Wetlands can be defined as places where water forms pools or flows that last long enough for plants and animals to base a significant part of their lifespan around. Some wetlands are permanent, others flow just below the surface, rising and falling with seasonal rainfall, and others last just a few months at a time. Wetlands are important as a source of water and habitat, for trapping nutrients and soil and retaining it within a landscape, and for maintaining surface and ground water quality. There are also scientific, educational and aesthetic values associated with wetlands.
Wetland types may include damp-lands and sump-lands, ephemeral wetlands, gullies and springs, marshes and swamps, rivers and creeks, flood plains and billabongs, lakes, underground wetlands, salt marshes, estuaries and mangroves, farm dams and other artificial wetlands.
Wetlands have declined since European settlement through draining and channelisation, burning of reed beds, trampling by stock, pollution, weed infestation, and severe alterations to wetting and drying regimes. Natural wetlands are a very high priority for protection and rehabilitation.
Natural wetlands usually benefit from protection and natural regeneration provided there are enough natural elements for this to occur. Constructed wetlands or those in a degraded state may require soil works to address a changed hydrological (water) regime in conjunction with active revegetation.
from, ‘riverways, Shortcuts to river Management Information in Australia, p 144. Greening Australia Ltd., 2005.