Alnwickhill Reservoir And Waterworks With Boundary Walls, Liberton Gardens, Edinburgh

Alnwickhill Reservoir and Waterworks, located at Liberton Gardens in Edinburgh, was constructed in 1875, with a second phase completed in 1888. Designed by engineers J & A Leslie and built by James Young and Son, this complex includes a reservoir with a capacity of 15 million gallons, two open settling tanks with capacities of 4.5 million gallons and 2.5 million gallons, respectively, as well as slow sand filters and a brick-lined tunnel network that feeds two outlet houses.

Outlet House 1 is one of two classical single-storey outlet houses for the service reservoirs. It is built from coursed, stugged ashlar with polished ashlar dressings, featuring a base course, rusticated quoins, and margins with chamfered arrises. The roof is stone slabbed. The south elevation has a central six-panelled door surrounded by a heavy pedimented and consoled architrave. Above and on either side of the door are engraved ashlar panels that display the names and dates of the works. There are arrow-slit windows on each side, and a pedimented gable with acroteria featuring anthemion decorations above.

The side elevations each have two windows with bracketed cills and ashlar surrounds. The former windows, which were louvred at the top in timber, have been replaced with aluminium frames. Inside, the building contains water filters and features a cantilevered stone inspection walkway around the walls, which are made of coursed stugged ashlar and lined with tiled brick below the water level. Stone arches lead into brick-vaulted storage tanks. The paths and stone steps outside were originally paved in ashlar and included a moulded drainage channel, though they now have concrete flagstones.

Outlet House 2 is situated at the top of a steep slope near the entrance to the complex, built into the slope at the rear. It uses the same materials and dressings as Outlet House 1. The south elevation also features a central six-panelled door with a heavy pedimented and consoled architrave, and a pedimented gable with dies above. The side elevations mirror those of Outlet House 1, each with two windows and bracketed cills. The interior is similar to that of Outlet House 1, with a roof braced by steel trusses.