In general, wetland definitions used in Queensland are based on those used in the Ramsar Convention on Wetlands (1971) — an intergovernmental treaty on the conservation of wetlands — or they are definitions derived from Ramsar. The principal wetland definition used in Queensland is contained in the Strategy for conservation and management of Queensland’s wetlands (1999). A Definition Guideline is presently under development that will summarise the range of definitions relating to wetlands in Queensland.

For the purposes of the Queensland Wetlands Programme the following wetlands definition, from the Wetland Mapping and Classification Methodology, applies:

Wetlands are areas of permanent or periodic/intermittent inundation, with water that is static or flowing fresh, brackish or salt, including areas of marine water, the depth of which at low tide does not exceed 6 metres. To be classified as a wetland, the area must have one or more of the following attributes:

1. at least periodically, the land supports plants or animals that are adapted to and dependent on living in wet conditions for at least part of their life cycle, or
2. the substratum is predominantly undrained soils that are saturated, flooded or ponded long enough to develop anaerobic conditions in the upper layers, or
3. the substratum is not soil and is saturated with water, or covered by water at some time.

Examples under this definition include:

• those areas shown as a river, stream, creek, swamp, lake, marsh, waterhole, wetland, billabong, pool or spring on the latest Sunmap1:25,000, 1:50,000, 1:100,000 or 1:250,000 topographic map1
• areas defined as wetlands on local or regional maps prepared with the aim of mapping wetlands
• wetlands Regional Ecosystems (REs) as defined by the Queensland Herbarium (Environmental Protection Agency 2005a)
• areas containing recognised hydrophytes as provided by the Queensland Herbarium
• saturated parts of the riparian zone
• artificial wetlands such as farm dams
• water bodies not connected to rivers or flowing water such as billabongs and rock pools.

Examples under this definition exclude:

• areas that may be covered by water but are not wetlands according to the definition
• floodplains that are intermittently covered by flowing water but do not meet the hydrophytes and soil criteria
• the riparian zone above the saturation level.

This definition is consistent with that in the Wetland Strategy, but includes three points of further clarification on the presence of wetland species and the composition of the substratum. These additional points enable an area to be identified as a wetland for mapping purposes and differentiate it from other areas.

Because of the great diversity of wetlands it is necessary to divide them into broad ‘groups’ or ‘types’. For the purposes of distinguishing these different wetland types, a classification system is required. One of the broader groupings of wetlands is based on systems (marine, estuarine, riverine, lacustrine and palustrine).