Detainees should have access to a sufficient quantity of clean water at all times. Available water supply should cover the drinking water needs of inmates and staff, and also be sufficient for food preparation, personal hygiene, cleaning, watering and any other basic requirements.
Since water supply is often limited, it is essential that it be managed and distributed in an equitable and rational manner. Water supply availability can be adversely affected in situations where prisons are overcrowded.
The strict minimum physiological needs of an individual are estimated at 3─5 litres of drinking water per day (ICRC). This minimum requirement increases if warranted by the climate and the amount of daily work and physical exercise performed.
Detainees should have access to water piped directly into their cells or dormitories. Where there are no taps inside the cells and dormitories, containers such as buckets and jerry cans should be available to enable detainees to store the quantity of water required. These water-storage containers should be cleaned and disinfected regularly and carefully capped to prevent contamination. The minimum amount of water that must be available inside the cells and dormitories is 2 litres per person/day if the detainees are locked in for periods of up to 16 hours, and 3 to 5 litres per person/day if they are locked in for more than 16 hours, or if the climate is hot (ICRC).