Former Filter House

The Department's description

Exterior description and setting

A long high single storey insitu concrete building.

The entrance gable approximately 10 metres wide has a central pair of narrow square headed doors with piers between and flat thin concrete canopy over supported on projecting side walls. The entrance platform (steps missing) is a thin flat concrete slab resting on 3 splayed concrete brackets. The barges of the 25º pitched roof are or were secured to moulded projecting false concrete purlins equally spaced. Most of the deep timber barge is missing and at the gable apex a wood finial. The ground slopes quickly across the width of the gable. The walls are insitu concrete, formwork joints showing, and have a painted finish.

The long wall facing N E and the Owenreagh River is 12 bays long without windows but having a high wide sliding door and 3 narrow square headed door openings. The wall has shallow recessed areas. All doors are secured and wall constructed as gable. The eaves line of the 1st two panels is higher than the remainder of roof. Gutters missing. The wall is painted and covered with a huge mural representating water being gathered in reservoir, filtered and ultimately arriving at a huge tap. Mural by Brush Strokes of Garvagh. The roofing appears to be corrugated sheet metal with long lengths of patent glazing at ridge level.

The remaining walls are similar without murals.

The building is sited at the lower end of the steeper part of Banagher Glen. The Glen area is now a nature preserve with access for public at limited times. Some landscaping has been carried out around the old filter house and provide car parks and picnic areas. It is pleasant if a little overgrown at the time of inspection . Adjacent and downstream are former settling ponds.

Historical information

The old filter house is contemporary with the reservoir i.e. 1934. It ceased working in 1968 when new water treatment works were constructed on Caugh Hill. The filter house for treating raw water contained 21 closed cylinders, 2.7 metres in diameter containing filtering sand, with air compressors, chemical pumps and Pelton wheels providing the necessary power.

References

Primary Sources
1. O.S. Map 1830 Rev. 1905 Londonderry sh. 30
2. Information displayed on building.

Criteria for listing: architectural interest

Not listed

Criteria for listing: historic interest

Not listed

Evaluation

An interesting example of a utilitarian filter house which though devoid of any architectural excitement enjoys a marvellous setting in a densely wooded glen with attractive burns, water falls and bird life.