Westport’s ‘sleeping giant’
The Buller River is one of the West Coast town’s best features. It’s also one of its biggest threats Joanne Carroll reports.
On a calm day, Westport’s Buller River is one of the West Coast’s scenic gems, home to a busy council-owned fishing port and famous for its abundant whitebait.
One of the country’s longest rivers, it flows 170 kilometres from Lake Rotoiti in the Tasman district through the stunning Buller Gorge and into the Tasman Sea.
But when it floods, it has the highest flow of any river in New Zealand with up to 12,700 cubic metres of water flowing out to sea every second. The township of Westport is effectively an island surrounded by the Buller and Orowaiti rivers and the sea.
The town has escaped major flooding for almost 100 years with the help of a man-made overflow channel into the Orowaiti River, regular dredging and river training walls. However, those walls are in need of maintenance and the Orowaiti overflow has become overgrown. The Buller River is getting shallower. The riverbed is fast building up with gravel, and Westport residents were warned in 2017 lives could be lost and up to $144 million of property damaged if a major flood were to hit the town.
The Buller has been called the town’s sleeping giant. Some say all it will take is more dredging. Others say the town, with its 5000 residents, has no choice but to shift within the next 100 years.
Climate change coming calling
The entire West Coast is grappling with the significant risks posed by natural hazards.
The West Coast’s four councils were warned in a report in March, by regional council planner Lois Easton, that those risks should be a priority focus.
Her report said climate change could exacerbate coastal, river and landslide hazards, with more heavy rainfall, increased coastal erosion and flooding, and greater potential impact from tsunami.
When it comes to Westport, the West Coast Regional Council presented the public with three options in February 2017: do nothing, build floodwalls, or cut a new channel from the Orowaiti Lagoon to the sea.
It is expected to cost up to $9.4 million to build a series of floodwalls around Westport and nearby Carters Beach, or about $4.2m for a new channel.
Three years on, neither have been put in place.
Some residents are fed up that nothing has been done. Others say the small ratepayer population cannot afford costly protection measures.
The Buller District Council is hopeful an answer will be found in a $1.5m application to the Government following a call for ‘‘shovel-ready’’ projects to stimulate the economy amid the coronavirus crisis.
The application includes money for maintaining existing floodwalls and gravel extraction.
‘It’s a monster when it gets going’
A group called Westport 2100 was set up in early 2019 to advise the regional council and the Buller District Council on what should be done to mitigate the risk of seven natural hazards on the town: the risk of flooding and gravel build-up in the Buller River, earthquakes, tsunamis, sea level rise, coastal inundation and increasingly severe weather events caused by climate change.
Council chief executive Mike Meehan said the working group had not yet decided on ‘‘the nitty gritty’’ solutions to the threat of the Buller River, but had discussed building more stopbanks or digging out more gravel.
Westport 2100 chairman Chris Coll said if the community did nothing, insurance companies might increase premiums or make insurance unaffordable.
‘‘This has become urgent,’’ he said.
‘‘The river is our main worry in terms of what it can do. It’s a sleeping giant. It’s a monster when it gets going.
‘‘It can vary from having a flood to an earthquake situation causing, like it did in the 1968 earthquake, a dam that could burst and threaten the town, so it’s got all sorts of risks and hidden threats that we have to be able to manage.’’
He believed they needed to do some gravel extraction and repair the rock walls and stopbanks that were built in the 1930s and had protected the town since.
Residents needed a clear evacuation plan put in place, but the town would have to move away from both the river and the sea within the next 100 years, Coll said.
Easton’s report predicted river hazards would be exacerbated by climate change due to more heavy rainfall, and more rain during winter would increase the risk of flooding and riverbank erosion.
‘‘Long-term Westport may not be a viable location to defend from numerous natural hazards ... the terraces above Westport are better locations than just moving slightly further inland, at a similar height above sea level,’’ she said.
Regional council chairman, miner and climate change denier Allan Birchfield was the only councillor to vote against receiving the report.
He acknowledged the Buller River posed a flood risk to Westport, and said he believed floodwalls were the best protection. The almost $10m price tag would not be palatable for residents, though, particularly given the oncoming recession caused by the coronavirus pandemic.
‘Just get on with it’
In December, the council decided ‘‘to investigate the formation of a rating district’’ for Westport ratepayers to pay for any work that might be done.
Regional councillor Laura Coll Mclaughlin said the feedback from Buller was ‘‘just get on with it’’.
Port manager Jackie Mathers said the port recently received $4m from the Government to replace its old wharf and jetties with a floating pontoon, which would help secure the Westport fishing industry’s future.
The industry was booming, with 500 tonnes of tuna landed in Westport in February alone, she said.
Westport is also home to the Deep Sea Fishing School and a fish processing plant that employs 120 locals, which was able to continue operating during the nationwide level 4 lockdown.
But there have been a few rocky years. The port ended the 2016-17 year with a pre-tax loss of $948,000 when its biggest customer, Holcim, closed its Westport cement plant.
When the cement ships left, the Buller District Council decided to stop dredging the Westport lagoon and Buller River bar and sell the dredge. It is still up for sale.
As a result, the gravel build-up in the harbour became so bad, some fishing boats were stuck out at sea when there was only 1.7 metres of water above the perilously high sand bar during low tide.
Mathers said she was constantly monitoring the bar and a few good river floods had recently helped clear it to 3m.
She believed the council would revisit its decision to sell the dredge.
It was currently being leased to ports around the country and had earned $1.37m to help offset the loss of revenue from Holcim.
Former harbourmaster David Barnes said the time had come for action.
A seafarer all his life, he was Buller’s harbourmaster between 1995 and 2005, and had written a comprehensive history of the Buller River.
He said the river flooded the town in 1860, and in 1880 it was in danger of flooding again so people redirected the river.
‘‘They recognised that everything was banking up and flooding up so what they decided to do was to get a couple of blokes with wheelbarrows and shovels and they dug a ditch straight through,’’ he said.
The problem was the river was beginning to zig-zag again.
‘‘My solution is simple and cheap. Every man and his dog has a front-end loader these days, so you need to go down and dig out the corners.
‘‘Just dig a straight channel and the river will do the rest.’’
He said the gravel building up in the river was causing the bed to rise, effectively damming it in parts and slowing it down.
‘‘If you don’t do something to the river it will break out and put another channel through the town.’’
Barnes believed the council needed to keep dredging the river between the Buller bridge and the river mouth.
While he was harbourmaster, the dredge removed 150,000 tonnes of gravel from the river every year.
‘‘We haven’t dredged for three years ... The harbour is building up. That is a big problem.
‘‘That stone is sitting in the harbour accumulating, that’s a mighty lot of stone. You’ve got a delta floodplain and the town is in the middle of it.’’
He said the council should keep the dredge, which was earning money and ‘‘paying for itself’’.
‘‘Why would you sell the only council asset that makes money?’’
Lynne Griffiths has lived next to the Buller River for 30 years and her home has never flooded.
She put that down to the dredging of the harbour over many years.
‘‘Why fix something that’s not broken?
‘‘Our rates are too high as it is. What do we get for it? Nothing. I don’t even have a footpath outside my house.
‘‘If they keep dredging the river there shouldn’t be a problem.
‘‘ I don’t think they should sell it,’’ she said.
Buller Mayor Jamie Cleine said there was no doubt the Buller River was one of Westport’s best features, but also one of its biggest threats.
‘‘The town is always at risk from significant flood and always has been.
‘‘The stopbanks put in after significant floods in the 1930s have worked well but I think it’s timely to make sure they are still appropriate and well maintained.’’
He said the council made a $7m application to the Government when it put the call out for ‘‘shovelready’’ projects to kickstart the economy after the lockdown.
Cleine said $1.5m would be for flood protection on the Buller River, including gravel extraction, maintenance of floodwalls and dredging.
The construction work would employ up to 60 people.
A proposal would go to the next Buller District Council meeting on May 27 to withdraw the dredge from sale.
The council hoped to expand the port to cater for a new industry exporting mineral sand, which could employ up to 200 people.
Mineral sand, which is abundant on the West Coast, could be refined into about eight products, including high value rare earth minerals, Cleine said.
Expanding and refurbishing the port meant the dredge would be needed to keep the harbour at a safe operational depth, though it could still be loaned to other ports around New Zealand.
He said selling the extracted gravel could also be an earner for the council.
‘‘I think success will be that everyone feels safe to live and invest in Westport.’’