Sydney's Big Wet Raises Dam Wall Issue

Sydney's recent downpour has again raised concerns about potential flood risks in Western Sydney and whether the raising of the wall at Warragamba Dam, is a viable option.

In late August, and following a week of ongoing, heavy rain, the Dam spilt, leading to claims from Stuart Khan, Associate Professor at the school of civil and environmental engineering at the University of NSW, that Western Sydney would be devastated by flood, if management options for the Dam weren't considered.

"I do get worried because I always look back at what happened in July 1998 … [when] about a thousand gigalitres flowed into that reservoir over about a couple of weeks," Associate Professor Khan told the Sydney Morning Herald.

"If the same inflow of water happened now … with the dams already full, western Sydney would be devastated. Penrith would be flooded, right down the Hawkesbury River."

Associate Professor Kahn had suggested that controlled releases of water from the Dam was one possible solution. 

The Hawkesbury-Nepean Valley Flood Management Review, which is still ongoing, also discussed the possibility of raising the dam wall by 15m or 23m, at a cost of about $1b. There are however  concerns this could lead to significant environmental damage.

The NSW Government has established a task force to lead Stage Two of the Hawkesbury-Nepean Valley Flood Management Review which builds on the findings of stage one and identiies opportunities to improve the ways in which future floods are managed.

The task force is working with key stakeholders as it undertakes its priority tasks, including local councils, the insurance industry, flood and water management and other government agencies. WSLD has been meeting with Infrastructure NSW to discuss flood mitigation strategies and recently hosted the agency’s CEO, Jim Betts, at a Patrons’ boardroom dinner with key regional stakeholders.