Dee Regulation Scheme - Llyn Brenig

Llyn Brenig

Further statutory powers were gained in 1973 to construct another major regulating reservoir in the Brenig valley - Llyn Brenig. This reservoir was first filled in 1979 providing an additional 60 million cubic metres. This increased the potential for abstraction from the river in the lower reaches to nearly 900,000 cubic metres per day.

By 2002 the authorised abstractions had been taken over by three statutory undertakings and British Waterways Board with a total licensed abstraction of 850,000 cubic metres per day. In addition a residual flow of at least 364,000 cubic metres per day is maintained over Chester Weir in all but the most testing of droughts, safeguarding the passage of migratory fish and limiting the ingress of saline water over Chester Weir during high tides.