Getijbarrière

Getijbarrière, or tidal barrier, is a flood defense structure designed to regulate tidal exchange in estuaries and coastal inlets. Its primary aim is to prevent seawater from propagating upstream during high tides or storm surges, reducing flood risk for adjacent low-lying land, infrastructure, and ecosystems, while still allowing normal tidal flow under calmer conditions.

Most tidal barriers consist of movable gates or barriers that can be closed automatically or remotely in response to water level data. Variants include vertical lift gates, radial gates, or sluice-type openings. They are integrated with control systems, sensors, and sometimes pumping facilities to manage residual inland water levels and navigation needs.

Operational use involves forecasting and real-time monitoring. In normal conditions the barrier remains open or partially open to permit tidal exchange; during rising water they close to limit upstream flooding. After the event, gates may reopen gradually. Regular maintenance, sediment management, and provisions for fish passage are important considerations in design and operation.

Environmental and economic aspects are central to project planning. Barriers can affect sediment transport, salinity, and aquatic habitats, requiring mitigation measures such as fish-friendly designs and ecological flow. Capital and maintenance costs, potential impacts on shipping, and coordination with broader flood defense strategies are factors guiding their deployment. Getijbarrières are most common in low-lying coastal regions with significant tidal ranges, notably in the Netherlands.