Construction Dewatering
Practical dewatering design, consenting and site monitoring for excavations, basements and infrastructure projects across Auckland, Waikato, and Nationwide.
Keeping Excavations Dry, Safe and Stable
Any excavation that extends below the groundwater table brings its own set of problems. Water finds its way in, ground conditions shift, and what looked straightforward on paper can turn into a stability issue on site. Earthtech’s groundwater engineers and hydrogeologists design dewatering systems that keep excavations dry and stable, whether that’s a basement, a shaft, a stretch of infrastructure trenching, or general earthworks below the water table.
A change to the groundwater table, even temporarily during construction, can also trigger the need for a dewatering consent from the Regional Council. We handle that side of things too, preparing the assessments and documentation that get projects through the consenting process without unnecessary delay.
Our team has genuine boots-on-the-ground experience working alongside contractors, not just at the design desk. That means our systems are built to be practical on site, not just correct on paper. We take the time to understand each project properly, so the dewatering design fits the way the job will actually be built.
How We Support Your Project
Dewatering methods vary depending on ground conditions and the scale of the works. We design and specify the right approach for the site, whether that’s sump pumping, vacuum spears, well points or deep bores, and we prepare the technical assessments needed for resource consent.
Design and Risk Management
Contractor Support and Monitoring
During construction, we arrange active groundwater monitoring to keep excavations safe and stable, and we can manage the setup of alert and alarm notifications for the health and safety and consent compliance elements that matter most. It’s the kind of support that means problems get caught early, not discovered on site.
Two Ends of the Same Problem
Most dewatering consultants sit on one side of the fence. We work both. Our team gets out on site with contractors during construction, and we’re regularly engaged by Councils and stakeholders to peer review other consultants’ dewatering proposals. That dual perspective means we know exactly what drives a workable dewatering solution, and what a consent authority needs to see to approve it. The result is practical, well-considered documentation that gets projects moving rather than stalling in review.
“We’ve had the privilege of working with Philip and his team for many years across a range of complex geotechnical challenges. His energy, technical excellence and genuine commitment to achieving enduring outcomes consistently stand out. Philip brings a level of sincerity and dedication that surpasses any other collaborator we’ve worked with in the industry.”
Andy O’Sullivan
Geotechnical Engineering
Our Construction Dewatering Projects
Ngaakooroa Stream Bridge Dewatering
Project Summary Elevated artesian groundwater pressures coupled with overhead power lines, created challenging conditions for bridge pile construction. Working with the project team, Earthtech provided a dewatering bore design solution to depressurise the artesian groundwater levels. Timeframes were very tight, meaning that the dewatering design, consenting and dewatering bore construction stages significantly overlapped. The project was delivered on time, and Earthtech assisted with real-time groundwater level control and monitoring during piling activities. Services Provided Groundwater analysis and design of a bore-field dewatering system. Preparation of the Assessment of Environmental Effects and consenting of the groundwater take (dewatering) and diversion activities. Ongoing involvement and contractor support during dewatering and piling activities, including assisting with the setup of groundwater level alert and…
Collins Road Wastewater Facility Dewatering
Project Summary Earthtech became involved in the project when unexpected groundwater conditions and piping in the excavation floor were encountered during construction of 7.8m to 9.1m deep excavations and shafts for wastewater infrastructure construction. We carried out groundwater investigations and pump testing to define a dewatering solution that provided a dry, safe and stable excavation during the 6-month construction dewatering period. Earthtech's involvement continued during construction, with the management of pumping rates and monitoring to ensure that neighbouring properties and infrastructure were protected from dewatering effects. Services Provided Groundwater investigations and pump testing. Groundwater analysis and design of a bore-field dewatering system. Preparation of Assessment of Environmental Effects and consenting of the groundwater take (dewatering) and diversion activities. Preparation of…
Talk to Our Dewatering Team
Whether you’re planning an excavation below the water table or need a second opinion on someone else’s dewatering proposal, our team can help early, before problems on site become expensive ones.
