Mangawhai dredging underway

Dredging

Mangawhai Harbor Restoration Society (MHRS) has started its annual dredging and sandspit stabilization program, continuing more than three decades of work to safeguard the harbor’s health.

photo courtesy of MHRS

The Spirit of Mangawhai II dredge was deployed mid-March, with operations scheduled through to July 31. Work is timed for autumn and winter to avoid disturbing the breeding season of the critically endangered fairy tern and other shorebirds, MHRS said.

New data from University of Auckland LiDAR surveys shows that the sandspit has lost 420,000 tons of sand over six years, with six areas now at risk of breaching.

MHRS is using dredged sand to reinforce two of these vulnerable zones, followed by dune stabilization using sand fencing and native plantings.

Dredging work also maintains tidal flow, helping prevent erosion and keeping the harbor navigable.