Billionaire Andrew Forrest’s plan to build a series of agricultural weirs on Western Australia’s Ashburton River faces growing opposition from Indigenous groups, including those of importance to Mr Forrest’s iron ore mining company, Fortescue Metals Group.

Mr Forrest’s private company, Tattarang, challenged the WA government in a tribunal last week over its decision to deny approval for the weirs under Section 18 of the state’s Aboriginal Heritage Act.