The tree that passes water

There is a tree in the forest of El Cedro in the Garajonay national park passing water for you to drink. It is situated just beside the beautifully-located chapel of Nuestra Senora de Lourdes which was built due to the initiative of an English lady. It is surrounded by mature trees and stands just above the babbling brook which runs along the floor of the valley all year. The area around it has a few wooden picnic tables and benches and is popular with locals and visitors alike. The water it 'tinkles' is cool, fresh and safe to drink except during  rare prolonged hot spells in the area in some years, but then park rangers will put up a sign warning you of the possibility that it may not be entirely safe to sip. How did the miracle of the water-passing tree come about ? Well, come and see for yourself if you can unravel the puzzling phenomenon…