Pond Boss Forums INTRO Questions & Observations 2nd winter kill in 5 yrs

Good morning, Fishhead.

First of all, let me express my sympathy! I would have thought that 16 feet of water in central Iowa would have been sufficient to avoid winterkill. Unfortunately, you seem to be caught in my part of the world.

The winter of 2000-2001 was REALLY tough (long, with much snow cover) up here in east-central South Dakota, and you obviously caught the same weather. If it's any consolation, we lost two ponds that we manage for a truly interested landowner. One pond is 7 acres and has a max depth of 27 ft, while the other is 3 acres with a max depth of 19 ft. The 7-acre pond was managed for smallmouth bass only, and it was sure sad to see 3-4 lb smallies dead along the shore. The 3-acre pond was managed under a largemouth bass/black crappie option, and those 12-inch black crappies dead along the dam were also a sad site. A 20-acre pond below the two smaller ones had no dissolved oxygen problem, and did make it through the winter OK.

Now, the worst part of my story is that we have Koender's windmill aerations systems [http://www.koenderswindmills.ca/] on both of the ponds that winterkilled. During cold, calm weather, the ice does freeze over the pond, but then the hole re-opens when the wind starts again. That spring was one of the low points of my pond management "career." Here was an interested landowner, with well-managed ponds, good treatment of runoff into the ponds through extensive grass filters, and aerators in place, and we still lost the two ponds. I guess we just live in a harsh environment. I will say that we immediately restocked both ponds, and they are doing well. We had no problems at all this past winter.

One of my primary questions about your pond involves the extent of vegetation coverage. I'm most interested in the rooted, submergent plants, if you know what I mean (not cattails or other similar emergent vegetation). As Shan already indicated, a 20% coverage of these plants is ideal for a bass-bluegill pond in the Midwest. Do you have more vegetation than this? If so, perhaps something should be done. If not, perhaps we could find a way to live with it.

Do you have any other big source of organic material that flows into the pond? You mentioned tree leaves. How much?? Should we build a small �check� dam to catch that organic load before it reaches your pond? Is there direct runoff from cropfields? Any source of additional organic material allows more decay under the ice, and the bacteria that break down the plant matter will use your dissolved oxygen.

As you already indicated, I'd guess that an aeration system is probably the best bet for your pond. You excluded wind-driven systems in your original post, although the Koender's windmills are actually up on a hill, and then an airline runs down to the pond. If you are only 75 feet from your new house, then electricity should not be a problem, and you certainly could run an electric compressor. From my time on this website, I've learned that I am FAR from an expert on aeration systems. Too big a compressor can cause problems, as can too small a compressor. Also, we always used to put the air release in the deepest part of the pond, but it seems that a moderate-depth shelf might be a better location. Let's see if one of the gurus will help out on this thread. If not, we can search some of the past posts, and �find� the experts. 

My best guess is that the Iowa DNR would restock your pond, as long as no fish are present. That may require a complete renovation (draining or chemical poison for the fish). Do you have a contact within the DNR? If not, I know quite a few of the fisheries biologists over there, and could find a contact for you. I�d probably need to know a specific town, rather than just central Iowa.

Well, those are my initial thoughts. Give this some thought, and get back in touch. My e-mail address is listed here. I sure hope this works out for you. As I said, I would have thought that you wouldn�t have such problems with a central Iowa location.

Dave