Water Sensitive Urban Design

Adelaide’s shifting climate is changing rainfall patterns. We expect:

• less annual rainfall, particularly over spring,

• more droughts, and

• increased number and intensity of intense rainfall events.

This is a big challenge - not only do we have to deal with reduced total rainfall, but we have to be ready for lots of it in short bursts. More than ever, we are a land of droughts and flooding rains. Changing rainfall patterns mean that we need to be wiser in how we use water. Rather than simply channeling stormwater out to sea, our councils are using a range of clever techniques to integrate natural water cycles into our suburbs. This allows us to improve the health of our waterways, increase trees and green spaces, better manage risks and decrease costs.

STREET TREE INLETS and verge soakers

Increasing periods of hot and dry weather are tough on our street trees and verge plantings, which require increased watering over dry periods. To help our trees get through dry periods, we are installing underground reservoirs street trees can access. These reservoirs are filled with water collected from the rooves of nearby houses or inlets installed in kerbside gutters that are specially designed to keep out debris, and allow rainwater to be collected near where it falls, rather than being flushed right out to sea. By storing water under our kerbs we can keep our trees passively watered in dry periods, while also decreasing the pressure on our stormwater during heavy rainfall events, reducing the risk of flooding.

NATural and artifical Wetlands

Sometimes referred to as the kidneys of the river, wetlands are important for improving water quality. By slowing down the flow of water, sediments and pollutants are removed, improving downstream water quality. Wetlands are also biodiversity hotspots, supporting large populations of fish, insects, frogs and water birds. We are working to restore wetlands in our region, as well as to create new wetlands. So far, we have built more than 30 wetlands across our region. Our wetlands include:

• Aldinga Washpool Lagoon

• Oaklands Wetland

• Tjilbruke Spring

• Urrbrae Wetland

• Warriparinga Wetlands

PERMEABLE PAVING

Much of our urban environment is paved with concrete and asphalt. When rain hits these hard surfaces, it drains away into the stormwater system. This means that most of the water can’t soak through the soil to water trees and recharge groundwater. If stormwater drains are blocked, local flooding can occur.

By using permeable paving, rain is able to penetrate through the paved surface to water trees. The City of Mitcham has led trials of several permeable pavement types, including some made from recycled tyres.

RAIN GARDENS

Rain gardens are planted features installed next to paved areas that allow stormwater to be collected, filtered and used by plants - just like miniature wetlands! Rain gardens are increasingly common across the southern region and can be seen in our streets, carparks and public places. Rain gardens can be used to grow all kinds of vegetation to make our suburbs greener, including native trees, shrubs and understorey plants to boost our urban biodiversity.

bringing it all together

Several water sensitive urban design (WSUD) features can be combined to create public spaces that are green, cost-effective and meet the needs of the community. For example the Norman Street Reserve at St Marys uses rain gardens, water detention and recycled stormwater to create a high quality green space that requires less irrigation and is less at risk from both droughts and flooding.

LEARN MORE

You can learn more about innovative water sensitive urban design projects, including ways you can improve water use in your garden, by visiting our partners: