Boy, do I have some practical experience here. I had a small marshy area back when it used to rain. I got a dozer in, dug it out and had a great little forage pond. Then, the droughts hit and it dried up. Except for a perennial wet spot. So, I got a backhoe and dug out the spring and created a drain. Wasn't that a great idea? I have recently brought in a bunch of bentonite for the bottom and am in the process of covering the bottom with clay. Hope it works. Essentially, the head pressure has reversed and I'm screwed. Since it is directly upstream from my main 1 acre pond, I have to take action.

My thinking is that a spring is nothing more than an aquifer, water bearing sand, with an outlet. That outlet can turn into an intake when the groundwater level changes or drops. The situation you are describing would scare the dickens out of me.

It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.

Without a sense of urgency, Nothing ever gets done.

Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP Grandpa