"We will be looking to delay any such decision for as long as possible," South Australian premier Mike Rann said in a statement released today.

It came after federal Environment Minister Peter Garrett announced a proposal to flood Lake Alexandrina with sea water from the Coorong would be subject to an Environmental Impact Statement (EIS).

Despite the initial proposal coming from the State Government, Mr Rann said "the last thing the Government wants to do is flood the lower lakes with sea water".

"The Government will leave no stone unturned in investigating all other possible options, such as bioremediation of affected areas and the use of lime, to protect the lakes from acidification," he said.

"Even under the very worst case scenario a small amount of sea water would not need to be introduced before some time in 2010, based on current modelling and advice."

Other long-term options for protecting South Australia's Lower Lakes system from acidification would also be considered, Mr Garrett told reporters in Sydney this morning.

"Today's decision means that South Australia's proposal will be subject to a high standard environmental impact statement," he said.

Mr Rann said the State Government would delay any decision to allow for maximum potential for good winter and spring rains and that if there was not enough freshwater inflows to maintain the Lower Lakes, "as a last resort, a minimum quantity of salt water would need to be introduced to manage the risk".