The mighty Mississippi starts as a small stream in Lake Itasca, Minnesota, and flows 1,300 miles to the Gulf of Mexico. Even before Mark Twain romanticized the Mississippi, it was the nation's principal interstate waterway, and continued to be a major transportation artery even after the coming of the railroad and interstate highways.
However, the towns and businesses that grew up along its banks have contributed to the water pollution that has plagued the river's health. For the millions of residents who live by its banks, the Mississippi supplies water for drinking, irrigation, power plant cooling, and recreation. It is said that by the time the water of the Mississippi has passed to the Gulf of Mexico, it has passed through seven different people.
The Mississippi River supports a diverse array of fish and wildlife that live in its channels, backwaters, and wetlands. According to the U.S. Geological Survey (USGS), the Mississippi Flyway is the migration corridor for 40 percent of North America's waterfowl and shorebirds. A 40-mile reach of the Upper Mississippi River has been characterized as the single most important inland area for migrating diving duck in the United States. And 154 species of fish and 50 species of freshwater mussels have been recorded in the river system.36
Downstream states bear the brunt of water-quality problems that accumulate as the river makes its course south. High rates of nutrient loading upstream have contributed to the development of a 7,700 square-mile zone of reduced dissolved oxygen in the Gulf of Mexico.37 Those same high-nutrient loads have also increased the amount of algae in the water, creating a dead zone the size of New Jersey. This area can no longer sustain sea life for most of the year.
The people of the Upper Mississippi River Basin have begun to respond. Recognizing this as a serious problem that doesn't just affect those downstream, they have begun looking for ways to help clean up the river. Government agencies have hitherto focused mainly on point sources of pollution: heavy industries, sewage-treatment plants, food-processing companies, slaughterhouses, and other large sources of wastes whose pipes empty into the river. However, just as the Pamlico-Tar River Foundation found, while some of these nutrients come from point sources such as factories or municipalities, approximately 90 percent come from non-point sources, such as septic systems and farm drainage lines.38
According to a 1994 U.S. Geological Survey report, 71 percent of U.S. cropland lies in watersheds where at least one agricultural pollutant violates criteria for recreation or ecological health.39 For example, the Minnesota River (a Mississippi River tributary) flows through land that is 92-percent agricultural, and 50,000 households on the banks of the river have inadequate sewage systems.40 While each farm or sewer alone contributes a small amount of damage to the river, cumulatively they generate an enormous amount of pollution.
Many groups are following the example of the Pamlico-Tar River project by joining together industry leaders and environmentalists to think of new solutions for these old problems that are not contemplated in typical Clean Water Act measures that target mostly point sources. For example, a state-level program called Reinvest In Minnesota (RIM) works to purchase permanent conservation easements along threatened watersheds to reduce the rate of runoff from agricultural soil. Efforts of this kind are in their infancy, but they point the way toward an effective strategy for safeguarding the Mississippi for the twenty-first century.