Knockbracken Reservoir

The Department's description

Exterior description and setting

Extensive complex on west side of Saintfield Rd comprising (1) reservoir and related structures (intake, pipe take-off, overflow), (2) river by-pass channel (3) scour valve and channel, (4) water attendant's houses and related building, (6) chlorination house and miscellaneous buildings (see map for locations).

1. Reservoir
This L-shaped open reservoir has been created by excavating the east bank of th Carryduff River and placing a large earthen embankment across the valley at its north end (1.1 on map). The inside faces of the reservoir are sloped and pitche to their wet sides with rubble stone. The water discharges from the Mourne Conduit into the reservoir at its south end, where there is a concrete-lined recess in the bank surrounded on three sides by a three-bar metal railing (1.2) The water falls over two vertical drops and down an incline into the reservoir. Metal baffle plates across the lower fall and a concrete post at the bottom of the incline break the force of the water and help its aeration.
The water is abstracted from the reservoir at its north-east end (1.3) . Here there are two vertical cast-iron standpipes (36in. dia) with valve stocks at th top which control the flow. Access to these valves is across a metal footbridge supported on two dressed granite piers (drawings show this to be a facing over concrete). At the north-west end of the reservoir the bank is broken to accommodate an overspill weir (1.4) which discharges into the Carryduff River, footbridge formerly spanned this overflow, but only its cast-iron piers now survive.

2. River by-pass channel
The Carryduff River has been diverted around the west side of the reservoir in an artificial channel. Just before it enters the grounds of the reservoir is a small cascade weir (2.1) which breaks its flow as it goes underneath the public road in two cement-lined segmental-headed culverts (2.2). There are two concret decked metal footbridges over this channel at the reservoir's overspill (2.3) . The river then cascades down a series of paired steps (2.4), at the foot of which the scour channel meets. This section of the channel has vertical random rubble walls. The river then continues down the valley along its natural course A short distance south of this complex is a modern lime dosing plant, similar t those at the Silent Valley and Dunmore.On the dry side at the foot of the embankment is a scour channel (3.1) which falls from east to west and discharges into the Carryduff River channel. This carries the outflow of the reservoir when accumulated silt is being scoured frc the abstraction pipes or the reservoir is being drained. There is a concrete-lined valve control well at its top end (3.2) . The channel is piped for a short section from the valve chamber, and part of the bank has random rubble revetments. At its bottom end is a series of steps which reduce the force of th flow before it meets the river.

4. Water attendant's houses
The original attendant's house is located on the east side of the reservoir within a mature planting of conifers (591 Saintfield Rd; grid 36426618; marked 4.1 on map). Known as Waterworks Lodge, it is a one-and-a-half storey/ three-ba dwelling of T plan with a one storey return in enclosed yard at rear. It was vacated about six years ago and now lies empty.
The house is orientated east-west; the top of the T is at east with principal gables to north and south. The roofs are pitched and of natural slate with ogee cast-iron metal gutters on projecting eaves. There are plain bargeboards to the gable ends, each with framed apex finials. There is a yellow brick chimney at either end of the main ridge. The walls are lined and painted smooth cement render over a smooth rendered base course (it has been in this state for over 3 years). A plain platband runs around at cill level on both floors. It is uncertain whether it is of stone or concrete as it is overpainted. All the windows have either been sheeted over with plywood or have metal security mesh fitted. Their cills are incorporated in the platbands.
The main facade faces north. At left is the slightly projecting gable of the left front room. A verandah runs across the facade to the right of this gable. It has a monopitched natural slate room carried on three round metal columns with decorative cast-iron brackets at top. The floor of the verandah is of alternating red and white tiles. The main door is at the left end of the verandah and leads into the middle bay of the house. It has been sheeted over with plywood. To its right are two 2/2 sliding sash windows. The gable at left has two similar windows, with a horizontal drip mould over (shared by both windows). At first floor, over the verandah, a gabled dormer rises from the eaves. It contains a semicircular headed window with run-moulded architrave. There is an identical window in the apex of the main gable at left. The east wall of the house has two 2/2 sliding sash windows at ground floor (on to each room). Each has a horizontal drip mould, these being a continuation of the facade moulds. At first floor are two gabled dormers similar to that at front right, and each with a semicircular headed window; these presumably light a front and back bedroom. This wall continues along the perimeter of the yard. There are two 4/4 sash windows which light the lean-to shed on the inside of the yard.
The south wall of the house was not inspected in detail as no access was gained to the yard. There is a flat roofed porch at centre, with half-landing light over, and a single storey lean-to shed abutting at either side. At right is a semicircular headed window in the gable apex. There is no window opening to the upper left side.
The west wall is blank save for a single 2/2 sliding sash window to the ground floor. This wall continues at right to form the perimeter of the yard. There ar two modern wooden windows along this wall in what may be original openings. The yard was originally accessed from the south though a wide opening flanked b square pillars with pyramidal caps. This entrance has been narrowed with concrete blocks and a modern pedestrian door inserted. At right, a large modern door has been inserted in the gable of the lean-to to enable access to a garage
A short distance south of the lodge is a one-storey building and enclosed yard (4.2). In the most recent past this building was used as a canteen by grounds' staff. It was formerly used to house a horse and trap belonging to the reservoir's water superintendent. The building is oriented with its gables to east and west, with the yard to south. The roof is pitched and of natural slate with half-round metal gutters. There are plain bargeboards to both gables, with a framed wooden apex finial to that facing east. The walls are wet dashed withcement over a smooth rendered base; the corners and opening trims are also smooth rendered. The east gable contains two entrances, both now sheeted over with plywood. In its apex is a circular window. The north wall is blank save f a series of metal ventilators. The south gable is blank save for a circular window in its apex. Although the yard was inaccessible, external inspection showed two wooden doors and two windows along the buildings south wall. The yard is entered through two high sheet steel gates. These are flanked by smooth rendered pillars surmounted by pyramidal concrete caps. The yard wall, which is coped with concrete, rises at south to accommodate the natural slate roof of a lean-to shed within the yard.
At the entrance to the grounds is a comparatively modern two-storey brick dwelling (4.3; 589 Saintfield Rd), now owned privately, but formerly the home the reservoir attendant.

5. Chlorination house etc.
In the immediate vicinity of the valve well are seven small brick buildings, a with flat concrete roofs and of comparatively recent date. These house flow gauges, valve stocks and chlorination plant. Also in this area is a relatively modern one-storey dwelling originally built for the chlorination plant attenda (5.1). It has since been sold off by Water Service and is now in private ownership.
The grounds are bounded along the main road at east by a concrete wall. This comprises 'rock-faced' concrete blocks laid in regular courses, with stepped concrete copings. Originally there was a hedge along the road, but this was removed when the road was widened and the present wall built. There is a pair modern steel gates into the grounds at its south end and another opening at north. Original drawings show the original entrance gate to be have been of wrought iron, with flanking screen. Internal description
Waterworks Lodge

Historical information

The Knockbreckan reservoir complex was originally the principal service reservoir from the Mourne Conduit, which brought water from the Mournes to Belfast. Advertisements were placed for its construction by the Belfast City & District Water Commissioners by October 1894. The contract was awarded to Mess Fisher and Le Fanu at a price of oe33,444. This firm also carried out the works at the Mourne end and went on to build the Silent Valley reservoir in the 1920 Waterworks Lodge is similar in design to the water attendants' houses at Sile: Valley (HB 16/2/17) and Dunnywater (HB 16/1/29), although it has a cement-which no trace is now evident. The original drawings for the house were signed by Messrs Robert and David Laidlaw of Glasgow (although one Alex Gaill may have been the actual contractor). They show that the wall render is an original feature. The building appears to have been completed around 1896. The original drawings show the following internal layout:
The Knockbreckan reservoir was being puddled in August 1897 and was completed in February 1900. It was opened by Robert McConnell on 2 October 1901. In its initla years operation, water was supplied only from the Annalong River, but with the completion of the Brackenagh tunnel in mid 1903, this supply was augmented by the Kilkeel River. In 1933 the Silent Valley Reservoir came on stream, followed in 1956 by the Ben Crom Reservoir.
The chlorination plant was added in 1953. Most of the water from the Mourne conduit now bypasses this reservoir and feeds directly into the larger of two covered reservoirs at Breda. Knockbreckan would have been abandoned had an increased demand for water not necessitated a continued supply from it to the smaller of the two Breda reservoirs. The complex will probably be abandoned once the conduit from Newcastle is relaid.

Sources:
Advertisement regarding construction of conduit contained in PRONI -
WAT1/3F/1/1.
Minutes of BCDWC Works Committee, PRONI - WAT1/3AC/1 (2 Aug 1897)
'The Mourne Scheme - general outline of the works', in Northern Whig, 21 June
1900 (contained in a book of newspaper cuttings in PRONI - WAT1/3F/3/2). Also in
same file is a description of the opening ceremony as reported in News Letter of
3 Oct 1901.
L.L. Macassey (1901), 'Mourne scheme and sundry works progress report, 15 April
1901' (PRONI - WAT1/3CG/6).
VAL 12B/20/11C (1896 valuation book entry).
Water Service, Westland House- drawings 3E1-3F11 (reservoir), 3E21 (house).
Specification and bills of quantity for chlorination plant in PRONI -
WAT1/3J/20.
Information from Mr R. Gracey, ex water superintendent, 589 Saintfield Rd,
Belfast.

Criteria for listing: architectural interest

Not listed

Criteria for listing: historic interest

Not listed