The island is short on potable water reserves, as rainfall is minimal (less than 50 cm p.a.) and the abundance of hot ground-water, containing diluted salts, contaminate any small quantities of precipitated water seeping through volcanic cracks and pores.

The only spring is on the eastern slopes, near the Monastery of Panayia Kyra, and the amount of water it produces is negligible.

Cisterns collecting rainwater had solved the problem in the past. All local households still maintain the old cisterns used for collecting rain water.

Today, a modern sea water desalination unit has made the problem less acute.