In short
Short answer: the Land Subject to Inundation Overlay (LSIO) is a Victorian planning overlay set out in clause 44.04 of the Victoria Planning Provisions and applied to land through each council's planning scheme. In the clause's own words, its first purpose is: “To identify flood prone land in a riverine or coastal area affected by the 1 in 100 (1 per cent Annual Exceedance Probability) year flood or any other area determined by the floodplain management authority”. (Department of Transport and Planning (Victoria), verified 27 Sep 2026)
An overlay sits on top of the land's zone and adds controls for one issue, whatever the zone is; a lot can carry several.
What it typically means for a buyer (Delora editorial, not legal advice): Land mapped as flood-prone in a major flood. Building works typically need floor-level and flood-safety conditions.
Check whether the Land Subject to Inundation Overlay applies to an address with Address Check. For a decision on a specific property, the official record is a Planning Property Report from VicPlan, and the council's schedule sets the local detail.
What the clause says
Clause 44.04 of the Victoria Planning Provisions (Land Subject to Inundation Overlay) states its purposes as: to identify flood prone land in a riverine or coastal area affected by the 1 in 100 (1 per cent Annual Exceedance Probability) year flood or any other area determined by the floodplain management authority; to ensure that development maintains the free passage and temporary storage of floodwaters, minimises flood damage, responds to the flood hazard and local drainage conditions and will not cause any significant rise in flood level or flow velocity; to minimise the potential flood risk to life, health and safety associated with development; to reflect a declaration under Division 4 of Part 10 of the Water Act, 1989; to protect water quality and waterways as natural resources by managing urban stormwater, protecting water supply catchment areas, and managing saline discharges to minimise the risks to the environmental quality of water and groundwater; and to ensure that development maintains or improves river, marine, coastal and wetland health, waterway protection and floodplain health. (Department of Transport and Planning (Victoria), verified 27 Sep 2026)
Ask your conveyancer: What flood level applies, and has the property flooded before?
Shown on planning scheme maps as LSIO.
What can I build? Worked examples
General examples of how state-wide rules apply, not an assessment of any property. The council's schedule and other overlays on the lot can add requirements; Address Check shows which apply to one address.
Example: extending a house on land in the Land Subject to Inundation Overlay
An owner plans a rear extension. Melbourne Water states that the Land Subject to Inundation Overlay requires a planning permit for buildings and works; councils in the Port Phillip and Westernport region refer those applications to Melbourne Water, and its consent may be needed before the council issues a permit (Melbourne Water, verified 21 Oct 2026). The permit exemption for a small second dwelling (granny flat) applies only where there is no flooding control (Department of Transport and Planning (Victoria), verified 20 Aug 2026), so a granny flat here needs a permit too.
How much of Victoria this covers
From the 2899 sample suburbs Address Check's export has processed so far — a lower bound, not a statewide total, until the export runs statewide.
106,841 land parcels and 192,844 addresses in the sample so far.
Councils with the most coverage
- Greater Shepparton (15451 lots)
- Casey (10437 lots)
- Cardinia (6294 lots)
- Campaspe (5392 lots)
- Wellington (4815 lots)
- Greater Bendigo (4174 lots)
Suburbs with the highest share
- Koo Wee Rup — 99% of addresses checked (2105)
- Hmas Cerberus — 99% of addresses checked (163)
- Bayles — 99% of addresses checked (215)
How it has changed since 2017
Vicmap Planning's published scheme history tracks where the Land Subject to Inundation Overlay has applied since 2017-07-30, recording when it was added to or removed from a parcel and the gazettal date where one is recorded. Address Check shows this timeline for any specific address — check below.