With the current ‘water crisis’ essentially a crisis in water management, the need to clearly understand domestic water use is critical. In recent years there has been a growing awareness of the need to manage demand in all water sectors. However, demand mechanics at the intra-household scale are not well understood, with many utilities adopting a ‘command and control’ mentality rather than engaging with household water users, their water use knowledge and behaviours. This paper describes the Water Diary, a method to generate intra-household water use data, as a tool to promote water use behaviour change through sensitising users to their water behaviours and practices. Anecdotal evidence, of participants' increased water use sensitisation encouraging behaviour change, received following each of three Water Diary surveys (2007–2009), was quantified in 2010 with questionnaires and interviews of 40% of households that participated in the Water Diary surveys. The interviews revealed only three households did not become more aware of their water use and all but four recorded water use behaviour change, consequent to Water Diary participation. Requiring a high level of householder participation, water diary keeping can sensitise householders to their water use, to the point of enduring behaviour change.