Waimea Dam’s latest deadline questioned as “overly optimistic”

The Waimea Dam’s latest $20 million increase and anticipated July to September 2022 deadline came under the scrutiny of the Tasman District Council on Thursday.

In a mid-year report released late February, Waimea Water Ltd revealed the construction costs to complete the dam will need to rise to $185m. A cost of $20m over the $164m estimate presented in February 2021 and $80m over the amount forecasted in 2018 when the decision was made to proceed with construction.

Along with council staff, community members who chose to tune into Thursday morning's Zoom meeting were met with obscenities including a racial slur from one anonymous attendee during Waimea Water Ltd’s presentation.

The persons were removed shortly after a handful of sound effects and voice recordings interrupted the presentation.

Waimea Water Ltd chief executive Mike Scott persisted with his update, explaining the anticipated cost increases before the proposed July to September 2022 deadline was labelled as “overly optimistic” by one Tasman District councillor.

Councillors Mark Greening, Christeen Mackenzie and Dean McNamara called into question Waimea Water Ltd's timeline, pointing to Scott’s estimate during the meeting of the amount of construction currently completed “at about 73 per cent."

This is just a three to four per cent increase from the 70 per cent estimate given for works completed by December 31, 2021.

Scott told councillors January 2022 was a “light month” in terms of productivity, to give staff a break from six-day weeks and 12 hour days.

Scott maintained the timeline was achievable but subject to “unquantifiable risks” at this stage.

Scott told the council that the total $185m figure was also exclusive of “unquantifiable risks” including the financial impact of any potential weather events and the uncertainties around Covid-19 related delays.

According to this latest report from Waimea Water Ltd, the most recent rise in costs was due to further “unforeseen geological issues” as well as the impact of Covid-19 on rising construction costs, materials and resource demands.

Further unforeseen geological issues from those identified in the February 2021 update included fractured rock on the left-hand side of the embankment where 30,000 tonnes of sand was necessary to treat the foundation defects, and had to be imported from as far as Marlborough and the West Coast.

Bisecting shear zones over the spillway were uncovered during 2021 and the excavation of the plunge pool identified similarly poor geology at the base of the embankment, with significant remedial work required on top of other issues.

“We’ve got these two shear zones at the worst possible place,” said Scott.

“Now we are facing further challenges where staff have to stay at home isolating”.