Blue Green Infrastructure Hamilton Northshore

With almost 1500 dwellings and the temporary site for the largest Athlete’s village for the Brisbane’s Olympic and Paralympic Games in 2032, there was a need to evaluate sustainable development of a 200-hectare precinct alongside the Brisbane River. The site will be significantly hotter in future due to climate change, with surface temperatures exceeding 65°C if unmanaged, according to urban heat modelling. The project represents a unique opportunity to implement leading practices in water servicing to achieve sustainable development goals and build a long-lasting community legacy.

Our assessment applied the concept of Blue Green Infrastructure (BGI) which is an approach to sustainable urban development that prioritises the protection, enhancement and restoration of existing ecosystems, hydrological and landscape features. It includes aspects that are living (‘green’) and the need to better manage water (‘blue’). The intricate balancing act for the strategy considered both present and future infrastructural dynamics, spanning water supply, wastewater, stormwater, streetscape, and the built form.

To explore the prospect of a cool, liveable destination point with water security and a climate positive site that creates a sense of place, we developed an innovative water servicing strategy. Our proposal incorporates biophilic urban design to minimise potable water use, mitigate urban heat impact, and ultimately enhance resilience. The project work showed that 80% coverage of tree canopy cover would be required to maintain liveable conditions in the future. Without this tree canopy cover, surface temperatures were modelled to attain 65°C. Concurrently, the strategic driver of climate resilience pointed the way to a recycled water supply solution. GHD coordinated with other specialist advisors who were working at the same time (urban heat, stormwater management, sustainability) to integrate and address multiple aspects and potential benefits.

Our assessment framework was used as the template for these other specialists’ assessments and helped define sustainability ratings. The opportunities identified have additional benefits for amenity, active transport corridors, protection of environmental assets (waterways, mangroves) and more.

A main feature of our plan was to identify a potential pathway on how to enhance this natural environment through the stage implementation of BGI infrastructure.

Using water-based modelling and cost analysis, a range of blended portfolio options were crafted for blue-green initiatives such as tree beds in road corridors, rain gardens, enhanced mangrove corridors, open spaces and the use of recycled water.

Concepts and recommendations included: connection to an existing recycled water scheme, sewer mining from a nearby trunk sewer, an underground treatment plant and extensive rainwater tanks. Importantly, the recommendations will help mitigate urban heat affects and cultivate biodiverse rich ecosystems as well as achieve potential cost savings in underground system upgrades. 

BGI has many benefits, encompassing not just water management but also the enhancement of community, social, cultural values and health. The outcomes from the process provide an example to other organisations about how to plan strategically, set targets, fund and manage BGI assets in the long-term fully realise the benefits that these can assets deliver.