History of the River Murray at Wellington The valley of the River Murray in South Australia, which includes the Wellington East location, has been significantly changed since European settlement, particularly due to the separation of the mainstream from its floodplain by levee banks from Mannum to Wellington, which were constructed from the mid 1800s. All of the Murray Valley below Wentworth has undergone major changes in flow regime, owing to the series of weirs, which control flows and water levels, and the barrages at the Murray Mouth. As a result of these changes, only 6.2% of wetlands (a total of 653.3 ha) are left on the floodplain between Mannum and Wellington (estimated area 10,500 ha) (Jensen, Marsh & Nichols 1999, Jensen et al 1996). Those areas that are left have been affected by changed water regime, willows, weeds, grazing, resulting in reduced biodiversity. Remnant wetlands in the Mannum to Wellington region have high conservation value and are considered to have national importance as a regional group, with a listing in the National Directory of Important Wetlands. The larger remnant wetlands are particularly important for waterbird nesting, breeding and feeding habitat, and smaller wetlands are of importance as habitat for small fish, frogs and macroinvertebrates. Since the 1920s, the Lower Murray has become a series of permanent lakes, and wetlands, which are connected to the river, are now permanently full. Their natural condition would have been semi-permanent or temporary, filling at least every second spring when river flows rose due to winter and spring rainfall in the catchment. The re-introduction of periodic drying cycles can kick-start regeneration and breeding processes in these wetlands, which have been kept full for the last 70 years. The natural flow regime for this reach of the river would have overflowed onto the floodplain 1 in 2-3 years with the spring peak flows. The Wellington East land parcel would have been a semi-permanent wetland, experiencing relatively frequent drying phases during late summer and dry years.