The Mississippi River, a deeply degraded watercourse

An illustrative example of a river with serious management problems is the Mississippi River in the United States. 
The combined Mississipi course with its tributary the Missouri River is one of the longest in the world (6,000 km).
Its basin has subcontinental dimensions (3,238,000 km2) draining a vast area of ​​the country. The deforestation and agricultural occupation of the basin that occurred at the end of the 19th century and first half of the 20th century, resulted in a dramatic change of the river regime in the middle and lower courses of the main tributaries (Missouri rivers, Des Moines, Ohio, etc.) and in the main valley of the Mississippi. 
Evaporation and infiltration decreased, soil erosion and runoff increased, resulting in higher flood peaks, with accumulation of floods both in the river plains and in the river delta, at its mouth in the Gulf of Mexico . The problems were exacerbated by the indiscriminate occupation of the flood plain and the elimination of river wetlands that helped cushion the discharges. 
In order to avoid the flooding of the properties, constructions and crops of the areas adjacent to the margins, numerous lateral levees were built that ended up by encasing the flow and creating the conditions for vigorous flooding (Ellis, 19932; Faber, 1994).
The floods of 1993 were particularly destructive: much of the floodplain of the Missouri River was flooded, causing serious damage to its riverside cities (Omaha, Kansas City), the Des Moines River, and the upper Mississippi River course, affecting an extensive zone of the states of Illinois and Missouri (the cities of Davenport, West Quincy and Hannibal) (Adler, 1993). Other catastrophic floods occurred in 2002, 2008, 2014 and 2017, indicating that far from solving the problems, rather they become more frequent and intense.
The management of the Mississippi is very complex due to the multitude of actors and interests that exist in such a large and populated basin. To solve them requires the convergence of political wills of the governments of more than 30 states, hundreds of municipalities, federal public power, the private interests of numerous companies, and the views of several tens of millions of people who live in the Basin, watershed, catchment area, socket, bowl, hollow. Under these conditions, it will not be easy to rethink the current degradation model to establish instead a comprehensive environmental and socially sustainable approach.