41 Edendarriff Road, Ballynahinch, Co Down

A complex of water supply infrastructure comprising a waterpipe attendant's dwelling, lime dosing plant, and airwell. Built as part of the Mourne Scheme, by which the Belfast City & District Water Commissioners brought water to Belfast from the Annalong and Kilkeel rivers in 1900–1901.

The attendant's house is a one and a half storey dwelling of two bays, rectangular in plan and orientated east–west with its gable facing Edendarriff Road. The pitched roof is natural slate with plain painted wooden bargeboards, moulded concrete kneeler stones, and ogee cast-iron gutters. A distinctive red brick chimney with yellow brick stepped quoins and cap rises centrally from the ridge. The walls are of squared rubble Silurian stone in irregular courses over a projecting basal course. Yellow brick is used decoratively in the projecting eaves, stepped quoins, and along the top of the base course. Window and door openings are trimmed with yellow brick heads and jambs (stepped), with stop-end chamfers to the latter. All window openings have shallow segmental heads and chamfered painted cills, probably of concrete. The windows are 2/2 timber-framed sliding sashes throughout, unless otherwise altered.

The main facade faces north. At the left is a one-storey porch with pitched natural slate roof, raised yellow brick verges, and concrete kneelers. Four granite steps and two concrete steps lead to a painted tongue-and-groove boarded door in the left cheek, with a small electric light above. A window pierces the west-facing gable wall of the porch. To the right of the porch, on the main block's wall, is a single window. The right cheek of the porch is blank. The east gable contains two window openings to the ground floor and two to the attic floor, aligned vertically. The south wall is blank except for a single ground-floor window to a bedroom at the left. An electric light is affixed at the right corner and a satellite dish at the left. The west gable is abutted on its left by a single-storey monopitched return running along the inside of the yard's north wall, which has an artificial slate roof and plastic gutters. Above this is a window to a half-landing, and above and to the right is a window to a back bedroom—a modern 1/1 top-hung plastic replacement of the original sash.

The yard projects to the south and west of the dwelling, with its entrance on the east wall. The yard wall is constructed similarly to the dwelling with yellow-brick trim and coped with rock-faced blocks. The original wide entrance now has a smooth render infill with a small sliding metal garage door inserted. Square masonry gate pillars flank the original opening, each with yellow brick quoins and a projecting flat concrete cap. A boiler flue projects from the west wall of the yard.

Just north of the house stands a four-stage square tower of quarried random Silurian rubble masonry, all strap-pointed (original drawings indicate it is stone-faced reinforced concrete). Each stage is delineated by a flush granite platband. The walls are plain except for a small circular ventilator on the top stage of the west wall and a roller-shuttered door on the east wall. The date "1985" is inscribed on a plaque set into the second stage of this wall. This is the lime dosing plant. Abutting its north wall is a low yard wall with a metal door at the east and a communications aerial at the west.

A short distance to the north, lying on the actual pipeline, is an airwell. Measuring approximately 3 by 2.5 metres in plan and 75 centimetres high, it is constructed of reinforced concrete with a crowned roof containing a metal inspection lid.

The plans for the waterpipe attendant's house and its five counterparts were drawn up by L. L. Macassey, engineer to the Belfast City & District Water Commissioners, and approved by the Board in February 1899. The contract (numbered 16, valued at £6806) for erecting all six houses was awarded to Messrs Courtney & Co in November 1899. By April 1901, all were nearing completion and were presumably occupied by the time the pipeline was officially opened in October 1901. Identical lodges stand at Tullybranigan, Ballybannon, Drumanaquoile, Ballykine, and Creevytenant. More substantial water-related dwellings were also erected at Silent Valley, Dunnywater, and Knockbreckan.

The lime dosing plant was erected in 1985 and is similar to plants at Silent Valley and near Knockbreckan. It contains a silo from which powdered lime is automatically fed into the water as it flows beneath, to neutralise acidity which might otherwise cause pipe corrosion.

The complex is of distinctive and attractive style, carefully executed with good use of contrasting yellow brick in its embellishment. Despite its modest scale, it is of undoubted historical interest as part of Belfast's first water supply from the Mournes and of industrial archaeological significance.