Help for coastal communities at risk of tsunami

Information released by MBIE’s Building System Performance team and the National Emergency Management Agency (NEMA) will help communities across New Zealand address a crucial issue – how do people living in low-lying, coastal areas evacuate in time from an impending tsunami?

To address this issue, MBIE has worked together with NEMA to produce a document which provides technical information on how to design tsunami vertical evacuation structures that can be used as a last-resort refuge for people in the event of a tsunami.

“They may be a good option for low-lying, coastal areas of New Zealand, where it may not possible for all those at risk to evacuate inland, to higher elevations, or out of tsunami evacuation zones before tsunami waves arrive,” says Jenni Tipler, Manager of Engineering at MBIE.

“We had been hearing from a number of communities that this was an area of real concern for them, so we worked together with NEMA to help develop information that will address this risk,” says Jenni.

“The information describe in detail the design elements of an effective structure.  Some communities will already have buildings available that can be identified as appropriate evacuation places, while other communities can use the information when building new structures in their area,” Jenni says.

The new technical information follow the release of the Assessment and Planning for Tsunami Vertical Evacuation Guideline for Civil Defence Emergency Management Groups in 2018.

“As New Zealand matures in its approach to tsunami risk management, we continue to address some of the more difficult challenges we face in managing tsunami risk,” said Sarah Stuart-Black, Director Civil Defence Emergency Management.

“Tsunami vertical evacuation structures provide a last resort option for life safety that Civil Defence Emergency Management Groups may wish to consider. Their use is most appropriate during local source tsunami events, when available evacuation time can be minutes.

“The two-phase information produced by the National Emergency Management Agency and the Ministry of Business, Innovation and Employment will help Civil Defence Emergency Management Groups ensure they are implementing the most appropriate and practical tsunami risk management measures, when considering tsunami vertical evacuation in their areas.”

The information provides another tool to help reduce the impacts of tsunami says Hawke’s Bay Civil Defence Emergency Management Group Controller Ian Macdonald.

“The development of technical information for tsunami vertical evacuation structures is important for Hawke's Bay coastal communities as it gives them another tool to help reduce the impacts of tsunami, especially those communities that do not have a safe area they can easily evacuate to after a long or strong earthquake.

“This will also give us the technical information to help our conversations with developers and infrastructure providers who want to consider these structures as part of projects in tsunami evacuation zones.”

The new Tsunami loads and effects on vertical evacuation structures information is available on the Building Performance website. The 2018 Assessment and Planning Guidelines for Tsunami Vertical Evacuation document is available on the NEMA website.

NOTE:

Tsunami vertical evacuation structures are considered a last resort option, if timely evacuation out of tsunami evacuation zones is not possible. Evacuation out of all tsunami evacuation zones should always be the first option. Remember: LONG or STRONG: GET GONE. If an earthquake lasts longer than a minute or makes it hard to stand, Drop, Cover and Hold during the shaking. As soon as the shaking stops, move immediately to the nearest high ground, out of all tsunami evacuation zones, or as far inland as you can.