Low Tide on the Inland Seas

Sailors in salty parts of the world concern themselves with tides and moon phases, but Great Lakes sailors have mostly been immune to such navigational particulars (We do have seiches in the Great Lakes, but they are mostly unnoticeable). However, this coming season promises to make all of us who sail the inland seas study up on our charts and pay particular attention to chart datums, depth and boat draft because water levels are at or below all-time lows in all of the Great Lakes. It's starting to look like a perpetual low tide in many of the ports and harbors around the lakes. If you're interested in more details, you can read the short news piece I recently wrote for BoatUS Magazine highlighting the record low-water levels in the Great Lakes and some of their impacts and causes.

Low water has rendered this boat ramp useless (L. Charlevoix - By K. Walters)

The cause of the extremely low water levels is a complicated equation likely involving warmer/dryer than usual recent summers, lack of ice cover in the winter and intentional water diversions away from the Great Lakes. I won't even attempt to decipher the political quagmire surrounding the last variable, but suffice it to say it can be a polarizing issue.

My point in writing this post is to provide Great Lakes sailors with some tools that might help cope with the low water predicted for the coming season. Help may also arrive in the form of emergency dredging if the states and feds can come up with an acceptable funding source (another even deeper quagmire!).

In most years, this sandbar is submerged in at least a couple feet of water.
(Photo by K. Walters)

Here's an excellent water levels resource from NOAA's Great Lakes Environmental Research Laboratory: Great Lakes Water Level Dashboard. The dashboard let's you use sliders to look at current, historic and predicted water levels for all five of the Great Lakes. You can view all sorts of graphical data such as lakewide monthly averages, lakewide annual averages, master gauge averages, low water chart datum, etc.

The U.S. Army Corps of Engineers provides weekly updates and a really nice graphical display showing forecasted levels in relation to the longterm average and last season. 

Lastly, the Great Lakes Information Network provides a look at the latest news and happenings in their Great Lakes Levels and Hydrology webpage.

If you know of other useful resources to track and deal with low water in the Great Lakes, please share them in the comments below.


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