How does your property face up against a flood?

by Metropol | December 10, 2025 8:39 am

Updated flooding predictions for parts of the city are now available and searchable on Christchurch City Council’s online flood map. Search the latest data for flood events that are predicted to happen every 10, 50, and 200 years.

“Anyone making decisions about a property or about flood readiness for their home or business can search the map and see whether the land may be affected by a specific predicted flood event,” says Head of Three Waters Gavin Hutchison. The updated mapping will help people to easily access the latest information and understand any predicted flooding for those events on a given property. “Similarly, people who are building or undertaking major renovations can check the calculated minimum floor level they may need to protect their house from floodwater. Where this isn’t yet available on the map, we can calculate it if people contact us.

“Checking our flood map is a great first step, but it doesn’t replace getting site-specific advice about the suitability of the land for any intended purpose, as well as getting information from other sources, such as a Land Information Memorandum (LIM), property file, or insurance assessments,” says Gavin.

The Council’s flood map uses localised information and provides a more detailed view of specific flood predictions for Christchurch than the national-level flood data released by Earth Sciences NZ (formerly NIWA) in October. Local flood predictions are calculated by recording flood-related data, putting it into a computer model of the city, and then checked against historical flooding. There are separate computer models for the different urban river catchments in Christchurch – the Avon, Heathcote, Styx, and Halswell rivers – as well as for the Sumner Coastal Catchment. Flood-related data includes land development, infrastructure projects, rainfall, tides and sea level, ground level, and climate change. In some parts of the city, a flood model update can mean more predicted flooding, such as where the latest climate predictions result in higher water levels. In other parts, it can be less, such as where the Council has completed projects to reduce flooding.

To access the flood map, go to ccc.govt.nz/services/water-and-drainage/stormwater-and-drainage/flooding-and-floor-levels.

Source URL: https://metropol.co.nz/how-does-your-property-face-up-against-a-flood/