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Coastal erosion and coastal flooding are the main coastal hazards in our region. Most of this threat is to buildings located within the zone of natural shoreline change. Coastal flooding will increase due to sea level rise caused by global warming. Find out more about threats to our coastal marine areas.
Our coastline
The Waikato region’s coastline has about 1,150 km of open coast and shoreline, including estuaries. Our coastline is made up of the following distinctly different areas:
- East Coast - Coromandel Peninsula.
- West Coast - Coromandel Peninsula and the Firth of Thames.
- West Coast - from just north of Port Waikato heads to the Mokau River mouth.
The East Coast has mainly medium-sized estuaries and wide sandy beaches separated by rocky headlands and cliffs. Some open coast beaches are backed by extensive areas of sand dunes.
The West Coast of the Coromandel Peninsula and the Firth of Thames is a mixture of rocky coastal fringe and narrow sand and gravel beaches. The West Coast (from Port Waikato to Mokau) features long sandy beaches, areas of cliffs and dunes and three large estuaries.
Our coastal environment is constantly changing as the shoreline moves and sea level varies. These changes become a hazard when they threaten human life and property.
Coastal hazards
Coastal hazards in the Waikato region include:
- coastal erosion
- wind erosion
- flooding
- storms
- climate change (sea level rise)
- tsunami.
The main coastal hazards in the Waikato region are coastal erosion and coastal flooding:
- Coastal erosion is a natural process that affects all coastal areas of the Waikato region, with the shoreline moving as part of normal beach behaviour.
- Coastal flooding occurs during large storms as a result of high tides, storm surges and large waves. Areas prone to coastal flooding include the low lying areas around the Firth of Thames, some eastern Coromandel Peninsula settlements, and large, intensively farmed flood plains in the Hauraki District which are near sea-level. High tides can also affect river flooding, increasing water levels some way up a river from where it flows into the sea.
Houses are at risk from coastal erosion or flooding in over half of our coastal settlements in the region. The risk from coastal erosion has been caused by building too close to the sea to allow for natural shoreline changes. In many cases coastal development has damaged vegetation and sand dunes that protect the shoreline. Climate change will worsen this situation due to rising sea level, changes in winds, waves and currents, and an increase in the strength and frequency of coastal storms.
Coastal flooding can also threaten ‘lifeline’ services such as water, power, telecommunication and transportation networks. Find out more about managing Lifelines to deal with unexpected emergency or natural hazard events.
What we are doing
Environment Waikato:
- has developed risk mitigation plans, which minimise the effect of natural hazards on the Waikato economy and community.
- investigates and monitors coastal hazards such as erosion and flooding.
- develops site-specific coastal mitigation strategies, based on the Coastal Flooding Regional Management Strategy and the Coastal Erosion Regional Management Strategy.
- is one of several local government organisations that manage Civil Defence and Emergencies in the Waikato region under the Civil Defence Emergency Management Act 2002. This involves planning, staff training and the provision of response teams ready to deal with emergencies and Civil Defence.
- has a Regional Coastal Plan that sets out methods of improving coastal hazard management. Our Regional Policy Statement includes significant resource management issues relating to our coastal resources.
- provides coastal flood protection and advice to territorial local authorities about risk from coastal erosion and flooding. We also develop region-wide strategies to manage coastal erosion and flooding. These strategies also identify issues that warrant further investigation.
- has prepared a Summary Report on Coastal Hazards and Setback Recommendations that covers information on beach erosion on the Coromandel. This report presents recommended development setbacks (minimum distances from the shoreline required for building activities) so that district councils can plan coastal development.
- works with beachcare groups with the local community and district councils to protect and restore beaches.
For more information, see our coastal hazards and coasts indicators, and check out our publications pages.
For policy information on natural hazards, see section 3.8 of our Regional Policy Statement.
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