Why low Lake Ontario levels mean high St. Lawrence levels
May 17, 2013 by SOS-admin | Comments Off
May 17, 2013 — We’ve reported for months – years even – that the Great Lakes, from Superior to Ontario, are at historically low water levels.
So we were surprised to get this news this week: regulators are lowering the gates at the Iroquois Dam near Ogdensburg because the St. Lawrence River is too high.
David Sommerstein pieces together the water levels puzzle.
Last weekend, shoreline homeowners and boaters between Ogdensburg and Massena were alarmed to look out the window and watch the St. Lawrence rise.
The shore was eroding away. A lot of people had their boats damaged. Docks were under water.
Dalton Foster is president of the Wilson Hill Association and an expert on water levels in this part of the St. Lawrence.
Here’s what happened. Regulators are trying to do something about those low water levels on Lake Ontario. So they’re letting less water through the hydropower dam near Massena. In other words, they’re trying to hold back water and store it on Lake Ontario.
The problem was, says Foster, west and southwest winds whipped up at the same time, basically pushing water across Lake Ontario and into the St. Lawrence.
That pushes more water down the river.
And because regulators were still letting less water go through the dam in Massena, the river had nowhere to go but up.
Like if you put more water into a bucket than you’re letting out, the water level goes up.
Hence the flooding Foster was talking about.
So Wednesday, regulators decided to try something else. They lowered the gates of the Iroquois Dam, a much smaller structure upriver from the big Massena power dam.
The gates of the Iroquois Dam are normally raised and kept above the water level to allow recreational boats to go back and forth.
That’s your water regulator – John Kangas, U.S secretary of the International St. Lawrence River Board of Control.
Picture a bunch of garage doors above the river. Wednesday, Kangas ordered those garage doors to be dipped down into the water. And that restricts the water flow and lowers the river several inches.
This doesn’t hold back the water. The same amount of water is going through the river. What it does is just change the river profile a little bit.
Dalton Foster in Wilson Hill says lowering the gates at Iroquois Dam has helped lower the River’s level…a little.
Yesterday it was down, but now it’s coming back up again, cause the wind has shifted again.
Ahh, those pesky winds from the southwest.
So we have two takeaways. Regulator John Kangas fears more dry weather this summer, so he’s trying to store 2 inches of extra water on Lake Ontario to release this fall.
Fall tends to be a kind of critical time. St. Lawrence is falling. Lake Ontario is falling. Ottawa River is normally falling. There might be a need to put a little bit more water down the St. Lawrence River to help out the downstream with their intakes and navigation.
To help with drinking water intakes and boating.
That’s why they’re doing that, and it’s very reasonable to do.
The second takeaway, says Dalton Foster, is one man-made change to this vast natural system has many consequences.
It will have many effects and it will have different effects all the way down the river.
That means if you live along the river from Ogdensburg to Massena, look out for your docks and boats.
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