IN THE DRIEST STATE IN THE DRIEST CONTINENT, South Australia’s European settlers have always faced the challenge of water supply.
The first settlers in Adelaide had to sink wells or have water carted to their houses. They did enjoy a leap in water services with the first piped water supply from the early 1860s.
By 1881, a deep drainage network enabled Adelaide to lead Australia in using a water-based sewerage system.
But, although it has constructed a barrage of reservoirs, South Australia in the 21st Century still depends for most of its water supply on the weather and its effect on the Murray Darling river basin.
Adelaide’s reliance on the Murray and Darling rivers makes the city the biggest single user of water from the million square kilometres of the rivers’ basin.
This can put South Australia as odds with the other states – Queensland, New South Wales, Victoria plus the Australian Capital Territory – who keenly guard their water share, especially for irrigators who produce 40% of Australia’s food.
South Australia’s interest in Murray water extends beyond a supply for Adelaide and other centres but also the environmental flows to its end-of-river lakes, river mouth and the Coorong.
The 2012 Murray-Darling Basin Plan was adopted by the federal government, with the states’ agreement, to ensure the basin’s health and to share water between users along the river. Disputes linger over this agreement.
Adelaide ultimate water-security fallback is the $.8 billion desalination plant built at Port Stanvac, operating, but not in full use, since 2011. The capacity of the plant is 100 gigalitres per year – about half of Adelaide's annual water needs. Part of a federal $228 million contribution to the desalination plant was that SA Water would reduce water pumped from River Murray.