Wastewater overflows at some beaches in north Tāmaki Makaurau/Auckland are set to "significantly" reduce, after Watercare opened a new pump station on Tuesday.
The $22.5m pump station in Mairangi Bay will reduce sewage discharges at Mairangi, and also at Browns Bay and Castor Bay.
Dirk Du Plessis, Watercare's project manager, said the new pump station will help protect the environment in heavy rain.
"The increased pumping capacity and the pump station's integrated storage wet well of 230,000 litres will play a major role in significantly reducing the number of wet weather overflows; helping to protect inlets, reserves and beaches for today's and future generations to enjoy," he said.
Built by infrastructure company Pipeline & Civil, the new pump station can handle up to 625L per second - double the capacity of the previous 60-year-old pump station, said Du Plessis.
The old one struggled to manage wastewater flows in heavy rain due to population growth, he added.
Du Plessis said the new pump station will be "highly resilient" in severe weather.
"Even if initial power goes out, another power source will kick in as the pump station is fed through two separate power sources," he said.
Sewage overflows occur at Mairangi Bay up to 10 times a year, but the hope is that'll no longer be the case.
That's because the pump station is fully automated, with four submersible pumps - and they'll keep working even if the pump chamber is flooded.
"Also, the pump station has a state-of-the-art odour control unit to eliminate bad odour," said Du Plessis.
Construction was tough, he said, taking nearly three years to build, and there were issues with access building a pump station right on the beach.
"The pandemic certainly caused delays, with problems getting the people and materials for the job."
Du Plessis thanked the community and said the support for and interest in the project was "great".
"Most residents, businesses and commuters have stood by us as they well understood the community and environmental benefits of these critical infrastructure projects."
Castor Bay and Browns Bay both have their own wastewater pump stations, which then feed into the new Mairangi Bay pump station.
The new pump station will connect with the East Coast Bays Pipeline (ECBP), a $21.5m project to install bigger wastewater pipes along a nearly 2km route to the Rosedale Wastewater Treatment Plant.
The ECBP is set to be completed next month, meaning wastewater can then be pumped directly from Mairangi Bay all the way to Rosedale.
