The Waimakariri District is exposed to a range of hazards and threats that may require a civil defence response. The hazards that have the potential to affect our community include flooding, earthquakes, snow storms, tsunami, fire, landslips and pandemic.
Other potential risks and hazards to the community include severe
meteorological events (e.g. wind, snow and drought), and long term
disruption to essential services such as electricity and fuel supplies.
Canterbury has a history of severe weather storms that cause flooding of rivers from their source in the mountains and sea surges that inundate the river mouth areas, especially of Ashley and Waimakariri Rivers.
While the Canterbury earthquakes of 4 September 2010 and 22 February 2011 remain vivid in our memories as two of the most significant and recent earthquakes in New Zealand history, there is a much longer history of earthquakes in New Zealand.
A major rupture of the Alpine Fault continues to threaten much of the South Island including Canterbury. There is a network of known fault lines in the west of the Waimakariri District and well defined areas of liquefaction prone land.
Canterbury has a recent history of significant snowstorms (1992, 2002, 2004 and 2006) that have impacted much of the region including Waimakariri. The western areas of the district are more prone to the impacts of snow storm due to their higher altitude and closer proximity to the alps.
The New Zealand tsunami report released 30 September 2013 described revised tsunami assessments for a number of regions of New Zealand, however there have been no significant changes to the tsunami assessment for the Canterbury coastline. The following tsunami information for Waimakariri District was produced well before the 30 September report but remains unchanged.
Along the Waimakariri District coastline, if you feel strong ground shaking it is most likely coming from an earthquake on land. Even if it is coming from an earthquake offshore it is very unlikely to have generated a tsunami. The consistent message across New Zealand is that if you are near the coast and feel strong ground shaking that lasts for more than 20 seconds (the longer the shaking, the bigger the earthquake magnitude), then you should move inland or to higher ground.
Council emergency management staff have further information about tsunami response plans for the District.
Warning time for a distant source tsunami could be as much as 12 hours; regional source could be as much as 3 hours. There will be no warning time for a near source tsunami. For further information on the Council's public warning system for tsunami, please see Tsunami Warning Arrangements - Public Information (pdf, 19 kB).
- The most likely tsunami scenario for Pegasus Bay is a tsunami
from South America - this gives approximately 12-15 hours to issue
warnings and evacuate people
- While we can't completely rule out a damaging local source tsunami
generated in Pegasus Bay, all indications are that the likelihood of
this is low.
Waimakariri District Council is responsible for fires in the rural areas of the District while NZ Fire Service is responsible for fires in the gazetted urban districts. Department of Conservation and Ashley Rural Fire District are responsible for fires within their respective lands.
Vegetation wildfires (fires that are burning out of control) are a risk predominantly in:
- Areas of heavy vegetation such as Ashley and Eyrewell forests, and the pine plantations within the District’s beach communities
- The western areas of the District where farmers use fire for land management
- Major river beds where off-road motor vehicle pursuits create fire risk.
Generally speaking these vegetation fire risks are significant only in the summer.
A landslide is the movement of rock and soil down a slope. Landslides can range in size from a single boulder in a rockfall to a very large avalanche of debris with huge quantities of rock and soil that can spread across many kilometres.
When a new flu virus infects many people around the world, it is called an influenza pandemic. If this happens, and the new virus enters New Zealand, many of us could become very sick.