Hazard guide

Flood risk explained

What Auckland Council flood layers mean when you are buying a home, in plain English.

Auckland uses several flood-related layers because flooding happens in different ways: rivers overflowing, rain running overland, water pooling in low spots, and planning rules for known hazard areas. iQHOME checks all four water-related flood layers at your property pin.

Layer

Flood plains

Areas modelled for river and stream flooding, typically based on a 1% annual exceedance probability (1% AEP) event, often described as a severe storm scenario. If your pin is in a flood plain, the property may be at risk of inundation from waterways during heavy rain.

Layer

Overland flow paths

Routes rainwater takes when it cannot drain fast enough, often downhill across roads, driveways, or sections. A property in or next to a flow path may see sheet flow or pooling during intense rainfall even if it is not beside a river.

Layer

Flood prone areas

Areas where water tends to collect on the ground during storms. These can include depressions, poorly drained pockets, or historic flooding locations identified by council.

Layer

Flood hazard areas (PC120)

Planning-related flood hazard classifications used under Auckland Unitary Plan rules. These can affect building requirements, earthworks, or consent conditions even when flooding is less obvious day to day.

What to do next

If flood layers appear at or near your pin, ask your lawyer about LIM notes, talk to your insurer, and consider whether a site-specific assessment is warranted. iQHOME is a starting point, not a final engineering answer.

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