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The Guide to Permanent Dock & Lake Deicing in Winter

written by
Linda McDonagh


When it comes to our marinas and lakes in the Midwest, it is all too easy to fall into the trap of thinking that there is no need for ongoing care during the winter months. After all, no one’s using their docks once temperatures fall. But it is important to realize well ahead of time that without providing the proper preventative care, ice can wreak havoc with your docks, hoists, and boats left in the water through the winter, which may result in thousands of dollars in damage.

Clarke’s team of experts brings years of expertise in diagnosing and implementing deicing solutions to prevent dock damage from ice. The below Guide to Permanent Dock Deicing comes from our wealth of knowledge and experience.

What Can Happen if You Don’t Prepare Your Docks & Marinas for Winter?

As you have undoubtedly seen before, ice forms on the surface of lakes at around 39 degrees Fahrenheit. At this temperature, the warmer water at the surface sinks towards the bottom, pushing the colder water to the top instead. Ice then develops as a result of falling air and water temperatures. Record high water levels many of our Midwest lakes are experiencing have been the most recent driver of damage to marina structures, boats, and waterfronts throughout winter.

Other lesser-known drivers are tides and seiches (pronounced saysh), similar to tides. Marinas, bays and in some instances lakes, experience Seiches – wave-like manifestations that occur as a result of wind or atmospheric changes-, which can also compound the problems from ice forming around permeant structures.

Winter ice damage that can occur to your permanent docks include:

  • Warping of your dock
  • Breaking and heaving of the dock structure
  • Mechanical and structural damage to docked boats

“The ice growth that results from both these falling temperatures as well as higher water levels from seasonal rain is the main driver of damage to marina structures, boats, and water fronts throughout winter.”

Deicers in a Marina







What Does Deicing Look Like for Your Docks in Winter?

As explained above, the bulk of damage caused during the winter months is largely due to ice forming along boats and pilings. Therefore, the best way to mitigate these damages is by preventing ice from forming at all, a process referred to as ‘deicing’.

How do you deice a pond or lake? Deicing can be accomplished several different ways depending on the depth of your waterfront, whether it is affected by high water, tides or seiches, the past seasons’ rainfall, and expected temperatures. The most common and environmentally sound method is by simply agitating the warm and cold water and propelling that warmer water towards the surface in lieu of cold.

How to Choose the Right Deicer for Your Dock

Deicing can be accomplished in several ways depending on the unique characteristics of your body of water. The two main types of deicers include:

  1. Dock mounted deicing units or circulators, also known as Agitator Deicers or Dock Deicers
  2. Subsurface aeration systems, also known as Bubble Deicers or Lake Bubblers

One important question is what size of deicer you need for a lake or pond. For example, in areas of six feet or more, a propeller-like deicer can be installed to create an artificial current that works by using a propeller to draw up warmer subsurface water to the surface – creating a continuous flow of warmer water to prevent ice from forming.

Alternatively, if you have a smaller area of focus, you could opt for a “forced air” deicing system. These utilize self-weighted air hoses on the bottom of the lake floor that pump out low-pressure, high-volume air through holes to bring warmer water to the surface. Like with the propeller system, these bubbles create a small amount of agitation on the surface and, with the warmer water, keep the above area free of ice. These subsurface aeration systems or bubble deicers don’t stir up the bottom lake sediment, which helps decrease the amount of thin ice, and also can be placed more precisely than dock mounted deicers or agitator deicers.

Experts from Clarke installing a deicing system to prevent ice from forming on docks and boats






Tips to Safely Install and Use Deicers for Docks, Lakes, and Ponds

While creating areas free of ice is vital for maintaining the structural integrity of your permanent docks, deicing solutions that are not properly managed can result in:

  • Thin ice areas that are dangerous for ice skaters, skiers, and ice sailors
  • Larger than needed open waters which lead to greater ice damage during spring melts
  • Significantly altering large areas of the lake’s temperature and light conditions can negatively impact algae and aquatic plant growth as well as the living conditions of fish.

As you can see, creating a comprehensive deicing plan for your lake or marina is not as simple as just installing a couple of deicers around the dock. It’s important to take into consideration the goals of deicing, the size of the lake, the size of the area you should be deicing, the aquatic conditions of the lake, local laws and required permits that may affect deicing operations, and the wintertime use of the lake.

Bubbler Deicer attached to a dock

Some quick tips to keep in mind may include:

  • Choosing the smallest possible size of an ice-free zone
  • Keep any pond or lake deicers away from the center of lake areas to minimize formations of thin ice
  • Utilize a timer or thermostat to make sure systems only operate when temperatures fall below freezing
  • Minimize the time deicers run to help prevent thin ice and reduce operating costs

Our experts at Clarke have years of experience working with a vast variety of lakes and communities and take away the stress and time dedicated to planning and implement the correct deicing solution for your marina. Clarke consultants work to properly assess and install deicing systems that will work with the unique needs of your community – from initial assessment to ongoing maintenance. Check out an example where our team designed and implemented a deicing system for a unique lakefront community.

To learn more, contact our team here, or check out other articles such as: