What to do in an emergency
Civil Defence & Emergency Management (CDEM) recommends all New Zealanders are always ready for floods.
In the very unlikely event of an incident at the dam requiring an evacuation downstream, Civil Defence or the New Zealand Police will lead the response.
There will not be an evacuation siren. The New Zealand Police or Civil Defence will attempt to notify people within the evacuation zone if they need to evacuate. The public will be alerted through established Civil Defence procedures. The primary means of notification is the Emergency Mobile Alert, in addition to messaging on Civil Defence social media and website.
After an earthquake that is long (longer than one minute) and strong (can’t stand up), it may not be possible to send notifications because other infrastructure unrelated to the dam (such as the electrical grid, cell phone towers and roads) may be damaged. In this case, you should rely on the severity of the event, other damage from the earthquake and your proximity to the river when deciding if you should evacuate.
The following are the links to key Civil Defence information and social media:
- Nelson Tasman Civil Defence and Emergency Management website
- Nelson Tasman Civil Defence and Emergency Management Facebook
Click here to see if your property is in the dam flooding evacuation zone. This map represents a ‘worst case’ conservative scenario. In the unlikely event an emergency develops and emergency services consider that an evacuation is required (most likely as a precaution), the extent of evacuation will depend on the weather and dam levels at the time and will be guided by the inundation mapping.
Your emergency preparations
How can you get ready for flooding following an emergency at the dam?
- Know if you are in the self evacuation zone (parts of River Terrace & Wairoa Gorge Roads, all of Lee Valley Road) or managed evacuation zone (both sides of the Waimea River from Brightwater to the coast).
- Follow Civil Defence’s advice on how to get ready.
- Read the Waimea Water EAP Fact Sheet and FAQ.
The Waimea Community Dam has been designed to be highly resilient, meeting the highest requirements of international engineering standards.
The dam is:
- Robust to a 1:150 year earthquake, with superficial damage only.
- Robust to a 1:10,000 year earthquake with no uncontrolled release.
- Able to pass a Probable Maximum Flood (equivalent to approximately three times the 1:100 year flood).
As well as being designed to withstand significant natural events like those above, it has built-in technology that enables any slow leaks to be identified so they can be remedied.
Waimea Community Dam’s emergency preparations
Waimea Water’s Damsafety System involves monitoring and maintaining the dam to ensure it performs properly and that people and property downstream of the dam are protected.
Part of being a responsible dam owner is to develop and test emergency plans. Good ongoing procedures and processes allow issues to be identified and resolved before they become emergencies.
The EAP has been prepared in accordance with the New Zealand Dam Safety Guidelines 2015, with input from our contractors and consultants, Civil Defence, New Zealand Police, Tasman District Council, and the other emergency services.
It will be in place for the life of the dam, with reviews scheduled every five years and updates made as necessary.
The EAP’s key components are:
- Preparation: monitoring any incoming flows into the dam to provide advance warning of possible floods. Setting up reporting and co-ordination plans with NZ Police and Civil Defence.
- Activation: how issues are identified and responses begun.
- Response: a contact flowchart and plan for who does what to respond to the issues.
- Monitoring: when and how monitoring is undertaken.
- Notification/warnings: in the highly unlikely event an emergency is declared (often even then only as a precaution), maps showing which areas might flood are used to implement emergency services’ evacuation plans.
Go here for more background reading.