but eyebrows were raised last May when large puddles were on the surface for a Waratahs-Brumbies rugby match.

Clint Gutherson then described the water-logged field as one of the worst he had ever played on after an NRL fixture in August, prompting a review.

After initially being relaid during the 2023-24 summer, new turf was again put down last summer before more drainage issues in the opening round of the NRL.

Further work was completed to stitch artificial grass into the turf to aid with drainage, before water pooling returned amid heavy rain at women's State of Origin in May.

It's understood previous testing on the turf had shown the presence of silt, a granular material often found in rivers which can reduce water flow and impacts drainage.

The turf farm used to supply the surface for Allianz Stadium and most Venues NSW grounds is based close to the Hawkesbury River.

That river flooded multiple times in the months before the 2022 install.

Turf from the same suppliers and farm has been used to re-lay other stadiums since then, without the same drainage issues.

The review comes as Independent MP Mark Latham has raised a litany of questions regarding the Allianz Stadium, Venues NSW and the surface in NSW Parliament over the past month.

Included in those were questions around player safety, insurances, repair work, turf suppliers for the new Penrith Stadium and why the drainage has continued to be an issue for so long.