Coastal Management

We're lucky to have some of the most beautiful and pristine beaches in New Zealand, if not the world, on the Coromandel, that's why we've adopted an ambitious programme to work with all stakeholders to manage the effects of climate change.

Making progress on our coastal erosion maintenance

Photo above: Whangamata Beach Access 8.

We're experiencing continued coastal erosion around our open East Coast beaches, with Whangamata, Pauanui, Tairua, Whangapoua, Mercury Bay, Cooks Beach among the notable spots.

"This is continuing as a result of back-to-back storms we’ve had since the beginning of June," says our Coastal Scientist Jamie Boyle. "As well as this, we’ve identified 14 sites around the district that require monitoring and consideration of mitigation alternatives to the ‘living with nature’ approach,” he says.

We will be considering how these issues and sites are best addressed through the upcoming Coastal Panel workshops associated with the Shoreline Management Plans.

Jamie explains more on why this happens to our dunes which you can read below.

“Coastal erosion is a district wide issue and the costs are significant to do any type of hard and soft work structures,” says our Mayor Sandra Goudie. “Protecting and enhancing the dunes we have left is critical to the future of beaches and existing beachfront properties.”

The options we have to react to coastal erosion are many and invariably costly.

"Our Council can’t just go in and do works as and when it sees fit," says Jamie. "As well as construction costs, there’s also consenting and consulting costs that have to be managed, and unless we can prove that critical infrastructure is at risk (parks and sand dunes don’t count as critical infrastructure), then the process can take a very long time."

Here's some indicative construction estimates for an 80m section of foreshore:

  • Brophys Beach (Ohuka Beach) - Maintenance work on the geotech wall scheduled in September 2020 has been deferred until 2021.The estimated cost for this work is $20,000.
  • Buffalo Beach - Maintenance also started on this week on the rock wall as recent inspections identified some damage and rock movement due to a series of easterly storms and large swells. Work will happen at low tide (weather permitting) over 10 days with an estimated cost of $10,000.
  • Flaxmill Bay - The consent is still being processed with assessment currently being done by Waikato Regional Council (WRC) in relation to the adaptive management plan associated with the five-year trial of the groynes. It is hoped that this will be accepted in the next few weeks by WRC, and then the construction could then begin.
  • Community planting days - Dune restoration planting dates for this season can be found here.

Dune erosion chat with our Coastal Scientist

Due to the recent storm events our dunes have eroded in Whangamata (pictured right), Pauanui and Whitianga. Our Community Facilities team are monitoring the areas.

"The current dune erosion is completely natural and the active dune that has lost sand is doing exactly what it should be doing and providing a buffer for wave energy," says Jamie Boyle our Coastal Scientist.

  • During long periods of settled weather, sand builds up on the visible part of the beach, including the dune. However, short-term erosion can happen during storms, as waves erode the beach and the dunes closest to the sea. This often leaves a near vertical cut in the face of the dune (an ‘erosion scarp’) as shown by the diagram below. The eroded sand is carried offshore into the surf zone, where it forms shallow bars that help absorb storm wave energy.
  • Significant dune erosion can occur in just a few hours, but full sand dune and beach recovery can take years.
  • After the storm, the beach area repairs itself first before the dunes can recover. Gentler wave action moves sand back to the shore, slowly rebuilding the beach. Dry sand is then blown further inland and trapped by sand binding vegetation to repair the eroded dune. The diagram on Waikato Regional Council's website shows how dunes are repaired following beach recovery.
  • Natural dune repair depends on a good cover of native sand binding grasses, such as spinifex and pingao, to trap moving sand.
  • Erosion through climate cycles sees shorelines on Waikato beaches move naturally over periods of decades, with the largest changes usually seen near estuary and river entrances. Though periods of erosion can continue for years, in most cases it is not permanent. When viewed over a long period, such as a hundred years, the shoreline is simply shifting backwards and forwards.

Waikato Regional Council have some great resources on dune erosion available here.

Diagram: Erosion scarp during a storm.

Coastal Management Strategy

Our beaches are one of the major reasons for people coming to visit and live here. But keeping them in such magnificent condition comes at a cost, given the effects of climate change, storm events and other natural processes. 

In 2018, our Council adopted the Coastal Management Strategy, which sets out a range of initiatives we will be taking over the coming years to better manage our coastal assets and understand the risk of coastal inundation and coastal erosion. The 2018-2028 Long Term Plan includes $2.6 million over three years to help us implement this strategy. 

This approach to coastal management activity ensures a district-wide approach, allowing us to better-manage our coastline from a holistic and long-term perspective. We work together public and private organisations such as the Waikato Regional Council, New Zealand Transport Agency (NZTA), the Department of Conservation, iwi and community groups with an interest in coastal protection.

‘Coastal management’ encompasses a wide range of projects to identify hazards and risks and develop Shoreline Management Plans to combat these, with a view to building ‘resilient’ coastal communities.

The CMS was adopted by Council in June 2018. You can download the strategy on the top right-hand-side of this page.