Bedrock find keeps dam build on track
Bedrock has been found at the site of the Waimea dam build in the Lee Valley.
Waimea Water Ltd chief executive Mike Scott said the geology at the site was as expected, and even better than expected in some spots.
‘‘It’s early days but we’re pretty happy,’’ Scott said. ‘‘We’ve cleared the overburden and we’re on bedrock.’’
Waimea Water is the Tasman District Council-controlled organisation responsible for the construction, operation and maintenance of the dam.
Scott said engineers from Waimea Water, Damwatch, Jacobs and SMEC, of Australia, had inspected the site. ‘‘They’re all pretty happy with it.’’
The geology has been identified as one of the major risks for the $104.4 million project. Bedrock is required to anchor the planned 53m-high concrete-faced rockfill dam.
Scott said the team on site had started clearing the right-hand abutment ‘‘and this is all good rock – this is all ready to go’’.
Some pockets of colluvium had been found – ‘‘rotten rock mixed with organic material, which is typically a very old landslide running up the gully’’.
‘‘We stabilised that and dug it out,’’ Scott said. ‘‘It was all expected, and it’s in the budget.’’
Excavation was under way for the lefthand plinth, which would be a 5.5m-wide leading edge of the dam, sealing it with the subsurface, he said. ‘‘They are ready to start pouring concrete for the left-hand plinth.’’
The rock was easy to see, shiny and hard, Scott said. ‘‘You can hear . . . the noise of the diggers scraping away from across the gully.’’
He said there was no reason to believe the project was not on budget.
‘‘The reality is we’re slightly behind our forecast – just a fraction behind because we started two months later, effectively – but otherwise, we’re on budget,’’ he said, adding that the total was about $2m to $3m behind the forecast.
The project timeline remained the same, Scott said.
‘‘We’re still arguably two months behind . . . because we started two months late.’’
Work at the site began in mid-March after a delay caused by the fire risk at the start of the year. ‘‘I still think we’ll catch it up.’’
Scott’s comments came ahead of a project update he gave on Thursday to Tasman District councillors. During that update, he presented a slide showing that 17 bores had been drilled in the area, the most recent in 2017. There had been no subsequent drilling to look for rock, despite some claims to the contrary, he said.
However, the contractor had had a rig on site to drill holes for explosives to blast through hard material that could not be dug out by an excavator. ‘‘That’s a different sort of drilling,’’ Scott said.
In response to a question from councillor Mark Greening, Scott said three more bores were scheduled to be drilled later this year along the site of the planned spillway.
The inaugural annual report for Waimea Water was also presented, and it showed a spend of $19.2m on the dam project to June 30. Of that, $6.3m was expended prior to the final go decision on items such as land acquisition, design, procurement, early contractor involvement, consenting, the project office and governance.
However, outside the meeting, Scott said $8.2m was the total pre-operating spend, which included insurance. The construction contract accounted for another $7.7m, with ongoing operations swallowing up $2.9m. Earnings from interest income provided $300,000.
Overheads such as staff, directors and offices totalled $700,000, Scott said.
The annual report shows directors’ fees of $134,000 plus ‘‘director services’’ of $324,000. A corresponding note about the director services says that prior to the recruitment of key management personnel, some directors performed ‘‘interim executive-level services’’.
Councillor Anne Turley asked for details of the reasons for the additional fees.
Waimea Water board chairwoman Karen Jordan outlined the roles carried out by some of the directors between the signing of the deal and key staff starting work. Those roles, including interim chief executive, interim programme director and interim commercial director, were taken on by some directors to meet commitments and avoid damages.
‘‘For example, in the first week of operation, we had about 15 key deliverables to meet our obligations on the schedule – our health and safety plan, our environment plan, vegetation plan, commitments of resource consents, all this stuff,’’ Jordan said.
Meanwhile, the Waimea Water team plans to hold a public meeting at Richmond Town Hall on September 25 to provide an update on the dam build and answer questions.
The event is scheduled to be held from 7pm to 8.30pm, and attendees are asked to email info@waimeawater.nz by September 22 to register and submit questions or topics of interest.