What the flood check looks at
Auckland Council publishes several flood maps. Each one answers a different question, and a property can be on one and not the others.
| Map | What it shows | Why it matters |
|---|---|---|
| Flood plain | Land a river or stream would spread over in a flood with a 1% chance of happening in any year | The most serious flood map. Affects insurance and building rules |
| Flood-prone area | Dips where rainwater pools if drains block or overflow | Matters if the house or garage sits in the dip |
| Flood-sensitive area | Land just above the flood plain | A bigger flood than mapped could still reach it |
| Overland flow path | Where stormwater runs across the ground when pipes are full | Common and often harmless, but nothing should block it |
We check each map against the whole section, not just the point where the address sits, and leave out maps that only touch the boundary line.
How to read the result
A map touching the section doesn’t mean the house will flood. A flood plain often covers only a back corner or a strip along a stream. Look at the map to see where the shading falls compared with the house and garage.
The council maps allow for heavier rain in future because of climate change, so they can show land that hasn’t flooded before.
After the January 2023 floods and Cyclone Gabrielle, insurers look closely at flood maps. Get an insurance quote before your offer is unconditional.
Check everything for one address, free
Flooding, the coast, land stability, zoning, planning rules and school zones, on one page. The full report with what to do next is $29.
See a sample reportWhat to do if a property is on a flood map
- Ask the agent and neighbours whether the property flooded in 2023 or before.
- Order the council LIM. It records known flooding and any council notices.
- Ask a building inspector to check floor levels, drainage and signs of water damage.
- Get an insurance quote early, and ask about the flood excess.
Read our guide to flood risk for more on each map and what it means for buyers.
Questions
Is a 1-in-100-year flood only once every 100 years?
No. It means a 1% chance in any year. Over a 30-year mortgage that adds up to roughly a 1 in 4 chance of at least one such flood.
Where does the flood data come from?
Auckland Council’s flood plain, flood-prone, flood-sensitive and overland flow path maps, the same ones the council uses for LIMs and building consents.
Does this replace a LIM?
No. It’s a quick screen you can run before you spend money on a LIM. If you go ahead with a house, still get the LIM. See what a LIM report includes.