Safety on Frozen Lakes
A few words about safety on the frozen lake as so many of us are enjoying winter days on it
now. Dr. Mark Curtis spent his career with McGill researching under frozen lakes and continues
to enjoy ice fishing. We turn to a conversation we had with him recently to get more insight into
lake ice safety.
Mark, is there such a thing as “safe ice?”
Not really, there is no such thing as safe lake ice - particularly at the beginning and end of the
time the lake surface appears ice-covered.
Why is that so?
Because lake ice thickness and composition are so variable.
Are there any particular concerns about the lake ice in our area?
Yes, there are. For example, there are very strong currents below the ice off of Baie D'Urfe
and the lake bed is very uneven. Water levels continually change quite dramatically in the
area from Ste Anne de Bellevue to Thompson Point (east end of Dowker). Both these
natural features can change ice stability from one area to another. You may have thick ice for
50 feet around you and yet suddenly find a weak spot just outside of that where you or your
pet could fall through.
Drainage pipes entering the lake from the shore can also cause the ice to deteriorate faster at
the exit point from the pipes.
Time of year makes a difference as I said with early winter and spring being the most
dangerous periods along with wide temperature fluctuations at any time as we have been
seeing of late in Montreal.
Do the authorities such as the police or coast guard publicly report the thickness of
the ice on our lakes?
Not that I have found. For the reasons given above for the potential variability in ice thickness
such reports could easily give a false sense of security to citizens.
What happens if you do fall through?
Well, there is what we call the 1-10-1 rule. It states that you have one minute to control
your breathing, 10 minutes of meaningful movement — every move you make is vital to
ensure that you’re safe and you don’t cause yourself any further harm. And you have one
hour of consciousness while on the ice. And sadly of course there is always the danger of
being swept away under the ice if you are caught in a strong current.
Do you have any suggestions for people who do venture on the frozen lake?
Well, hopefully, if you’re traveling on a snowmobile or walking on the ice, you have some
rescue equipment with you. The hand-held spike things you can use to dig into the ice and
help pull yourself out, are good to keep on your person at all times when you’re out on
the ice, just in case you happen to go through.
You are of course safer if on skis than if walking as the skis will distribute your weight more
Finally, be aware of the ice depth that you do need to be safe. The Red Cross recommends
Did you know ice thickness should be:
15 cm for walking or skating alone
20 cm for skating parties or games
25 cm for snowmobiles.
Avoid going out on the ice at night.
Can you recommend any online resources for further information?
Yes, there are several but the most comprehensive one is at
Thank you Mark for sharing this information.
I would also draw readers' attention to Councillor Andrea Gilpin's recent Facebook post that
noted: "it is higher levels of government than the Town that has jurisdiction over the lake itself."