A year of digging work is set to begin on one of Auckland's busiest road corridors.
Transpower's much anticipated North Auckland and Northland project will see the undergrounding of cable between the Pakuranga and Penrose substations.
The cable will be installed in stages starting along Burswood Dr and Ti Rakau Dr, then from Pakuranga Creek to Reeves Rd, before moving to the south eastern highway.
It will then go across the Waipuna Bridge and on to Waipuna Rd and along Ireland Rd to the Penrose substation.
It's a challenging task but one project director Paul Duffy says has been been well-planned to minimise disruption.
The project is to introduce a new circuit across Auckland that reinforces supply into the city and to the north.
"It's a major piece of infrastructure," Mr Duffy says.
"Everything north of Penrose is on a single supply and this will provide a second route into the CBD and north."
The cables will give security of supply and additional capacity for growth.
Disruption along the route will be inevitable, especially for motorists, Mr Duffy says.
"We've put a lot of planning in. We've been working for three months now in the transmission corridor.
"We started away from the roads to iron out any teething issues and fine-tune the process we will be employing."
The work will be confined to roughly 300-metre stretches at a time. Trenches will be dug, plastic ducts laid and then the trenches backfilled.
The cable will be pulled through when all the ducts are in place.
"We're looking at 12 months but we won't be in the same spot. It will be a rolling process of work.
"If we didn't do that we would have two to three kilometres open at a time."
In readiness for the job Waipuna Bridge has been strengthened to cope with the heavy cable that will be pulled underneath it. Every 10 metres of cable weighs a tonne. The Pakuranga to Penrose stage is the southernmost of four stages.
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