Protecting Waterfront Assets: Dock De-icing Spring Follow-up

As spring approaches and Cazenovia Lake's ice is about to break up, now is a good time to discuss some additional considerations for dock de-icers. As we previously discussed, these systems can be very effective at protecting docks and other waterfront assets. De-icers are excellent at preventing ice jacking (where ice grips and lifts pilings). However, they can inadvertently increase the risk of other forms of dock damage during the spring thaw if not managed correctly. This situation occurred last spring when ice piled up and did significant damage to some docks on the east side of the lake.

Your risks will vary a lot depending upon where you are on the lake and what the weather does to the ice as it breaks up. It is a common misconception that de-icers protect against moving ice. In reality, they only protect against static pressure and expansion. During the "ice out" phase, your dock becomes a sitting duck if it is the only solid structure in a large patch of open water. If a de-icer makes an excessively large area of open water around your dock, it provides a clear path for large, heavy ice floes to accelerate, creating a "runway" effect. In windy spring conditions, these moving sheets of ice can pick up significant momentum and crash into your dock harder than if they were restricted by surrounding ice. This is another reason to keep your area of open water as small as possible around your docks and really focus on de-icing the pilings only.

Place de-icers under the dock, use thermostats and if practical, use multiple smaller de-icers to minimize and focus open water where needed near the dock. Your goal should be to create just enough open water to separate the ice from the pilings. This leads to less turbulence and less large-ice movement.

Running your deicer too late into the spring prevents a thin, stabilizing sheet of ice from forming. Experts suggest turning off de-icers in early March to allow a thin connection to form between the dock and the main lake ice. This thin layer is usually too weak to cause "jacking" damage but strong enough to act as a buffer against shifting ice cakes. With a little attention to lake and weather conditions, you can minimize your risk by turning your de-icer off before the ice breaks up; when you can still freeze a layer of ice, but the long-term forecast shows a warming trend and before winds start shifting the ice. Allow a controlled freeze-in where some thin ice can help protect your dock.

Want more information? Email us at info@cazlake.org or check out cazlake.org.