Environment Waikato is disappointed some beachfront property owners have started to build an additional boulder wall at Mokau in an attempt to protect their properties from coastal erosion.

Severe storms earlier this month battered the frontal dunes at Mokau, causing one bach to slip into the sea.

Earlier this year an agreement was reached with affected property owners that a resource consent application would be made for an existing boulder wall. However this wall is now being extended without authorisation and prior to the application being lodged with council.

Because these further works are unauthorised, Environment Waikato has served abatement notices on the land owners who are building the new wall, instructing them to cease.

Environment Waikato coastal manager Hugh Keane said managing coastal erosion at Mokau was extremely difficult given the high energy coastal environment and council could not condone property owners ignoring the Regional Plan rules.

“We’re probably dealing with the worst case scenario here when it comes to managing coastal erosion – a West Coast dune system adjacent to a river mouth.”

The frontal dunes at Mokau have been identified for many years as a high risk zone under the Waitomo District Plan.

Environment Waikato and Waitomo District Council have been working with the Mokau community for the past decade to find solutions, but few have proved practical given the challenging environment.

“Two years ago councils ran a series of meetings with the Mokau community and we engaged coastal experts to look at practical options to manage erosion,” Mr Keane said.

“Unfortunately, given the high risk environment, there were no cheap options. The cost of building a properly designed seawall was estimated at $1.3 million, but the community felt that was just unaffordable and impracticable.”

In the past few years, affected property owners have tried to protect their properties by building unauthorised seawalls out of sandbags, boulders and timber – but the council says these structures can only be considered temporary and could exacerbate the erosion problem for unprotected properties.

“Some of the unauthorised walls are breaking down and the nylon sandbags are floating loose, and could become a potential safety hazard to boaties,” Mr Keane said.

“In addition, if property owners continue to build these makeshift structures, public access along the beach may become difficult.

“While we recognise the plight of the affected property owners, there is really no easy solution to this problem.”

Environment Waikato will continue to monitor the situation and in the interests of public safety, and for the stability of adjacent land, urges people not to add to the existing seawalls.