Wednesday, July 11, 2018

Lake Michigan Water Levels

This is one of the better websites I've seen in terms of serving technical information.

Thinking back on Lake Michigan 2018 and all thoughts ultimately have links to water levels.  Here is a simple tabulation of the mean June elevation of the water surface for "Michigan-Huron."   We are up to nine visits total; almost two months of time studying the lake and the near-shore fishery.

2010 nil year - we were too late and had no chance of seeing a fish
11    578.12
12    577.66
13    577.59
14    578.67
15    579.69
16    580.18
17    580.31
18    580.64
(1) While there is a long-term average, it'd be a reach to say that there is a "normal" water level for Lake Michigan.  Same thing is true for many water bodies, e.g. Lake Pepin for which there is no "normal" year re flows and weather.  The middle image below shows the "meander belt" of stage spanning approximately six feet: 576 to 582 feet.  That's a lot of variability.  Rain and snowmelt come to mind, but another important driver, according to the local resource experts: if the lake (or a lot of it) freezes over in winter, the evaporation stops thereby profoundly impacting the local water cycle; meaning higher water coming.  On the long-term then, the angler must be ready with an adaptive management approach.

(2) Our first good year was 2011; we didn't know it at the time but we were fishing low water.  We should have given more weight to one landowner who said basically this, paraphrased: "The carp didn't used to come in here.  But then the water left and the carp came."  Or maybe that was 2012 or 2013, years in which the water dropped even further to a period-of-record low point in January 2013.

(3) Since our June 2013 fishing the lake has risen up past the "average" such that now there are 3+ feet of water on top of the water surface we fished that year.  In 2013 we watched carp traversing bays with dorsals out of the water; just slogging along.  Now those paths are topped by a great volume of water such that the sun's energy is not enough to heat them up to the point of making them desirable for fish (carp or bass for that matter).

(4) The data seem to indicate that there is nothing to suggest that the water level will continue to increase or even "stay high" for whatever period of time.  The period of record shows remarkable cycling rise and fall patterns.  It's high now but it's been higher.  Can only read and react.  There isn't a recipe or a point on the map that alone begets outstanding carping.  It's not good casting skill or the right fly or gear; it seems to boil down to these: commitment to setting aside the time to go, watchfulness and data study, adaptability in planning, willingness to walk a long way questing after the fish as needed.

Andrew D. Gronewold, Anne H. Clites, Joeseph P. Smith, Timothy S. Hunter, A dynamic graphical interface for visualizing projected, measured, and reconstructed surface water elevations on the earth's largest lakes, Environmental Modelling & Software, Volume 49, November 2013, Pages 34–39