PMF (probable maximum flood)
The PMF is the largest conceivable flood for a catchment, used in NSW to define flood-prone land and the outer boundary of flood planning controls.
Ask Chalkline about this →The PMF (probable maximum flood) is the theoretical largest flood that could ever occur in a given catchment, calculated from the most extreme possible combination of rainfall intensity, duration, and catchment conditions. In NSW flood planning, the PMF defines the outer boundary of flood-prone land: any property below the PMF level is technically flood-prone, even if only the area below the FPL (flood planning level) carries active development controls (verified 2026-05-09: NSW Flood Risk Management Manual 2023).
On a Section 10.7 planning certificate, a property is disclosed as flood-affected if it is within the Flood Planning Area (below the FPL) or between the FPL and the PMF. The Low Flood Risk Precinct covers land between the FPL and PMF. For most residential development, the PMF boundary is relevant mainly for sensitive or hazardous uses (hospitals, care facilities, caravan parks) subject to optional LEP clause 5.22.
Also known as: probable maximum flood
Category: Approvals, flood management
Related
See also
- FPL (flood planning level)
- AEP (annual exceedance probability)
- DCP (Development Control Plan)
- Section 10.7 planning certificates NSW
Last updated: 2026-05-09. Verified: 2026-05-09. Quarterly review for currency.