My wife and I were lucky enough to be able to build a log cabin on some mountain property that has been in the family for generations. On the property is a spring pond (147' x 81') that typically has a foot or two of water on it from early spring to mid-summer. This time of year it dries up and we would like to change that.

The goal is to create a little mountain oasis that has water in it year-round for trout and the local wildlife.

In these early planning stages, I'm trying to figure out the following and would love to get some advice and suggestions from you all.

Water: Pond sits in a low area and collects spring run-off for the main source.
-There is a natural spring that I'm working on developing about 100 yards away. I plan to gravity feed the spring and I estimate it to be 1/2-1 gpm once developed.

-I'm estimating the pond to be around 500,000 gallons and am hoping to get an average of 5' of depth. If we can go deeper without blasting we will, but I think that's going to be about the max based off the septic dig not far away. I've heard most trout really need areas of 6-9' ft but can do with much less if you have water movement.

Questions: What is the best way to figure out evaporation for the area?

I have a ton of other questions, but I think the water is obviously going to be the most important part so I'll start there.

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