By Adam Coleman

A study has found rainwater tanks present an affordable solution to the water shortage problems of Melbourne, Sydney and South-East Queensland and could potentially delay the need for desalination plants.

The report was compiled by economists Marsden Jacobs Associates for the Australian Conservation Foundation, Environment Victoria and the Nature Conservation Council of NSw. It  found the widespread installation of rainwater tanks in Australian capital cities would mean big savings in water, energy and money. 

The report found that if governments deployed rainwater tanks to five per cent of households each year in Sydney and South-East Queensland (SEQ), dams and desalination plants planned for 2010 could be delayed past 2026 in Sydney and 2019 in SEQ.

The report found rainwater tanks are cost competitive with dams and desalination plants as well as being up to five times more energy efficient than desalination plants and twice as energy efficient as the proposed Queensland’s Traveston dam, per megalitre of water produced.

Most Australian houses are suitable for a rainwater tank, according to the report.

In Sydney 65 per cent (or 1.1 million houses), in SEQ 73 per cent (or 900 000 houses) and in Melbourne 72 per cent of existing houses have potential for a rainwater tank.

“While 38 per cent of households in Adelaide have rainwater tanks, fewer than 6 per cent of the houses in Melbourne, Sydney, South-East Queensland and Perth do,” saysACF urban water campaigner Kate Noble.
“Rainwater tanks collect and store water far more efficiently than dams, especially in times of drought. As the climate changes we should be installing tanks to take advantage of the rain that does fall on our rooftops,” she said.

Making it mandatory?

The Local Government and Shires Associations of NSW is calling on the NSW State Government to consider enabling councils to introduce mandatory rainwater tank policies for new dwellings.

"Local Government encourages the installation of rainwater tanks, and several councils, including North Sydney, have expressed interest in mandatory installation of these tanks in their local area for new dwellings," says president of the Local Government Association of NSW, Genia McCaffery.

She says councils are also encouraging the installation of rainwater tanks through other initiatives.

“Parramatta Council, for example, will roll out a program later this year offering tanks to residents at a subsidised rate, with interest-free loans. Some councils would like to go beyond the water reduction targets that apply to their local area, which for most new residential development is currently 40 per cent.”