Spelga Dam, Kilkeel Road, Hilltown, Newry, Co Down, BT34 5XL

Spelga Dam

This extensive complex is located on the south side of the Hilltown–Kilkeel road at the top of Spelga Pass and comprises five distinct elements: the dam proper with related water channels, gates and walling, a dam superintendent's house, a garage, and a quarry. The reservoir created by the dam covers what was formerly Deer's Meadow, a summer booleying area in the medieval period. A section of the original road was submerged during construction; a new section was built around the north and east sides of the reservoir, and a hump-backed rubble-stone bridge can still be seen at times of very low water.

The Dam

The dam spans the River Bann's narrow and precipitous exit from Deer's Meadow. It is a mass-concrete gravity dam with a vertical wet face to the east, a steeply pitched dry side to the west, and two straight wings meeting at a central point on the upstream side. Corrugated metal panels are affixed to the top of the wet face to prevent overspill during stormy conditions at high water. At the apex stands a small octagonal valve house with a flat roof and granite block walls, with an entrance door to one cheek and windows to five other sides; the openings have concrete dressings. The tower is approached by a metalled path running along the top of the dam with metal handrails to each side and gives access to an internal inspection gallery running along the base.

Three draw-off levels are provided in the abstraction pipe. Symmetrically arranged on either side of the tower are four banks of triple siphons—a later addition, these are self-activating and designed to carry off excess floodwater. Between each set of siphons is a vertical metal sluice gate spanned by a concrete footbridge as part of the walkway across the dam; these sluices are also later additions to the original spillway. The discharge from each pair of siphons is confined by raised training walls to an open tank at the base of the dry face (termed a 'bucket'), lined with ashlar granite to minimise erosion. From there it passes over a vertical weir into a common stilling pool, from which it overspills a second weir into the discharge channel proper. This arrangement prevents undermining of the dam's foundations and ensures that the energy of the falling water is dissipated before it enters the discharge channel. The scour pipe also discharges from the base of the dam into the common stilling pool.

A small concrete footbridge spans the discharge channel, and another crosses the holding tank on the south side of the channel. All channels in the vicinity of the dam have vertical concrete-rendered walls. A large enclosed concrete cistern is immediately below the dam on its south side. Further downstream is a small weir and compensation flow recorder. The north bank of the reservoir is pitched with granite rubble for a short distance above the dam.

Along the north bank, in a public carpark, stands a prominent granite plinth of quarry-faced granite blocks, all ribbon-pointed, into which are set three plaques. The left plaque is bronze, recording the dam's construction by the Portadown & Banbridge Regional Waterworks Joint Board between 1954 and 1957. Its dimensions are given as 1132 feet long, 98 feet high, and basal thickness of 102 feet. Some 80,000 cubic yards of concrete were used to create the 148-acre reservoir with a capacity of 600 million gallons, drawn from a 1,740-acre catchment. A diagrammatic cross-section is also included. The middle plaque is circular and of polished granite, reading 'Portadown & Banbridge Regional Waterworks Joint Board 1948' with a depiction of a water fountain. The right plaque is bronze, dated 1960, outlining the dam's historical development. It records that the proposal was initiated by the Portadown & Banbridge Joint Water Board in 1946, which was absorbed into the Regional Joint Board in 1948 and comprised Portadown Borough Council, Newry Urban District, Newry No.1 Rural District, Banbridge Rural and Urban Districts, Tandragee Rural District, Dromore Urban District, and Downpatrick Rural District; the dam also supplied the Kilcoo area of Kilkeel Rural District. Construction began in 1954, concrete pouring commenced in October 1955, water began to flow into the reservoir in August 1957, and it overflowed the cill in November of that year. Together with Fofanny, it supplies 6.5 million gallons per day, with a compensation flow of 0.5 million gallons per day. Something appears to have been mounted on top of the plinth but has been removed.

Gates and Walling

The top of the dam is accessed by a metalled track from a small parking area on the north side of the reservoir. This area is enclosed by a rubble granite wall coped in concrete, with a pair of steel gates hung from ribbon-pointed granite blocks with pyramidal concrete caps. Raised capital letters reading 'Spelga Dam' are affixed to the gate. On the outside face of each pier is a bronze plaque. The left plaque records the laying of the foundation stone by Dame Dehra Parker, Minister of Health and Local Government for Northern Ireland, on 18 May 1956. The members of the Board's Working Committee are also given, with the chairman R.J. Morgan J.P., O.B.E. Various professionals are noted, including its Engineer, J.B. Lakely; Consulting Engineers, R. Ferguson and S. McIlveen; Contractors, John Laing & Son Ltd; and Resident Engineer, J.A. Soye. The right plaque notes the official opening of the dam by N.T. Dickson, Vice-Chairman of the Board, on 30 June 1960. Details are given of the Working Committee and officials as per the left plaque. Similar but smaller gate piers stand on the roads into the superintendent's house and into the garage.

Superintendent's House

The house is located down from the dam, on the north side. It comprises a one-storey, four-bay dwelling with a pitched natural slate roof, plain painted bargeboards, two granite block chimneys, and plastic rainwater goods. Walls are of painted cement wet dash. The main elevation faces west and has a porch to the third bay from the left, its left cheek containing the half-door entrance and the other facing a top-hung 1/1 double-glazed window. A double-glazed window is present to each remaining bay. The right gable has a window at right. The rear elevation faces the dam and is abutted at right by a wall which encloses a small yard and outhouses, all with small transom lights. Two windows face left, and the left gable is blank.

Garage

Down the slope to the south-west of the house is a one-storey, two-bay garage. The roof and walls match those of the house. Two large tongue-and-groove sheeted doors are set to the south wall. The gables are blank. A glass-brick window is present to the north elevation.

Quarry

A short distance up the slope immediately west of the dam is a large quarry from which granite was extracted for the make-up of the concrete used during the dam's construction. Up-slope from it, at its south-western corner, is a small concrete post on which an alignment sighting instrument was formerly mounted.