Changes suggested for a $1.4-billion-dollar project to redevelop Cleveland's Toondah Harbour do not go far enough to protect internationally recognised wetlands, the Australian Conservation Foundation says.

Documents obtained by the ABC made clear the department rejected the 2017 application from Walker Group Holdings, because it would cause “permanent and irreversible damage” to the wetlands.

ACF chief executive Kelly O'Shanassy says the development would destroy 40 hectares of the Moreton Bay site, which was one of Australia’s most important migratory shorebird feeding and breeding wetland habitats.