Harsh winter benefits Great Lakes water levels
Fri, 07 Mar 2014 02:22:12 GMT —
Grand Traverse Bay keeper John Nelson always keeps a watchful eye on the water that surrounds Northern Michigan. It's his job and his passion. When he looks out his office at the Watershed Center, the view hasn't changed much in the past few months. The bay has been frozen over for months, and blanketed with snow.
But Nelson confirms what a recently released U.S. Army Corps of Engineers report states, that all of this cold weather, thick ice and heavy snow will have a noticeable impact once the temperatures climb.
According to federal officials, this winter's deep freeze and heavy snowfall will help nudge Great Lakes water levels closer to normal over the next six months. The U.S. Army Corps of Engineers says lots of water is stored in the huge snow pack that will melt this spring. The water content in the snow piled up around Lake Michigan is 30 percent higher than at any other time in the last decade.
And a good winter couldn't come at a better time, just 14 months ago, Lakes Michigan and Huron slumped to their lowest levels ever recorded. Low lake levels have a huge impact beyond beauty, economically, a lack of water can lead to empty marinas and slower shipping traffic to name a just a few.
Nelson points out that good snowfall is only part of the recipe for increasing lake levels. In fact, it even depends on what type of snow has fallen. Lake effect generated snow really doesn't add anything additional to the lakes since the water that fueled those flakes originated in the lake itself. System snow is what makes a difference.
According to Nelson system snow is only half the solution. He says "what drives lake levels are the balance between evaporation and precipitation, so more precipitation and less evaporation makes the lake levels come up." Evaporation is a massive force in Mother Nature, and actually has its biggest effect, not in the heat of the summer, but rather in the fall and early winter. The longer the ice stays out on the Great Lakes, the cooler the lake will be this summer and fall, which means less evaporation months from now.
Evaporation according to Nelson is an often overlooked factor in lake levels. It's significant. Nelson says "look at Niagara Falls, look at the water gushing over Niagara Falls. The evaporation loss of the water of the Great Lakes is ten to fifteen times more per day than the water going over the falls."
Reversing a trend in nature often takes time. Historically, the lakes have always gone through high and low periods. While our extraordinary winter may not be a long term solution, it maybe a step in the right direction.