Flood defence, treatment, networks.
Built on the Dutch coast — we understand water as well as we understand stone.
What this discipline covers.
Hextal was founded on the Dutch coast, in a country where 26% of the land lies below sea level. Water management is not a service we offer. It is the existential challenge that shaped our company. The Water and Environment division manages 1,840 km of water mains, flood defence systems, treatment plants, storm water networks and environmental remediation projects.
Our flood defence expertise spans hard and soft engineering: concrete sea walls and storm surge barriers alongside managed retreat schemes, wetland restoration and natural flood management. We led the engineering on three of the six Delta Works structures and continue to maintain and upgrade the system that protects 3.8 million people in the Netherlands.
The division also delivers water treatment and distribution networks for municipalities and utilities across Europe, including membrane filtration plants, desalination facilities, and the rehabilitation of ageing Victorian-era pipe networks in the UK and Ireland.
Selected works.
Brenner Base — North Approach, Tube T-3
22.4 km twin-bore alpine tunnel beneath the Stubai range. Hextal led the TBM consortium and the cross-passage civils. Excavated material reused as aggregate within a 40 km radius — net-positive on embedded carbon vs. EN 16627 baseline.
Berlin Hauptbahnhof — Southern Concourse
14,800 m² extension, glass-and-steel canopy spanning four ICE platforms. Built without interrupting service.
Maasvlakte III — Caisson Dry Dock
A 1.2 km automated container quay built on a man-made polder.
How we approach this discipline.
Hydraulic modelling
Every flood defence, treatment plant and distribution network is modelled hydraulically before design begins. We simulate extreme events, not average conditions.
Asset condition assessment
For rehabilitation projects, we survey existing infrastructure using CCTV, sonar and ground-penetrating radar to build a complete picture of asset condition before designing the intervention.
Trenchless installation
Pipe jacking, microtunnelling and horizontal directional drilling minimise surface disruption in urban environments. We install new mains beneath live roads without excavation.
Commissioning and handover
Water quality testing, pressure testing and SCADA integration are completed before any network enters service. We do not hand over until the water is clean and the system is controlled.
The people behind Water & Environment.
Pieter de Vries
Pieter has spent his entire career at Hextal, starting as a dredging cadet in 1992. He now leads the marine division, responsible for 38 active port projects from Maasvlakte III to the Tangier Med expansion.
Our water & environment team includes engineers, project managers, site supervisors and specialist consultants working across the full project lifecycle.
Other disciplines.
Bridges, tunnels, rail & highways.
From cable-stayed crossings to bored alpine tunnels — the load-bearing arteries of European movement.
Renewables, transmission, storage.
Offshore wind foundations, HVDC interconnectors, pumped storage, hydrogen-ready substations.
Quays, locks, dry docks, breakwaters.
If a continent rests on its coastline, we work where the rock meets the salt.