Lakes Alexandrina and Albert (the Lower Lakes) are freshwater lakes located at the end of the Murray-Darling River system. They were designated as an Icon Site under the Living Murray Program in 2004 and in spring 2008 a vegetation monitoring program was established to assess objective V3: maintain or improve aquatic and littoral vegetation in the Lower Lakes. Vegetation monitoring has been undertaken every spring and autumn to correspond with the highest and lowest water levels each year. Sites were established on lakeshores and in selected wetlands and the vegetation assessed at set elevations from +0.8 (spring high water level) to -0.5 m AHD (height above mean sea level).
The first two years of the monitoring program coincided with a period of record low water levels. During this period, significant engineering interventions were undertaken to manage water levels and mitigate acid sulfate soils. In August 2010, water levels in the Lower Lakes rose to historical high levels and all engineering interventions were removed.
Over the 15 years of condition monitoring, a total of 167 taxa (including 77 exotics) were recorded. There was a large change in the plant community between the early surveys, which reduced through time (except in seasonal wetlands where there were seasonal patterns). The large changes between the early surveys were due to the colonisation of terrestrial taxa between 2008 and 2010 and subsequent extirpation and colonisation of submergent, emergent and amphibious taxa after spring 2010 following increased flows. The reduced rate of change between the recent surveys suggests that a stable plant community may be developing. In seasonal wetlands the patterns were due to seasonal inundation. Submergent species were abundant in spring, when seasonal wetlands were inundated but absent in autumn, replaced by amphibious and emergent taxa.