Ports of Auckland Outfall Upgrade, Auckland, Stanley Street

Auckland Council engaged McConnell Dowell to deliver the Ports of Auckland outfall project. When complete, it will significantly upgrade the stormwater system in the downtown port area, increasing its capacity to deal with flooding. The new outfall will operate in parallel with the existing culvert, allowing either culvert to be isolated for maintenance and cleaning in the future.

A three-metre diameter micro-Tunnel Boring Machine (m-TBM) was used to bore under Quay Street to install the new 270-metre stormwater pipe. The pipe runs from the south-eastern end of Quay Street (east of Spark Arena and west of shops and services at 8–14 Quay Street), across the Ports of Auckland site, and connects to a new outfall to the sea. With the completion of the new outfall, the existing 80-year-old 2.1 x 2.3-metre box culvert, which is in poor condition and requires remedial works, can be taken offline for repairs

Stalwarts of the New Zealand building and construction industry McConnell Dowell were also tasked with carrying out remedial works on the existing box culvert. This was always going to be a significant challenge in a tidal area. And it didn’t disappoint. Though the very experienced McConnell Dowell team, ultimately, had its measure.

Dean Carter, Project Manager says the company lives by their promise of “Creative Construction”. “Traditionally, in this situation, you’d have a temporary bulkhead, built using timber and steel to isolate the water flow. We thought, after serious consideration, we’d look for other, potentially better, options.”

For an innovative sealing cushion to fit their (almost) square culvert, they turned to BurrowTech.

Hayden Powell from BurrowTech says the German designed and manufactured sewer sealing cushion is proven to be the safest and most economical pneumatic pipe stoppers available. “Typically, our sewer sealing cushions require no additional bracing and are suited for all types of pipe cross sections.

“The sealing cushions have an extremely long service life, (40 years), and no manhole access is required. They’re also repairable and re-usable.”