WSUD in Victoria: BlueFactor, MUSIC and when each applies
STORM has been replaced by Melbourne Water's BlueFactor for the small-site pathway. MUSIC still covers complex sites. This guide maps the Victorian planning clauses, what each tool needs, and the mistakes that generate RFIs.
Why it matters
Victorian planning applications that trigger stormwater or integrated water requirements need a tool result, not a vague WSUD paragraph. Melbourne Water's BlueFactor has replaced the STORM Calculator for the small-site pathway. Larger or more complex sites still need MUSIC. Getting the tool wrong — or citing a STORM score after councils have stopped accepting new STORM projects — is a common RFI.
- Developers: BlueFactor is free for Victorian planning applicants and fits most townhouse and apartment sites under 1 ha without public roads. MUSIC costs more and needs a modeller — budget it when the site is complex.
- Architects: roof area, permeable paving, rainwater tanks and treatment assets are design inputs. Leave space for tanks and raingardens before the landscape package is locked.
- ESD consultants: BlueFactor can support a BESS assessment; MUSIC remains the tool for wetlands, sediment ponds, public roads and sites over 1 ha.
Checked against Melbourne Water, BlueFactor documentation, Yarra City Council guidance, and Victoria Planning Provisions Clauses 53.18, 55.05-1 and 58.03-8 on 5 November 2026 (Australia/Melbourne). Your council's current guideline takes precedence.
STORM status — state it accurately
Melbourne Water states that the STORM Calculator has been replaced by BlueFactor. BlueFactor is the successor tool for assessing whether development meets stormwater management requirements under relevant planning policy. Source: Melbourne Water — BlueFactor stormwater assessment tool.
Yarra City Council states that from 14 October 2025, it will not accept any new projects using STORM, and that BlueFactor is the preferred tool for assessing stormwater quality for developments less than 1 hectare that do not include any public roads. MUSIC remains preferred for more complex developments. Source: Yarra — BlueFactor.
So: STORM is no longer the recommended tool for new Victorian planning assessments; it has been replaced by BlueFactor for the small-site pathway. Do not lodge a new STORM-only score where the responsible authority has moved to BlueFactor.
Victorian planning hooks
| Clause | What it covers | Tool note |
|---|---|---|
| Clause 53.18 — Stormwater management in urban development | Applies to many subdivision, building and works applications (with listed exemptions). Purpose includes retention, reuse, mitigation of stormwater impacts, cooling, habitat and amenity. | Council/Melbourne Water guidelines then nominate the assessment tool |
| Clause 55.05-1 — Permeability and stormwater management (ResCode) | Objectives for permeable surfaces and stormwater management for two or more dwellings on a lot / residential buildings in the relevant band. | Decision guidelines note: "Blue Factor tool to achieve a 100% Blue Factor score or MUSIC Tool." Source: VPP Clause 55.05-1 notes. |
| Clause 58.03-8 — Integrated water and stormwater management (apartments) | Apartment developments: integrated water and stormwater management objectives and standards. | Council ESD policies typically call up BlueFactor or MUSIC via the SMP/SDA |
Note on Clause 55.03-4: in the current Victoria Planning Provisions, Clause 55.03-4 is Entry objectives (safety, accessibility and identification of building entries) — it is not the stormwater clause. Permeability and stormwater for ResCode sit under Clause 55.05-1. Cite 55.05-1 (and 53.18 / 58.03-8) rather than 55.03-4 for WSUD.
Council ESD local policies (typically Clause 15.01-2L) then require an SDA or SMP that includes stormwater modelling. See When is an SMP required? for dwelling and GFA triggers.
BlueFactor vs MUSIC — which tool
| BlueFactor | MUSIC | |
|---|---|---|
| Best for | Single houses, townhouses, apartments and smaller commercial sites that meet the size/road criteria | Complex treatment trains, wetlands, sediment ponds, public roads, car parks, sites over ~1 ha |
| Size / form limit | Up to one hectare (10,000 m²); no public roads (Melbourne Water / BlueFactor criteria) | No BlueFactor 1 ha / road restriction — used when BlueFactor criteria are not met |
| Cost | Free for planning permit applicants within Victoria (BlueFactor) | Licensed modeller / software cost |
| Typical target | 100% stormwater treatment compliance on-site (common pathway), or a council-specified minimum with other measures | Council / Melbourne Water best-practice pollutant reduction targets for the treatment train |
| Also used for | Supporting BESS stormwater credits | Subdivision and precinct-scale WSUD |
Sources: BlueFactor FAQ (size, roads, MUSIC preference for public roads / car parking); Melbourne Water BlueFactor page; Yarra BlueFactor guidance.
What each tool needs — and what it outputs
BlueFactor — typical inputs
- Site area and roof / impervious / pervious breakdown
- Rainwater tank volume and connected roof area (BlueFactor guidance commonly references at least 2 kL per 100 m² of total roof area, with water collected from at least 60% of new roof area — confirm current FAQ)
- Treatment assets (for example raingardens, permeable paving) and their sizes
- Demand assumptions where reuse is claimed
BlueFactor — typical outputs
- A BlueFactor score / compliance result (planning packages commonly aim for 100% on-site treatment compliance)
- A report suitable to attach to the SDA or SMP
MUSIC — typical inputs
- Catchment nodes (roof, road, other impervious, pervious) with areas and soil parameters
- Treatment nodes (swales, bioretention, wetlands, ponds, tanks, GPT) and sizing
- Rainfall / climate template for the site
- Met performance objectives for TSS, TP, TN and gross pollutants as set by the authority
MUSIC — typical outputs
- Mean annual load reductions vs the performance objectives
- Treatment-train schematic and report for the planning submission
Council ESD policies
Most CASBE councils' Clause 15.01-2L ESD policies list STORM/MUSIC (now BlueFactor/MUSIC) as tools that support an SDA or SMP. Expect the stormwater chapter of the SMP to include either a BlueFactor report (small site) or a MUSIC report (complex site), not a prose claim that "WSUD will be considered". Link the result to the landscape and civil drawings so RFIs do not ask where the tank or raingarden went.
For the full ESD report pathway, see Sustainability Management Plans (SMP). For Makao's integrated water work, see Water design.
Common pitfalls
- Lodging a new STORM score after the responsible authority has moved to BlueFactor (for example Yarra from 14 October 2025).
- Using BlueFactor on a site over 1 ha or with public roads — MUSIC is the recommended path.
- Claiming tank reuse without demand — BlueFactor and MUSIC both need credible demand if reuse offsets treatment.
- Design drawings that omit the assets in the model — tanks, raingardens and permeable paving must appear on the architectural/landscape set.
- Citing Clause 55.03-4 for stormwater — that clause is Entry objectives; use 55.05-1 (and 53.18 / 58.03-8).
- Leaving stormwater out of the SMP until after landscape is fixed — resize then becomes expensive.
How Makao can help
Makao prepares BlueFactor assessments for qualifying Victorian sites and coordinates MUSIC for complex sites as part of ESD/SMP packages. Start with Water design or the SMP guide.
Questions or corrections: contact Makao.
