WSUD: Water Sensitive Urban Design

Water Sensitive Urban Design, commonly shortened to WSUD, is a planning and design approach that coordinates stormwater catchments, water-quality treatment, rainwater reuse, permeability and landscape-based measures across a development site.

Rather than treating stormwater as a separate late-stage consideration, WSUD incorporates appropriate measures into the site and landscape design. These may include rain gardens, bioretention areas, permeable paving, rainwater tanks, vegetated swales, passive irrigation systems and selected rooftop treatments.

A WSUD report may be required where a planning authority requests evidence of the proposed water-sensitive response. The appropriate scope depends on the applicable requirements, site conditions, runoff catchments, available space and proposed treatment measures. WSUD documentation may coordinate with civil stormwater information, but it does not replace detailed drainage or hydraulic design.

WSUD stands for Water Sensitive Urban Design. It is a planning and design approach that considers how water moves through a development site and how the built environment can reduce its impact on stormwater systems, local waterways and surrounding environments.

In a conventional drainage response, stormwater may be treated primarily as something to collect and discharge. WSUD takes a broader site-based view by considering how water can be captured, slowed, filtered, reused, absorbed or integrated into landscaped areas before leaving the site.

A WSUD response may be required where a development needs to demonstrate how runoff, impervious surfaces, water quality, landscape areas and treatment measures have been coordinated as part of the planning approval pathway.

WSUD establishes the broader water-sensitive site strategy. It does not replace detailed civil drainage design, detention sizing or hydraulic calculations. Where quantitative water-quality verification is required, selected treatment measures may also be assessed through STORM modelling .

The required evidence and reporting format will depend on the relevant council and planning pathway. Review the WSUD planning documentation requirements .

Stormwater behaviour is central to Water Sensitive Urban Design. Every development changes the way rainfall interacts with the site, particularly when roofs, driveways, paths, car parks and other impervious surfaces are introduced.

Areas that previously allowed rainfall to enter soil or move through vegetation may instead become defined runoff catchments. Water can then move across roofs and hard surfaces toward drainage points, landscaped areas or proposed treatment measures.

A WSUD response considers how these catchments relate to the wider site strategy. It identifies where runoff originates, how it moves through the development and which surfaces can realistically be connected to water reuse, filtration or landscape-based treatment measures.

Once the site catchments are understood, the next question is how the proposed measures support the required water-quality outcome. Explore water quality and treatment .

Water-quality objectives depend on the approval pathway

The required stormwater treatment outcome can vary according to the state, council, planning scheme, development type and assessment method. A WSUD response should therefore be based on the requirements that apply to the particular site rather than a generic treatment target.

The planning documentation should identify the proposed measures, show where they are located and explain which site catchments they are intended to treat. Where quantified verification is required, the performance of those measures may be assessed separately through an approved modelling pathway.

Where quantitative verification is required, the treatment performance of selected measures may be tested through STORM modelling . The next step is to consider how these measures can be incorporated into the landscape and site design .

WSUD features vary depending on the site, project type, planning pathway and available space. A small residential development may require a different response from a townhouse site, mixed-use building, commercial development or larger urban renewal project.

The purpose of these measures is to help manage stormwater runoff, support water quality objectives, improve infiltration where suitable, reduce pollutant loads and integrate water-sensitive design into the built and landscaped environment.

A good WSUD strategy does not simply list features. It explains how those features work together, where they are located, how they respond to the site and how they can be maintained over time.

The right WSUD feature depends on the site

Not every project needs every WSUD measure. The appropriate response depends on council requirements, stormwater objectives, site grading, soil conditions, impervious area, landscape space, building layout and the level of assessment required for the planning submission.

The assessment should make the proposal easier to follow

A clear WSUD report creates a traceable relationship between the applicable requirements, the proposed measures, the catchments being treated and the drawings submitted for approval.

The required report format and supporting evidence will depend on the relevant authority and approval pathway. Review how this is typically documented within the WSUD planning submission .

A WSUD report or WSUD response may be required as part of a development application, planning permit, council submission or environmental planning requirement. The exact pathway depends on the location, project type, council controls and the way stormwater and water quality requirements apply to the site.

In some projects, WSUD is requested as a dedicated report. In others, it may be addressed through stormwater documentation, sustainability reports, landscape plans, civil drawings or a broader planning submission. The important point is that the water-sensitive design response needs to be clear, coordinated and relevant to the approval pathway.

Because requirements vary between councils and jurisdictions, WSUD should be reviewed early. It can affect site layout, landscape zones, drainage strategy, rainwater tanks, permeable surfaces, treatment measures and the way documentation is prepared for assessment.

Why early review matters

WSUD can influence the physical design of a project. If it is considered too late, treatment measures may be difficult to locate, landscape areas may be insufficient, stormwater documentation may not align, or drawings may need to be revised before submission.

The information required for a WSUD report depends on the project, council pathway, development type and level of assessment required. In most cases, the report needs enough project information to show how stormwater treatment measures are integrated into the actual site design.

A WSUD assessment is usually supported by architectural drawings, site layout plans, landscape information and stormwater or civil documentation. These documents help identify where runoff is generated, how water moves across the site and where treatment measures are proposed.

The stronger the documentation, the easier it is to prepare a clear WSUD response. If the drawings do not show the proposed treatment measures, rainwater tanks, permeable paving, landscape zones or maintenance access clearly, the project may need clarification before the report can be finalised.

Clear documentation usually leads to a clearer WSUD response

If the proposed WSUD features are visible in the drawings and coordinated with the landscape and stormwater design, the report can more clearly explain how the development responds to water quality, runoff and planning requirements.

The cost and timing of a WSUD report depend on the size of the development, the applicable planning pathway, the quality of the available drawings and the level of assessment required. A compact project with clearly documented measures will generally involve a different scope from a larger or less resolved development.

The main question is not simply how large the site is, but how much review, coordination and supporting evidence is needed to produce a clear and defensible water-sensitive design response. This may include catchment review, treatment measure coordination, drawing mark-ups, planning documentation and, where required, separate quantitative verification.

A project-specific review is therefore the most reliable way to confirm both scope and timeframe. Current drawings and any council correspondence usually provide enough information for an initial assessment.

What is needed for an accurate scope review?

Send the current project drawings, site address and any council request, planning condition or relevant stormwater-quality requirement. Landscape and civil information should also be included where available.

For a fuller list of typical inputs, review the project information usually needed for a WSUD report , or send the current documents for review .

WSUD, civil stormwater design and broader sustainability reporting can all contribute to the same planning submission, but they perform different functions. Understanding those boundaries helps the project team commission the right work and maintain consistency across the documentation.

A civil or hydraulic stormwater report typically addresses how water is collected, conveyed, detained and discharged. A WSUD report focuses on the water-sensitive site strategy, including runoff catchments, water-quality treatment, reuse, permeability and the integration of proposed measures into the site and landscape design.

Broader sustainability documents may reference the WSUD outcome alongside energy, materials, transport, waste and other planning-stage commitments. Those documents coordinate multiple sustainability categories but do not replace the detailed water-sensitive response.

WSUD does not replace civil stormwater engineering

WSUD defines and documents the water-sensitive site response. Civil or hydraulic consultants remain responsible for the detailed drainage, detention and discharge design where those services are required. The two scopes should be coordinated, but they should remain technically distinct.

WSUD defines the water-sensitive site strategy. Depending on the approval pathway, that strategy may be supported by quantitative treatment modelling or referenced within broader planning-stage sustainability documentation. These related Knowledge Hubs explain the boundaries between those services.

Unsure which document has been requested? Compare WSUD with stormwater and broader sustainability reports .