The High Bridge Water Tower, in Highbridge Park between West 173rd and 174th Streets, on top of the ridge on the Manhattan side of High Bridge, was built in 1866–1872 to help meet the ever-increasing demands on the city's water system. The octagonal tower, which was authorized by the State Legislature in 1863, was designed by John B. Jervis, the engineer who supervised the building of the High Bridge Aqueduct. Water was pumped up to a reservoir next to the tower – now the site of a play center and public pool built in 1934–1936 – which then provided water to be lifted to the tower's tank. This "high service" improved the water system's gravity pressure, necessary because of the increased use of flush toilets.