Scour valve house etc, Silent Valley Reservoir, Head Road, Kilkeel, Newry, Co Down, BT34 4PU

Although built as one unit, this complex actually comprises three distinct elements: 1. Valve scour house Small one-storey rectangular building on island in middle of overflow channel. Two 36" diameter outlet pipes from dam (HB16/02/064) run into the basement of this building; their flow is controlled at valve tower (HB16/02/022). At the scour house, the pipes make a right-angle to the screening rooms. Valves at this abrupt turn can be opened to flush accumulated silt into a short length of tunnel which opens into the discharge channel. The building is of rock-faced granite blocks in irregular courses over a projecting base, and with a flat concrete roof. Embellished with stepped quoins and oversailing copings, all in ashlar granite. Two windows in north and south walls, and one at west, all 1/1 wooden-framed with plastic security sheeting. Metal roller door on east wall, with ashlar granite surround. Accessed via footbridges from east and west sides. These are of concrete, faced with rock-faced granite. Arches have brick soffits, rusticated granite voussoirs and ashlar granite stringing over. Parapets have rusticated copings and terminal piers. 2. Outlet tunnel When the scour valves are opened, the water discharges into a short length of horseshoe-profiled brick-lined tunnel. This emerges into the discharge channel through a pedimented arch of classical design. The arch voussoirs are of ashlar granite (with keystone), stepped into rock-faced granite spandrels in regular courses with an ashlar pilaster either side and entablature over. A stone in the pediment thereon is inscribed '1932' (the year the dam was completed). Immediately above this arch is a sloping grassed area enclosed by granite walls leading up to the scour valve house. 3. Discharge channel The subterranean overflow tunnel from the bellmouth intake (HB16/02/023) emerge into the open discharge channel just above the scour valve house. It exits through a horseshoe shaped arch of similar design to the outlet tunnel arch. The arch spandrel continues up to a parapet embellished with rusticated copings and ashlar stringing. Just below the tunnel, the channel bifurcates around the scour valve house emplacement. The bed of each channel is pitched and stepped granite. They reunite below the scour valve outlet tunnel as a sloping channel which eventually continues as the Kilkeel River. The vertical sides of the 45ft wide channel are of concrete faced with rock-faced granite blocks in irregular courses and with rusticated copings over.