Sources of sediment and phosphorus in tarago reservoir

The quality of the water from Tarago Reservoir in Gippsland, Victoria is lower than that from Melbourne Water's other supply reservoirs. In 1991, the reservoir experienced a minor toxic algal bloom. At the time phosphorus was considered to be the limiting nutrient for algal growth (Hecky and Kilham, 1988) and as most phosphorus transported in Australian waterways is attached to particles (Oliver, 1993: Cullen, 1995), the supply of sediment and associated phosphorus was considered to be one of the major contributors to the poor water quality. To assist Melbourne Water target sediment and phosphorus control measures, a combination of field observations and sediment tracing techniques was used to identify the dominant contributing areas.