Extreme Spring 2017 Water Levels

Following one of the wettest months of April on record, the first week of May 2017 also was the wettest recorded since 1900. This has led to wide-spread flooding in eastern Ontario and Quebec, many of Toronto’s islands being closed to the public until at least the end of June, and a string of flood disasters along the shores of Lake Ontario.

(Transcript of Lawrence Gunther’s bi-weekly 12-minute segment on Live from Studio 5 broadcast over AMI TV and Audio across Canada)

Q. Welcome back Lawrence, when can we expect things to return to normal?

A. If the drier conditions of the past week continue, outflow is expected to surpass inflow, at which time Lake Ontario’s water level will peak and begin to gradually decline. However, owing to the huge surface area and large volume of water on Lake Ontario, it will take several weeks to significantly reduce levels, and longer to return to more average water level conditions. We may be looking at mid-July before things return to normal.

Q. Just how high are water levels now?

A. The water level of Lake Ontario is the highest it has been since reliable records began in 1918, breaking the previous record set in June 1952. It’s about 80cm higher than it is normally at this time of year. In Montreal, the St. Lawrence is about 140 CM higher than normal for May.

Q. What does it mean for the fish and other aquatic life?

A. Fish are taking advantage of access to new territory and the opportunities to feed and spawn. You may have heard of the Common Carp now spawning on the baseball diamond here in Toronto? The colder water may have slowed down the spawn of these fish, but it won’t impact their survival.

Q. When will it be safe to go on to the water?

A. As outflows rise, navigation conditions worsen in the St. Lawrence River from the Thousand Islands to Cornwall. The danger comes from dams being opened to allow water to flow freely, meaning the levels in parts of the St. Lawrence are actually lower than normal, and that sections of the River have returned to its original natural state, that includes the emergence of rapids that haven’t been seen in over 60 years. There’s also the issue of all the debris that was once on shore and is now flowing freely downstream – things like trees, docks and in some cases, boat houses.

Q. Don’t the U.S. and Canadian governments control the water level?

A. A new water level management plan was put forward by the International Joint Commission for the Great Lakes and St. Lawrence, and it were agreed to by the United States and Canada in December 2016. The old plan was in effect since 1963. The new plan was designed to stop the reduction of wetlands along the shores and loss of habitat for wildlife. The new plan called for higher water levels in the spring to be maintained longer so these wetlands could recover. With this record wet spring, a lot of people are now blaming the new plan for the flooding. In fact, the IJC has been doing all it can to bring water levels down, as called for in both the new and old plans during emergency situations, but there’s just so much water. Lake Erie and widespread heavy rainfall on the lake and across the Ontario drainage basin are the problem. Unfortunately, the real loser in all this may be wildlife that depends on wetlands for their survival, should another new plan be implemented with the goal of keeping water levels low.