Is it for real you guys has been lossing water from lake ?
Oh, it's real, all right. Lake Superior (the largest fresh water reservoir in the world, I believe), the northern-most of the five Great Lakes, has been dropping at an alarming rate, it seems. Some of it, at least, is ascribed to years of below-average precipitation in the region and above-average temperatures resulting in less ice coverage, thus more evaporation. But the scientists studying it don't believe these issues can account for it all.
One current theory is that channel dredging, to allow really big ships (container ships, ore carriers, etc.), has resulted in too high a flow out of the Great Lakes. Ironically, these same carriers are finding themselves having to reduce their loads considerably due to dropping lake levels. There was at least one incident not long ago, I'm told, where a big ship got stuck in the channel
, could not be towed off, and had to have some of its cargo off-loaded to get under way again.
Then again: About a decade or so ago, Lake St. Clair (not one of the Great Lakes, but a kind of widening of the straights between Lake Huron, to the north, and Lake Erie, to the south), experienced uncommonly high water levels. But, since then, it has steadily dropped.
Is it an annual thingy or part of An Inconvenient Truth ?
There is seasonal variation. In the spring-time and through early summer, the Great Lakes basin is usually replenished by melting snow pack in the region and from northern Canada. Also spring precipitation rates are higher. As summer wears on, these sources diminish or disappear, the longer, hotter days increase evaporation, there's less average precipitation, and the lake levels tend to drop.
Still: Lately (several years), it's become worse than "normal." (Whatever that is.) There's now talk of trying to find ways to decrease flow out of the Great Lakes. I even heard mention of doing something at the south end of Lake St. Clair. Though how they'd manage that, I have no idea. There is a lot
of commercial and recreational traffic through the south end of that lake and on the Detroit river. I can't imagine locks, for example, being very practical. (Not to mention the cost to put them in.)
Is what we're seeing on the Great Lakes and their connected waterways part of An Inconvenient Truth? Maybe. I know it damn sure is "inconvenient."