Roadworks on the M1 may have caused additional flooding in dozens of Gold Coast homes last year, according to a new hydrology report.
The independent report found a number of homes may have been flooded because of upgrades that were being done to the M1 Pacific Motorway near Tallebudgera Creek.
Transport Minister Mark Bailey said his department commissioned the report after concerns were raised from residents that bridge works on the creek contributed to their homes being flooded during the rain events in February and March of 2022.
"The modelling has shown that potentially 25 properties may have had additional flooding above the floorboards where ordinarily, they may not have had it below the floorboards," he said.
Mr Bailey said flood-affected residents would be informed of the report's findings.
They will also be eligible to apply for relief from the Resilient Homes Fund, a $741-million program funded by the state and federal governments.
"I take out my responsibility, the Minister for Transport [and] Main Roads, very seriously in terms of making sure we are looking after people who need to be assisted," he said.
The flood modelling used for the analysis showed the M1 construction works caused flood level increases in Tallebudgera of up to 90 millimetres in Larch Street, Daffodil Street and Elm Court in, and increases greater than 125mm occurred in Heather Street and Kentia Court.
Flooding forced family out for a year
Jane Maujean's house on Daffodil Street was one of the properties impacted by the flooding.
"We got completely flooded, completely inundated … water out on the street to waist level," Ms Maujean said.
"So it went through pretty much every property in this area, and then we just had to clean it all up, and get out of here."
She said her family moved back onto their property today to start rebuilding — after living in temporary accommodation for a year — only to find a letter from the Department of Transport and Mains Roads informing them of the report's findings.
"The analysis also indicated flooding impacts may have been slightly increased with the Tallebudgera Creek catchment due to the temporary works that were in place in the creek in February 2022. As a result, the analysis suggested your property's habitable floor may have been impacted," the letter said.
Ms Maujean said she had heard rumours about its impacts but had "so much to sort out in our lives."
"So interesting to come back a year later, and there's a letter in our letterbox saying there could be some contribution to the flooding in this area," she said.
Government assistance welcome
Another Tallebudgera resident, Amanda Allen, also received same the letter.
Ms Allen said her family's home flooded after completing a $600,000 renovation on their property.
She said it was unexpected as her property didn't flood when Cyclone Debbie hit the region in 2017.
"They had to rip out like $100,000 worth of brand new cabinetry. They had to rip up our brand new bathrooms because they couldn't guarantee the waterproofing — it was literally all brand new," she said.
She welcomed the assistance from the state government, after suffering huge financial losses.
"They want to give me some money, bring it on," she said.
The report outlined the rainfall totals and flood levels in the Tallebudgera Creek catchment in February and March, and found that the flood event in February was a one-in-50 year event, which was not accounted for in the original flood risk assessment submitted for the road upgrades.
The report states that while the flood risk assessment initially submitted for the bridge works was "sound and acceptable", it recommended the risk assessment should be "revisited" in case of similar rain events occurring in the future.
The report was prepared by SLR Consulting Australia in October last year.
