Lagan Weir


Jul 17, 2022

Prior to the building of the weir, the river Lagan was tidal and low tide would expose mudflats, which were unsightly and emitted a strong smell, particularly in the summer months.

It was built in 1994 and contains a footbridge.

Construction of the weir, installation of an underwater aeration system and maintenance dredging has led to environmental improvements in terms of water quality and biodiversity.

On occasion, at high tide, the weir can operate as a barrage. If the river level is too high this can have such negative effects as causing erosion of the river banks, reduce air draft for vessels needing to pass under any of the river’s road bridges and in extreme cases, increase the risk of flooding to low areas.