Water Sensitive Urban Design

Below are some examples of how WSUD is used to protect and preserve the water cycle through urban planning. These approaches aim to support natural processes, rather than work against them.

Image	Description
	Rainwater tank Rainwater tanks help reduce the amount of water that leaves a property. They also support people to use less drinking water by collecting rain for uses like watering gardens or flushing toilets.
	Wetlands Constructed wetlands are built to look natural and fit into the landscape. They slow down stormwater during heavy rain, clean the water by filtering out pollution and fine particles, and provide green spaces for people to enjoy.
	Gross pollutant traps Gross pollutant traps (GPTs) trap rubbish like plastic and litter, and sediment pieces over 5mm, to prevent it washing into rivers, lakes and oceans. This helps to make it easier to treat stormwater downstream. There are many types of GPTs, but they all perform a similar function.
	Swales Swales are shallow channels that carry stormwater across a site. They are usually planted and / or grassed. As water flows through, the grass and other plants help to slow it down and absorb excess nutrients. Swales can trap small pollutants like sediment and litter which helps to clean the water before it reaches creeks, rivers or the ocean. They also provide greenery and support local biodiversity.
	Raingardens Raingardens can be built on private land or street verges. They direct water from stormwater pipes or rainwater tanks into specially designed garden beds. As water moves through the raingarden, plants and soil absorb and filter pollutants. This process improves water quality before it enters the stormwater system, reduces the need for extra watering, and helps keep plants healthy. Raingardens also cut down on potable water use and make the site more sustainable.

Plants and grasses are an important part of many WSUD systems. They help capture and filter nutrients, improve water quality and support broader environmental goals.

Using native species in WSUD, particularly plants that are naturally found in our local area, is essential because:

• They provide habitat for local wildlife
• They are adapted to the region's unique climate and soil conditions, including sandy soils, which gives them a better chance of surviving long-term.

For more information about choosing suitable local plants for WSUD, and landscaping requirements, please see the following documents:

• Water Sensitive Urban Design Guidebook for Developers PDF, 5721.76 KB
• Wollongong Development Control Plan 2009, Chapter E06 Landscaping PDF, 311.3 KB

A treatment train is a series of stormwater management systems that work together to clean water as it moves through the environment. Each stage targets different types of pollutants.

By combining WSUD systems in the right order, treatment trains help keep waterways clean, reduce stormwater volumes, reduce costs and help each part of the system work more efficiently.

Below are some common examples of how different WSUD systems can be combined to form an effective treatment train.

Sediment basin and constructed wetland

Sediment basins capture finer sediment like sand and gravel before water flows into downstream WSUD systems like wetlands or bioretention areas. Constructed wetlands then provide further treatment through a series of densely planted ponds that filter and improve water quality.

Gross pollutant trap (GPT) and swale

GPTs remove litter and coarse sediments. Stormwater then enters WSUD assets like swales, wetlands or other measures where dense planting and / or grass slows, filters and cleans stormwater before it reaches creeks, lakes or the ocean.

Rainwater tank and raingarden

Rainwater tanks collect runoff from hard surfaces like roofs, reducing the amount of stormwater entering waterways. The stored water can be reused for garden irrigation, toilet flushing, and other non-drinking purposes. Tanks can also be connected to raingarden beds that filter runoff from the lot, remove pollutants, and improve water quality before it leaves the site. This approach reduces maintenance needs and improves overall system performance.

WSUD is becoming an essential part of modern urban planning across Australia.

The resources below are available to help developers understand current planning rules and use WSUD effectively in their projects, and for the benefit of our wider community and the environment.