Nikolai flood barrier

Secret but safe

connecting people

River barrier systems are very important for protecting the residents of cities by the water. In the Free and Hanseatic City of Hamburg they separate the city from the Elbe River’s water masses. Such structures, if well designed, are bastions against the forces of nature. Achieving a look that fits the cityscape seems a small challenge in comparison, but in the ideal case we achieve both: protection and attraction!

paving the way

The Nikolai River Barrier guarantees adequate water levels in the inner-city canals. The ever-rising water levels of the Elbe River require the protective structures to be checked, repaired and strengthened on a continuous basis. High-precision mechanical engineering solutions were thus called for – one of GRASSL’s specialities. Drives, steel gates and lock sills were replaced. By locating the drives at the centre, no asymmetric loads are placed on the steel members. And it was possible to preserve the existing concrete structure.

creating construction culture

The Nikolai River Barrier not only offers interesting views over the historical Speicherstadt (warehouse) district. As part of the waterfront area of the Zoll Canal, it also invites passers-by to linger. The technology hidden underneath the seats performs its duty reliably, redundantly and steadily. Front row seat? Yes please!

Year of completion


Type of intervention


Contracting authority

Freie und Hansestadt Hamburg



Construction material

Reinforced concrete, steel

Type of structure

Hydraulic structure

Services Grassl

Basic assessment, preliminary design, detailed design, planning for approval, preparation of tendering, building inspection, damage analyses

Latest news about the project

Nikolaifleet Canal opened to shipping

On 23 February 2021 the Nikolaifleet canal was opened to shipping after comprehensive remedial maintenance …