In one corner of my yard there is a well, which provides water for my house and for one of the neighbours. Basically, it is a pit with a deep drill-hole. The water comes from the drill-hole, and inside the pit there is a pump with a pressure tank. When the pit is properly covered, the pump and the pipes won't freeze in the winter. There have been occasional problems with the pump, but otherwise the system is fairly OK.
http://www.enormouselk.com/?q=erkkasblog/images/31st-july-2014

Ah, and if the bottom of the the bathtub is too hot, I use a piece of a cheap foam mattress to make it convenient.