Onetangi Beach protection

Current status | Options

Onetangi Beach

Onetangi Beach is approximately 1.6 kilometres long, situated on the southern shore of Onetangi Bay, Waiheke Island. The beach is bounded by the western headland of Onetangi Bay and a rock promontory in approximately the centre of the bay.

Onetangi Beach is dynamic and changes during periods of high and low wave energy. During high energy the beach erodes and during prolonged periods of low energy the beach accumulates.

A long term management solution is needed to protect and enhance the existing values and qualities of Onetangi Beach, for the enjoyment of the community. It is recommended that a management strategy be implemented to take into account the future deterioration of Onetangi Beach. The strategy is to develop a long term approach to:

beach access controls
provision of a dune vegetation buffer
preventing parking seaward of the existing road, and provision of public parking outside the coastal hazard zones
catchment based stormwater controls to reduce peak flows and concentrated stormwater discharges
planning methods to control increased development within the coastal hazard zone
removal of Auckland City structures within the current hazard zone
sand transfer to increase the width of the upper beach area, by transferring sand from the lower beach

The development of the road along Onetangi Beach has substantially changed the natural dune/beach processes by building over and seaward of the historic dune crest. The current buffering capacity of the dune system is low.

At present the upper Onetangi Beach appears very healthy, with significant volumes of sand accumulating on the upper beach since monitoring began in 1998. The beach has accumulated approximately 50m³ of sand between December 1998 - March 2001. This evidence supports the opinion that the beach appears to be reasonably stable.

Recent photographs (March 2002) show similar beach levels to those of March 2001 and the rapid growth of isolated clumps of spinnifex plant.

In the future Onetangi Beach has the potential to be affected by:

storm induced erosion
erosion from climatic fluctuations
long term erosion trends
impacts from sea level rise

The present healthy state of the beach is an extreme beach state position, with cyclical changes meaning that reduced beach levels from erosion are likely to occur in the future. Potential climate change effects could also intensify the erosion process.


1915	1930	1940	1961

1980	2001	2002	2002