We have an approximately 1 acre pond that doesn't stay full, but does stay consistently at about the same level. We can get a good rain that fills it up, but it will drop 3-4 feet over the next weeks. The pond has a spring that nearly always feeds it from the north. The most curious matter though is the fact that jets of air stream up from fissures in the rock after a large rain. I swam down and located the source of the air, then attempted to pack one of the fissures with bentonite, but the air just came out further down the crack. Erosion has been an issue around the pond, revealing lots of the bedrock. As I mention in the video post I linked to, we recently had a sinkhole entrance open up in our pasture, but I don't know the extent of the underground geologic features that may contribute to this phenomenon. The spring that feeds the pond comes out of the hill maybe 3 feet above the sub-full level the pond stays at. Have any of you seen something similar? The only thing I can figure is there is an air filled cavern that connects to the pond via the fissures in the rock. When the water rises, the weight of it displaces the air in the caver, pushing it out through the cracks. I would really like to get the pond to hold maximal water so I can stock it accordingly, but I am concerned that the water may go both ways through the cracks--into and out of the cavern I've theorized is there--which makes me think anything I plug the leaks with will be pushed up and away from the hole(s) just as much as the water pressure presses it down to seal. I'm not familiar with image/video hosting options, so I've linked to my personal FB page where I posted a video you can reference. Any insight would be greatly appreciated. [img]https://www.facebook.com/aj.allison.75/videos/1220699855596015[/img]
