Cardiff Bay Barrage

Cardiff Bay Barrage is a tidal structure that closes off the bay from the Severn Estuary and houses three lock gates for boat passage between the two water levels. The barrier also includes fish passes and spans across the entire width of the bay with multiple access points.

The barrage was approved in 1993 and construction started in 1994 to convert the bay from a tidal estuary into a freshwater lake. This major change made the waterfront suitable for new housing and public spaces instead of industrial use.

The barrage transformed the old docklands into a place where people now live and gather, with restaurants, galleries, and shops lining the waterfront. The bay became the social heart of the city rather than an industrial zone.

The barrage is easily accessible on foot from the surrounding waterfront, with walking paths and public areas for exploring along the edge. Several vantage points let you see the structure and watch how it manages the water flow.

The barrage uses an oxygen injection system that keeps the bay's water healthy by pumping air into deeper layers where stagnation can occur. Few visitors notice this hidden technology that works quietly to maintain the environment.