The Step-by-Step Process for Conducting a WSUD Assessment

With urban areas producing up to five times more stormwater, WSUD assessment can help minimise its impact. However, the main hurdle homeowners face is not knowing how the process works. 

The good news is that once you understand the WSUD process, it becomes much simpler to plan for and manage. 

In this guide, we’ll walk you through the entire WSUD assessment process and how to guarantee your project achieves compliance without delays. 

How to Conduct a WSUD Assessment: Step-by-Step

The WSUD assessment process helps you see what goes into achieving compliance and how early design decisions can make approvals much simpler. Many projects face unnecessary delays because the WSUD requirements weren’t considered from the start.

Let’s walk through how the process works in clear, practical steps.

Step 1: Preliminary Site Evaluation and Data Collection

Every WSUD assessment begins with a detailed site review. This stage involves studying the land’s slope, drainage patterns, and soil types to understand how water naturally flows. 

Our WSUD team of assessors collect rainfall and runoff data to build a complete picture of the site’s hydrology. This early analysis is critical because it determines what kind of stormwater treatments will actually work. 

For instance, clay-heavy soils might not support infiltration systems, while sloped areas may need detention basins. Knowing these conditions helps you avoid design changes later. 

Step 2: Early Design Considerations

Once the data is collected, the next step is to incorporate WSUD principles into the project design. This means deciding how water will be captured, treated, and reused throughout the site. 

At this stage, the assessment team identifies opportunities to include elements like rain gardens, vegetated swales, or permeable pavements. Early design integration makes sure stormwater management isn’t treated as an afterthought.

Step 3: Modelling and Simulation Using WSUD Software

This is where the technical side begins, but it’s also one of the most crucial steps. Personally, we use the Blue Factor scorecard system to calculate total hard-surface areas across a site and assign treatment types. 

However, that’s not the only option, as some accreditors also use MUSIC (Model for Urban Stormwater Improvement Conceptualisation). It allows us to simulate stormwater runoff, pollutant reduction, and flow performance in detail. 

Both of these tools confirm whether your proposed systems meet the necessary targets for pollutant removal. 

Step 4: Selection and Specification of Treatment Measures

In this step, WSUD assessor’s must choose the appropriate WSUD treatment systems. These may include rainwater harvesting tanks, bio-retention systems, or infiltration trenches, depending on what best suits the site. 

The main issue here is that not all councils allow the same options. For example, Maroondah Council does not permit rain gardens to be nominated as treatment types. This means developers may need to pay a development construction fee to offset their WSUD score. 

Step 5: Preparation of WSUD Documentation

After the design and modelling are finalised, accreditors help you compile a complete WSUD report ready for council submission. This report includes: 

• Detailed specifications demonstrating WSUD compliance
• Blue Factor scorecard modelling results
• Treatment layout plans
• PDF documentation for maintenance and treatment types

The report is designed to clearly communicate how the project meets WSUD standards. This also reduces the risk of revisions or delays during the review process. 

Step 6: Council Submission and Review

Now that you have the complete report, submit it to the local council as part of the planning permit process. Councils use these reports to verify that your project aligns with their stormwater management and environmental guidelines. 

Because each council has slightly different requirements, reports that meet one area’s standards may not automatically satisfy another’s. 

That’s why our team at PassivEnergy verifies that all WSUD documentation complies with local regulations, including Melbourne Water and other regional authorities. This makes the approval process as smooth as possible. 

Step 7: Compliance Verification

Once everything’s approved, it’s time to put the plan into action. This stage focuses mainly on ensuring each WSUD element, such as rain gardens, swales, or tanks, is installed exactly as designed. 

There’s also a post-construction inspection to confirm everything operates as expected. Your council will notify you as the property developer when they will be out onsite to inspect.

Let the Experts Handle the Complexities for You

Preparing a WSUD report may sound simple at first, but in reality, the process involves far more details than most people expect. Because of that, it can quickly become frustrating to manage on your own. 

But the best part is, with PassivEnergy, you don’t have to worry about anything. 

We handle every stage of the WSUD assessment in Australia, starting from modelling to preparing the final document for submission. All we need from you are a few key documents, such as site plans, elevations, and floor layouts. Once we have those, we take care of the rest.

Save yourself from stress by contacting PassivEnergy today!