York Historic Environment Record

River abstraction and treatment works of 1846 for the York Waterworks Company by Thomas Hawksley, with filters by James simpson. Water was raised using two Cornish engines built by Low Moor Ironworks. Three Simpson designed slow sand filters were built together with two subsiding reservoirs, a service reservoir at Severus Hill, and a system of mains to the city. Further slow sand filters were added in 1878. In 1902, two further slow sand filters were built, together with four rapid gravity filters (reputedly the first in England) which lasted until the 1950s. The `Severus Tower' at SE580519 was built in 1914 using the Kahn system of reiforced concrete. Diesel engines were installed in 1923, and replaced by electric pumps in 1930. In 1937, the No.3 new treatment plant was built with a `spiral clarifier', reputedly the first in England, and unique, but dismantled in 1996. The Siwards How Tower, the largest capacity water tower in Britain, was built in 1956. Further extended in 1963.