It was the biggest crowd yet for the annual Ōtaki River Walkover, with nearly 200 people bussed along the river road in four buses and several joining the tour at Chrystalls Bend.
“This is a special community day,” Max Lutz president of the Friends of the Ōtaki River volunteer group. “Most importantly we see two councils, Greater Wellington Regional Council and Kapiti Coast District Council working together.”
Once on board the first stop was the Waitohu Valley Road bridge to view the post June floods clean-up of debris and clearing the stream channels. Ringawhati Road bridge was observed, it had fared badly too, with the northern abutment washed out. This was followed by a trip to the upper Rahui Road and through to the top of the Haul Road at the east end of Carl Lutz’s farm.
Following very heavy rain overnight, the river was running high and very muddy. At the Harper’s stopbank and the fairway corridor, east of Chrystall’s Lagoon the river corridor is 250 metres wide and has 80 metre buffer zones each side. Ground erosion in this area has been a problem. The Ōtaki Flood Management depot guys have been busy removing or topping the oldest willows allowing for rejuvenation. Over the winter they have planted 14,000 willow stakes where some of upper reaches have been cleared. These are all budding now.
“Willow planting is very important in this area,” GWRG Flood management’s Graham Campbell said. “We can top them and mulch them to their base, they sprout and we get another 20 years growth from them.”
Repairs after the June floods, when 1,000 tonnes of rock was lost downstream, will include cutting a new channel to “force” the flow away from the southbank and Harper’s stopbank of which only half now remains.
“This was an eight year return flood, with the gorge flood gauge reading seven metres above normal,” Mr Campbell told those on the tour.
Protection work on the upper Rahui is primarily vegetation, while stopbanks, rock groynes and gravel extraction aim to keep the river towards the north banks. In many areas the native dotterels and pied stilts have returned to former nesting sites, these are being protected from river works.
For most of the 200 people it was a short walk from the Waimanu Stream to Chrystall’s Lagoon and a welcome morning tea break. During morning tea, Max Lutz spoke of the education programme they have been doing with the schools. In June Ōtaki College students planted out the 1,000 trees they had potted last year thanks to funds from Westpac Bank. Te Horo School has received $5000 from the Philipp Family Foundation for the trees they’ll plant out next year and Winstone’s Aggregates had donated $5000 and will join in planting “their” section next year, too.
“Our intention was to manage the river, but rivers don’t like being managed!” Chris Laidlaw GWRC chair told the crowd. “When I first came here 10 years ago the whole area was just beginning to be restored and relationships were nowhere as positive as they are now. Ōtaki and Waikanae rivers are the jewels in the crown for the Wellington region.”
Nathan Guy, Minister of Primary Industries, spoke of his first visit to the walkover 10 years ago and the restoration work done “… since 2000, about 60,000 trees have been planted. This is a real community project. It links central and local government, businesses, schools and others.”
Among works completed has been the “moving” of the Chrystall’s Bend river channel towards the south, deepening the channel, installing debris fences to help widen the banks and completing the Chrystall’s stopbank.
“Earlier, the river was over where the buses are now, on the haul road,” Max told them. “The river’s been moved towards where it is now — where we’re standing was the riverbed!”
He also paid tribute to Arthur Manz who had died a few days before. “Arthur has been on many of our planting days and river walkovers, He was well known as the principal of Ōtaki and Waitohu Schools.”
The next stop was close to the Ashford Park southern boundary, where Winstone’s project manager, Dan McGregor, spoke of the proposed use and future of the park and Winstone’s quarry manager, Shane Hagai, outlined the work at the Ōtaki Lakes quarry between Stresscrete Concrete and Ashford Park.
Gravel extraction has been increased to 130,000 tonnes per year to use on the McKays to Peka Peka expressway. They have brought in an extra drag line machine and a mobile screening plant to cope with the increased work. The dragline, which scoops gravel from the lake bed, is currently 13 metres deep. Out of work hours the lake is already used by the waka ama, surf club and canoe polo club for training purposes. Canoe polo also holds competitions on the lake.
“We have the Peka Peka to Ōtaki section of the expressway scheduled to start late next year. This will be a three to four year project. Then it’ll be back to our normal little Ōtaki work!” Mr Hagai concluded with a laugh.
After travelling through the quarry area for a close up look at the dragline and screening operations, the next stop was where the expressway twin bridges will pass over the river and travel east of the Ōtaki Railway township.
The Peka Peka to Ōtaki (PP2O) expressway project manager, Rowan Oliver, said the bridges would be approximately 300 metres long and be about one metre apart. “We will retain vehicle and pedestrian access to the walkway, Chrystall’s Lagoon and planting areas throughout construction and the nesting habitat will be protected.”
The detailed designs for the Te Horo overbridge, Ōtaki River and Rahui Road bridges should be available for final community consultation and approval before going out to tender.
The extremely heavy rain the previous night, September 17, and the river running high, the haul road under the road and rail bridges was under water and impassable for the buses, which necessitated a drive across to busy highway to the Winston’s lookout, next to their main screening plant and the western highway to the beach stopbank and walkway.
This end of the river is narrow and gravel extraction is important to prevent the riverbed from filling.
“The (western) stopbank was built in 1949, the river was dredged out and dumped (on the bank), it is not a proper stopbank,” Te Horo resident and former land agent, Colin Davies said. “It’s too high, too steep and too close to the river. I’m not proposing moving it, but it could be lowered.”
To a quip he should be on the GW team, he replied “I don’t have the university degrees for that!”
Down river a bit further and a pause near the transmission line towers, and the information they are to be upgraded and strengthened as part of the general maintenance. Onwards to the lagoon and floodgates with just a pause to see some of the work through the windows.
The final call was the Waitohu Stream project on Convent Road. “The June floods were severe and the water flow constricted” Mr Campbell said. This part of the Waitohu is flat and swampy and there is little we can do to dissipate the water. The flood management plan is for a stopbank to prevent the Waitohu from flooding back into the Rangiuru Stream. The current stopbank was made when the Mangapouri Stream was diverted to the Waitohu instead of the Rangiuru.”
They are currently working with some of the landowners so they can complete this section of the stopbank.
From there it was back to the depot for a light lunch for those able to stay and a chance to view FOTOR’s nursery and propagation work.
Representatives of the Te Horo School Garden Club, Charlie Simpson, Matthew Bird and Nikita Allen were at the Ōtaki River Walkover to collect a $5000 cheque from Ray Mackle trustee of the Philipp Family Foundation, to help with expenses for the trees they had potted up and later planted out along the Chrystalls Bend walkway.
“Dr Philipps is very interested in conservation,” Mr Mackle told those on the walkover. “The foundation has been involved in funding for three years.”
Charlie thanked the Philipp Family Foundation for their cheque.
Friends of the Ōtaki River, Trevor Wylie secretary and Max Lutz chair receive a $5000 cheque from Winstone’s quarry manager, Shane Hagai and Dan McGregor project advisor.
“We decided our objective is to take part in one of these tree plantings, we’ll be back next year to plant our section.”
Mr Hagai also presented FOTOR members with 25 high viz vests “to remember the health and safety regulations!” he grinned.
The annual walkover is part of the memorandum between Greater Wellington Regional Council and the Ōtaki Friends of the River.