Clean rivers by design

Article image - Clean rivers by design Design features allow pollutants to be removed from stormwater with no additional maintenance.

Manningham Council, Victoria, has developed a new system that provides a low cost method to clean stormwater with little or no ongoing maintenance requirements.  

Melbourne has an amazing network of recreation areas alongside its waterways.  

These areas need to be kept clean, healthy and safe for the community.  

Cleaner, healthier waterways improve the amenity and liveability of urban environments and support river biodiversity. 

Pollutants entering waterways from the urban stormwater system are a significant threat to ecological health of rivers and their biodiversity.

Melbourne has been at the international forefront of waterway protection through the development of water sensitive urban design (WSUD).  

These systems utilise plants and soils to remove pollutants from stormwater prior to discharge to waterways, actively enhancing water quality and protecting aquatic species.

WSUD systems installed to date have been effective at removing pollutants and nutrients, but have typically been costly to install and maintain.  

The new system used by Manningham Council, known as ZAM-WSUD (Zero Additional Maintenance Water Sensitive Urban Design), was developed in collaboration with Melbourne Water, Monash Water for Liveability and the Co-operative Research Centre for Water Sensitive Cities.

ZAM-WSUD installations typically use nature strip grasses planted in a specialised soil profile to filter stormwater using a process known as biofiltration.  

Trial installations have been installed in more than ten location across Manningham and appear to be effectively achieving the ‘Zero Additional Maintenance’ objective.  

Laboratory testing has confirmed that grasses are very successful at removing key waterway pollutants, and have demonstrated total nitrogen removal rates of 80 percent, well above the industry best practice target of 45 percent removal.

Information about the ZAM-WSUD project and technical details are publically available through the ZAM-WSUD handbook. 

The second edition of the handbook has now been released and is available at: