Angry farmers say they will fight plans to charge landowners in the Adelaide Hills for using water out of their own dams.

Water authorities will release an updated draft of the scheme today, that will require over 2,100 existing users in the western Mt Lofty Ranges to obtain water licences for dams and bores.

They'd be metered under the plan but water for stock or domestic use wouldn't be.

Peter White from the Farmers Federation says he fears the move will open the floodgates to more costly regulation.

Photo: Getty/Getty Images News/Mark Dadswell/Staff