NSW has a total area of 80,160,000 hectares (801,600 square kilometres). The Macintyre and Dumaresq rivers form part of the state boundary with Queensland, while the Murray River forms part of the southern NSW-Victorian boundary.
Eighteen of the 89 Australian bioregions are represented in NSW, but only 2 of these 18 bioregions, Cobar Peneplain and NSW North Coast, lie wholly within the NSW boundary. The other 16 are shared with the bordering states and territories: Australian Capital Territory, Victoria, South Australia, Northern Territory, Queensland and Jervis Bay Territory. The bioregion with the largest area in NSW is the Darling Riverine Plains bioregion.
Diversity of NSW landscapes
The diversity of NSW landscapes is evident in the wide range of the state's bioregions.
- sandy deserts – Simpson-Strzelecki Dunefields, Channel Country, Murray Darling Depression
- riverine plains – Riverina, Darling Riverine Plains
- rocky ranges – Mulga Lands, Broken Hill Complex
- rolling downs – Cobar Peneplain
- lush rainforests – NSW North Coast, South East Corner, South East Queensland
- rugged mountains – Sydney Basin, New England Tableland, Australian Alps, South Eastern Highlands
- undulating ranges– Brigalow Belt South, Nandewar
- fragile, wooded grasslands – NSW South Western Slopes
The 18 bioregions found in NSW vary considerably in the types of natural values they contain, and although they all have some representation in protected areas, there is great variation in the extent of each reserved.
The bioregion with the highest proportion reserved is the Australian Alps bioregion, with almost 90% protected. The reason for this high proportion is the prevalence of the alpine environs of Kosciuszko National Park, which dominate this bioregion.
Note: These figures were current in 2003 when The Bioregions of New South Wales was published. In 2020, the most poorly reserved bioregion in NSW was Broken Hill Complex, with almost 2% under reservation.