Major restoration of Cornwallis Road complete

Work to restore Cornwallis’ flood-damaged drainage network and rebuild a missing section of Cornwallis Road in New South Wales is now complete.

The restoration of the drainage network and levee, led by Hawkesbury City Council in partnership with NSW Public Works, delivers robust and resilient protection for landowners along the low-lying and flood-prone section of the Hawkesbury River.

The initial damage in Cornwallis was caused by the March 2021 flood in the Hawkesbury River, which caused the previous drainage system from the 1970s to fail.

Attempts to repair the system following this event were unsuccessful as subsequent flooding in 2022 caused further erosion and breaching of the riverbank, resulting in the formation of a small bay.

A 180-metre section of Cornwallis Road was also lost, necessitating a full redesign and significant expansion of repair plans.

The NSW Reconstruction Authority, Transport for NSW, NSW Public Works and the Environment Protection Authority have all worked alongside the Hawkesbury City Council and local landholders to design a resilient and effective drain repair and road restoration.

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“For far too long, residents have been forced to take lengthy detours, sometimes adding half an hour or more to their daily journeys,” said NSW Minister for Roads and Regional Transport, Jenny Aitchison.

“Completing this project restores a safer, faster and more reliable connection for Hawkesbury communities.”

These efforts were also impacted by minor floodwaters on five occasions, including the May 2025 flooding event.

Rebuilding the damaged network required:

232 precast 2.4 metres x 2.4m concrete stormwater box culverts
2,880 tonnes of concrete
25 kilometres of steel reinforcing bar
15,000 tonnes of sandstone foundation boulders and
28,000m3 of backfill
Two tonne steel floodgates.
250m of Cornwallis Road was also reconstructed to return the road to its original state.

“This project is a testament to what collaboration across government can achieve when we put comminuties at the heart of our work,” said NSW Minister for Recovery, Janelle Saffin.

“Even with minor flooding occurring during construction, the teams pushed through to deliver a solution the community can rely on – one that will better protect them and offer peace of mind for years to come.”

The $11 million project was jointly funded by the Federal and NSW governments through the Disaster Recovery Funding Arrangements (DRFA).