Simplified hazard analysis for Dunedin
Nobody can predict with any accuracy when our next emergency will occur. Often emergency events are predicted on the likely time between events of a given severity. This is only an indication of the risk level - Invercargill suffered three 'one hundred year' floods in a five-year period.
The only sure thing is that one day we will be affected by a major disaster. The following tables give an indication of the risks we face in Dunedin.
You need to think about which of these events could affect you at home and where you and members of your household spend a lot of other time, such as work, childcare and places of education or recreation.
In any emergency - phone 111
Coastal hazards
| Hazard Likelihood | Description |
|---|---|
| At least 10% chance of happening this year | |
| 1% - 10% chance of happening this year | Storm surge (up to 2 metres) Long term sea level rise |
| 1% or less chance of happening this year | Tsunami or storm surge (up to 3 metres) |
Earthquakes
| Hazard Likelihood | Descriptions |
|---|---|
| At least 10% chance of happening this year | Minor felt effect - no serious damage (from local faults) |
| 1% - 10% chance of happening this year | Buildings damaged, roof tiles falling, chimneys break, furniture moves (from local faults) Up to 2 minutes shaking causing widespread damage and disruption (from Alpine Fault) |
| 1% or less chance of happening this year | Widespread building and bridge failure, ground cracking and landslips (from local faults) |
Flooding
| Hazard Likelihood | Description |
|---|---|
| At least 10% chance of happening this year | Minor events only from river and stormwater |
| 1% - 10% chance of happening this year | River events: Leith, Lindsay, Kaikorai, Contour Channel, Waipori, Waikouaiti, Strath Taieri, Owhiro (except through Mosgiel) Stormwater events: South Dunedin |
| 1% or less chance of happening this year | River events: Taieri, Silverstream, Owhiro (through Mosgiel) |
Landslide
| Hazard Likelihood | Description |
|---|---|
| At least 10% chance of happening this year | Induced by heavy rainfall (minor scale) |
| 1% - 10% chance of happening this year | Geological origin |
| 1% or less chance of happening this year | Earthquake triggered |
Meteorological
| Hazard Likelihood | Decription |
|---|---|
| At least 10% chance of happening this year | Heavy rainfall (100mm in 24 hours) Heavy snowfall (>15cm at 200m) Strong wind (100kts or 185km/hr) Hail storm (>5mm stones) Lightning - around 300 strikes to the ground each year in Dunedin |
| 1% - 10% chance of happening this year | Heavy rainfall (more than 100mm in 24 hours) Heavy snowfall (30cm at sea level) Strong wind (130kts or 240km/hr) |
| 1% or less chance of happening this year | None |
Technological hazards
Due to the totally random nature of these events and their contributing factors, no estimated probability can be given for the following:
- Major urban or rural fire
- Exposion or leakage of gas
- Major hazardous substance incident
- Major transportation accident
- Failure of dam or structures
- Sabotage of essential utility service
Last reviewed: 25 Jul 2008 2:10pm
Phone us on 477 4000
