To drought-proof city’s water supply, Sydney proposes a second set of pipes

Brett Walton in Circle of Blue:  The City of Sydney, one of 38 political subdivisions in Australia’s largest metropolitan region of the same name, is in the final stage of preparing an ambitious master plan that seeks to refashion its water infrastructure to meet the constraints of a water-scarce future.

One of the oldest sections of Australia’s 224-year-old hub, the City – which includes the central business district and is home to 185,000 of the 4.6 million people in greater Sydney – envisions a second water-distribution network that would provide water for purposes other than drinking. This parallel system would tap into new sources like salty water, purified by waste heat from power plants, as well as existing sources, such as recycled wastewater and rainwater, which are typically flushed out to sea.

“For a major urban centre to have two networks — one delivering potable water and another delivering non-potable water — it would be ground breaking in Australia,” Monique Retamal wrote in an email to Circle of Blue. Retamal, a researcher at the Sydney-based Institute for Sustainable Futures, helped to develop the City’s water plan. “As far as I am aware, there are no other similar plans elsewhere in the world.”

The city council not only wants to adapt its obsolete infrastructure to a changing climate, said Bhakti Devi, the city’s manager for water strategy. Because cities worldwide will soon be confronting the same problems, the City also wants to be a pioneer for urban water solutions globally....

Sydney and Sydney Harbour Bridge taken from North Shore, 19 March 1932. Shot by E.W. Searle