Water System DIY question

We had a spring fed (4x6x2-block enclosure) for our camp water for years. The top (a metal plate) was ground level. We had a good spring feeding it and as long as we left the faucet running, it never froze. Once set up, you should treat it with bleach in the spring and fall to kill bacteria that will find it's way in.

Our spring feeds from probably half a mile up the hollow. 3/4 inch plastic with a home made strainer jammed in the rocks feeds the line which runs on the cart path and never is buried more than an inch or two. The line runs into a 20 gallon stainless tank above the camp. In the winter when its hooked up we let the faucet run and it never freezes and the tank still overflows. We "inherited" this from a neighbor that drilled a well....he had a couple hundred gallon milk tank for a feed and had to reduce the pressure into his house. This works for the few days of freezing weather during deer season. If I had to design something more permanent for use winter long, I'd probably install a stock tank heater on a thermostat