As it happens i have a stream flowing past my garden...is it
easier/better to use that as a heat source than burying pipes? I have
considered seeing if it'd be possible to have my own hydro electrical
generator running of it too..but am unsure where to start!

Is the stream fairly fast flowing and consistently full during the months
when heat is needed?

yes


Is it prone to heavy flow with attendant rock movement?

no. It a small stream about 5 foot wide and a foot deep, but there are no
rocks in it. In the summer flow is greatly reduced, but there is still
flow.

My dad has a
small river at the bottom of his garden and it can be very destructive to
anything that gets in it's path.

--
Clive Mitchell
http://www.bigclive.com