Are we over-investing in desalination?

THE AUSTRALIAN Productivity Commission has published a draft report titled Australia’s Urban Water Sector, finding reforms can be made to current approaches to water management.

According to the draft report, government response to severe low water availability has been to implement prolonged and severe water restrictions, and invest a lot in desalination.

This, according to the report, was an over-investment, since less focus on desalination and using non-desalination sources could have equally assured supply of water.

As a result, money has been lost, with water restrictions effectively slashing consumption, but also the value associated with consumption.

Desalination kerfuffle

The report estimates the decision to invest in desalination as opposed to lower-cost alternatives will cost Melbourne and Perth consumers and community $3.1 to $4.2 billion over 20 years, depending on modelling assumptions.

Source: Flickr/Lance Cheung

It pointed to the possible risk that desalination plants may be built but not used, citing the example of Santa Barbara, California, which built a desalination plant during a 1991 drought. The drought ended before the plant was on-line, and the plant was mothballed after construction.

Writing for The Conversation, Paul Willis, who is a research fellow at the Monash Sustainability Institute at Monash University, was critical of the report, which he contends prioritised economic factors over sustainability or conservation.

According to Willis, water restrictions and other conservation measures were “programs that effectively stopped Melbourne from running out of water during the recent drought.”

He also pointed out that conservation of water used in showers is on par if not more important than trying to limit desalination from a sustainability point of view, since “the energy used to heat water in the average domestic hot water unit is about ten times the energy used to desalinate the same volume of water.”

The alternative approaches

An alternative suggested by the report, which it points out has been ruled out by governments due to uninformed opposition by communities, is indirect potable use of recycled water.

Source: Flickr/tanakawho

The National Water Commission has stated there are no public health barriers to the indirect potable use of recycled water, and the approach is used overseas.

The reported suggested community and decision makers need to be much better informed about the costs, benefits and risks of the various approaches to water consumers, in order to ensure the best choices are made.

Other alternatives include urban-rural trade and aquifers, which were overlooked in favour of large investments in desalination.

Willis agreed on this point, writing that “the Commission’s critique of one-size-fits-all approaches to water management opens the way for a greater diversity of water supply, disposal and re-use systems.”

However, he contended that the Productivity Commission needs to think beyond water delivery and look at the other benefits of water conservation measures, water sensitive urban design and local water solutions, such as energy savings and waterway protection.