What the floods have taught us about infrastructure

There is no such thing as a one-size-fits-all solution to the floods experienced yet again in Australia. But a common approach can help mitigate risk and prepare for the future of water infrastructure.

The feedback from water managers around recent flood events has been characterised by shock and awe. It has been about how stormwater infrastructure can cope with the levels of water that submerged parts of Byron Bay and Lismore, Brisbane, and Sydney in recent times. There is no single solution for issues resulting from extreme weather events like those experienced recently. Not only are councils trying to control unprecedented volumes of water, but solutions also depend heavily on local conditions and challenges.

“It’s a mistake to walk into a council area and assume they all have the same problems and they all should be taking the same approach,” said John Weaver, Contracts Manager at pipeline infrastructure company, Interflow. “It depends on the age of the area, on population growth, ground type and much more.”

“Newcastle, for example, is an old city with stormwater problems amplified by earthquakes. That’s very different to a newer area like Camden. A town like Dubbo has problems underneath the highways because of subsidence. In other towns, stormwater problems are caused by a build-up of silt in the pipes. Do we assume there is no solution? Absolutely not.”

The secret to success can be shared between water managers everywhere. It means using recent events to create greater awareness of Australia’s stormwater infrastructure and the condition of underground assets. Furthermore, it involves utilising modelling to plan future developments of water infrastructure and residential and commercial buildings.

Stormwater management in the future

“Look to New Zealand for an excellent example of preparation for the effects of climate change on water infrastructure,” Weaver said. “Asset owners and town planners are focussing management strategies on flood events increasing and rising sea levels.

“They’re doing a lot of modelling. They want to ensure that if there are future land developments or growth corridors, they fit into what’s predicted to happen with water.

“In Australia, our focus has been on water security, on getting ready for the next drought. It’s correct to focus on water security. But at the same time, increasingly regular and extreme rainfall events also deserve attention. Directions filter down from the Commonwealth to the states and asset owners around water security. These are typically mandated. They provide an excellent model for us to manage increasingly challenging stormwater issues successfully.”

Practical solutions for current infrastructure

Outside of emptying dams and preparing communities, there is little that can be done in the way of an emergency response to such flood events. According to Weaver, the focus should instead be on developing greater awareness of the current state of existing infrastructure. Water managers can also put management plans that extend their useful life and improve their performance.

“There are two sides to innovative and successful asset management,” Weaver said. “One is around building new assets. The other is around what to do with existing assets. For example, a major authority we work with is about to embark on a huge renewal program. We’re working with them and a few other contractors to develop options to renew their assets without increasing the chances of flooding.

“That works very well – taking an asset owner’s good ideas and running them through a review program that includes advice from highly experienced contractors. This ensures that the solutions are as good as they can be. Knowing their infrastructure’s real-time, current condition is the most powerful insight for a water manager.”

Gradually, all stormwater assets are deteriorating. If a water manager constantly monitors those assets, they will know when they require maintenance. They will enjoy certainty around the order projects should be carried out. It allows them to engage with specialist contractors to plan and design solutions that extend the assets’ lives while improving their performance.

Understanding assets

Such insight means asset owners will know when a swift response is required to ensure public safety. An example has been experienced in work contracted to Interflow by Ipswich City Council. Interflow is restoring a failing section of the pipeline running beneath a popular and busy outdoor recreational space.

It also means custom solutions can be designed and developed well before they become catastrophic. In this situation, they are undergoing a bespoke renewal of the stormwater drainage culvert running beneath the bustling Brisbane Corso. Interflow’s unique structural relining of the culvert, which was exposed to the Brisbane River’s rising tides, meant costly cofferdam construction could be avoided while all structural requirements were met.

More was delivered for less when a 50-year extension of life for a vital culvert running beneath a busy street within the Sunshine Coast Council was achieved. Without any traffic, telecommunications, electrical or water disruptions, the unique solution involving the installation of a glass-reinforced liner eliminated the need for excavation, enabling a 25 per cent cost reduction.

Planning for an ageing infrastructure

Before the major flood events of the last few years, many Australian councils were already facing the realities of water infrastructure assets built before 1970, beginning to reach the end of their life cycle.

An Infrastructure Australia report identified ageing infrastructure as a critical issue across Australia. External pressures included a growing population, a rise in single-person occupied dwellings and increasingly frequent extreme weather events.

Water managers face an infrastructure cliff while simultaneously experiencing a rise in community expectations driven by flood and associated weather events. According to Weaver, a proactive approach must begin with definitive insight into the condition of all parts of the infrastructure, informed by advice and input from those who’ve been there before.

For more information, visit www.interflow.com.au