No.1 Reservoir

An underground reservoir with a capacity of 413,000 gallons, built in 1824 for the Cheltenham Water Works Company to designs by James Walker (1781–1862), civil engineer of Limehouse.

MATERIALS Reservoir built in limestone, with brick roofing. Portal is in rubble stone with limestone ashlar dressings, and wrought-iron railings.

DESCRIPTION The reservoir is entirely contained underground, but is entered by an above-ground portal, built into the higher ground to the rear. The portal is circa 2.5m high, and consists of an entrance bay with square top, central entrance doorway with a flat limestone lintel over, and limestone ashlar quoins. The portal is flanked by curving ashlar walls which sweep downwards and forward to meet the ground; these walls are topped by spear-headed railings, which continue to either side.

The underground reservoir measures 25.6m square overall, and the internal height is 4.3m; its capacity was 413,000 gallons (1.878 Ml). The structure consists of four parallel rectangular chambers with walls of limestone masonry, inverted-arched masonry floors, and brick jack-arched roofs. Four arched openings in the stonework of each of the internal walls allow water to flow between the chambers.