Stormwater quality assessment and reporting for councils and authorities.
Many councils require new development to demonstrate that stormwater leaving the site meets best practice targets for pollutant reduction. In practice this means a STORM or MUSIC (and now Blue Factor) assessment showing that the proposed treatment reduces total suspended solids, total phosphorus and total nitrogen to the required degree.
The treatments themselves are not complicated: rainwater tanks connected to toilets and laundry, raingardens, permeable paving, vegetated swales. The difficulty is that they need space, and space is settled by the site layout well before anyone runs the numbers.
Bringing the assessment forward, early in the design process, can ensure that these measures are seamlessly integrated into the design. A raingarden that has a place in the landscape plan costs far less than one retrofitted into a courtyard at the end of the process.
Stormwater quality assessment and reporting demonstrating compliance with the best practice objectives in the Urban Stormwater Best Practice Environmental Management Guidelines, as applied through the relevant planning scheme.
Assessment is undertaken using STORM or MUSIC or Blue Factor as required by the responsible authority, and issued as a report suitable for submission to council.
Required by developers, architects and owners at planning permit stage, for residential, mixed use and commercial development where a stormwater management plan forms part of the application.
Stage 1 — Project Initiation. Studio Bun reviews your site, roof and landscape plans, confirms the assessment method required by the responsible authority, and issues a proposed pathway together with a fixed fee covering the full process.
Stage 2 — Preliminary Assessment & Design Advice. The proposed design is modelled, adjusted and assessed. We issue a Preliminary Assessment Report setting out what is required for compliance. This stage identifies the key challenges to the project and the improvements available, whether to exceed compliance or to reduce the cost of meeting it.
Stage 3 — Design Iteration & Optimisation. Between the preliminary and final reports we allow two rounds of minor changes to the design, and a meeting to review the recommendations. From here we can focus on cost efficiency or on performance, as the project requires.
Stage 4 — Final Reporting. Once the treatment strategy is settled, we issue the final stormwater management plan and WSUD report for submission to the responsible authority. Changes after issue, including responses to further information requests beyond those included, are charged at an additional rate.
Site and catchment analysis, including impervious area take off
STORM rating assessment, Blue Factor assessment or MUSIC modelling as required by the authority
Options analysis where the initial strategy does not meet the targets, with the space, capital and maintenance implications of each
Sizing of rainwater tanks, raingardens and other treatment measures
A stormwater management plan drawing showing treatment locations and catchments
A maintenance schedule for the proposed treatments
Two rounds of minor changes between preliminary report and finalisation
A final WSUD report for submission
Where a site is too large or complex for the STORM or Blue Factor tool (broadly 2,500m²), councils often require MUSIC modelling instead, a more detailed treatment train analysis against total suspended solids, phosphorus and nitrogen reduction targets. We offer MUSIC modelling for these larger residential, commercial and mixed-use developments as a separate, scaled service.
A few items sit outside this scope and can be quoted separately:
Hydraulic and drainage design, including pipe sizing and detention
Flood modelling and overland flow assessment
Civil engineering documentation
Geotechnical investigation and infiltration testing
Landscape design and planting schedules
Responses to authority requests for further information beyond two rounds
Biodiversity assessment (see biodiversity sensitive urban design)
This service assumes a residential, mixed use or commercial development, with site, roof and landscape plans sufficiently developed to establish catchments.
Studio Bun offers fixed sum packages for WSUD reporting, priced on site area, the number of catchments and whether a STORM, Blue Factor or MUSIC assessment is required. This service can be packaged with BESS assessments, sustainable design assessments or sustainability management plans if required.
Contact us for a quote.
What is WSUD?
Water Sensitive Urban Design is an approach to managing rainwater and stormwater in a development so it leaves the site cleaner and in smaller volumes than it otherwise would. In practice it means measures like rainwater tanks, raingardens, biofiltration and permeable paving. Most Victorian councils require a development to meet WSUD targets as a condition of permit.
Do I need a stormwater report for my planning permit?
In most Victorian councils, yes. If your development increases impervious area, you'll usually need to demonstrate you meet the council's WSUD and stormwater quality targets, most commonly via a STORM rating. Send us your site details and we will confirm what your council requires.
What is the STORM Rating Tool?
STORM is Melbourne Water's free online tool for demonstrating that a development's stormwater treatment meets the required reduction targets. A STORM rating of 100% or more means the proposed measures satisfy the target. It's the standard compliance method for most small-to-medium residential sites in Victoria.
What's the difference between STORM and MUSIC?
Both assess stormwater treatment, but at different scales. STORM is a simpler tool suited to smaller sites and is what most house and townhouse projects use. MUSIC is a more detailed model required for larger or more complex developments, or where a council specifically asks for it. We offer STORM, Blue Factor and MUSIC assessments.
Can WSUD be bundled with my energy assessment?
Yes — this service can run alongside your NatHERS or DtS compliance work, which keeps coordination simple and often the overall engagement more efficient.
Send through your site plan and drawings for a fixed-fee quote.
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