Part of Kahotea Farming Ltd's 100ha of land that was overrun with water in the days following Cyclone Gabrielle. The overall area flooded is estimated to be about 950ha across three farms and was up to 3m deep in places.
Part of Kahotea Farming Ltd's 100ha of land that was overrun with water in the days following Cyclone Gabrielle. The overall area flooded is estimated to be about 950ha across three farms and was up to 3m deep in places.
If you take a close look at satellite imagery of Hawke’s Bay in the wake of the cyclone, one giant new puddle south of Hastings stands out among the devastation.
That puddle comprises three farms in Central Hawke’s Bay. As rain poured through and over the Waipawa River on February14, it changed its course and formed a lake covering 950 hectares.
To give some idea of the scale of the water, the lake was five and a half times the size of Hawke’s Bay’s most romanticised lake - Tūtira - the lake that inspired the waiata Tūtira Mai Nga Iwi.
Satellite imagery made available to the public earlier in March through Toitū Te Whenua Land Information New Zealand (LINZ) Basemaps and LINZ Data Service online platforms shows how Hawke’s Bay looked from above in the days after Cyclone Gabrielle, from February 21 to March 8.
Amid the destruction wrought by landslides on hills, bush lines that have disappeared, and silt deposited across valleys and floodplains, the now-drained lake in Te Aute, near Ōtāne, is still somewhat remarkable.
Chris Dolley, group manager of asset management for Hawke’s Bay Regional Council, said it was created by an overtopped stopbank.
“During the cyclone, water overtopped a stopbank on the Waipawa River, causing a breach, and flowed down the Papanui Stream, an old river course of the Waipawa River. We have put in place a temporary repair to this breach, and are working on a permanent repair,” Dolley said.
Right in the path of the river’s new path were several farms, including Drumpeel Farms, Kahotea Farming Ltd and Ludlow Farms.
Hugh Ritchie, of Drumpeel Farms, and Simon White, of Ludlow Farms, said the “old river course” that the Waipawa River travelled down was actually the path of a flood that happened in the 1800s.
“The Waipawa river always used to flow to the Tukituki and it was in 1867 that the Waipawa breached through the Papanui and flowed down our valley and created a big lake then,” White said.
“It actually flowed there for roughly 19 years or so and it wasn’t until about 1884 when some of the local farmers got together and wanted to redivert it back to its original flow to the Tukituki.”
This time, it took a group of local contractors about three days to get to the breach to redivert the full force of the river flow due to how dangerous the area was.
It took another few days for the contractors to plug up the breach enough to stop the new lake from filling up, and to eventually completely redivert the river.
A bulldozer pushes the land back to where it was before the Cyclone Gabrielle flooding on Drumpeel Farm, Otane. Photo / Warren Buckland
Ritchie said 550ha of Drumpeel Farms were turned into a lake that was up to 3m deep in places.
White said about 300ha of Ludlow Farms were covered in water of a similar depth, while Miles McBain, of Kahotea Farming Ltd, said about 100ha of their farmland had been flooded.
McBain said the biggest lasting impacts on Kahotea Farming Ltd from the flooding had been financial - from the loss of crops, fencing and irrigation equipment - rather than topographical or environmental.
“I can’t speak for Hugh or Simon, but my farm had not so much [soil structure change]. We had a layer of silt but we’ve worked that in already and it is not so bad.”
White said they still could not get onto parts of the Ludlow Farms farmland as it was saturated and covered in sticky silt.
“We are basically thinking that part of the farm is still not going to be able to be farmed through the winter.”
Ritchie said his daughters and some of the neighbours rowed in boats across the top of the maize crops and over the top of the property a week after the flooding.
Ritchie said there had been a lot of soil movement, which had left holes and reduced the quality of the topsoil, but it was hard to tell the longer-term effects until more testing could be complete.
“I would have thought it would take about three to five years to get the production to what it was [in the worst hit areas] but the other areas that have gained some soil might be better as long as the drainage is okay, but there is drainage work to do, which we will do over the next two or three years,” Ritchie said.
He estimated that about 100ha of Drumpeel Farms would have medium to long-term significant damage that would require monitoring.
Satellite imagery from LINZ taken days after Cyclone Gabrielle, showing a body of water formed in Central Hawke's Bay. Hugh Ritchie's neighbours and daughters were able to row across their farmland a week after the cyclone. Photo / Land Information New Zealand
Dolley said the regional council was conducting a comprehensive post-event analysis of Cyclone Gabrielle including flood impacts and would provide information as soon as they could.
“There are many factors which will influence how the land is restored and in what timeframe. We are working closely with landowners and other agencies to develop strategies and work towards restoring the landscape.”
