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A harbour that nearly disappeared is now a legacy we are determined to protect. Mangawhai Harbour is at the heart of local life, and its future matters.
Mangawhai Harbour Restoration Society (MHRS) was formed to restore and protect our harbour. To understand why this work matters, we need to look back to the crisis that threatened to destroy it.
Fight for survival
In 1978, a storm ripped a 600-metre-wide breach through our iconic sandspit. Further storms and Cyclone Bola in 1988 worsened the damage. By 1990, the harbour entrance had closed completely, disrupting tidal flows and leaving the upper harbour stagnant.
The only access to the ocean was through the treacherous breach.
Frustrated by institutional inaction, locals took matters into their own hands. On February 11, 1991, more than 40 machines and more than 100 volunteers took part in the Big Dig, reopening the northern entrance and channel and starting work on closing the southern breach.
The permanent bund was completed five years later, and MHRS grew from those early efforts.
Maintaining the harbour’s tidal flows
Annual dredging keeps the main channel navigable and maintains the tidal movement essential to a healthy harbour. The dredged sand is returned to the sandspit, helping protect the barrier between harbour and sea.
Protecting the sandspit that protects our harbour
LiDAR surveys show our sandspit and dunes have lost 420,000 tonnes of sand, with six low points at risk of breaching. Volunteers have planted more than 150,000 spinifex and pīngao plants and installed over five kilometres of sand fencing to stabilise the spit.
Further sand placement is urgently needed to reduce the risk of another breach.
Protecting our harbour’s ecological balance
Mangroves have expanded from a handful of trees in the 1950s to more than 111 hectares, almost one fifth of our harbour at full tide. Together, restricted tidal flows from our causeways and nutrient-rich sediment run-off create conditions that encourage mangroves to colonise new areas.
As mangroves spread, they narrow waterways, restrict tidal flushing and encroach on saltmarsh. These habitats provide food, shelter and nursery areas for fish, birds and other wildlife. MHRS removes juvenile mangroves in consented areas to maintain the harbour’s ecological balance.
Guardianship takes all of us
An annual targeted rate of $80 per ratepayer within the harbour area helps fund this work, alongside grants and community funding. Our volunteer committee and dedicated, hands-on community volunteers lead the effort, supported by specialist contractors and partners including the Department of Conservation, Te Uri o Hau, Kaipara District Council and Northland Regional Council.
The Big Dig saved Mangawhai Harbour from collapse. That work is far from finished. Today, the challenge is keeping the entrance and channel open, protecting the sandspit and maintaining the balance between open water, saltmarsh and mangroves. This is the harbour our community swims, fishes, sails and gathers around. Protecting it means preserving a place central to Mangawhai life.
To find out more about MHRS and its work to protect Mangawhai Harbour, visit mangawhaiharbourrestorationsociety.com
