Dam, valve tower, bridge and outflow on Pontsticill Reservoir

Cadw's description

Location

Prominently sited on the W side of the A470 Merthyr Tydfil to Brecon road approximately 6km NW of Merthyr Tydfil.

History

Dam to the Pontsticill Reservoir planned in 1913 but built in 1923-7 by the Taf Fechan Water Corporation to provide water for S and SE Wales. The engineers for the scheme were Sir Alex Binnie & Deacon and T F Harvey (of Merthyr), the resident engineer F V Stillingfleet.

Exterior

Long dam of clay core and earth bund construction, with pitched stone revetment to inner face of embankment and full length stone wall above, inner face of sloping earth bank and low stone wall supporting roadway above.

Valve tower, rock-faced coursed stone with copper-sheet spire. Gothic style octagonal tower rising from the water on octagonal base. Lower masonry is corbelled out on stepped corbels with pointed arches between. Moulded plinth, base stepped forward on W for piers of porch to square-headed door with renewed gabled timber hood. Narrow lancets on other sides with stone voussoirs and hoodmoulds, stepped eaves. Tall octagonal roof in 2 pitches, clad in copper sheet, with iron vane.

Bridge runs from W side of reservoir to abutment in front of door and is carried by one stone pier with blockwork above. Bridge is of lattice steel type. Abutment on land end has walls of rockfaced stone. Outflow is a convex-sided large funnel in the reservoir, below the bridge, with concrete ribs and lining of brick or stone.

Reason for designation

Listed for its special historic interest as an integral part of the water-supply system for South Wales, an integral part of the system of impounding reservoirs in the Taf Fechan system and a major Welsh civic engineering scheme which has survived largely intact. The structures are also of special architectural interest: the picturesque Gothic valve tower, bridge, outfall and dam form a prominent landmark of definite quality and character. Group value with the other listed items within the Taf Fechan system.

Note: Situated within 2 Communities/Authorities - Talybont on Usk, Merthyr Tydfil (Rec no.81199) & Vaynor, Powys (Rec no. 87640).