Dire warnings for lake levels
Georgian Bay Forever executive director David Sweetnam (right) discusses water level data with an attendee at a presentation sponsored by the Thornbury Yacht Club, Wednesday, January 16, 2013. Morgan Ian Adams/Collingwood Enterprise-Bulletin
THORNBURY — The powerpoint slides fly by, projected on the wall of the L.E. Shore Library.
For the uninitiated, the statistics and data associated with these bar and line graphs could be overwhelming. David Sweetnam stands at the front of the gallery, providing an easily-understood explanation for each one.
Every once in awhile he stops to field questions from the 50 or so people — most of the them members of the Thornbury Yacht Club, the sponsor of the evening — who have shown up on a snowy January night to hear about water levels in the Great Lakes.
But it’s not so much the water levels in the Great Lakes, but specifically, in lakes Huron and Michigan. In December, it hit a record low, falling a centimetre — on average — below the average record low set in December, 1964.
The average recorded level for the lakes last month was 175.61 metres; the previous low water mark — since water levels began to be recorded in 1918 — was 176.62.
So far in January, the recorded water level in Michigan-Huron is 175.58 metres, while the record for the average monthly low is 175.6 set in 1965.
Michigan and Huron are the only lakes in the system to see record lows this winter; according to information from the U.S. Army Corps of Engineers, Superior is about 20 centimetres above the record low set in 1926, while St. Clair, Erie and Ontario are all sitting about 40-to-60 centimetres above record lows set in the mid-1930s.
Last summer, as the International Joint Commission toured the Great Lakes region to hear comment on the Upper Great Lakes Study Board recommendations, they heard concerns — especially in Georgian Bay — about the state of the water levels in the middle Great Lakes.
The Upper Great Lakes Study Board recommendations are to modify the regulation plan for Lake Superior, create a system-wide advisory board to monitor lake levels, and revise
the management plan to adapt to the continuing decline of water levels. In other words, a do-nothing approach according to Sweetnam, the executive director of Georgian Bay Forever, a grassroots organization created in 1995 that’s been lobbying the IJC and governments on both sides of the border to act on water levels — among other issues facing Georgian Bay and the Great Lakes.
The IJC is expected to make its recommendations, based on that report, to the Canadian and U.S. governments at some point in the next couple of months.
When the IJC came through the area in July, the prediction was water levels would skirt above the record lows; it wasn’t until September that the predictive modelling used by the U.S. Army Corps of Engineers started to suggest the lake levels for Michigan and Huron were hovering more in the record low territory than previously thought.
“No matter where I go around the middle Great Lakes, people are very concerned,” said Sweetnam, who also carries the title of Georgian Baykeeper.
On this night, Sweetnam is warning of dire consequences of inaction: he expects that 18% of boat slips, including marinas, will be unusable this season because of low water levels; invasive plant species such as phragmites are moving into former wetland areas, choking out the native vegetation; algae growth has exploded as the low water levels allow the sun’s rays to penetrate deeper into the water.
In Collingwood, for example, the yacht club is faced with moving its three docks out of the basin and into the harbour.
And it's more than just an environmental or tourism issue, says Sweetnam, it's also an economic one. Every 12-inch (30 cm) drop in water levels equates to a $14-million loss in revenue for shippers — and about $140 million in raw material sitting on a dock. The economy of the Great Lakes, he says, equates to $4.6 trillion a year — not a trifling number for politicians trying to decide what to do.
While Sweetnam cites the reasons for the decline in water levels in Huron-Michigan as tied partly to the erosion in the St. Clair River — now stabilized — and the theory the land is ‘bouncing back’ from the glacial era, a significant part in the drop can be attributed to climate change.
In fact, climate change is happening so rapidly, “it’s changing the way the predictive models predict,” he said.
In 90 years or so, the weather we normally experience in southern and central Ontario will become the norm in places like Thunder Bay; central Ontario will be more like South Carolina is today.
Sweetnam puts up a slide from 1979 that shows nearly 100% ice coverage on the lakes during a period in February; a second slide from a more recent February shows only ice coverage in the bays and inlets along the coast. While those are extreme examples, on both ends of the scale, says Sweetnam, the trend shows a 71% decrease in ice coverage over the last 40 years. And less ice coverage means more evaporation.
The middle lakes evaporate at 87,000 cubic feet per second, an average derived from data from 1948 until 2006. As a comparison, the Chicago Diversion — water from Lake Michigan at Chicago through the Chicago and Illinois Rivers to the Mississippi River — draws about 3,000 CFS; the waterline between Collingwood and Alliston is pumping about 3.88 CFS.
Combined with a 32% decrease in average precipitation for the month of November, and only about 87% of what it would normally receive in precipitation over the previous 12 months, it meant the middle lakes lost 131,000 CFS during November when it would normally gain 27,000 CFS.
That's why lake levels dropped faster than normal in the fall, said Sweetnam.
"When the IJC came around, it generated a lot of interest," said Sweetnam. "And now people are seeing it, and the numbers we see (at presentations) are getting bigger.
"We're seeing a huge increase in people concerned about this as a high-priority issue."
Sweetnam expects that once people start returning to their cottages in the spring, it will become a difficult issue for governments — on both sides of the border — to ignore, though he did acknowledge federal governments, the IJC, and groups around the Great Lakes are coming on board.
Georgian Bay Forever is touting a couple of recommendations, including a $1.8-billion plan to regulate the flow going into the Niagara River at Lake Erie; that should slow the flow further upstream, assisting with lake levels in both St. Clair, and Huron-Michigan.
"Hopefully there will be a recommendation to do some kind of action, or at least explain what the action could look like," said Sweetnam. "They have to do more than just do nothing.
"The money is not a big issue, especially when there is a cost to doing nothing, especially what this means to shipping; it may be a small percentage (for transportation), but it is critical… the economic impact is significant, and it's been missing from the conversation."