Craig Coch Dam & Valve Tower

The height of the reservoirs enabled water to reach the outskirts of Birmingham by gravity alone, without the expense of pumping. Provision was made for future expansion in the Claerwen Valley where the scheme was brought to its current state by the Claerwen dam in 1952.

Bronze plaque from dam (removed to visitor centre) says " Craig Coch Reservoir Total Capacity 2,000,000,000 gallons Top Water Area 217 Acres Top Water Level 1,040 feet above Ordnance Datum Height of Dam above River Bed 120 ft Depth of Foundations below River Bed 10 ft Length of Weir 390 ft Thickness of Dam at Base 104 ft

Estimated quantity of masonry 80,000 cubic yards"

Curved masonry dam with massive heavily rock-faced blocks. To ends, spillways with parapet walls, spillways broaden as they drop, surfaced with hard grey stone; walls turn, becoming parallel with river. On East side is outlet partly submerged at time of inspection.

Dam supports viaduct on 13 arches carrying roadway over dam. Contrasting rock-faced and smoother stone. Piers support segmental arches with keystones; bandcourse at road level, parapet with coping and heavy rock-faced capstones; 3 arches from each end, is polygonal refuge corbelled out. Abutments to viaduct have doorways to interior of dam. Opposite E refuge is attached polygonal valve tower; copper dome with lantern and fish weathervane, waterspouts to parapet, paired windows to each face set back from buttresses; this stage corbelled out over narrower stage, with barred intakes, which runs down below water level.

Interior said to contain original operating machinery.