Water efficiency in Australia at the crossroads

Widespread flooding across Australia has the potential to push back hard fought water-efficiency gains made over the past decade. It’s concerning to think that the devastating floods may have shifted the water management mindset in Australia and effectively masked what still is a critical water challenge for communities across the entire nation.

The danger is that the floods have taken people’s attention (including decision makers in communities) off the critical water supply issues we still face and will increasingly face in the future. Australia’s water management challenges are alive and well.

Supply solutions such as desalination plants are just one part of the puzzle. Just as important is what lies beneath the surface. Leakage from pipes due to high water pressures and ageing assets continue to impact heavily both in terms of economic and environmental cost. When above ground is flooded it can be easy to dismiss the enormous amounts of water lost underground.

The challenges can stem from a range of issues including pipeline pressure, water leakage management, measurement discrepancies and metering inefficiency. If these are addressed adequately, we can go a long way towards waterproofing our cities and regional areas - saving money and helping to protect the environment. If left unchecked, we may never know the full extent of our water crisis until it’s too late.

Water demand management is the adoption and implementation of a strategy by a water authority or consumer to influence water demand and usage. Water demand management can include public education, water rationing and restrictions, plumbing codes and bylaws, metering, tariff structures, pressure reduction, leak detection and repair, and industrial and commercial re-use/recycling.

While water rationing and restrictions are reactive measures and indicative of a breakdown in water management, the other measures previously mentioned can be implemented as part of proactive water-efficiency strategies.

Water data forms an integral part of the data set required to plan, design, implement, operate and maintain water supply and distribution systems.

To efficiently and effectively manage water supply and distribution systems requires the measurement of the water volumes supplied into, within and out of a water network. Comparing the volume of water entering a specific area through a large meter, with the volume registered by customer meters, is an initial important step in the management of water demand, losses and wastage. However, measurement accuracy remains difficult.

There can be both real loss (such as leakage) and apparent water loss (due to flow measurement errors) within a water supply and distribution system.

In well-managed systems, the majority of real losses are caused by background leaks, long-running reported leaks and reported leaks where repair has been delayed for a particular reason.

Australian authorities implemented numerous water-efficiency projects in response to the prolonged drought between 1996 and 2007. These projects provide an opportunity to assess efficiency measures. This requires taking into account the various types of meter measurement errors and their interactions in the determination of water imbalances.

However, without adequately investigating how to account for and report the ‘apparent’ losses, they can be incorrectly interpreted as real losses, which can have significant implications now and into the future in terms of water management design and implementation.

Any responsible water management strategy needs to work from the ground up by first establishing a true and accurate picture of the current water efficiency and losses. Unless this is achieved, there is a real risk that the resulting programs and capital works aren’t addressing a key source of the water woes. Errors in or omissions from the water data adversely affect the communication, comprehension and decision-making processes.

Ultimately, these data errors will affect decisions regarding the adequacy or inadequacy of the investments in the associated capital works required to reduce water losses. The real danger is that during a period of flooding, these important details can become lost in the wash.

*South Australian-based engineer Edgar Johnson is the Leader for Water Efficiency at GHD, an engineering, architecture and environmental consulting company.