Building water security for our region’s future
Published Friday 21 June Work on the massive Waimea dam project is progressing well with the access road half-completed, says the company building it.
Waimea Water Ltd chief executive Mike Scott on Thursday presented Tasman District Council with a six-month progress report on the $104.4 million project.
“We’re well under way and progress is good,” Scott told councillors.
Despite a three-week “mobilisation” delay at the start of the year because of a high fire risk in the region, the team was about halfway through the construction of the 6.5km access road to the site in the Lee Valley, near Brightwater.
Waimea Water along with its consulting engineer, Damwatch Engineering, and contractor, a consortium of Fulton Hogan and Taylors Contracting, was looking at opportunities to reduce costs, optimise the design and de-risk the project.
Geology was one of those risks and it would be better understood once the excavation got under way, which was due to begin in the fourth quarter, Scott said.
Earlier, during the public forum section of the meeting, mayoral aspirant Maxwell Clark raised some concerns about the project that he said were circulating in the community.
“Is it correct that despite extensive drilling, you have been unable to locate solid bedrock to anchor the dam structure to,” Clark asked.
Scott responded during his presentation, saying the team had not started excavating yet so he could not say how much rock was there nor comment on its quality. However, he expected it would be found.
“We certainly know there’s a lot of bedrock around,” Scott said. “If you stand in the valley in the river and look up to the right hand side abutment, there is very steep, shiny, hard rock. It’s clear to see.”
Clark also asked whether construction of the road had been halted “due to a seam of toxic asbestos being found”.
Scott said work had not shut down. There was “naturally occurring asbestos in the rock” near the start of the road and some tests were done.
“The air quality samples came back as negative,” Scott said.
In the next two months, construction of the access road would continue along with work on river diversion. There was a plan to start clearing vegetation in the dam reservoir footprint area as well as commencing construction of temporary coffer dams.
Planning was also under way for the carbon credits required and on a project to restore wetlands at Rough Island, which was part of the biodiversity management plan for the project.
Set to be about 53m high, 220m long, 6m wide at the crest and constructed of approximately 430,000 cubic metres of rock, the physical dam is scheduled to be completed by October 2021. That will be followed by the filling of the reservoir with the final commissioning due by February 2022.
Waimea Water is a joint-venture partnership between Tasman District Council and Waimea Irrigators Ltd. It is a council-controlled organisation governed by a board of seven directors. One of those directors, Doug Hattersley, joined Scott for the presentation. Two others – Ken Smales and Bruno Simpson – sat in the public gallery.
Councillors later adopted Waimea Water’s final Statement of Intent 2019-20, which had changed little from the draft document they received in March.