The low-lying areas of Mayes Swamp and Doughboy Swamp on the Collombatti-Clybucca floodplain were historically natural backswamp wetlands. Significant drainage infrastructure constructed over the 20th century has promoted rapid drainage and lower surface and groundwater levels. This has resulted in exposure of acid sulfate soils that discharge acidic waters (pH ~ 3). Prolonged inundation after floods can also lead to ‘blackwater’ runoff which has very low dissolved oxygen. These processes degrade the wetland areas and impact downstream aquatic ecosystems in the wider Macleay River Estuary.
In recent years, the Department of Transport for NSW (previously NSW Roads and Maritime Services (RMS)) purchased a large area of low-lying land on the Collombatti-Clybucca floodplain for biodiversity offsets as part of the Pacific Highway upgrade project. This land includes the Mayes Swamp and Doughboy Swamp areas. These areas have been identified for rehabilitation to improve the wetland habitats of the floodplain and improve water quality.
Three years of data collection and analysis und...
