As of September 9th, the Mississippi River water level at La Crosse has fallen down to around 5.2 feet. Looking back, this is the lowest that the Mississippi has been in La Crosse since June 11, 2010!
The summer of 2010 was rather wet, with round after round of rainfall, both locally and well upstream across Minnesota and northwest Wisconsin. The Mississippi rose as runoff from all of the rainfall moved downstream from the tributary streams, and into the main stem of the Mississippi River. Water levels fluctuated between 6 and 9 feet all through last summer, and then the large rain event of September of 2010 led to a crest over 13 feet on September 27th.
With so much water remaining in the tributary streams, as well as lakes, lowland swamps, backwaters, and even the groundwater, water levels remained high all through the winter months.
In fact, the winter of 2010-11 saw the Mississippi River hover between 6 and 7 feet, which had never happened before in records dating back to 1874.
This, of course, led to a heightened risk for flooding last spring, and the Mississippi experienced moderate flooding during the month of April 2011. Since that time, the river has been falling ever-so-slowly, with periodic rain events resulting in some rises from time to time. But now that we have had several weeks of relatively dry weather, water levels are finally starting to return to what would be considered "normal" for late-summer and fall.