Just a tiny proportion of water in the whole of the world is fresh and most contained in ice caps and glaciers, so whats left is very little. We all probably know that the hotter countries have little rainfall and need to conservetheir water in a different way for drinking, agriculture and hygiene. Its not suprising that heads turned towards the sea to supply all these needs but historically it was thought to be too expensive as a lot of energy is required. Luckily as we continue to evolve and new technologies are invented, desalination plants have become a good way to convert sea water into fresh water.
The water on Lanzarote is desalinated which is why you cannot drink straight from the tap. There are 2 plants producing water on the island. One in Arrecife which is visible from Costa Teguise and the other further south in Yaza. Both of which produce 30,000 cubic metres of water a day.