Nelson City Council has completed its significant landslip recovery programme two years ahead of schedule, marking a major milestone in the city’s recovery from the August 2022 storm that damaged 570 properties and triggered 550 landslips.
The storm, described as the worst to hit the region in 50 years, left 109 homes red-stickered and caused 18 significant slips on council-owned land across urban Nelson.
Since then, the council has completed more than 45 resilience and recovery projects, including flood repairs, retaining walls, intake upgrades and culvert improvements aimed at making the city more resilient to future weather events.
“The completion of the slip recovery work is a major milestone,” Nelson Mayor Nick Smith says.
“This was the worst storm to hit our region in 50 years and the most complex work was the slip remediation programme. I applaud the council staff, engineering consultants and contractors on getting these fixed ahead of schedule and under budget.”
The council received $12.3 million from central government to support recovery efforts, including $6 million for landslip betterment projects, $6 million for property buyouts and $300,000 to monitor the Tāhunanui slump.
With government support, the council spent close to $10 million purchasing 20 storm-damaged properties, including 13 in The Brook.
“This milestone moment would not have been possible without Government support. The cost-sharing package totalling $12.3 million made the work affordable for the ratepayer. There are no easy answers when property owners are affected by such disasters and their homes are uneconomic to repair. Our pragmatic approach, with support from Government, enabled people to get on with their lives,” Nick says.
The decision to purchase properties on Brook St followed geotechnical investigations in November 2023 that identified an unacceptable risk from council-owned land above the homes.
Known as “slip zero”, “the Brook St site was the final significant slip to be remediated. Four years of work culminated in a protective bund and upgraded stormwater infrastructure designed to withstand future severe weather.
“We're extremely lucky that the weather has allowed us to complete our recovery programme before our region experiences another significant weather event,” executive director delivery Alec Louverdis says.
Each slip site required a tailored solution.
At Brook St, the council installed a debris fence similar to those used on State Highway 1 near Kaikōura. The mesh catch fence is secured with ground anchors drilled six metres into the hillside. A smaller version was installed at the Miro St slip site below Grampians Reserve.
“We've undertaken remediation approaches that have never been done in Nelson before,” Alec says.
“While the underlying cause was the same at every site, a slip triggered by heavy rain, the remediation approach and methodology for each was significantly different.”
In the Maitai Valley, a flying fox was used to transport materials across a steep river gorge to repair a damaged 12-metre section of Nelson’s above-ground raw water pipeline from the Maitai dams.
At Atmore Tce, a specialised spider drill secured a concrete ground beam and reinforced geomat mesh by drilling ground anchors seven metres into the hillside.
Although the slip recovery programme is complete, wider resilience work continues.
The first four stages of Regional Infrastructure Fund work in the Maitai have been completed, with the final stage scheduled to begin in early 2027. Planning is also under way for mitigation projects in Little Todd Valley and Glenduan, alongside several smaller intake, culvert and rock-armouring projects already completed.
The council has received a further $9 million from the Regional Infrastructure Fund.
“The potential for flooding is always a consideration, but our mindset has shifted from a ‘when it happens’ mentality to preparedness, planning and resilience,” Alec says.
To mark the milestone, Nick, Nelson MP Rachel Boyack, contractors and council staff gathered on Brook St for a community barbecue and public art project.
Kaumātua and iwi blessed the site before residents later painted concrete blocks that will form part of the new storm protection measures.
“Nelson is a stronger, more resilient city than it was four years ago,” Nick says.
“We’ve rebuilt smarter and better, we’ve looked after the people it hit hardest, leveraged funds off central government and we're better prepared for whatever comes next. That’s something every Nelsonian can be proud of.”
