St Marys Bay is an inner coastal suburb of Auckland, and one of New Zealand’s oldest and most historic areas. As part of its Healthy Waters management plan, Auckland Council commissioned McConnell Dowell to build infrastructure that would improve wastewater management and water quality in the area.
The maritime project involves laying over 1km of pipeline in St Marys Bay to eliminate three marine outfalls, including building a 450m marine outfall pipeline to deliver overflow further away from the coast, as well as renewal of a failing stormwater outfall.
McConnell Dowell is lead contractor on the project, and provides all works including tunnelling, shafts, drainage and concreting. It’s a $44 million project that’s been running for almost 2 years and is due to finish in 2021.
Managing works in a busy residential area
One issue for the project team is managing environmental impact at tunnel work sites. The team have consented noise levels that they need to stay within, as well as specific hours they are allowed to work. The McConnell Dowell team needs to ensure the community is not impacted.
In particular, one of the tunnel shafts is a challenge, as it’s situated in a very tight space in a crowded residential area - with houses in close proximity.
Henry McKee, Site Engineer on the project, explains, “Having a 25m deep hole in a small residential space is difficult, and we needed to make sure we managed the noise and vibration levels throughout the works.”
To do this, McConnell Dowell implemented SiteHive. They use SiteHive cloud-based software to visualise and manage the environmental impacts, linking through to a SiteHive Hexanode for noise monitoring and a Bartec Rock unit for vibration data.
Continuous, real-time data provides a complete record of site events
SiteHive allows the team to see what’s happening on site and monitor the environmental impacts all the time, rather than just in snapshots. This gives them confidence and security when dealing with residents and other stakeholders.
Henry explains, “We are managing works in a tight residential area, and using SiteHive means that we can monitor noise levels continuously. In the past we would have had to take a snapshot of noise levels, but SiteHive is really useful because we can monitor all the time.”