Mississippi River Overview
The Mississippi River is one of the world’s major river system in size, habitat diversity and biological productivity. It is the third longest river in North America, flowing 2,350 miles from its source at Lake Itasca through the center of the continental United States, to the Gulf of Mexico.
When compared to other world rivers, the Mississippi-Missouri River combination ranks fourth in length at approximately 3,902 miles (6,275km) following the Nile (4135mi/6650km), the Amazon (3980mi/6400km), and the Yangtze (3917mi/6300km).
River length is a difficult measurement to pin down because the river channel is constantly changing. For example, staff at Itasca State Park, the Mississippi's headwaters, say the Mississippi is 2,552 miles long. The US Geologic Survey has published a number of 2,300 miles (3,705 kilometers), the EPA says it is 2,320 miles long, and the Mississippi National River and Recreation Area maintains its length at 2,350 miles.
At Lake Itasca, the river is between 20-30 feet wide, the narrowest stretch for its entire length. The widest part of the Mississippi can be found at Lake Winnibigoshish near Bena, Minnesota, where it is wider than 11 miles. The widest navigable part of the Mississippi is Lake Pepin, where it is approximately two miles wide.
At the headwaters of the Mississippi, the average surface speed of the water is near 1.2 miles per hour - roughly one-third as fast as people walk. At New Orleans, on 2/24/2003, the speed of the river was 3 miles per hour.
Mississippi River Watershed
The Mississippi River watershed is the fourth largest in the world, extending from the Allegheny Mountains in the east to the Rocky Mountains in the west. The watershed includes all or parts of 31 states and 2 Canadian providences. The watershed measures approximately 1,837,000 square miles, covering about 40% of the United States and about 1/8th of North America.
Communities up and down the river use the Mississippi to obtain freshwater and to discharge their industrial and municipal waste. We don't have good figures on water use for the whole Mississippi River Basin,but we have some clues. A January, 2000 study published by the Upper Mississippi River Conservation Committee states that close to 15 million people rely on the Mississippi River or its tributaries in just the upper half of the basin (from Cairo, IL to Minneapolis, MN). A frequently cited figure of 18 million people using the Mississippi River Watershed for water supply comes from a 1982 study by the Upper Mississippi River Basin Committee. The Environmental Protection Agency simply says that more than 50 cities rely on the Mississippi for daily water supply.
For nearly 200 years agriculture has been the primary user of the basin lands, continually altering the hydrologic cycle and energy budget of the region. The value of the agricultural products and the huge agribusiness industry that has developed in the basin produces 92% of the nation's agricultural exports, 78% of the world's exports in feed grains and soybeans, and most of the livestock and hogs produced nationally. Sixty percent of all grain exported from the US is shipped via the Mississippi River through the Port of New Orleans and the Port of South Louisiana.
In measure of tonnage, the largest port in the world is located on the Mississippi River at La Place, La. Between the two of them, the Ports of New Orleans and South Louisiana shipped more than 286 millions tons of goods in 2001.
Shipping at the lower end of the Mississippi is focused on petroleum and petroleum products, iron and steel, grain, rubber, paper and wood, coffee, coal, chemicals, and edible oils.
To move goods up and down the Mississippi, the U.S. Army Corps of Engineers maintains a 9-foot shipping channel from Baton Rouge, LA to Minneapolis, MN. From Baton Rouge past New Orleans to Head of Passes, a 45 foot channel is maintained to allow ocean-going vessels access to ports between New Orleans and Baton Rouge.
At Lake Itasca, the average flow rate is 6 cubic feet per second. At Upper St. Anthony's Falls, the northern most Lock and Dam, the average flow rate is 12,000 cubic ft/second. At New Orleans, the average flow rate is 600,000 cubic feet per second.
There are 7.489 gallons of water in a cubic foot. One cubic foot of water weighs 62.4 pounds. A 48 -foot semi-truck trailer is a 3,600 cu. ft. container.
At Itasca, it would take 10 minutes for one semi-trailer of water to flow out of the lake into the Mississippi.
At St. Anthony Falls, the equivalent of 3 semi-trailers full of water go over the falls every second. At New Orleans, the equivalent of 166 semi-trailers of water flow past Algiers Point each second.
The Mississippi River and its floodplain are home to a diverse population of living things:
- At least 260 species of fishes, 25% of all fish species in North America;
- Forty percent of the nation's migratory waterfowl use the river corridor during their Spring and Fall migration;
- Sixty percent of all North American birds (326 species) use the Mississippi River Basin as their migratory flyway;
- From Cairo, IL, upstream to Lake Itasca, there are 38 documented species of mussel. On the Lower Mississippi, there may be as many as 60 separate species of mussels;
- The Upper Mississippi is host to more than 50 species of mammals;
- At least 145 species of amphibians and reptiles inhabit the Upper Mississippi River environs.