Combined stormwater flooding results for WCC for a 1yrARI event including climate change. Includes the following catchments: Owhiro Bay, Horokiwi, Haitaitai & Kilbirnie, Karori, Roseneath, Island Bay, Lyall Bay, Southern CBD, Tawa, Johnsonville, Khandallah, &Miramar, Wilton

Purpose:

Wellington City Council and Wellington Water are working together to create an updated flood hazard map for Wellington catchments.

The main purpose of a flood hazard map is to provide up-to-date information to the community. It takes into account sea level rise and increased rainfall caused by climate change and will help people better prepare for existing flood risks and avoid inappropriate building in floodplains.

The flood hazard map gives you the opportunity to see what your suburb would look like in a once in 10 year flood and a once in 50-100 year flood.

The flood hazard maps, once verified, will appear in District Plans, will be available on LIMs, and will be a key document in the consents process. Current flood plans are available through the Council website.They’ve been completed to best practice standards and have been peer-reviewed by an external independent party.

Data Details

Vertical Datum: 1953 Wellington City Vertical Datum.

Coordinate System: NZGD 2000 New Zealand Transverse Mercator

Smoothed Flood Modelling Results categorised into the following depth bands:

0.05 – 0.10 m

0.10 – 0.25 m

0.25 – 0.50 m

0.50 – 1.00 m

> 1.00m

Data Traceability

GIS data published by: Modelling Team (Rebecca Buchanan) 17-06-2020

Original smoothed layers created by: Jacobs (Keith Hastings)11-06-2020

Modifications:

08-07-2020: Added Khandallah and Miramar

22/2/2022 - Removed negative sized Area polygons and zero sized Area polygons from the base feature class, then re-published. There were about 1,000 of them.  The total amount of records dropped from about 17,000 to 16,000. Chrissy S.