Many people use dock de-icers to protect permanent docks and boathouses from ice damage. However, if these devices are not properly managed or installed, they can create large openings with thin ice that are unsafe for recreation during the winter months. These large areas of open water can also lead to greater ice damage to a dock.
Types of de-icers:
Bubbler: Works by releasing small air bubbles from a submerged perforated hose powered by an air compressor typically located on a dock or inside a boathouse. Bubbler de-icers don’t stir up lake bottom sediment and are less likely to cause dangerously thin ice conditions.
Agitator: Works by circulating the lake water toward the surface. The entire device is submerged in the water and contains a fair amount of lubricating oil that can leak directly into the water from failed seals. This device needs to be used with a timer and/or thermostat to limit the amount of open water.
Both of these de-icers only need a few hours each day to do their jobs! In addition, a device that runs for only 2-4 hours a day will significantly reduce operating costs.
Negative Impacts of a De-Icer Device
There are several potential negative impacts associated with the use of de-icing devices including:
Opening up too large an area causing dock damage by allowing ice floes more room to accelerate in windy conditions
Altering lake water temperature and light conditions which may impact algae and plant growth. As a result, this could also impact feeding habits of fish and other aquatic organisms
Disturbing bottom sediments releasing nutrients such as phosphorus which will result in an increase in algae
Creating a safety hazard which can significantly reduce or prohibit winter recreation opportunities
De-icers are expensive to buy and operate and they do not guarantee less ice damage
Circulator de-icers are noisy
Tips for Safe and Effective Use of Dock De-Icers
It’s the law to get a permit and post a warning sign about open water and thin ice conditions (RSA 270-33). Here are some other tips to help you use dock de-icers safely and efficiently:
Choose the smallest possible size to maintain an ice free zone around your dock
Set up your de-icer to form a narrow open water area around your dock (bubbler device works best for this)
Point a circulator device in a vertical direction rather than at an angle towards the middle of the lake to minimize dangerously thin ice
Use a thermostat or timer to run the de-icer only when the air temperature drops below freezing
Run the device for only 2-4 hours a day
When the time comes to replace your dock, consider installing one that can be removed from the water (such as the cantilever type). This would eliminate the need for a de-icer device at all!
To download a copy of LSPA’s Dock De-Icer Pamphlet, click here.