Jan 29
The Waterways We Love - The Mighty Mississippi River (Part 10)
- Richard Crowder
- 4 hours ago
- 5 min read
While not the longest river in the United States -- that honour goes to one of its many tributaries the Missouri River -- the Mississippi River is perhaps the most recognized, most famous, and possibly the most idolized river in song and in verse. Just ask Mark Twain, or blues man Muddy Waters!
The Mississippi is roughly 2,350 miles (3,780 km) long from its source in Lake Itaska in northern Minnesota to its delta just south of New Orleans, Louisiana on the Gulf of Mexico. Its tributary, the Missouri River, is close to 200 miles longer than the Mississippi. In addition to exploring the Mississippi River in this Part 10, the next Waterways We Love segment in Part 11 will delve into the major navigable tributaries that feed the Mississippi as it winds southbound through the heartland plains of America.
Lake Itaska is just over 100 miles (160 km) south of the Canadian border and sits a little northwest of Duluth, Minnesota -- the most westerly point on Lake Superior. Lake Itasca is some 1,475 feet (450 m) above sea level. With twists and turns as befits a slow-moving river, the Mississippi heads roughly due south. It flows some 680 miles (almost 1,100 km) through Minnesota – one of only two states that the river flows “through,” the other state being Louisiana.
However, the mighty Mississippi forms the border between eight U.S. states. In order from north to south they are Wisconsin, Iowa, Illinois, Missouri, Arkansas, Kentucky, Tennessee, and Mississippi. To visualize the massive impact of the Mississippi River, consider that its watershed, which includes some of the longest and largest rivers in the United States, partially or fully drains 32 states and two Canadian provinces between the Rocky Mountains and the Appalachian Mountains!
Between Lake Itasca and the twin cities of Minneapolis/St. Paul, a distance of roughly 200 miles (320 km) along the river, are 14 dams but no locks, so there is no through-boating unless you are able to portage or trailer your boat. Each of these dams forms a sizeable lake behind it which supports all manner of recreation including boating, fishing, and outdoor activities, as well as providing hydroelectric power.
Immediately north of Minneapolis/St. Paul is the last of these dams: the Coon Rapids Dam, constructed in 1914 to provide hydroelectric power to the local county. It ceased providing such power in 1966. Under control of the United States Army Corps of Engineers (USACE), in addition to providing power these dams also store and control the release of spring runoff water to the rest of the Mississippi to maintain optimum navigation water levels.
The next section of the river, some 664 miles (1,069 km) between Minneapolis/St. Paul, Minnesota and St. Louis, Missouri, is often referred to as the Upper Mississippi. This “Upper” section of the river is distinct from the “Lower” Mississippi from St. Louis to New Orleans because the “Lower” section has no locks or dams. The “Upper” section however has 29 locks and dams, each capable of handling the busy commercial barge traffic on the river.
The most northerly such lock and dam is St. Anthony Falls in Minneapolis with a vertical lift of 49 feet (15 m), the highest lift (or drop) of all 29 locks and dams. The physically largest lock and dam is #19 at Keokuk, Iowa, some 100 miles (160 km) upstream from St. Louis. Re-constructed in the mid 1950s, the dam itself is over three-quarters of a mile (4.620 feet or 1,408 m) long with 119 separate moveable gates while the navigation lock is the standard commercial size 1,200 feet (366 m) long and 110 feet (34 m) wide and with a vertical lift of 38 feet (12 m). It can accommodate a full length of barges. The powerhouse with its 15 generators was once one of the largest hydro-generating facilities in the world.
There are no dams or locks per se south of St. Louis as the Illinois, Missouri, Arkansas, and Ohio rivers supply enough water to the Mississippi for navigation purposes. There are, however, thousands of wing dams (or dikes) and levees the entire way south to New Orleans to direct and control water and sediment in order to maintain the optimum navigation channel. The current is stronger in this section, too. A single barge can be as long as 1,200 feet (365 m) consisting of 15 barges -- five long by three wide and pushed by a single towboat or tug.
The US Army Corps of Engineers maintains a 19-foot (5.7 m) deep navigation channel between Minneapolis/St. Paul and Baton Rouge, Louisiana. Between Baton Rouge and south to New Orleans, the channel is 45 feet (13.7 m) deep to accommodate ocean-going ships. The river itself flows another 100 miles (160 km) south of New Orleans through its enormous delta and a distributary before opening up into the Gulf of Mexico. The ever-growing delta consists primarily of the eons of silt transported down and then deposited by the river at its mouth. This delta actually starts forming as far north as Memphis, Tennessee!
It takes water about 90 days to flow the 2,350 miles from Lake Itasca to the Gulf, thus producing an average speed of roughly one mile (1.6 km) per hour. However, in certain sections, that current can be three or even four times faster depending on water volume. From where the tributary Missouri River joins the Mississippi at St. Louis south to where the Ohio River joins, average water depth is about 30 feet (9 m). With the inflow of the Ohio River, average depth increases dramatically to between 50 and 100 feet (15 to 30 m). The deepest part of the Mississippi is around New Orleans where it can be as deep as 200 feet (60 m).
In addition to the aforementioned cities of Minneapolis/St. Paul, St. Louis, Baton Rouge, and New Orleans, other notable cities on the 1700 (2,735 km) navigable miles of the Mississippi include La Crosse, Wisconsin, Dubuque, Iowa, Memphis, Tennessee, and Greenville and Vicksburg, Mississippi. As well as attracting nearly half of all migrating North American waterfowl and almost 300 species of birds along the Mississippi Flyway, the river itself is truly one of the wonders of pleasure boating in the world.
What a thrill it must be to experience boating the entire Mighty Mississippi River from Minneapolis/St. Paul right through to New Orleans and out into the Gulf of Mexico or upstream in the opposite direction. Ensure you have done your homework ahead of time knowing that high water at certain times of the year can bring flotsam and jetsam and increased current flow. Ensure also that you know the locations of overnight docking, anchorages, and food and fuel supplies appropriate to pleasure boats. You might also like:
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