The Ōhau Channel diversion wall is designed to protect Lake Rotoiti from nutrient-rich polluting water from Lake Rotorua. Photo / File
The Ōhau Channel diversion wall is designed to protect Lake Rotoiti from nutrient-rich polluting water from Lake Rotorua. Photo / File
The Bay of Plenty Regional Council says it will accelerate trials to identify possible fixes for the deteriorating Ōhau Channel diversion wall.
Former Rotorua Mayor Kevin Winters admitted partial responsibility for the situation and pledged to help find a lasting solution at a meeting today.
Concerned community boards remainsceptical, however, and warned legal action remains an option.
Built in 2008 to protect Lake Rotoiti from nutrient-rich polluting water from Lake Rotorua, the $11 million wall began corroding in 2014 because of previously underestimated microbial damage.
Last month, local groups issued a letter of demand to the regional council, with Rotorua Mayor Tania Tapsell backing urgent calls for a long-term solution.
The regional council denied breaching consent, citing improved Lake Rotorua water quality and disputing harmful leakage. It said the wall was structurally sound and repairs could be costly and unnecessary.
The lakes community groups presented their case again at today’s regional council meeting. They pressed for urgent attention to corroding king piles, which they said were necessary for any long-term solution.
They rejected the council’s recommendations of a “dynamic adaptation pathway planning” solution. That proposal would involve the council monitoring and investigating the wall unless diverted to other solutions by further information.
This pathway was eventually approved at the meeting, but concerns around its timeline and Lake Rotoiti’s degrading quality resulted in two amendments: that all investigations and trialling options be expedited and options for improving Lake Rotoiti water quality be hastened.
This would include trialling work, particularly involving the king piles, described as the most critical structural component.
The council believed the king piles would be sound until 2038. However, their integrity is key to any long-term solutions and repair options would be assessed.
Holes visible in the Ōhau Channel diversion wall. Photo / Supplied
Before today’s decision, an initial dive inspection and structural analysis was scheduled for next year.
Winters labelled previous trials a “waste of time” and was “really disappointed” with the council’s report, calling it a deference rather than a decision.
The regional councillor was Rotorua’s mayor when the wall was approved and constructed.
Winters is stepping down at October’s election but suggested he would not take his “eye off the ball” again.
Former Rotorua mayor and Bay of Plenty Regional councillor Kevin Winters. Photo / Andrew Warner
“It was my fault as Mayor of Rotorua,” he said. “I dropped the ball in terms of the due diligence from our engineers at the time and it came back to bite me big time. I am not going to let this be a second time in terms of a long-term solution going forward.”
Councillor Jane Nees agreed there was a “serious problem”.
“I don’t agree it is not as pressing as staff are telling us,” said Nees.
She suggested they could not be certain Lake Rotoiti would not worsen and, no matter what their next steps were, work needed to be expedited.
Lakes Water Quality Society chairman John Gifford (left) speaking at a Bay of Plenty Regional Council meeting. Photo / Mathew Nash
Regional council chief executive Fiona McTavish said she had been advised legal action was a possibility from the community groups.
Lakes Water Quality Society chairman John Gifford told the meeting they would rather avoid legal action but had done “due diligence” and it remained “on the table”.
As for the expediting of the repair investigations, he remains unconvinced.
“The proof will be in the delivery,” said Gifford.
“I think even though there was some indication of urgency, it is hard to see how that is going to roll out practically.”
The trial and inspection regime was budgeted at $1.9m under the council’s most recent long-term plan.
Mathew Nash is a Local Democracy Reporting journalist based at the Rotorua Daily Post. He has previously written for SunLive, been a regular contributor to RNZ and was a football reporter in the UK for eight years.
– LDR is local body journalism co-funded by RNZ and NZ On Air.
