Water Sensitive SA

A line in the sediment – changing our behaviours to protect our waterways

Silt and suspended solids washed into the stormwater system have negative consequences for creek and waterways in the urban catchments of Adelaide, smothering aquatic habitats and depositing toxic sediment that can remain in the environment for a lifetime.

In November 2023, more than 70 people joined Water Sensitive SA to delve into the impacts and share strategies from across Australia to manage silt laden stormwater, including how biofilters and wetland asset performance reduces with high silt influxes, to policies that direct civil contractors to keep soil onsite during constructions and building site compliance.

Dr Kathryn Russell shared work from researchers at the University of Melbourne, together with Melbourne Water, that has found the volume of soil potentially lost during a greenfield land development of seven years is equivalent to the same volume that is washed from a mature neighbourhood over a 50-year period. The bulk earth works and road/civil phases pose the greatest risk of sediment causing stormwater pollution.

The impact of sediment in stormwater on local WSUD assets is also a key concern for SA councils, with investments in biofilters, raingardens and wetlands at risk from mobilised silt and debris choking their functionality and increased maintenance requirements from more frequent cleaning, as Dr Kerri Muller explained.

Introduction (8:44) | Belinda Dohring, Program Manager, Water Sensitive SA

Sediment supply fluxes associated with greenfield developments (23:02)  | Dr Kathryn Russell, Research Fellow (Geomorphology), University of Melbourne

How sediment limits the capacity of WSUD assets (21:35)  | Dr Kerri Muller, Principal Ecologist, Water Sensitive SA

In Queensland, erosion and sediment control is well managed by the construction industry thanks to an extensive behaviour change approach, providing tools to help follow legislative requirements and ongoing engagement to adopt best practices out on sites, where large rainfall events can wash a substantial load of sediment into nearby watercourses.

And in the Parramatta River urban catchment, education and compliance of construction site best practice to ensure the stormwater is protected is paying dividends through the Get the Site Right campaign – a joint taskforce of more than 25 state and local authorities and catchment groups that conducts a “blitz” across the catchment, with more than 65% of building sites inspected demonstrating good sediment management.

Key elements of a successful ESC program and what is now commonly implemented in Queensland’s construction sites (33:30) | Leon Rowlands, Director, Switchback Consulting

Compliance – Get the Site Right campaign (11:19) | Nadia Young, Coordinator, Parramatta River Catchment Group

Panel discussion | Dr Kathryn Russell, Dr Kerri Muller and Leon Rowlands, facilitated by Belinda Dohring


Russell K (2021) Potential sediment supply fluxes associated with greenfield residential construction. Anthropocene, Vol. 35.

Russell K, Fletcher T and Vietz G (2017) Global sediment yields from urban and urbanizing watersheds. Earth-Science Reviews, May 2017.

Scallan B (2021). The economic cost of erosion and sediment loss from construction sites. Perth NRM.

Acknowledgement of Country

Water Sensitive SA acknowledges Aboriginal people as the First Peoples and Nations of the lands and waters we live and work upon, and we pay our respects to their Elders past, present and emerging. We acknowledge and respect the deep spiritual connection and the relationship that Aboriginal and Torres Strait Islander people have to Country.