Sign In / Register
Mangawhai will commemorate one of the most defining moments in its history next month, marking 35 years since the community-led “Big Dig” saved the harbour from environmental collapse.
February 11 marks the anniversary of the 1991 operation, when locals took matters into their own hands to reopen the Mangawhai Harbour entrance after years of storm damage and bureaucratic delay left the waterway stagnant and dying.
The crisis started in 1978 when a severe storm tore a 450-metre breach through the southern end of the Mangawhai sandspit, disrupting tidal flow. Cyclone Bola in 1988 worsened the damage, and by 1990 the harbour mouth had closed completely. With circulation cut off, the lagoon became heavily degraded.
Faced with mounting environmental damage and little official action, a group of determined locals organised what became known as the Big Dig.
At dawn on February 11, 1991, more than 40 bulldozers, excavators and scrapers moved onto the sandspit. Working around tides and the clock for four days, hundreds of volunteers carved a 30-metre-wide channel, restoring tidal flow and flushing the harbour.
In the weeks that followed, attention turned to closing the dangerous southern breach. About 5000 sandbags were placed by hand, with assistance from 20 personnel from Papakura Military Camp, who were training in Mangawhai at the time and volunteered their help. Heavy machinery then constructed an initial sand bund wall.
Northland Regional Council later supported the effort with machinery and rock, enabling the reconstruction of the rock groyne to protect the reopened entrance.
Key figures involved included Gary Berghan, Noel Cullen, Torchy Jeffery, Jim Wintle and Richard Bull, along with many others, worked without legal consents and under the threat of prosecution.
The momentum from the Big Dig led to the formation of the Mangawhai Harbour Restoration Society (MHRS), which continues to oversee the harbour’s management. Coastal engineer Andre LaBonte and international expert Professor Bob Dean later helped develop a scientifically robust and legally compliant long-term solution.
Current MHRS chair Peter Wethey said the legacy of the Big Dig continues to shape Mangawhai today.
“Everything we enjoy now exists because the community refused to accept inaction,” he said. “What began as a rescue mission has matured into long-term stewardship and kaitiakitanga.”
Recent drone surveys have shown more than 420,000 tonnes of sand have been lost from the sandspit in the past six years, raising concerns about future breaches.
An invite-only anniversary event will be held at Mangawhai Museum on February 21 to honour the original participants. The public can also engage with the history through exhibitions at the Mangawhai Museum and Mangawhai Art Gallery, and through the book They Dared the Impossible by historian Beverley C. Ross.
