Stormwater which currently flows out to sea will be captured and used to supply almost a third of Adelaide’s water under a $400 million initiative to reduce the reliance on the River Murray.

The State Liberals have today announced a major plan to harness almost 90 gigalitres of wasted stormwater which escapes into Gulf St Vincent each year.

Releasing Stormwater Harvesting - Securing Our Water Future in the countdown to the 2010 election, Opposition Leader Martin Hamilton-Smith said Adelaide’s water supply was under severe stress.

“Currently, we pump 80GL of water from the River Murray each year yet we let 160GL of stormwater flow out into Gulf St Vincent,” Mr Hamilton-Smith said. “This waste must end. We can no long afford to let precious water from our roofs, creeks and drains run out to sea.

“The State Liberals will harness up to half of Adelaide’s wasted stormwater in a $400 million plan to provide a new source of water for Adelaide, reducing our reliance on the River Murray. Under Premier Rann we’ve had six years of inaction and rhetoric over securing our State’s water supplies.”

Metropolitan reservoirs have about five months supply of water remaining, according to SA Water figures last week.

Under the Liberal’s plan, creeks and stormwater run-off will be fed into 13 metropolitan wetlands established from Gawler River in the north to Willunga Basin in the south. They will store about 89 gigalitres of stormwater – almost a third of Adelaide’s 220 gigalitre annual water usage – where it will be cleaned and pumped into the aquifer for future use.

The plan is modelled on the successful projects being undertaken by Salisbury Council, which intends to harness 20 gigalitres of stormwater using this process.

Shadow Water Security Minister Mitch Williams said: “Stormwater reuse is a simple, low cost solution to our water crisis”. “Rains from the weekend should be used to bolster our water supplies but will instead end up in the Gulf,” Mr Williams said.

Work on the stormwater re-use scheme will begin in the first term of a Liberal government.