Hee hee, good point, Scott!
Sounds like a "water table" pond, one that fills to the level of the water table and no further. They often have no outflow, but have very stable water levels as even runoff flows back into the ground water table. They are very common in lowlands near the coast or near large bodies of water. They are usually pretty good water quality compared to ponds filled only by runoff.
I will watch for pics, but the first thing you want to do is make sure you have established vegetation on the land around the pond that slopes back to the pond. Grass is great, but you want to limit fertilizer on this land as much of it will wash into the pond leading to algae blooms. Getting vegetation all around will prevent rain from washing dirt and it's accompanying nutrients into the water. Remember, if I am right and this is a groundwater pond, and if you have a well, this is one step removed from your drinking water!!! You want to get this pond under control, and stabilizing the surrounding watershed is the first priority.
Once we see pics, we can start working on the pond itself! There are several people here that are experts on management of "natural" ponds. One of the best is turtlemike, who specializes in hybridizing and raising lilies and marginals in mud ponds. I'll make sure he sees this thread once there are some pictures posted!
Steve
