Torhaven WSUD and Stormwater Treatment Ephemeral Wetland
Defence Housing Australia
Construction is complete on an ephemeral floodplain wetland at Defence Housing’s new residential estate Torhaven, at Deebing Heights. This unique project demonstrates that floodplains can provide best practice urban stormwater treatment whilst also enhancing floodplain function. Due to the site constraints (steep topography and dispersive soils), a new solution for managing stormwater within the floodplain was required. We needed to answer a range of questions to determine how to successfully design an ephemeral floodplain wetland to achieve two objectives:
1) Reliable treatment of urban stormwater runoff; and
2) Increased engagement of the floodplain generally for multiple benefits.
This required detailed site inspections and interpretation, assessment of flood flows and velocities, inundation frequency and duration analysis, design and modelling of configurations and close liaison with Council. The outcome is a new, innovative design solution for challenging sites, which results in an improvement in floodplain function and confidence in the management of stormwater from new developments. The benefit of this approach points to ephemeral floodplain wetlands potentially becoming part of the urban stormwater management ‘tool kit’ for challenging sites, meeting load reduction objectives for new developments plus delivering a solution that results in multiple benefits to the environment and the community.
Awarded Stormwater Queensland Excellence Award 2019 and Finalist for Australian Water Association - Infrastructure Project Innovation Award 2019.
