A massive project upgrading Auckland’s water quality is a step closer to being finished.
The central interceptor is a supersized tunnel running from Mangere Pump Station, through Mount Roskill, Western Springs, on to Point Erin in Herne Bay.
When completed next year, it would be more than 16km long.
With a capacity for 250,000 cubic metres of wastewater, its seven-year construction has come at a cost of $1.6 billion.
It is expected to improve clean waterways and open spaces, reduce stormwater overflows, and ensure capacity for homes and people.
The southern half of the tunnel was now completed, and a new pump station opened. The new station could process 1300 litres a second — meaning sewerage and stormwater won’t overwhelm the city’s system in big storm events.
Eventually, it would reduce overflows in creeks and beaches by 80%.
Ghella Abergeldie JV geotechnical and instrumentation manager Peter Yee said the subterranean environment of Tāmaki Makaurau has made the job easier.
“[It’s] really good conditions. Not too hard, not too soft — just rock.”
With the new station set to last 100 years, Yee said he was proud to have contributed to something that would be enjoyed by future generations.
The full environmental benefits of this work won’t come into play until the remaining central interceptor tunnel running from Mt Roskill to Herne Bay was completed in 2026.
The $1.6 billion Watercare project was also coming in largely at budget, with a small rise for inflation.
