Environment – Mangawhai dune care update

Mangawhai’s coastal environment continues to benefit from the dedication of the Mangawhai Harbour Restoration Society (MHRS) and its ongoing work to protect and enhance the area’s fragile dune system. Over recent weeks, three key initiatives have been progressing: the annual fencing programme, a brushwood fence trial and preparations for the annual dune grass planting season.

Our annual fencing programme is now complete, with more than 275 metres of fencing installed or upgraded at several locations along the coastline. These fences help stabilise sand movement, protect sensitive dune vegetation and reduce trampling of newly established plantings.

Well-designed fencing plays a critical role in dune management by helping stabilise shifting sands and allowing native vegetation to establish and thrive. Protecting restoration areas remains an important part of safeguarding our beaches for future generations. The ongoing support of committee members and local volunteers has once again been instrumental in completing this work efficiently and to a high standard.

We have also recently completed a new 15-metre brushwood fence trial to investigate an alternative method of dune stabilisation. Brushwood fencing uses natural materials placed strategically across wind corridors to trap windblown sand and encourage dune formation.

The trial, approved by the Department of Conservation and Te Uri o Hau, will help determine whether this type of fencing is more durable than the hessian we currently use. The fence was relatively straightforward to install, and we constructed a T-section at each end. If it lasts three to four times longer than hessian while effectively trapping sand, it could become our preferred fencing system in the future.

The trial is expected to provide valuable information that will support future dune management projects and complement our existing planting and fencing programmes. Continued monitoring over the coming months will help determine its long-term effectiveness and whether it could be used more widely along the coastline.

Preparations are also underway for our annual dune grass planting programme, which plays a vital role in restoring and strengthening Mangawhai’s foredune system. We expect planting to begin midway through this month.

Native sand-binding species such as spinifex and pīngao are planted each year to help stabilise dunes naturally, trap windblown sand and improve coastal resilience. This year, we plan to plant more than 3000 plants. These species are uniquely adapted to New Zealand’s coastal environments and form the foundation of healthy dune ecosystems.

Community participation remains at the heart of this programme, with volunteers contributing thousands of plants over the years. Each planting season builds on previous efforts, creating stronger dunes that are better able to withstand storms, erosion and increasing coastal pressures.

Together, our annual fencing programme, brushwood fence trial and ongoing dune planting efforts demonstrate MHRS’s commitment to protecting Mangawhai’s coastline. Thanks to the continued support of our volunteers and community, we are making steady progress towards healthier, more resilient dunes for future generations.