Border Rivers catchment
The Border Rivers region is based around the Macintyre River and the Dumaresq River, which merge to form the Macintyre River. The Macintyre River ultimately becomes the Barwon River. The region is bounded to the east by the Great Dividing Range, the north by the Condamine-Balonne and Moonie regions, the south by the Gwydir region and to the west by the Barwon-Darling region. The slopes region lies west of Ashford and Texas to below Boggabilla and is characterised by undulating country with numerous permanent and semi-permanent billabongs. The plains region is downstream of Boggabilla where the terrain is undulating to flat. Floodplains stretch west towards Mungindi.
The Border Rivers region covers 45,675km2 or 4.4 per cent of the area of the MDB. The Macintyre River's main tributary is the Severn River. The principal tributaries of the Dumaresq River are the Beardy River and Ottley's Creek. Major water storages constructed since the late 1960s enable irrigated agriculture on the plains. The Weir River is the only significant tributary downstream of Boggabilla.
The rivers and wetlands of the Border Rivers also provide habitat for a range of large and small bodied native fish species many which used to be widespread in the Murray-Darling Basin but now have a patchy distribution. Native fish species found in the Border Rivers include golden perch, Murray cod, purple spotted gudgeon and unspecked hardyhead (Davies et al. 2012; Wilson and Ellison 2010). The Border Rivers (Macintyre, Severn and Dumaresq rivers) are part of the endangered ecological community aquatic ecological community in the natural drainage system of the lowland catchment of the Darling River which is listed under the NSW Fisheries Management Act 1994.
The Border Rivers catchment is an ecologically significant area because it includes:
- a diverse range of flora and fauna species, including waterlilies, river red gum, river cooba, freckled duck, weeping bottlebrush, New England tree frog and brolga
- species listed as vulnerable under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), such as great egret, Australian painted snipe, Murray cod and Warra broad-leaved Sally
- river-fed wetlands
- a wetland of national importance
- large wetland areas which provide large amounts of organic carbon essential to ecosystem function and which supports a diverse population of waterbirds
- small effluent creeks that support waterbird breeding.
The only wetland identified as being nationally significant is the Morella Watercourse/Boobera Lagoon/Pungbougal Lagoon located on the Macintyre River floodplain. This site is considered one of the most important Aboriginal places in eastern Australia. As one of the few permanent waterbodies in the northern MDB the complex provides refuge for wildlife during periods of drought.
Sundown National Park also has ecological significance, hosting 11 rare and threatened animals, five rare or vulnerable plant species and permanent waterholes supporting a diverse range of waterbirds and aquatic biota.