Keeping swans from migrating
I was told, if I were able to keep the lake from freezing solid, and food was available, our trumpeter swans would probably spend the winter here. If this indeed was the case, and they wintered over, I knew we would have a much better chance of having them as permanent residents.
How hard could it be to keep part of the lake open throughout the winter? There must be many ways to keep a lake from freezing. Nothing is impossible; just some things are more difficult than others. I have seen boats left in lakes with air bubbles rising around them. Compressed air is pumped below the boat and the rising bubbles bring warm water to the surface, keeping the water open. If it works to keep the ice from crushing a high priced boat, it would surely work to keep an area open for our swans.
Compressed air seemed like the perfect solution. The next minor detail was how to get the compressed air needed to run my bubble machine. The nearest electricity is almost a mile away. At last count, I had about 212 feet of extension cords. This includes the six-foot cord my wife has on her reading lamp. Setting an air compressor by the pond and running a cord to it was out of the question.
We do have a constant source of running water from the spillway. I thought about building a generator run by water that would create electricity to run the air compressor. This seemed way too complicated with many moving parts. I have found in my life's experiences; the more moving parts involved in a project, the more prone to failure that project will be.
The next idea was to create compressed air directly from the water falling from the spillway. This summer's lack of rain lowered the level of the lake so no water was currently escaping. This would be the perfect time to build my compressor. I was sure I only had a short time to complete my project before I would have to be fighting the force of the water.
Feverishly, I installed a pipe that would direct the water downward and accelerate the flow. I angled two tubes into the main pipe that would act as venturis, injecting air into the water. When the water fell to a horizontal pipe, the air, now under pressure, would be released into a holding tank, that could then be pumped back over the damn and run the bubble makers.
In the heat of the summer, I spent several hours working on a way to prevent the ice from forming. It worked well, as no ice formed until December. This had everything to do with the air temperature and nothing to do with the air compressor. We never did get enough rain to overflow the spillway.
When the lake was built in 1993, I was told it would take a year or more for it to fill. It took less than six weeks before it was full and running out of the spillway. Until this year, it had never stopped running.
I still do not know if my water-powered air compressor works, but the swans lost faith in the project and headed south. Last week, I heard from the Department of Natural Resources that our swans were in southern Missouri, well on their way to Louisiana. Down there, they do not have to depend on strange people and their strange contraptions to keep the water from freezing. I can only hope they have a safe migration and return next spring.
Walter Scott is an outdoors enthusiast and freelance writer from Bloomfield, Iowa.