South Australian Premier Jay Weatherill has refused to rule out a high court appeal to block the Murray-Darling Basin Plan, which he describes as woefully inadequate, if substantial changes aren’t made.


Mr Weatherill’s announcement comes as South Australia prepares its submission for the Murray-Darling Basin Authority (MDBA) on the plan.


"On the face of it it doesn't look adequate, but we're prepared to participate in good faith in the process to see whether we can improve it," Mr Weatherill told the ABC.


Mr Weatherill complained over the traditional treatment of South Australia while demanding upstream states leave a greater portion of water for both South Australia and environmental flows.


Mr Weatherill has echoed the concerns voiced by the Wentworth Group of Concerned Scientists in accusing the plan of lacking in scientific substance. 


Federal Environment Minister Tony Burke is expected to make a final decision on the Plan by September.