Works to tackle sediment build-up in Havelock Marina are essential to the future of the aquaculture industry and health of the marine environment, according to Ngāti Kuia Environmental Manager Raymond Smith.
A karakia was held by local iwi representatives from Ngāti Kuia and Rangitāne last Thursday, to mark the commencement of works to improve Havelock channel access by Port Marlborough.
The project is backed by a $9.9 million loan from the Government's Regional Infrastructure Fund.
Lead contractor Isaac Construction started preparations for extensive dredging on Monday to remove sediment worsened by major storm events in 2021 and 2022.
The work also follows concerns from local boaties, who reported last year that sediment build-up had restricted marina access to high tide and made navigation through the channel dangerous.
Dredging will begin in January 2027, with sediment being dewatered within the marina and transported to a site south of Havelock. The area will eventually be restored to agricultural pasture.
The upgrade will also see wooden jetties D, E and F replaced with concrete pontoons and a new 20-metre jetty constructed.
Accessways and carparking areas are set to be raised, marina infrastructure designed to higher levels, and shoreline protection incorporated to reduce inundation risk, according to Port Marlborough.
Isaac regional manager Sean Walsh says carpark access will be disrupted until 18 December, when land-side works will be halted until early February for minimal disturbance throughout the busy summer season.
CEO Rhys Wenborn says the work will "create a layer of resilience" for Havelock in the face of growing storm frequency and severity.
Approximately 259,000 tonnes of suspended sediment is deposited in the Havelock estuary from the Te Hoiere/Pelorus Sound annually, making it one of the "muddiest" estuarine areas in New Zealand, according to a 2024 Environmental Defence Society report.
Port Marlborough states that sediment maintenance volumes have jumped from 1,500 cubic metres to roughly 20,000 cubic metres every five years since the 2021 and 2022 storms, resulting in build-up from widespread landslides and high-volume river run-off.
DOC says that high sedimentation levels can smother marine habitats, clog filter-feeding organs and reduce water clarity.
Ngāti Kuia's Raymond Smith says the impact of this on shellfish stocks and local aquaculture is becoming starkly apparent, referencing the Southern Scallop Fishery closure in 2017.
"The scallops have collapsed, the mussels are collapsing, other species are collapsing. So we need every bit of contribution to dredging the channel and pulling out these piles of all sediment.
"It just keeps coming and coming from the river."
Importantly, he says taking action now will help "look out for future generations."
"It keeps the Ala Moana open for us. This is our industry, the greenlip mussel capital of the world. It's got to keep going. We've got to keep it pumping."
