The water tower stands to the north of the cathedral. It was built in the 1160s under the direction of Prior Wibert, located close to the dormitory passage as monks washed their hands here in the 'laver' (water basin) en route to the cathedral. Water rose from a source over 1 km away in what is now Military Road - the conduit house (Image 1) - and having passed through settling tanks was stored in a large tank in the water tower (Image 2). The lower sections of the tower retain their elaborate Norman dog tooth arches (Image 3) whilst those above were re-built in the time of Prior Chillenden (1391 to 1410). The water system was elaborate and important for the well-being of the Priory - first for drinking and cooking, then for washing, and last for the removal of sewage. The structure has attracted graffiti - some of it well carved (Image 4).
Amazingly, the water tower can be recognised on a waterworks plan of around 1165 (Image 5). It has survived in Trinity College Library Cambridge, bound within a volume known as the Eadwine or Canterbury Psalter.
Sources: Fergusson (2011); Sparks (2007); articles by John Hayes Prior Wibert's waterworks in Chronicle 1977 (p.17) and by Tim Tatton-Brown The Precincts water supply in Chronicle 1983 (p.45)