The water supply was made by the capture of rainwater collected on the forts roof and filtered through a sand filter.
A fort of 2 machines gun used to have a 1800 liters water tank to ensure drinking and toilet, while a 300 liters water tank, located in the shell-proof combat compartment, was used fot the machine- guns cooling and for the supply of the sink, situated in the shell-proof rest chamber.
Bottles of sodium hypochlorite were placed in every fort, their amount corresponding to the calculated dose of the bunker water tanks. It was then necessary to make a filtering through a dechlorination filter. Autonomy: 30 days for a garrison of 20 men, with 25 lt of water per day and man.