Sweetwater being tested for new Kaitāia water supply

The official Sweetwater ribbon-cutting team in June, 2022, Trudy Allen (left, Ngāti Kahu), Far North Deputy Mayor Ann Court, John Paitai (Te Rarawa) and then Far North Mayor John Carter. Photo / Susan Botting - LDR Northland

Water from the Sweetwater aquifer that is supposed to be Kaitāia’s long-awaited new $13 million-plus water supply is days away from being tested in the town’s treatment plant, but there’s no date yet for when the supply will be fully functional.

Far North District Council has released more information on the controversial scheme after questions from the Northland Age, The final approved budget for the scheme is $13,630,171. This includes $3m provided by the Provincial Growth Fund.

It has been widely reported that the initial cost for the scheme in 2010 would be $2.6m, but the council says that was never the budgeted cost at any stage.

The council first started to explore getting waters from the Sweetwater aquifer in 2010 when then Far North Mayor Wayne Brown made an agreement with avocado grower Tony Hayward. At that stage it was estimated that the project would cost around $2.6m, but by October 2020, the cost had ballooned to an estimated $15.3m.

“It’s unclear where your $2.6m figure comes from and what it includes. However, our project timeline shows that one production well [PW1] was drilled at Sweetwater in 2010 and an initial concept design was then produced in 2011. It is likely that [$2.6m] is related only to this work,” the council said in response to the questions.

“There was no further activity on the project until 2019 when FNDC passed a resolution to confirm the Sweetwater bore site as the preferred option for an additional supply for Kaitaia. The scope of the project was then defined as:

1. Installation of two water bores into the deep shellbed aquifer at the Sweetwater site

2. A primary sedimentation structure, 125m³ buffer tanks, 60L/s booster pump station, power supply and telemetry at the Sweetwater site

3. Construction of 14.2km of new DN315 watermain from the bores to the existing Kaitāia Water Treatment Plant (WTP).

Excluded from the scope were any infrastructure changes required to the existing Kaitāia WTP to ensure that both aquifer and Awanui River water could be treated and blended.”

The Kauri Dam, which was once a back up water supply for Kaitāia is getting emptier by the day, and is about to be decommissioned

Council chief executive Guy Holroyd said, as detailed on the council’s Kaitāia Water Project webpage, the project to access raw water from the aquifer at Sweetwater was launched following the 2020 drought that hit Northland.

“In just three years, we have drilled new bores, come to agreement with several landowners to allow a pipeline to cross their land and built that pipeline to Kaitāia,” Holroyd said.

“During that build time, the country went into lockdown for the Covid-19 pandemic and was subsequently hit by a global supply chain slowdown. While the completion date has been extended, this is far from excessive when considering the external and unforeseen factors we have faced.”

He said the date when water from Sweetwater will finally start being used in Kaitāia permanently will be determined once the plan has been tested.

“Any supply will also need to comply with the drinking water standards regulated by Taumata Arowai before being supplied to customers.”

Holroyd said the site blessing in June 2022 was to celebrate the milestone of infrastructure construction being completed.

“The next critical project step was to implement the commissioning plan of the Sweetwater supply. After considerable discussion over options, in late September 2023 the council instructed its three waters alliance partner, Far North Waters, to proceed with a plan to introduce Sweetwater groundwater to the Kaitāia water treatment plant at intervals.

“This would help to confirm the production capacity of the water bores and Kaitāia WTP requirements to blend bore water with existing raw water taken from the Awanui River.”

He said this plan has been implemented and the expectation is that Sweetwater groundwater will be fed into the Kaitāia WTP for testing this month. In advance, a period of flushing water will be completed involving several days of bore pumping.

When asked why it had taken so long to get the system up and running, when it was supposed to have been supplying water in May last year, he said operational commissioning needed to be determined and tested.

He also said there had been a collapse of bores at Sweetwater, and issues with silica in the water, but the council’s plan will confirm the treatment and commissioning of the supply.

The council said compensation had been paid to several landowners where pipelines had to go over, but would not say how much in total.

“Compensation for easement interest is appropriate and determined by valuation performed by valuation professionals. Compensation is formalised by agreement reached with landowners, these agreements are confidential between the parties and therefore unable to be disclosed.”

While no date has been set for the Sweetwater water to start going into Kaitāia homes and businesses, one of the town’s potential back-up water supplies - The Kauri Dam - is almost empty and is being decommissioned.

Des Mahoney, secretary/trustee for the Ngakahu/Ngakohu Whanau Ahuwhenua Trust which owns the land the dam is on, said the Kauri Dam on Okahu Rd, is presently being decommissioned.

“The raw water from the dam will no longer be available. The pumps will be turned off during this weekend,” he said in a social media post on Friday.