Towards the end of the Cold War, in the late 1980s, many water authorities were privatised. As part of the sale, the purchasers were expected to construct suitable protected premises from which to control operations in the event of war breaking out.
Southern Water had three such Control Centres - at Chatham, Brede, and here at Twyford, near Winchester. The Twyford shelter was constructed in a disused reservoir, close to the Twyford treatment works. The bunker was completed in 1990 and had everything needed for a team to survive for up to 60 days: NBC filtration, air handling, generator and dormitory and toilet facilities.
The bunker was made surplus to requirements in the late 1990s and sold at auction. Initially used as a secure datacentre, the site was later sold again in 2009 and is now the headquarters of the Natural Death Centre.