[ total water use = agricultural water use + domestic water use + industrial water use ]
Water usage does not include in situ non consumptive uses of water like in mining, fisheries, energy, navigation and the environment.
'Water use' and 'water withdrawal' are used as synonyms, although, if non-conventional waters are used, withdrawal will be lower than water use.
Water demands are met by water production.
Water production:
renewable: withdrawals from surface water (rivers, lakes, reservoirs) and from groundwater (aquifers recharged by precipitation);
non-renewable: withdrawals from deep aquifers that have a negligible rate of recharge on the human time-scale, or withdrawals of "fossil" water (ancient and deep non-rechargeable aquifers);
non-conventional: desalination, waste water treatment.
