Without seeing your pond it would be impossible to tell you whats going on. IME I see this quite often here in MN:

The spoils (soil excavated out of the hole) from the digging of the pond were most likely spread around the outside edges of the dug hole. Obviously, it is much less expensive to spread the dirt on site than to truck it away. The spoils then create a raised rim around the dug hole. Depending on the amount of soil removed, the rim could be 1'-6' high. This rim is above the natural water table. Its mixed soil and most likely not hold water. Not saying this is what you have but by drawing it down you will quickly learn how the water flows back in and probably see the natural water line of the current water table.

The poor mans water level (a inter web search with surly explain this better than I can here but I will try): A 5 gallon bucket filled with water and a couple hundred feet of flexible 1/2" tygon tubing. The tubing is fixed and sealed into the side of a 5 gallon towards the bottom. Plug the other end of the tubing with a threaded bolt. Water seeks its level no matter what. Set the 5 gallon bucket 2-3' above ground level. Measure the distance from the resting bucket to the ground. With the 5 gallon fixed and filled with water, it is a reference point for level. A person could walk, up to the length of the tubing, remove the bolt, and the water in the tubing will come to rest. Measure the distance from the water to the ground. This will tell you how much higher or lower from the bucket that point is. For example, the bucket is sitting 2' off of the ground. You walk the tubing to a spot and take a measurement. The water in the tubing is 3' from the ground. The rise in soil is then 1'. I hope this makes sense. My father showed me this years ago and built me one for about $10.


Last edited by mnfish; 06/03/15 09:14 PM.