Paroo-Darling National Park contains the wetlands of the Paroo River overflow, including semi-permanent freshwater lakes, which are listed as Ramsar Wetlands under the Convention on Wetlands of International Importance. These wetlands support an abundant and diverse waterbird community.
They also contain artesian mound springs. These are a highly restricted landform in Australia and listed as an endangered ecological community. They form the largest active spring complex in NSW, are the only known springs in NSW that are on a lakebed, and are the only examples protected within the NSW reserve system. A number of other threatened plant species and communities are also present in the park and state conservation area, as well as a range of threatened animal species.