Upper Nihotupu Dam back in business after repairs to flood-damaged watermain
Watercare’s 100-year-old Upper Nihotupu Dam is again supplying water to Aucklanders after its raw watermain suffered damage during the Anniversary Weekend storm.
The Upper Nihotupu raw watermain that carries dam water to the Huia Water Treatment Plant was damaged by landslips in multiple places after the storm.
Watercare head of production Peter Rogers is thrilled to have the dam back in service.
“Upper Nihotupu Dam officially turned 100 in April, but because of the storm damage to the raw watermain, we haven’t been able to abstract water from the dam for the past six months. There’s been a huge amount of work from our team and contractors to repair the damage over the past few months.
“The weather certainly complicated matters, as did the terrain. Most of the materials and equipment, including small excavators, had to be flown in by helicopter.
“One slip around Quinn’s Bridge took out a couple of the raw watermain supports so before we could fill the pipeline with water we had to reinstate those and repair the bridge itself,” says Rogers.
“Once the repairs were complete, the team has been slowly recharging the raw watermain by running a low flow of water through it and checking it was operating as it should be.”
Rogers says they had been manually increasing the water flow and keeping a close eye on it. Everything had been going smoothly, so they switched it back to run on auto at its normal capacity.
“It’s great to have the dam back in service again, well before the summer months when water consumption rises significantly. On average it supplies about 22 million litres of water each day, so it does play a big role in Auckland’s water supply scheme.
“From an operational perspective, this dam provides a really important water source for Auckland. It’s gravity-fed, so we don’t have to rely on pumping which makes it one of our cheaper and more sustainable water sources.”
Upper Nihotupu Dam is Auckland’s highest dam and one of 12 dams that supply water to Auckland.