Hölscher Jensen was awarded Dewatering Contractor Project of the Year for our ongoing work with Denmarks largest dewatering project, for the Nordhavn Tunnel project in metropolitain Copenhagen. The project’s risk-led approach coupled with compartmentation and targeted grouting with responsive pump control to limit geotechnical and environmental uncertainty at each construction stage, has created an unusually large scale dewatering project in a dense urban-marine setting, requiring disciplined hydraulic control to succeed.
The dewatering scope was abstraction of approximately 16–20 million m³ of groundwater over ~28 months, with reinfiltration used strategically to stabilise heads and minimise advective transport. A defining feature is the use of distributed reinfiltration as a hydraulic barrier to protect sensitive structures and minimize the risk of mobilising contamination.
Across heterogeneous strata—from marine sands to Copenhagen limestone—the team has maintained excavation stability and target drawdowns under live city constraints, supported by an integrated network comprising 19,4 km of pipework that ties together pumping, reinfiltration and water treatment plants for discharge to Copenhagen harbor. An achievement enabled by our solution-oriented approach, dedicated effort, and strong collaboration with the project’s main contractor to revise and improve the dewatering plan as needed.
The project’s high priority of Environmental Health and Safety has been a focus point throughout, with monthly and annual recognizions of project Safety Representatives. Notably, Hölscher Jensens’s Safety Representative Luca Garrone was recognised as Safety Representative of the Year 2024 for proactive engagement, including the reporting of 25 near-miss incidents within a single year—helping to prevent hazardous situations and reinforcing a safety culture that matches the project’s technical ambition.
Dewatering at the Nordhavn Tunnel, will continue for the remainder of the project – currently estimated to be finalized mid-2027. We are looking forward to continuing our strong collaboration with the main contractor BESIX-MTH JV, until the project’s successfull completion.
