The Lower Mississippi River Water Trail

Forecasting and Monitoring River Levels

Before departing on any river journey of any length visit website http://www.srh.noaa.gov/lmrfc/?n=lmrfc-mississippiandohioriverforecast  for the latest prediction from the NOAA Lower Mississippi River Forecast Center.  You can also receive daily predictions from any of the 10 NOAA weather radio stations along the Lower Mississippi River at 11am, 5pm and 11pm (???).

 

Be forewarned: In rainy periods the river might rise higher than expected.  The converse is also true: during droughts it might be lower. 

 

As with all predictions, the forecast is only as good as previous records have demonstrated, and the viability of the current forecast model used for calculations.

 

For best river runner practice, watch the river carefully during any journey and make your own observations & measurements for your own predictions.  A river full of driftwood is one sign of a rising river.  The sandbars of the Mississippi tend to create foam in a rising river.  If you see foam floating off the bank its probably a rising river.  The more foam you see the faster the rise.  In a fast rise there will be piles of fresh yellow-white foam that looks like its was just skimmed off a pot of boiling chicken soup.  A rising river tends to be muddier, and also moves faster and is in general more turbulent than a falling river.  On the other hand a falling river is mostly free of driftwood.  There is very little foam in a falling river, and none of the big piles of shiny yellow-white foam that look like fresh whipped cream on a rootbeer float.   The falling river runs clearer and is slower and less turbulent.  (Although, remember that the Mississippi can always have areas of great turbulence on any kind of rise or fall).

 

When the DeSoto Expedition lumbered out of the deep Delta swamps and found the big river it was certainly a rising river as described in their chronicles:  "The stream was swift, and very deep; the water, always flowing turbidly, brought along from above many trees and much timber, driven onward by its force..."

(pg 225, Gentleman of Elvas)

 

Another sign of rising vs. falling river can be seen the pass at the mouth of any lakes (such as Tunica Lake or DeSoto Lake) or at any of the passes, such as Trotters Pass.  If the water is flowing into the pass, it is certainly a rising river.  If it is flowing out it is a falling river.  During lower water levels the outflow will be greener.  If there is no flow, there is no change, its a steady river.  If there are any towboats churning by in your vicinity -- wait until they have passed before making a decided observation.  A passing towboat can make the river rise and then fall as much as half a foot!

 

Water Color: Lastly, watch for changes of water color as your journey progresses.  Sometimes it is only a subtle change, sometimes dramatic.  The Mississippi varies from muddy orange/yellow/green in high waters to a clearer orange/green in lower water levels.  When the Ohio is flooding the color is darker browns & greens.  When the Upper Mississippi is flooding you will see an even darker hue.  When the Missouri is flooding there are more warmer muddy tones, more muddy-orange and muddy-browns, and also more fine suspended silicate.  When the Arkansas is high it pours into the Mississippi with muddy-yellows and oranges.  When it is low it is clear-green.  Whenever you see green water it is probably richer in the blue-green algae which propagate in calmed waters. The river is always telling a story, if only we could learn its language!  With some careful artistic discernment you can tell if the Missouri is flooding all the way down in Mississippi by the water color, even though you are 500 miles away!

 

Measurement: The simple method described below will help you make good decisions about how & where to camp, and how high above the waterline you should pull up and then tie your canoe or kayak so it doesn't get battered by waves of passing towboats during the night.  You don't need any formal measuring device or special training.  You can make a game out of it.  Parents, this could be fun lesson for your children.  Ditto for Boy Scouts or Girl Scouts. 

 

Procedure: Monitoring & Predicting River Rise with a stick:

Here's what you can do to get a good reading without any electronics or modern technology.  We call it "the stick method."  After you make a landing for an overnight camp place a stick solidly at the edge river at water level near your camp.  (Do the same at 2 or 3 other locations, just in case one stick gets washed away.)  Now draw lines in the sand or mud above the sticks at an even interval = to the height of one stick. 

Here's how to choose interval: pick out a short stick and use it as your measuring rod.  It doesn't matter exactly how tall this stick is in inches or feet, but it should be shorter than your knee cap (because the Mississippi River never rises or falls more than 4 feet in 24 hours).  Pick a stick of any length up to knee level and use it to mark vertical height of one stick between lines.  If you have doubt about vertical height, use the surveyor's trick and squat down or crouch down to stick height holding the stick in front of you and eyeball a level line from water's edge across the stick to the bank rising behind.  Mark that location and then repeat, making lines for each vertical rise of the unit 1 stick.

 

Now plant other sticks into the sand to help identify & save your lines.  As you set up your tent, gather firewood and cook supper watch the river line in relation to your sticks.  You will soon be able to decide if the river is rising or falling.  If its a fast rise or a fast fall you will be able to see it rise or fall against your designated measuring stick.  If necessary during a fast rise, pull your canoe or kayak further up the bank above the fast rising waters.  After supper enjoy sunset and watch the changing river.  Before you go to sleep make one last inspection.  If necessary move your vessel even higher.  Survival on the Mississippi always favors the cautious!  The next morning arise and check your stations.  Now you will know for sure how fastly the river is rising or falling.  During a falling river: as the river falls you can make lines below your original stick using the same method, add lines as the water falls.

 

For more reading: Mark Twain's 1883 Life on the Mississippi contains some useful descriptions of the rising and falling river.

 

Reference: for accurate river levels refer to the various gages along this section of river.  For the latest river levels and week forecast, visit the NOAA Lower Mississippi River Forecast Center:

 

http://www.srh.noaa.gov/lmrfc/?n=lmrfc-mississippiandohioriverforecast