Sediment News
April, 2025
City of Wanneroo Sediment Control Success Story
Business Case justifies employment of a dedicated Dust and Sediment Compliance Officer to improve land development outcomes
Poor industry practices during land development are contributing to sediment filling river pools and wetlands, increased turbidity, weeds on sediment accretions and habitat for mosquitoes all of which result in declining ecosystem health in waterways and wetlands of the Swan Coastal Plain. Drainage infrastructure is also impacted by sediment, reducing capacity, increasing flooding risk and infrastructure maintenance costs.
Prior to 2023, frequent occurrences of sand and litter drift into road and other reserves, residential properties, neighbouring land, bushland, wetlands and stormwater systems and numerous public complaints was a significant concern for the City of Wanneroo.
A proactive approach was required to achieve better land development management and building site outcomes and to reduce the need for prosecution. The City prepared a Business Case to employ a Dust and Sediment Compliance Officer, to undertake daily surveillance and educate and support industry. Potential costs savings related to:
a) Officer time to respond to and resolve past complaints from state and local elected members and residents;
b) Asset repair, maintenance and renewal costs, including cleaning stormwater pits, pipes and GPTs, re-profiling damaged landscaping and Water Sensitive Urban Design assets and re-establishing vegetation; and
c) Traffic management.
A Dust and Sediment Compliance Officer was employed by the City, and a new sediment management procedure established. The Dust and Sediment Compliance Officer works closely with Land Development Engineers, attends start-up meetings, forms relationships with Site Superintendents and contractors, and regularly inspects sites.
Concurrently, the City takes a performance-based approach with land developers and where there is evidence of unsatisfactory performance, will impose Civil Engineering 12-month Defects Liability Period Bonds and Landscape Establishment and Maintenance Bonds, calculated as 5% of the contractual value of the works.
The results have been ‘sed-to-be-mint’, with this success story shared recently with officers from the Cities of Armadale and Swan and members of the Sediment Task Force. Coordinated by the Department of Biodiversity, Conservation and Attractions, the Sediment Task Force brings together the knowledge of the private and public sectors to share information and learnings to prevent sediment leaving construction sites, so water quality is not degraded.
Greater clarity and consistency regarding sediment management compliance procedures by City staff means officers are well supported to take enforcement action. There has been 100% compliance with the City’s new 48-hour Infringement Notice, which constitutes a modified penalty of $500 and is issued without further warning under the Planning and Development Act 2005.
A significant reduction in public complaints was quickly achieved and contractors are now contacting the City outlining sand drift and sediment controls they are installing.
Improved on-site dust and sediment control mean less toxic contaminants adhered to soil and sand particles, and less microplastics and other construction site litter entering the City’s drainage network after rain and potentially making its way into the City’s parks, bushland and wetland assets. This is important, as Lakes Joondalup, Neerabup, Badgerup, Mariginiup and Jandabup contain rare and protected flora and provide critical habitat to a range of native animal species.
For further information, contact bronwyn.scallan@dbca.wa.gov.au
Sediment Task Force Meeting Site Tour of best practice sediment control at an Alkimos Beach subdivision site. Photo credits: DBCA