Farmers in 10 of Murray-Darling Basin's 23 communities would allow the flooding of their lands' easement covering more than 1 million hectares.

The Australian Floodplain Association (AFA), which links landholders and conservation groups, announced on Thursday the decision of the graziers that would permit the Murray-Darling Basin Authority (MDBA) to legally flood the land, if needed.

AFA President Mark Etheridge explained that the decision would help restore healthy rivers and communities without the MDBA worrying about a lawsuit.

The largest easement pledges come from farmers in the Paroo and Lachian river catchment areas. At least almost 400,000 hectares have been signed up with is about one third of the size of Sydney. The one million hectares target is expected to be reached in early 2012.

With this development, the MDBA could pump more water back into the system higher than the 2,750 billion litres under the draft plan under discussion. Environmentalists and graziers said at least 4,000 billion litres is needed to flush salt through the Murray mouth and restore floodplains and wetlands.