Flood lock renovation Gouda

The flood lock in Gouda, a nearly 100-year-old national monument, plays a crucial role in managing water levels along the Hollandsche IJssel and is therefore vital to water safety in the Netherlands. Due to the lock no longer meeting several key standards, its renovation was included in the High Water Protection Programme (HWPP). In a building team with Rijnland District Water Control Board, Van der Ven, Witteveen+Bos and TAK, Iv worked on the integral design for the renovation. Iv was responsible for the entire design, from the feasibility study through to the detailed design for implementation.

This project was characterised by the complexity of combining technical safety requirements with the preservation of the lock’s heritage value. The monument status imposes strict limitations on what is possible. A major challenge was the deterioration of the concrete due to Alkali-Silica Reaction (ASR), which caused cracking and threatened the structural integrity of the lock. Full removal of the ASR-affected concrete was not an option. Following extensive core sampling, an innovative solution was chosen: partial demolition of the concrete structure and the addition of a new, reinforced and anchored concrete shell approximately 25 cm thick. This shell is watertight and capable of absorbing forces in the event of continued ASR activity.

Another significant challenge was the fluctuating water levels in the Hollandsche IJssel. At Gouda, the water level is influenced by tidal movements, with variations of up to two metres throughout the day. Complicating matters further, the pumping station (which discharges water during rainfall and admits water during drought) could not be taken out of service. A temporary construction pit was identified as the best solution to enable the renovation. This pit will be installed in phases, with one of the two flow openings being sealed off at a time to ensure safe working conditions.

Iv’s work contributes to an upgraded flood lock that will ensure water safety for the next 30 years. It can be operated safely, and has been restored to its original state as a national monument.