LAW governing water management in the Murray-Darling Basin is constitutionally flawed, irrigators have told a Senate inquiry.

The upper house inquiry into the Water Act today heard from National Irrigators' Council chief Danny O'Brien, who said its economic and social impacts were not given proper consideration.

"(They are) mentioned, but in our view the Act gives primacy to the environment," he told the committee in Canberra.

Mr O'Brien welcomed Water Minister Tony Burke's assurances that he could deliver a balanced plan for the basin and vowed to work with the federal government to achieve that outcome.

But he said the constitutional basis of the Act was problematic.

"There may need to be amendment or at least change (to laws) because the worst outcome . . . would be a balanced plan getting up and going through the parliament, then being torpedoed in the High Court."

Mr O'Brien said activities such as fish and land management needed to be part of the plan to ensure the river system's health.