Unsustainable urban development and the continuing loss of biodiversity are officially acknowledged as two of Australia’s most pressing environmental challenges. Under existing Australian statutory and land use decision-making frameworks, a problem exists in the protection of biodiversity, even though it is legislatively prescribed as being a fundamental consideration. This paper suggests that Australia’s existing environmental laws and regulations are inadequate to protect biodiversity when it comes in direct competition with determined urban expansion. The research crucible of Gosford on the NSW Central Coast is used, as it is and has long been one of the major growth corridors of Australia’s most populace city, Sydney, and yet it holds important biodiversity and natural systems. By critically examining Australia’s legal, economic and social heritage paradigms, this paper demonstrates that change is needed in planning, assessment and review systems if Australia is to meet the modern demands of Ecologically Sustainable Development in the urban context.