Trucks dashing across dam inflicting damage to Mercury Energy's hydropower plant

Trucks and cars are damaging a road across a hydropower stations dam but its owner is trying to work with rather than against those living around the plant on the Waikato River.
Mercury Energy is lifting the profile of its $75 million modernisation project at its Karpiro power station, to educate motorists using the road across the top of the plants dam.

The company started a five-year project in 2019, to upgrade the power station, replacing the original turbines and generators installed during the early 1940s.

The plant opened in 1947 and the dam in front of it, across the river, included a road for easy maintenance access.

* Plans back on track to deliver turbine blades to Turitea Wind Farm
* Mercury threatens to pull plug on tourist spills at Aratiatia Rapids
* Waimea dam hydro proposal sparks concern over river life

International engineering firm Andritz provided a 3D render of the new components to be installed inside the Karpiro plant.

Over time, the narrow, single-lane road became a public shortcut from State Highway 1 to Cambridge or to the Mighty River Domain which hosted major events.

In the past three years, Mercury reported 17 incidents on the road where cars or trucks get into trouble damaging the bridge along the road or holding up traffic.

We have had examples of big trucks, which should not go across the dam because of its curvatures and narrowness, causing damage, General Manager Portfolio Phil Gibson said.

We have services such as sewer pipes attached to the bridge and they can be ripped off by trucks trying to get across.

Christel Yardley/Stuff
The narrow road across the dam will be closed more often for the power plants $75m upgrade.

The power company closed the road for regular maintenance on the dam but it had noticed online discussions where people were asking why the bridge was closed more often.

We have to close the road more now because of the work were doing on the redevelopment project, Gibson said.

We broadcast the road closure details far and wide so people arent surprised. Its when they turn up and are surprised, that they take a chance and try to cross.

There were cameras on the road across the dam and the company could take down number plates to pass on to police.

Mercury Energy
The road across the dam gives people access to each side of Lake Karpiro, connecting State Highway 1 with Cambridge and Maungatautari.

But we would rather work with the community, than against it.

Mercury was working with the Waip District Council to make it difficult for heavy or oversized vehicles to cross.

It included installing a gantry, speed cushions on the road and more signs to explain the road closures.

Gibson said the work at the power station was a rebirth of its assets.

They are 1945 vintage and due for replacement which means we are taking out each of the generators and turbines and replacing them with brand-new ones.

We are also putting in new head gates that control the water from the dam into the turbines and generators, they are a key safety element and need to be replaced.

New components were being shipped form overseas and assembled at the power station.

Thats going to require us to have some big cranes on site to move the gear around into place and so there will be a few more outages (road closes) than normal over the next four years.

Gibson said the new generators and turbines were expected to operate for 50 years or more.

He recognised the 75 years of service the original components had given to help power the country.

The turbines would have been made overseas at a time when a world war was consuming all of the good quality steel to make ships and tanks.

It says a lot for the quality and workmanship of the people who built the power station.

Gibson said the company understood access across the dam was important for the community and for those running events at Lake Karpiro.

And we will continue to look for better ways to communicate when the interruptions to the road are going to be put in place.


Our Partner