Eastern Coromandel Tsunami Strategy

On this page: About the project, Whitianga and Mercury Bay, Wharekaho (Simpsons) Beach, Cooks Beach, Hahei and Hot Water Beach, Matarangi, Whangapoua, Kennedy Bay, Kuaotunu and Opito Bay, Whangamata , Whiritoa, Pauanui and Tairua

About the project

The devastating earthquake which struck Japan in 2011 was a graphic example of the threat posed by tsunami generated just offshore. Research undertaken in 2012 provided new information about the risk of such a big tsunami hitting Whitianga as a result of a major earthquake in the Tonga-Kermadec trench to the north-east of New Zealand.

To address the risk of tsunami affecting the eastern coast of the Coromandel, Thames-Coromandel District Council, Hauraki District Council and Waikato Regional Council have developed an Eastern Coromandel Tsunami Strategy. The initial work undertaken in 2012 for Mercury Bay was followed up in 2013/14 with work in the Tairua and Pauanui communities, Whangamata and Whiritoa in 2014/15, and Matarangi and Whangapoua in 2015/16.

The work undertaken from 2013 to the present assessed the risk of tsunami affecting the eastern Coromandel from both Distant and Near sources (click here for each of the coastal areas.)

A report on the effects of the 1960 Chile tsunami undertaken in 2014 uncovered new information of the tsunami impact on Whitianga, especially the susceptibility of Whitianga to both Distant and Near source tsunami.

Therefore, further assessment of Whitianga tsunami impacts was undertaken in 2016 to address both the new information from the 1960 tsunami study and to be consistent with the work undertaken in the other eastern Coromandel areas since 2013. The 2016 tsunami assessment also included the areas of Wharekaho (Simpsons) Beach, Cooks Beach, Hahei and Hot Water Beach.

After each assessment, public open days or information sessions were held for each community. The open days provided a great opportunity for people to learn about tsunami hazards and risks on the Coromandel and an opportunity to provide input on how risks should be managed.

The tsunami assessments have been used to assist communities understand what to do when there is a tsunami threat. To know more about evacuation procedures due to a tsunami threat, please click here.

Whitianga and Mercury Bay (2016)

Tsunami open day at Whitianga.

Tsunami assessments

Managing Tsunami Risks in Mercury Bay [PDF, 2 MB]

Numerical Modelling of Tsunami Inundation in Whitianga, Mercury Bay, Hahei and Hot Water Beach - 2016 [PDF, 6.7 MB]

Numerical Modelling of Tsunami Inundation in Whitianga, Mercury Bay, Hahei and Hot Water Beach - 2016 (APPENDICES) [PDF, 15 MB]

Maps - Near Source - ‘Maximum Credible Event’

Map: Tsunami modelling - elevation of area [PDF, 12 MB]

Map: Tsunami modelling - water flow depth

Map: Tsunami modelling - water flow speed

Map: Tsunami modelling - hazard classification

Maps - Distant Source

(note that Whitianga is the only significant area along the eastern Coromandel that is susceptible to tsunami inundation from a Distant Source event)

Map: Tsunami modelling - water flow depth

Map: Tsunami modelling - water flow speed

Map: Tsunami modelling - hazard classification

Whitianga (2012)

The information below is based on work undertaken in 2012 for Whitianga. Please note that while the new tsunami impact assessments provided above have been undertaken in 2016, the outcomes below still provide good guidance for Whitianga.

Map: Tsunami modelling - ground elevation, flow depth, flow speed and hazard

Tsunami recommendations:

Whitianga's Tsunami Risk Management Plan was presented to the Mercury Bay Community Board on 19 June 2012. The finished Whitianga Tsunami Risk Management Plan provides a roadmap for risk management actions – initially over a period of three years.

Download a copy of the full plan here [PDF, 204 KB]

The Whitianga plan was the pilot project, and first off the blocks because Whitianga is the most at-risk part of the Peninsula, because the shape of its bay would make the effect of a tsunami worse.

The primary actions to be undertaken from this first plan include:

Warnings: upgrading the siren system to provide better coverage of the town, and support options for warning such as local telephone trees and neighbourhood support groups

Evacuation: moving the official Southern evacuation point to the forestry road, and investigating the options for improving evacuation road access to State Highway 25

Public education and awareness: formalisation of an on-going programme to target the school, visitors and residents

Land-use planning: investigation of long-term options for ensuring vertical evacuation sites at the school and the CBD, and development of policies that will restrict development and redevelopment of critical facilities in the future. Implementation will involve the collaboration of council, Mercury Bay Community Board, the Emergency Services Committee and community members. It is anticipated that the working party will continue in some form to oversee implementation, and progress will be reported back to the Community Board at regular intervals f

Useful Posters

Download three of the planning posters (PDF 5MB) that were displayed at the June 2011 Tsunami Open Days held at the Whitianga Town Hall. These show examples of what Whitianga could look like in the future and why land use planning is needed.

Cooks Beach, Hahei and Hot Water Beach

Tsunami Open Day

10am-12pm
Saturday, 17 November
Cooks Beach Community Hall

The tsunami open day is an opportunity for the local community to learn about tsunami and the potential threat to Cooks Beach, Flaxmill Bay and Ferry Landing area.