We take a look at Rain Bank, a remarkable stormwater harvesting system beneath Brisbane’s iconic South Bank Parklands.

Opened in 2013, Rain Bank diverts and treats stormwater runoff from a highly urbanised 30 hectare catchment area in West End and South Brisbane to service up to 85% of the Parklands’ irrigation needs. The treated water can also be used for other purposes such as water features and providing flushing water in compatible toilets.

The idea for the project was first hatched in 2004 during drought conditions and heavy water restrictions in Brisbane, and has allowed the ongoing irrigation of South Bank Parkland’s subtropical landscape. It’s delivered a raft of other environmental benefits, too, as well valuable lessons in building sustainable infrastructure for cities.

Where is it?

If you live in Brisbane you may have walked past the underground plant and storage facility many times without realising it’s there.

The Rain Bank is located in the northern section of the Parklands, between the ABC building and the rainforest walk areas. While a lot of the infrastructure is underground, there’s a viewing area where visitors can learn about the system and the importance of water conservation and stormwater harvesting in general.

Lessons for sustainable cities

Rain Bank’s design and build makes an excellent case study on building water-smart and sustainable cities.

1. Cities can be giant water supply catchments

By harvesting available water in South Brisbane for irrigation, toilets and water features in the Parklands, Rain Bank reduces the consumption of more expensive potable (drinkable) water needed for drinking, swimming pools and showers.

2. Urban stormwater harvesting systems can also reduce pollution

Rain Bank’s retention and treatment of up to 77 megalitres a year of stormwater from a highly urbanised catchment removes a significant amount of pollutants that once originally discharged directly into the Brisbane River.

3. Use of existing infrastructure means these systems can be built in busy, highly urbanised areas

The design of the stormwater harvesting scheme partly used existing infrastructure, which reduced costs and minimised disruption to the public. Extensive investigations confirmed where stormwater pipes were actually located under the precinct, followed by detailed modelling to understand their capacity.

4. Being open to all ideas and thinking long term means better infrastructure

During the drought, South Bank Corporation invested resources in formally assessing all ideas put forward: sewer mining, bore water, roofwater harvesting, stormwater harvesting and desalination of river water.  Stormwater harvesting became the preferred long-term choice for the precinct due to practicality, cost and yield, as well as providing opportunity for community education about water conservation in the design.

What’s next for South Bank?

A stakeholder workshop in 2016 generated a range of ideas for water and energy initiatives. This was driven by Business South Bank’s goal for South Bank to be Australia’s most sustainable business precinct.

One of the key ideas out of the workshop was a precinct-wide water harvesting network which could expand or duplicate Rain Bank to include additional rainwater capture from the roof catchments and additional storage.

Read the case study

The Cooperative Research Centre for Water Sensitive Cities has published a case study The South Bank Rain Bank: Urban stormwater irrigating Brisbane’s iconic parkland. It’s available at the Business South Bank website