Most villas and apartments are
sensibly built with an underground 'sturner'. This is used to store the rainwater that is collected from the roof during the winter months (and hopefully not during your stay!) and is used for the villa water supply. Consequently, it may be unwise to drink - although washing your hair with the water will leave it incredibility soft. When the sturner runs dry, water often has to be trucked in at great expense to the owner.
Therefore, during your visit:
Do not water the garden without the owners permission.
Make sure taps are not left running.
Take showers - although a bath with a close friend is permitted!
If there is a power cut, you may find your water
supply agoes off, as water from a sturner is drawn via an electric pump.
new villas and apartments, are now supplied with mains water unless located
in very remote areas. This water is safe to drink if boiled for tea/coffee
etc, but is is advisable to check beforehand.