$40 million project boosts flood resilience
This time the rain on Alec Louverdis’ tin roof did not see him lose sleep.
The night before the Nelson City Council’s infrastructure group manager was to help mark the completion of the a $40 million Saxton Creek flood resilience project, the region was under a heavy rain warning.
But the council manager was unfazed that the storm would cast a cloud over the Saxton project. “I had absolutely no concerns,” he said.
That’s because the Saxton Creek upgrade, a nine-year, four-stage, two-kilometre project from Champion Rd to the Waimea Estuary, is designed to cope with a 1-in-100-year flood, up from a 1-in-5-year capacity.
The creek’s threat to surrounding homes and businesses was vividly demonstrated in the 2011 and 2013 floods that caused millions of dollars of damage in the area, spurring the Nelson and Tasman councils into action over a waterway that straddles their boundaries.
In the event on Friday there was only a steady drizzle at the opening ceremony where council staff, contractors and Associate Regional Development Minister Mark Patterson gathered at the headwall of the Main Rd Stoke culvert.
The open box concrete culvert was part of the final, three-year stage of the project, a complex engineering feat to widen the creek and channel it through two large industrial yards to the estuary.
The previous three stages saw the creek widened from the top of its catchment. Around 4500 tonnes of rock armour and detention dams were used to reduce water velocity.
Louverdis said the project was one of the most complicated the council had been involved in.
The challenges began before any work started, requiring protracted negotiations with up to 40 landowners over boundaries and fencing to accommodate the creek widening. Ownership changes meant sometimes the council was on the verge of an agreement only to have to start again with a new owner.
Ex-tropical cyclones Fehi and Gita in 2018, the August 2022 atmospheric river of rain and more flooding in May last year set the project back, requiring extensive cleanups, but also underlined its importance.
Other challenges included the impact of Covid, and the complicated diversion of creek water through pipes while contractors worked. A population of large eels also had to be moved.
Louverdis said the upgrade also had recreational benefits. A walkway built alongside the landscaped creek bed and margins was a “lovely place to be”.
Nelson mayor Nick Smith said the project was a significant milestone in improving Nelson’s resilience against damaging storms.
He said in an area of rapid residential and business growth, as well as the continued Saxton recreational development, investment in infrastructure was vital to support that.
The council was proposing to spend another $144 million over the next 10 years on stormwater and river protection infrastructure.
Patterson acknowledged the previous Government had contributed $7.5 million to the final stage of the Saxton project. He said the coalition Government’s $1.2 billion regional infrastructure fund would make investments in similar projects and its fast-track consent legislation would speed them up.
“This project is an example of a project that has taken too long,” he said. “Consenting takes too long in New Zealand and we are determined to fix that.”