The Lower Mississippi River Water Trail
National Weather Service:
USGS Water Data:
Water levels according to the St. Louis Gage (SLG)
Low Water = 4 to 12 SLG
Medium Water = 13 to 24 SLG
High Water = 25 to 30 SLG
Flood Stage = 30 SLG and above
(SLG = St. Louis Gauge)
Flood Stage Warning: above 30 SLG paddlers are advised to stay off the river. Limited access. Most landings and approach roads will be underwater. Most islands will be gone. No easy camping. All sandbars will be covered. Fast waters with many hazards. All islands and landings will be surrounded by flooded forests full of snags, strainers, sawyers and all other dangerous conditions associated with floodwater moving through trees. Docks, wharves, dikes and any other man-made objects will create strong whirlpools, violent boils, and fast eddies. Towboats will create large waves. The Rivergator will not describe the river and its islands at any levels above flood stage.
High Water Note:
At 38 SLG the U.S. Coast Guard will consider closing the St. Louis harbor to navigation.
Major Flood Stage: 40 (Harbor Closed to recreational boaters)
Moderate Flood Stage: 35
Flood Stage: 30
Action Stage: 28
Water Levels and Dikes
In the St. Louis area you can use the following scale to gauge water flowing over dikes, although some dikes vary in height. Also some have been “notched” in recent years as result there will be a middle notch that you can paddle through at much lower levels of water, some places down to 0 St. Louis Gauge.
Using the St. Louis Gauge:
10-12 SLG water flowing through notches only
13 SLG – rocks still exposed on all dikes
14-15 SLG dikes starting to go under, some flow through breaks & low spots
16 SLG dikes completely under, but little flow
18-20 SLG good flow and lots of boils & turbulence
22 SLG strong flow, some turbulence, no dikes exposed anywhere
25 SLG river bank full
>30 SLG Flood Stage
Warning: above 30 SLG paddlers are advised to stay off the river. Limited access. Most landings and approach roads will be underwater. Most islands will be gone. No easy camping. All sandbars will be covered. Fast waters with many hazards. All islands and landings will be surrounded by flooded forests full of snags, strainers, sawyers and all other dangerous conditions associated with floodwater moving through trees. Docks, wharves, dikes and any other man-made objects will create strong whirlpools, violent boils, and fast eddies. Towboats will create large waves. The Rivergator will not describe the river and its islands at any levels above flood stage.
Reading Google Maps
You can learn a lot about the Mississippi River using Google satellite maps, bearing in mind certain parameters. Firstly the Google map-images were recorded from space during a season of low water, hence the islands and sandbars are at their largest, and many back channels that are open at higher water levels appear to be closed. Unlike highways which don’t change shape or position with the seasons, the islands of the Mississippi River and their back channels are dramatically affected by water levels. And so the paddler needs to remember that the shapes of low-lying landmarks like the sandbars and wetlands seen on Google Satellite Maps or Google Earth is probably not what they are like on any given day when you are out on the river. Be forewarned not to assume that the perfect-looking sandbar you see on you iPhone will be there!
Secondly, river levels change with the Google Maps zoom. Take Choctaw Island for example. When you go to Satellite view for the Mississippi River near Arkansas City you will see that Google employs various depictions of Choctaw Island. (I have created map at: http://g.co/maps/wmese) Use the zoom tool to change scale. Pay attention to scale icon at bottom left. At zoom 1″ = 1 mile and above you can see the back channel partially open & flowing well. The water level is probably around 3AG. However change the zoom to 2″ = 1mile and lower you will see the back channel almost completely occluded by sandbars. The water level in this depiction is certainly -4AG or lower.
Thirdly, for amorphous locations like river confluences and shifty river islands, what’s seen on Google Terrain may not be what’s seen on Google Satellite. The maps from the mouth of the Arkansas are a good case in point. Click on the map I created for the Mouth of the Arkansas Round Trip http://g.co/maps/syhs8 Look at it in Terrain, and then go to Satellite. You will see that the Arkansas River channel occupies different channels! This is not a mistake on Google’s part. What you see in Terrain is from the 1972 USGS survey. Since then the Arkansas has chosen a new path and carved out a new confluence location two miles from the older one. This is the nature of this ephemeral river-scape. It will be interesting to see how the current Arkansas River channel changes in the upcoming years, and how well Google will keep up with it.
The title Rivergator is derived from the national best-seller The Navigator first published in 1801 by Zadok Cramer, with 12 subsequent printings. The Navigator described the Mississippi Valley for pioneer settlers streaming out of the Eastern United States in the first great wave of continental migrations that eventually led to the settling of the Wild West. Thomas Jefferson and other leaders were fearful that the French or the English would get there first. With the Lewis & Clark explorations and the introduction of the steamboat to the Mississippi River in 1812, Americans followed the big rivers up and down through the heart of the country, and The Navigator was their guide. In this spirit I have adopted the name Rivergator with the hope that Americans will rediscover their “wilderness within,” the paddler’s paradise created by the Lower Mississippi River. And that the Rivergator will be adopted by successive generations of canoeists and kayakers, and re-written as the river changes. Zadok Cramer also invented the numbering system for Lower Mississippi River Islands, a system that survives to this day.
Towboats are a paddler’s most dangerous hazard. Towboats can’t stop easily, and they often can’t see you. But the good news is they move slow (10-14mph) and their motions are usually predictable. In general upstream towboats seek slow water and downstream seek fast water. The most dangerous place around any tow is in front of the tow. It is usually safe anywhere behind their route of travel. Never try to outrun a tow, and never paddle across their line of travel. Carry VHF marine radio and monitor channel 13 for traffic in the nearby vicinity. For more information, go to: https://www.rivergator.org/paddlers-guide/safety/