Peter Pan said:
Not trying to be put the spanner in the works here chaps but is not boring into a living tree to get water not a good practice to undertake? Unless you are desperate for water what is the point?. Water is free from a tap after all. Such an exercise might damage a tree. Water is free from a tap after all. I have heard that sap water from a birch tree this time of year with all its nutrients and all that can have properties to help those with cancer but other than that cant the tree be left alone as nature intended it to be. Can the wise men amongst us educate me of the merits of such an exercise,
I'm probably not the best person to answer your question Peter (and definitely not a wise man) but I'll give it a go and someone more knowledgable can correct me later.
Birch sap is not just water and though no official research has been conducted on it's positive properties as far as I'm aware, it is claimed that it can help lots of different ailments such as arthritis and other joiont problems. It is sold as a health drink in several different countries and is also believed to help people with pollen allergies, this alone makes it worth while for me as hayfever can be a bit of a pain for someone with an interest in the outdoors.
As for harming the trees, to my knowledge as long as it is done properly (a huge, deep hole is not necessary), and the hole is covered up afterwards by either a clay or a wooden plug, then it shouldn't do the tree any harm.
Check out this link for more info
http://www.hs.fi/english/article/The+birch+sap+is+flowing+again/1101979291529
hope this improves your opinion of the birch tappers.
Heath