Do you remember the parched lawns last christmas when you weren't allowed to use the sprinklers?

The cause: toxic blue-green algae in the water reservoirs. Run-off from fertilizers, intensive industrial waste and sewage is the most probable cause. However by managing the land better this may be avoided.

At the University of Queensland Glen Lockhead, a PhD student of the high performance computing group, is developing a computer visualisation tool to guide land management practices. By modelling possible nutrient movement he can analyse where their combined effect might result in a hazard to our water ways and reservoirs.

Blue-green algae outbreaks affect many of Australia's rivers, estuaries and reservoirs. The blooms are assisted by environmental issues including land clearing, damming of rivers, declining rainfall, nutrient inflows, overfishing, carp infestations and salinity - and in some cases, waterways can literally turn green overnight.

The toxic blooms and their harmful effects on water quality are well recognised, but extensive studies are needed of algal dynamics to understand how to predict and control the outbreaks.