Thanks Cecil, and Dwight. My pond is a sand pit created from gravel mining. The water level is determined by the groundwater (no contributing drainage area). My take is that the ice has formed, and as spring runoff increases from the two nearby major rivers, the groundwater is rising thus raising the ice level. I agree with the horizontal heave and that's why I've built the piers for stout. They weren't designed to be lifted, however. The structure has gotten through one winter and everything is in tact. It's just that this year, the water (ice) level has come up much sooner this year, and is almost touching the bottom decking.
Any additional thoughts? I agree with the aerator, and have a nice portable pump, and available power supply on the dock. It's about six foot deep at the end of the platform, so I think I will get out the ice auger, punch a hole, and drop an air line. I don't think I will worry about a diffusser. I'll put a brick on the end and drop the air line down the hole. Can't hurt, and this may avoid lifting the platform. Another two months and we'll be looking at spring thaw...
