Australian dams must be fit for drought and flood

The impact of the east coast floods demands careful consideration of whether our dam infrastructure and its operation are appropriate for the anticipated stresses of climate change, according to professional services company GHD.

Steve Fox, Australian Dams Leader at GHD, suggests a rethink may be needed for Australia’s dams to serve the community better and meet the challenge of more severe droughts and floods.

GHD’s recent Aquanomics report details these economic impacts while predicting floods are expected to cost the Australian economy AUD64 billion between 2022 and 2050.

Steve said, “Australians are often surprised to learn that since most of our dams are primarily intended for water storage, they currently can’t play an effective role in mitigating floods.

“The reality is most of Australia’s dams were built over 50 years ago and they are still operating to rules set at that time. For example, they typically cannot lower dam levels before forecast rain events, in case there’s another drought around the corner.

“It may be the time to change our thinking in response to calls to use our existing infrastructure to stem or divert water from flood-vulnerable areas where they have available capacity to do so.

“Two things should challenge our thinking. First, climate change; every degree of global warming translates to around seven percent more water in the atmosphere, so our dams need to be prepared for more rain.

“What we’re seeing now is what a 1°C rise in temperatures brings, but realistically we’re likely to go to between 1.5° and 3.0°C, despite current efforts to limit the rise.

“Second, we now have much better climate forecasting. We know whether we’re going into a La Nina or El Nino weather pattern, so why wouldn’t we adjust our dam operating rules to suit?”

But Steve acknowledges this won’t be easy to do.

“Adding meaningful flood mitigation to existing dams is expensive and it takes time. It requires studies in river system management, setting specific planning and operating rules, understanding environmental trade-offs and ensuring communities are genuinely part of that planning. Nevertheless, given what’s at the stake, the sooner we start contemplating and exploring these challenges the better.”

About GHD

GHD is a leading professional services company operating in the global markets of water, energy and resources, environment, property and buildings, and transportation. Committed to a vision to make water, energy, and communities sustainable for generations to come, GHD delivers advisory, digital, engineering, architecture, environmental and construction solutions to public and private sector clients. Established in 1928 and privately owned by its people, GHD’s network of 11,000+ professionals are connected across 160 offices located on five continents.