Deagon has a flat topography and one of the boundaries of the suburb is Cabbage Tree Creek . The Creek’s catchment is largely urbanised but the Boondall Wetlands, which is separated from Deagon by the Creek plays an important role in providing essential habitat for a range of birds and animals, including migratory birds, which make their way from the arctic circle. The Boondall Wetlands near Deagon have ecosystems that are fresh as well as areas that are salt water. The smaller reserves such as Brighton and Deagon Wetlands are fresh water only. The Deagon Wetland is an important remnant of tea tree woodland on a 50ha site. Notable bird species include the striped honeyeater and the white-cheeked honeyeater.