Hawkesbury City Council (HCC) has finally admitted the failure of their own drains was the cause of the catastrophic collapse of the river levee at Cornwallis. NSW taxpayers will now foot a multi-million dollar bill for repairs.

In its first full update on the remediation works at Cornwallis, HCC blamed old “1970s” pipes and flooding for the disaster, which began in March 2021.. The collapse of the river bank cost local turf and horse farmers tens of millions of dollars in property damage and lost business.

The environmental damage was so significant that a 2022 NSW Parliamentary flood inquiry described the collapsed river levee at Cornwallis as “major destruction.”

“That is not a pothole. That is a grand canyon in the middle of Sydney. This is Sydney. It is major destruction. Why are you not onto the State Government and saying, "This is beyond our capability?" Inquiry Chair Walt Secord said. 

"Flood waters" rushing into Cornwallis and Richmond Lowlands at the beginning of the June flood

“This is major erosion. It is changing the course of the river. When we were there, we were warned not to go too close to the edge because it may, in fact, snap off. Heaven forbid, as more rains come, there will be more erosion. Can you understand why those farmers are so worried? They have seen their land values drop. They have seen their properties wash away. Can you see why they are upset?” 

In a media release today - almost four years after the first cracks appeared in the Hawkesbury’s bank - HCC painted a different view of the damage. A far cry from the “canyon” Secord described after visiting the site in 2022, HCC today described the formation of a “small bay” when the “1970s drainage system” collapsed.

“The initial damage at Cornwallis was caused by the March 2021 flood in the Hawkesbury River, with the 1970s drainage system failing as a result of that event. Subsequent flooding in 2022 caused further erosion and the breaching of the riverbank, resulting in a small bay forming. A 180-metre section of Cornwallis Road was also lost,” the HCC media release said. It also failed to mention the millions of dollars of ratepayers' money - and council time - that was wasted when they ordered the wrong pipes for the job.

The Hawkesbury Post wrote to Hawkesbury Council on 9 and 14 January this year, inquiring about about the progress of the works at Cornwallis, requesting photos to show landholders of the progress. The Council did not respond to either email.

The broader damage at Cornwallis was caused after the council and Liberal state government failed to make a fairly straightforward repair to Cornwallis Road after it collapsed during the March 2021 flood.

Residents had warned the council that further damage to the road and environment by not repairing it before the next flood, would be extensive and the cost to local businesses substantial flood.

When the floods came again in March 2022, the road was not repaired. The damage to the road, riverbank, and farmland was catastrophic. Subsequent floods worsened the damage each time, with water filling up the lowlands before resuming its natural course down the river. Turf farmers at Pitt Town have noted that it takes hours longer for floodwaters to reach them since the collapse of the river levee.

Work to repair the damage has been slow, with various levels of government and multiple government departments grappling with how to repair the mess. Federal Member for Maquarie Susan Templeman said she welomed the work by the nSW Government and Hawkesbury Council to finally get the job underway.

“This has been a tortuous process for the landowners and the turf growers and farmers affected by not just the initial flood damage in 2020 but the subsequent worsening of the issue because of the delay in repairing it," Templeman said.

“It’s highlighted that councils alone may not have the capacity to manage major disaster reconstruction, particularly those projects running into the many millions of dollars. I think lessons have been learned at both a local and state government level.

“The landowners and growers affected have demonstrated tremendous patience in the face of repeated delays. Like them, I can’t wait to see the work concluded," she said.

The drainage system across the Lowlands and Cornwallis has been a longstanding issue. The damaged and unmaintained infrastructure continues to worsen flood damage in the area. Despite Hawkesbury City Council hiring consultancy firm Molino Stewart as far back as 2022 to assess and propose solutions. Yet the community is still waiting to see the final report on how to fix the system.

A draft Molino Stewart report obtained by the Hawkesbury Post through a GIPA (formerly known as Freedom of Information) suggest that resolving the drainage issue might take a long time or may not happen at all. The draft report dated 3 January 2024 indicates that much of the landscape has changed irreversibly.

"It is possible that some of the changes to the landscape cannot practically be reversed or mitigated, and so the impacts that have been sustained following the recent floods will continue after every flood," the draft report concluded.

The report attributes the drainage issues to two main factors: the failure of landowners or the Council to maintain flood mitigation and drainage infrastructure, and on-farm practices that have altered the topography or drainage pathways.

"Both of these sets of contributors include actions or inactions that have taken decades to incrementally create the current situation. This includes the gradual deterioration of infrastructure or the lowering or raising of paddocks, principally through turf farming," the draft report states.

HCC said that restoration of Cornwallis Road and drainage works will begin this month adding that Council had "collaborated with the NSW Reconstruction Authority, NSW Public Works, and the EPA to design a long-term drainage and road repair solution."

The project, funded by the Australian and NSW Labor Governments, is expected to take 30 weeks, with completion targeted for September 2025, "weather permitting." The cost was not advised by HCC but the Hawkesbury Post understands that it now runs into the tens of millions.

Below: Aerial view of Cornwallis courtesy of Hawkesbury City Council (date unknown). The new square box culverts can be seen on the left. They will replace the incorrect culverts previously purchased by Council.

The new box culverts can be seen on the left. They will replace the incorrect culverts previously purchased by HCC