The pumping station, built by John Rennie at Claverton, 4.8 km (3 miles) from Bath, transfers water from the River Avon to the Kennet and Avon Canal, the motive power coming rom the river itself. At this point the canal is cut into the valley side 14.6m (48 ft) above the river.

The breast shot water wheel is 5.3m in diameter (17'6") and 3.7m wide (12ft), now in two parts as altered by the Great Western Railway Company in 1902-03, provides drive to two cast iron working beams which operate lift and force pumps. When the sluices are opened and two tonnes of water each second flow onto the forty eight wooden slats the wheel turns a full revolution every twelve seconds. The pumping station no longer pumps water to the canal. Just before it passes under the railway line, the water is diverted back into the river. 

Through a wall and via a large coupling the waterwheel directly drives the "Pit Wheel". This is a cast iron frame with 204 wooden gear teeth. At 4.9m (16 ft) in diameter this wheel runs partly in a pit cut into the floor. Engaged with the Pit Wheel is a Cast Iron gear of 64 teeth, incr easing the rotation to 16 rpm. On the same shaft are mounted the 4.9m (16 ft) flywheel and two cranks. Each crank drives a vertical connecting rod powering the "rocking" beams of the Beam Engines overhead.

At the driven end of each 5.5m (18 ft) long Cast Iron Beam, is a Watt parallel linkage. These provide a vertical motion to the pump piston rods, which drive down into the 0.5m (1ft 6in) diameter bores of the two lift pumps. The pumps take their water supply from the river outside, via valves with rope seals and wooden seats, each stroke of each pump lifts 227 litres (50 galls) of water to the canal above via the large green pressure vessel mounted outside the building. The whole machine delivers 0.5 million litres (98,500 galls) an hour.

The Grade II Listed Building, constructed of Bath stone, operated continuously from 1813 to 1952. it was re-opened in 1978 following restoration by the University of Bath and the Kennet and Avon Canal Trust.