Why we need to invest in water security, even when the dams are full

Before the Millennium Drought, full dams had a confident Victorian government state that no new supply augmentation would be required. Yet, within the year of that assertion, a new desalination plant was announced to secure water supply for Greater Melbourne as storage levels dropped 52 per cent between June 2006 and June 2007. This change of position was not due to poor planning or inaccurate information – simply that conditions changed more rapidly than the historical averages and cascades of unprecedented events were underway. As a result of climate change, history has become a poor predictor of the future, which tells us that equating full dams to supply security is a fallacy.

The good news is that unprecedented doesn't have to mean unprepared.

The solution is to support our water sector in taking a longer-term view and exploring new water supply options before we need them. The solutions that can make the biggest impact on water security – such as desalination plants – have the longest lead times for implementation. A report by Infrastructure Partnerships Australia points out the relationship between drought events and water infrastructure investment, clearly showing that we tend to invest in supply security only when we face critical supply issues.

The report goes on to comment that, “While many of these assets have proven to be invaluable during subsequent periods of drought, the best time for sensible, long-term planning is when the dams are full.”

Why? Because large projects are not quick fixes, taking seven years or more to implement due to the necessary approval pathways and the need for specialist skills and equipment. By making investment decisions now, before the next drought strikes, we can avoid the much higher costs of knee-jerk reactions and rushed implementation schedules.

Discussions of new water infrastructure will kick off a familiar debate about whether this government spending is really needed, especially after so much rain and when cost of living pressures are high. Communities are feeling the crunch of interest rates and governments are constrained by post-COVID debts. Water prices are one of the aspects of household affordability that governments influence directly, so they are also encouraging low increases by deferring investment and sweating existing assets. As tempting as deferrals are, failure to invest in water security now would simply create a much larger cost burden for our children (or maybe even us), who will have to undertake a bigger program of works during the next drought.

Luckily, the water sector never stops thinking about how to keep supplies secure and how to keep it flowing for our health, environment, and the economy. Utilities, government agencies and the private sector have been seeking to better plan water needs into the future, factoring in continued population growth and climate variability. Melbourne and Sydney, for example, have public information relating to supply security out to 2035 or 2050, depending on various scenarios. Sydney Water alone has identified $34 billion of new investment over the next 10 years.

Some of these investments include scaling up the use of water sources that do not depend on rainfall, in order to improve our resilience to climate-related water shortages. New water sources, like purified recycled water, are in that mix. Research conducted by the Water Services Association of Australia found that producing purified recycled water is generally cheaper than desalination and needs to be considered as part of a portfolio of water supply options.

Unfortunately, the political appetite for drinking recycled water continues to be low despite these advantages. A GHD survey of 241 water professionals found that over two thirds of respondents identified budget pressures or political will as the biggest barriers to increasing water supply options that do not depend on rain.

This type of supply augmentation is becoming much more widely accepted in many other countries including the UK, USA and Singapore. Over 35 cities around the world including Singapore, Los Angeles and Cape Town have adopted purified recycled water as part of their drinking water supply but in Australia it is still only exploratory for direct use in taps.

There are many options on how to improve our supply security for the future, but the one thing they all have in common is that they require long-term planning and appropriate investment. So even though budgets are tight, and dams are full, the best time to think about water security is today. Utilities need community support to let governments know that they back the investments needed to secure a safe and resilient future. Water is our most crucial resource and acting now is the most prudent way to secure it.