Why is it a problem?
The Bayswater Brook Catchment is the fifth highest contributor of nutrients into the Swan River. Everything that enters the drains within the catchment is discharged into the Swan and Canning Rivers and surrounding wetlands.
Plants require nutrients, specifically nitrogen and phosphorus to grow. However, in high quantities these nutrients can cause many water quality problems, in particular algal blooms. The increased algae growth decreases the amount of sunlight available to the other plant life in the water, which prevents photosynthesis from occurring and can also lead to fish kills.
Excessive algal growth can cause anoxic conditions. The algae will grow until it has exhausted all nutrient supplies, and then it will start to die. In the process of decomposition, the algae will consume all the available oxygen in the water, resulting in anoxic conditions. Other organisms that require oxygen will either need to leave the ecosystem or die. Water bodies that experience algal blooms also have a foul odour due to the decomposing dead organic matter and are usually unsuitable for recreational purposes. This occurs in the Swan River and your local wetlands!
What is being done?
The Bayswater Brook Working Group, consisting of the City of Bayswater, Swan River Trust, Perth Region Natural Resource Management (Perth NRM), Water Corporation, Department of Water and CSIRO are working together to reduce the amount of nutrients entering the river by implementing a Local Water Quality Improvement Plan for the Bayswater Brook. The plan targets the current ecological condition, water quality and pollutant loads of the catchment. It applies the treatment train approach to achieve a water quality target of a 30% reduction in nutrients entering the Swan River by 2015. This approach focuses on 5 stages that will play a role in achieving this target; prevention, minimisation, reduction, amelioration and treatment. The old saying “prevention is better than cure” applies to this approach, with the city enforcing techniques to prevent the problem from occurring.