Tararua District Council is determined to ensure that its plans to repair Dannevirke’s trouble-plagued dam will not only be right, but will also ensure it lasts for future generations.
But some level of water restrictions will be extremely likely over the summer as the council continues to plan the repairs.
Tracey Collis, Bryan Nicholson, Chris Chapman, John de Villiers and Kerry Sutherland address residents on the water issues. Photo / Leanne Warr
Residents had the chance to air their concerns in a public meeting held last week and hear what had been done so far, raising a few questions around the dam as well as other issues.
Council infrastructure group manager Chris Chapman outlined the background to what had been happening with the dam, from when a leak was discovered by staff in July last year, to the situation as it stands now.
Further leakage was discovered, as well as a potential concern in the dam wall, and experts Tonkin + Taylor were brought in to assess and carry out investigations, providing a report to the council.
Chapman said the report provided some explanations around the whole system and how it worked, and some of the risks and recommendations around what the council needed to mitigate those risks.
He said they had investigated options around repairs, functional improvements and mapping of potential underground aquifers to ensure Dannevirke could grow into the future.
“We know we can’t be reliant on just one source of water, so we’ve been looking at potential other sources.”
Staff had also been out with locals investigating potential springs and bores, and bulk flow meters had been installed.
The dam was still leaking, albeit at a reduced rate, and was being monitored, with a maximum level of 9.5 metres being maintained, leaving Dannevirke’s water situation in a better position than the same time last year.
Chapman said repair planning was getting under way.
He said it was more than likely the dam would have to be drained completely, all of the liner removed and a lot of civil earthworks done, as well as checks and balances put in so it would meet new dam safety regulations, which would come into effect in 2024.
Once repairs got under way, the dam could potentially be out of action for 12 months, and the council needed to have a good plan in place for when that happened.
Chris Chapman understands the issue has been frustrating for residents. Photo / NZME
Chapman understood residents were frustrated, wanting them to just get on with it and fix it.
“There are some pretty big long-term implications around what we do here and now,” Chapman said.
“I certainly don’t want to be the reason that someone in 10 years is back up in front of you saying, ‘Why didn’t they do this 10 years ago?’”
He said they needed to understand the implications, because ultimately it was up to the councillors to make the decisions and they needed to make the best decisions for the community, for this generation and the next.
Mayor Tracey Collis addressed one of the bigger questions of who was to blame, saying there were many things.
She said the same technology that was available 10 years ago wasn’t available now.
“There are many aspects. Multiple failures. There are different aspects of that we would have done differently.”
Council chief executive Bryan Nicholson outlined how the planning and repairs would be funded through capital works and the cost would be spread over generations.
“I know there’s so many questions around ‘why do we need this, why do we need consultants’. We want to do this once and we want to do it right. We don’t want to go in here with our eyes closed and start guessing at what we should start fixing, spend a significant amount of money, and [then] we’re still where we are today.
“We’ve got to get this right, and there’s people out there [who] are absolute experts in these areas.”
Dannevirke was likely to have some water restriction measures in place, although Chapman advised he wanted to keep those to a minimum.
Staff would monitor the town’s usage over summer, as well as keep an eye on river levels and weather forecasts.
Residents asked a number of questions, with one asking if they had considered taking water from the Manawatū River.
Chapman said that hadn’t been looked at in detail, but added that pumping costs to get water up to the treatment plant would be huge.
The council hadn’t ruled out walking away from the troubled dam, with Chapman saying they would need to understand the implications of the dam safety regulations, including cost and limitations.
He said they hadn’t completely ruled it out, but it was very unlikely.
