The establishments must be open, at least for the duration of the season, to persons who need to use the waters.
In communes classified as hydromineral resorts, the duration of the season is the same as that for which tourist tax is levied in the resort. However, at the beginning and end of the season, the Prefect may, by decree, authorise the partial opening of establishments. In other communes, the length of the season is set by prefectoral decree.