A short but intense cloud burst over Wairarapa has resulted in predictable surface flooding and bridge closures.
Metservice meteorologist Alwyn Bakker said intense episodes, in addition to some “pretty sustained” rainfall, saw the region’s gauges clocking fairly high readings over the weekend.
“A few stations got about 15mm of rain in a single hour from 7-11am on Saturday.
“That was probably the biggest chunk in the Tararuas.”
Over 48 hours from Friday, Pahiatua recorded 90mm of rain, while Masterton racked up 60mm, leading to rivers rising across the region.
Waka Kotahi NZTA decided at 8.30pm on Saturday to close the Waihenga Bridge into Martinborough due to the rising Ruamahanga River.
It was reopened at 3.50am yesterday.
Despite the targeted rainfall warnings, Bakker said South Wairarapa only received about half of Masterton’s rainfall during the same period.
Regardless, 30mm in Featherston was enough to cause widespread surface flooding on the town’s main drag and the predictable “lake” at SuperValue.
The water woes led to frustrated residents venting on social media, and demanding answers from South Wairarapa’s mayor and councillors.
“What we would like to know in Featherston is when somebody plans on doing something about this?” one resident said.
“Everyone knows it’s a problem here. I would have gone to the market, but I can’t swim across the lake.”
In response, South Wairarapa Deputy Mayor Melissa Sadler-Futter gave assurances that Featherston’s flooding was “high on the local elected members’ priority list” and meaningful work was happening behind the scenes.
Featherston councillor Rebecca Gray echoed the deputy mayor.
“I want to reassure everyone here that although the wheels of local governance turn painfully slowly, they are turning.”
She said South Wairarapa District Council [SWDC] was currently waiting on an update from Wellington Water, who was mapping the town’s flooding.
The council is not the only one.
Last month, the Times-Age reported on an impasse between government agencies and SWDC, who disagreed on how best to fix Featherston’s flooding and, importantly, who was responsible for the solution.
Wellington Water blamed two partially collapsed culverts belonging to Waka Kotahi NZTA for the surface flooding outside SuperValue.
While NZTA agreed the culverts could contribute to the problem, it pointed the finger at KiwiRail earthworks on nearby land, claiming the work had exacerbated the issue.
KiwiRail also denied responsibility.
However, Wellington Water said once the modelling project was complete, it would be in a position to provide NZTA, KiwiRail, and SWDC advice on what was causing the flooding and how to remedy it.
Wellington Water said it was planning drop-in sessions this month and next for residents to share flood photos to validate the model.
