Is that ice safe yet

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Carol Baldwin
Local Journalism Initiative Reporter
Wakaw Recorder

The Water Security Agency (WSA) issued a reminder last week urging the public to verify ice thickness before venturing out onto frozen surfaces.

With colder temperatures arriving and ice forming on water bodies across the province, the WSA emphasizes the importance of ice safety. Ice does not freeze uniformly, and its strength can vary significantly from one area to another. The timing of when ice becomes safe at a specific location can change each year, making it essential to check the thickness annually rather than relying on past experiences. Ice fishing is a popular winter pastime on lakes in Saskatchewan and Wakaw Lake is no exception.

As a guideline, at least 10 cm (four inches) of ice is needed to walk on, 20 cm (eight inches) to drive a snowmobile or ATV, and 30 cm (12 inches) before driving a car or light truck on the ice, and more than 30 cm (12 inches) to support a heavy truck. The Canadian Red Cross says that for ice to be considered safe to go out on, it must be at least 15 cm thick to be safe to walk on. If a group of people are venturing out onto it, 20 cm thick is safe. At least 25 cm thick is best for snowmobiling, and it should be even thicker for bigger vehicles — 30 cm or more for cars and light trucks, and 40-50 cm thick for anything larger.

The Saskatchewan Water Security Agency is a unique organization in Canada, bringing together the majority of the government’s core water management responsibilities in one place. We manage the province’s water supply, protect water quality, ensure safe drinking water and wastewater treatment, own and manage 72 dams and related water supply channels, reduce flood and drought damage, protect aquatic habitats, and provide information about water. The Water Security Agency is a Treasury Board Crown corporation. 

Every winter there are news stories of people being rescued after falling through thin ice. Any activity on ice has risks and guidelines are provided to help individuals decide whether to venture onto the ice. After a significant cold spell, lakes and ponds can freeze over rapidly, and the ice will grow thicker the longer the temperature remains below freezing. However, ice thickness can be unpredictable and difficult to assess. Clear, hard ice is the only ice recommended for travel. Ice that looks slushy; has thawed and then frozen again; is near moving water; is layered, caused by sudden temperature changes; or has structures on it, such as pressure ridges, should always be avoided.

There are several ways to determine if ice is safe before venturing onto it, and measuring thickness is just one important factor in evaluating ice safety. The most accurate method is to take direct measurements by cutting or drilling into the ice, but this requires stepping onto the ice itself. Another way to obtain a reasonable estimate from the shoreline is to observe the colour of the ice. The strongest and safest types of ice are blue or clear. This type of ice forms when cold weather causes the surface of a lake or pond to freeze directly, resulting in very dense ice. 

To assess the ice, check for any visible cracks, breaks, weak spots, or abnormal surfaces. Noting the colour of the ice can help you decide whether it’s worth proceeding to the next step of testing it. However, do not rely solely on your eyesight. If you see flowing water near or at the edges of the ice, cracks or holes, or if the ice appears to have thawed and refrozen, these should be considered warning signs. Additionally, look out for any abnormal features, such as pressure ridges caused by currents or winds. 

While colour can be a useful indicator, it should not be the only factor you consider. For example, any colour of ice that is subjected to a flow of water underneath will be weaker than ice that is not affected by such pressure.

White ice or ‘snow ice’ is white because it forms when a layer of wet snow freezes on top of blue ice that has already formed. Snow layers contain a lot of air, which ends up as air bubbles trapped in the ice structure. While it can be reasonably thick, the air bubbles weaken the ice, so it may not be safe to walk on and extreme caution should be used. This is especially true if there have been recent swings between warm and cold weather or if there is moving water under the ice like on the river. Also, if there is a layer of fresh snow atop the ice, the snow may conceal thin ice underneath. Snow on top of ice also acts as insulation, trapping heat that will prevent the blue ice from growing thicker. White ice can be safe if the base layer of blue ice is thick enough. However, without a way of drilling down to see exactly how thick that blue ice is, it is probably best to avoid being out on it.

If unfamiliar with an area, talk to local people because ice is rarely the same thickness across a body of water and can change. 

Use common sense and if in doubt, find an alternative and do not go onto the ice. 

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