A special transport pontoon carrying an enormous concrete threshold was to leave Kallo in Port of Antwerp to Nieuwpoort harbour channel. This is a major component of the storm surge barrier currently under construction by the Agency for Maritime Services and Coast. This storm surge barrier will protect Nieuwpoort against extreme storm surges. 23.5 metre wide, 42.1 metre long and five metre high, that is the size of this concrete threshold that was under construction at Kallo over the past few months. This threshold will soon be installed in the harbour channel at Nieuwpoort between both abutments of the storm surge barrier. Later, it will hold the steel barrier in normal, open position.The storm surge barrier is necessary to protect Nieuwpoort and the hinterland against floods. Coastal harbours are the most at risk of floods when storm surges occur. Nieuwpoort too is currently still unprepared for the high water levels that can occur during heavy storms. For the protection of Nieuwpoort, at the Flemish Authority are currently investing EUR 58 million in the construction of storm surge barriers in the Yser estuary. The infrastructure is one of the measures in the Coastal Safety Master Plan that will protect our whole coastline against heavy storm surges until 2050.Upon arrival in Ostend, the threshold is hooked onto a crane on a second pontoon the Matador III. The concrete threshold weighs more than 4,500 tonnes. Pontoon will be submerged so that the threshold is entirely covered by water. The load to be lifted then only weighs 1,210 tonnes. This operation takes 16 to 20 hours. Once the threshold has arrived in the harbour channel at Nieuwpoort, it is lowered between two abutments. This takes approximately one day. Finally, the threshold still needs to be anchored. For this, the harbour channel will be closed off completely for about 10 days. During the whole process in Nieuwpoort, divers are present to check that the positioning happens correctly. Installing the concrete threshold is a major milestone in the construction of the storm surge barrier. The MSC Agency launched the works in the spring of 2018. In the Nieuwpoort harbour channel, both concrete abutments and guide walls were built and the trench for the laying of the threshold was excavated.This autumn, construction works will start for the bypass drains. These are lateral pipes in each of the abutments. They will ensure that the spring tide flow rate never exceeds three knots. Then, the steel barrier still needs to be installed, as well as the mechanical parts and the fenders, and the service building will be installed on the abutment on the right bank. The project should be completed in 2025.