The level at which all freshwater resources available for use are being used. Beyond this level, water supply for use can only be made available through the use of non-conventional water resources such as agricultural drainage water, treated wastewater or desalinated water, or by managing demand. A range between 500 and 1 000 m3/person per year has often been used as a proxy to indicate chronic water scarcity (Falkenmark, 1989).