What is a wetland?

Riverine wetland – Darling River in flood, January 2012. Melissa Hull, OEH
Riverine wetland – Darling River in flood, January 2012. Photo: Melissa Hull, OEH.

A wetland is exactly what the name suggests: wet land. Wetlands are areas that are inundated by water cyclically, intermittently or permanently and can have fresh, brackish or salt water, which is generally still or slow moving. This covers a wide range of habitats, including lakes, lagoons, estuaries, rivers, floodplains, swamps, bogs, billabongs, marshes, coral reefs and seagrass beds.

An area doesn't need to be permanently wet to qualify as a wetland. It just needs to be wet long enough for its plants and animals to be adapted to – or even dependent on – wet conditions for at least part of their life cycle. Many wetlands in inland NSW can be dry for 10 years or longer, before being inundated after heavy rainfall and then staying wet for several years, allowing wetland plants and animals to regenerate and reproduce.

What are Ramsar wetlands?

Ramsar wetlands are internationally recognised wetlands. They are listed under the Ramsar Convention, which requires protection of their ecological character through wise use principles’. There are 12 Ramsar sites in NSW, covering a wide range of wetland types. They include inland floodplain wetlands such as the Macquarie Marshes, Gwydir Wetlands and Millewa Forests; estuarine wetlands such as Myall Lakes; inland lakes in the Paroo River Wetlands and alpine lakes such as Blue Lake.

Types of wetlands in NSW

NSW wetlands are diverse and have unique characteristics and wildlife. They are found along the coast, in estuaries, on floodplains, within freshwater rivers and lakes and even on cliff sides.

There are many different methods used for classifying wetlands around the world. Classifications can be based on vegetation, geomorphology, hydrology, or physical and geographical attributes, or a combination of these features. For example, under the Ramsar Convention there are 42 wetland types worldwide.

The system used here is based on the one developed by the US Fish and Wildlife Service (Classification of wetlands and deepwater habitats of the United States, Cowardin et al. 1979) and recognises five principal types of wetlands in NSW:

  • Marine wetlands are found along ocean beaches and in shallow ocean waters, and around rocky headlands and islands to the extreme high water mark. These occur along the length of the NSW coast.
  • Estuarine wetlands are found in bays and other partly enclosed waters that are tidal and sometimes have freshwater inflows. Examples are the Myall Lakes near Bulahdelah, the wetlands in Botany Bay, the lower Hunter River near Newcastle, and the Tweed Estuary.
  • Riverine wetlands are found wholly within freshwater rivers channels and do not feature emergent trees or other plants.
Marine wetland – Dark Point, Myall Lakes NP, rocky headland and sandy shore, Photo: Fiona Miller, OEH

Marine wetland: Dark Point, Myall Lakes National Park, rocky headland and sandy shore. Photo: Fiona Miller, OEH

 
Mangroves, Urunga coast.  Image & copyright Shane Ruming

Estuarine wetland: mangroves, Urunga coast. Photo: Shane Ruming

 
  • Lacustrine wetlands are areas of fresh water occurring in natural depressions or in a dammed river channel such as lakes and reservoirs, which lack emergent trees and other plants. They are also called inland freshwater lakes (InlandFreshwaterLakes.pdf, 3.49MB) and examples include Lake Pinaroo in Sturt National Park, the alpine lakes in Kosciuszko National Park, the upland lakes on the New England Tableland, and the Menindee Lakes near Broken Hill.
  • Palustrine wetlands are vegetated areas of non-tidal water with emergent trees and other plants such as inland floodplain swamps. Examples include the Macquarie Marshes north of Dubbo, the Millewa forests near Deniliquin, and coastal melaleuca swamp forests in Myall Lakes National Park. Inland floodplain swamps can be in a dry phase (InlandFloodplainSwampsDry.pdf, 1.8MB) for several years, before they receive sufficient inundation to change to their wet phase (InlandFloodplainSwampWet.pdf, 1.85MB). A palustrine system can exist directly adjacent to, or within a lacustrine, riverine or estuarine system.
Lacustrine wetland – Peery Lake, Paroo-Darling NP, Photo: Neal Foster, NSW Office of Water

Lacustrine wetland: Peery Lake, Paroo-Darling National Park.
Photo: Neal Foster, NSW Office of Water

 
Palustrine wetland – marsh club-rush sedgeland, Gwydir Valley, Photo: Daryl Albertson, OEH

Palustrine wetland – marsh club-rush sedgeland, Gwydir Valley.
Photo: Daryl Albertson, OEH

More information about the different types of wetlands in NSW, including their health and models of how they work, is available in the 2010 State of the Catchments reports.

Significant wetlands in NSW

Specific NSW wetlands are recognised internationally under the Ramsar Convention, such as the Hunter Estuary Wetlands near Newcastle and Lake Pinaroo in the state’s far north west. The ecological values of wetlands are also recognised and protected in other ways.

Wetlands listed in the Directory of Important Wetlands in Australia, or DIWA wetlands, are nationally significant wetlands. The Directory also provides information about the values of wetlands, including plants and animals that rely on wetlands, their social and cultural values and some of the ecosystem services and benefits they provide. There are 187 DIWA wetlands in NSW, including iconic wetlands such as the Macquarie Marshes, Myall Lakes, Menindee Lakes, Great Cumbung Swamp, Lowbidgee Floodplain, Paroo Overflow, Wingecarribee Swamp and Lake George.

State Environmental Planning Policy 14 (SEPP 14) identifies the most environmentally sensitive coastal wetlands in NSW. Developments, proposed adjacent or close to SEPP 14 wetlands, require special environmental assessment and development conditions to ensure that the values of wetlands such as coastal lakes and lagoons (CoastalFreshwaterFloodplain.pdf, 1.2MB) are protected.

Many wetland vegetation communities in NSW are listed as endangered ecological communities (EECs). These communities have been listed as EECs to recognise their ecological importance, and include coastal saltmarshes, mound springs, upland swamps (UplandHangingSwamps.pdf, 3.56MB) in the Blue Mountains and on the New England Tablelands, coastal floodplain forests, sedgelands in the Gwydir Wetlands and peat swamps such as Wingecarribee Swamp.

Page last updated: 01 March 2013