The major issue affecting waterway health in South East Queensland is the increased amount of mud (or sediment) entering our waterways.

Erosion is the primary source of sediment in our waterways and most commonly comes from farming/rural land, worn away river and creek banks and urban construction sites which, unmanaged, expose large amounts of soil that can be easily eroded during rainfall events.

During the January 2011 and 2013 floods, over 20 million tonnes of sediment was washed off the land and into our waterways. The retail value of this soil if purchased from a landscape supplier would be more than $1 billion.

Sediment in our waterways reduces water clarity and contains pollutants such as nutrients (nitrogen and phosphorus) which threaten the livelihood of the people and industries that rely on healthy waterways. Sediment also smothers aquatic plants, such as seagrass, reducing the amount of food available for turtles, dugongs and fish, impacting on our fisheries.

When large amounts of sediment are washed off the catchments into our dams, it places extra burden on water treatment processes to produce quality drinking water. During the 2013 flood, the region’s largest water treatment plant at Mt Crosby was forced to shut down due to the amount of sediment entering the plant from the Brisbane River.

What is Sediment?

Sediment are particles that are washed off the land into waterways and come in all shapes and sizes - from larger sand particles to smaller mud, clay and silt particles. Too much sediment can cause harm to the plants and animals that live in our waterways.


ESC Tool Kit

Healthy Waterways, together with the Department of Environment and Heritage Protection, has released an online resource to help combat the increasing amount of sediment running off building sites and impacting Queensland’s waterways and communities.

Find out more

What You Can Do 

  • Plant native vegetation along waterways. 
  • Retain soil cover by mulching. 
  • Cover exposed soil.
  • Seek property management advice from SEQ Catchments or your local council.

Find out more