Green light for pipeline replacement

The replacement of a section of high-risk pipeline which supplies the only source of drinking water to Featherston has been green-lit by the South Wairarapa District Council [SWDC].

At yesterday’s Strategy Working Committee, councillors found favour with a $2.75 million option to replace and trench the section of pipeline that crosses the Tauwharenīkau River down to 4 metres.

The pipe is at high risk of failing and was previously found to be exposed in the riverbed.

Temporary solutions had been pursued by the previous council, but recent expert advice urged the council to adopt a more permanent solution.

Councillor Pip Maynard, who abstained from voting on Wednesday, said more consultation with mana whenua needed to take place before she could endorse the “replace and trench” option.

Three options were presented to the SWDC committee, two of which would have still left the council carrying a risk of the pipe failing in a large river flow event.

Option 1 was to “do minimum” and involved keeping the existing pipe as is and doing annual maintenance.

Option 2 was to reinforce the existing pipe, which provides some resilience to high river flow events and scour protection, but the condition of the internal pipe is still unknown.

The third option, which was recommended by council staff and Wellington Water, was the replacement of the pipe using a trenched installation under the river. The report explicitly mentioned that iwi did not support the first two options.

When Maynard asked if mana whenua supported the preferred option, she was told engagement was in progress.

According to the report to the committee, the Waiohine and Tauwharenīkau are “Te Awa Tapu o Ruamāhanga tributaries and therefore of particular importance to iwi and mana whenua”.

“Because of the high level of interest for Māori, this project will require the development of a Mana Whenua engagement plan,” the report said.

Councillors also expressed their wish to have Wellington Water’s tender pool of contractors expanded to include Wairarapa firms to avoid unnecessary cost escalation.

SWDC partnerships and operations manager Stefan Corbett said if the decision was to “go ahead’ with Option 3, the council and Wellington Water would move into the detailed design phase.

He said councillors would have “full visibility” of cost breakdowns.

Councillor Aaron Woodcock, who is a businessman and contractor, said he was “dubious” of the prices offered up by Wellington Water.

“Where have these figures been plucked from?” he quizzed.

Fellow councillors agreed with Woodcock’s sentiment, to which Corbett said: “What I’m hearing is there is a very high interest from councillors that we are intimately involved and get the assurance that consideration is being given properly to assigning local contractors where possible and that value for money is reflected.”

Along with approving the replacement option, councillors voted to release ring-fenced funds of $150k in the 2023-24 Annual Plan for Wellington Water to progress detailed design on the replacement of the pipe section. – NZLDR

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