Lake Huron’s April rise beats seasonal average

LAKE HURON—While Lake Huron levels are still near the record low, Manitoulin Islanders can take heart as their Great Lake has seen a rise of 24 centimetres over the month of April, more than double April’s usual rise of 11 centimetres, not enough, however, to float the Chi-Cheemaun ferry at its full capacity.

“From a lake perspective, that’s great news, but it comes with the bad for those people on the low side of the lake,” said Chuck Southam, water resources engineer, boundary water issues, with Environment Canada, noting the flooding in some parts of the province.

He said it was important to realize that chart datum isn’t the lowest we can go in terms of low water levels, something he thinks many people don’t understand.

Mr. Southam noted that Lake Huron is still experiencing some spring run off and, thanks to some wet weather at the beginning of the month, the levels are still rising and still on average. Another six centimetres in May and five centimetres in June are needed to maintain the average rise in levels, he added.

Watching the radar over Lakes Huron and Michigan, the engineer said he was pleased to see rain falling over these Great Lakes, explaining that April 1 had a lake-wide mean of 175.63 metres (the depth to the lake’s bottom) and by April 30, it was 175.88 metres.

“The wet weather in April, and precipitation falling right on the lake with snowmelt and runoff saw the lake rise 13 centimetres more than it does on average,” he noted excitedly.

On the Environment Canada website, the projected highs and lows range drastically from April to May, thanks to this major increase. They are now projecting that even with a dry summer, the summer levels would be approximately 10 centimetres above the record low of 1964. A wet scenario will see Lake Huron go above chart datum, and slightly better than last year’s levels. “Right now, statistically, it’s likely that this summer’s levels will be similar to last year’s,” Mr. Southam added. “That’s better than I thought one month ago.”

He noted that last year, levels peaked early, coupled with no snow or ice cover, then saw a long decline over the summer and into the fall that ultimately led to a new record low (from data collected between 1918-2012) for December.

Lake Huron levels are currently 16 centimetres below last year’s levels for this time. The monthly mean was 176.03 metres, with the high reached at 176.09 metres in June before a continual fall during last summer and fall.

The Expositor explained to Mr. Southam that the Chi-Cheemaun ferry had yet to set sail due to low water levels (before the announcement that the ferry would sail Friday). Mr. Southam noted that the levels were higher so far this month than they were at the same time in 2003 when there wasn’t a disruption to ferry service. On May 9, 2003 the lake-wide levels were 175.88 metres (below chart datum, 176 metres). On Friday, May 17 of this year, the levels read 175.80 (below chart datum). “It’s pretty well exactly the same,” he said.

He reminded Islanders of the rebound effect, noting that land on Manitoulin has rebounded (risen) 10 centimetres in upper Lake Huron since the Chi-Cheemaun set sail in 1974, adding to the effect of low water levels.

South Baymouth resident Brent Leeson, who has been watching levels closely for some time, also brought it to The Expositor’s attention that the October 2012 levels for Lake Huron were lower than this May’s levels with the ferry still not setting sail. In October of 2012, levels were closing in on 175.7 metres.

“They first started talking about not running the boat when the channel was too shallow, then that disappeared, then it was the bumpers,” Mr. Leeson said.

Mr. Leeson questioned why the ferry could sail in October, and not now, when the water was even lower. When he heard the news on Friday of the estimated six-to eight-week repair time needed via The Expositor’s Facebook page, he came to the newspaper for answers armed with water levels data.

The Expositor contacted Owen Sound Transportation Company CEO Susan Schrempf with respect to these questions. As for the 2003 levels, Ms. Schrempf looked up May’s numbers and said the levels were 1/800th of a metre out from chart datum and that one day’s levels cannot count, as it should be a stretch of at least one week of data, but as for last fall, she admitted that yes, the levels were indeed lower.

“We weren’t happy about operating that way, that’s why we brought it to the government in June (of last year),” she said. Transport Canada launched a study into the fenders beginning last July, the results of which were released in January 2013. “We took that report and realized we couldn’t sail,” she said. “Safe is chart datum (for fender levels). If we knew that in the fall, we would have cancelled sailing then too.”

“We knew it was difficult, and that the vessel was getting damaged (last fall),” Ms. Schrempf admitted.

When asked if the delay in sailing was an insurance issue, as rumour had it, she responded, “I don’t think that’s a rumour. If you have a report that shows that continuing to sail would be unsafe, not only would we lose our insurance if something were to happen, we probably would never get insurance again.” Ms. Schrempf noted that there are plenty of recent examples of studies done and then ignored with tragedies ensuing, not unlike the Algo Centre Mall or Bangladesh garment factory tragedies.

“In this case, it says ‘chart datum,’ and that’s what we’ll adhere too,” she said. “I think it’s a good question, and I’m glad he asked it,” she said of Mr. Leeson.

Ms. Schrempf explained that chart datum is based on the Tobermory levels, as that is where the Environment Canada water level gauge is located for that area of the lake and that there are 13 centimetres difference between the South Baymouth and Tobermory wharves and that the Island fenders are already lower. Less water is needed to sail in South Baymouth than its counterpart, the Tobermory harbour.

As for what the rest of the summer will hold, “Unless things get really wet, it’s going to be another tough summer,” Mr. Southam admitted, adding that ideal conditions for this Great Lake would be a wet summer with a slow fall decline followed by a wet spring.