SA's Government yesterday received a draft environmental impact statement into building a temporary weir at Wellington, above Lake Alexandrina.

The report described the state's water security as at extreme risk, saying without a freshwater solution, the Government will have no choice but to build the weir.

Greens Senator Sarah Hanson-Young says a Wellington weir won't save the parched Lower Lakes region.

"This and other proposed weirs will do nothing to save the Lower Lakes, but instead will set down the path for the SA Government to flood the lakes with salt water," she said in a statement on Friday.

"This weir would be environmentally devastating for the lower Murray.

"Damming the river and flooding the lakes with salt water does not amount to protecting them."

The Environment and Heritage draft report is open for public comment until April 8, after which the report will be forwarded to the Federal Government to decide whether to approve the state building the weir.

Senator Hanson-Young said an integrated strategy is needed to rescue the lower Murray and Coorong and called on federal Environment Minister Peter Garrett to reject the weir proposal.