Background Information
The Mississippi River is one of the world’s longest rivers, stretching from the upper Midwest to the Gulf of Mexico, and is the lifeblood of the environment, wildlife and communities of the region. It is a source of drinking water for 15 million people, it supports agriculture, fuels industry and recreation, and it forms the gateway for efficient transportation of goods by ships. Yet, in recent years, the Mississippi River has befallen a dry spell.
The reason for this dry spell is a complex mix of man-made and natural causes. In the Upper Mississippi, a long-term warming trend has resulted in greater evaporation from the nation’s largest water body and less precipitation. Further downstream, the effects of climate change and more frequent droughts are further drying up the waters. On the flip side, man-made modifications of the river, such as dams and locks, have changed the way the river works, reducing its flow and levels, and resulting in diminished sedimentation that form wetlands, marshes and floodplains.
Relevant Data and Perspectives from Experts
The Intergovernmental Panel on Climate Change (IPCC) cites long-term trends of reduced snowpack and runoff in the Midwest, as well as earlier peak runoff times, as leading contributors to decreased flows in the Mississippi River. The decreased flows have been more pronounced in the South and Middle sections of the river. The US Army Corps of Engineers (USACE) notes that, since the mid-1900s, the average annual flow has decreased by 18%.
Environmental scientists note that drought is only one of the factors affecting river flow in the Midwest; snow and changing water use priorities, among other associated factors, are causing additional deficits of water in the Upper Mississippi. In the Lower Mississippi, climate change is the dominant force behind decreasing river flows. In particular, higher temperatures are leading to increased evaporation from the river, in addition to it being diverted for agricultural and industrial purposes, leading to water deficits downstream.
Insight and Analysis
The drying up of the Mississippi River is concerning for several reasons. Despite recent attention being focused on the effects of climate change, the effects of river modifications and changing water use priorities have been largely overlooked. The decrease in river flow affects the ecology of the region, as well as the natural resources that the river and its tributaries support.
Water levels are critical for navigation, commerce, and recreation. In 2018, industry groups and the USACE reported disruption in freight shipping due to low water levels. Navigation restrictions were measured based on the between the navigation pool’s “shock points of 12 feet and 9 feet (3.66 m and 2.75 m) at St. Louis.” There is evidence to suggest that the USACE’s management of their dams and releases is not helping the situation much, as they are not fully taking into account upstream and downstream water levels.
Implications for Sustainability
The lack of attention given to the effects of changing water use priorities, combined with the effects of natural drought and man-made modifications of the river, has significantly worrying implications for the future sustainability of the Mississippi River. Despite the efforts of environmental groups and industry to come up with solutions to support water levels in the long term, the magnitude of the situation cannot be understated.
The USACE manages many of the resources allocated to support water flow, including the proposal of barge lock extensions at major river junctions. However, in spite of these measures, the USACE has argued that more needs to be done: they propose more sustained, systemic infrastructure improvement projects, noting that “improvements to locks and dams need to be balanced with dredging, bank stabilization and other efforts to reduce sediment in the river.”
Social Implications
The Mississippi River is a source of ecosystem services for the region. These services include providing water for drinking and agriculture, enhancing water quality, and reducing air and noise pollution. The downstream effects of decreasing river flow are not limited to environment, as the drying up of the river also has significant economic and social implications.
The economic effect of reservoirs, locks and dams is such that industry and commerce rely heavily on the navigation of the river’s currents. The USACE estimates that locking and dams keep around $7.07 billion per year in freight transportation costs low; this is a huge factor when considering the economies of the cities along the Mississippi.
Low water levels also mean that recreational activities are limited. The revenue generated by hunting and fishing activities dependent on the river, as well as the tourism associated with water recreation, is also at risk.
Policy Solutions
The fate of the Mississippi River highlights the value of cooperation between states and federal governments. To prevent further depletion, governments need to come together to implement policies to conserve and sustainably manage the river’s resources.
State legislatures are needed to create and enforce laws to prevent further people from practices which deplete the river’s resources. Refocusing and refining agricultural policies, including crop production and water practices, can also offer solutions to reducing water losses from the river’s watersheds. And, at the federal level, enough support must be allocated to ensure effective long-term water storage and management.
Good river management practices are also essential for controlling river flows. The USACE, for instance, advocates for partnerships and agreements with stakeholders to implement practices such as dredging, bank stabilization, and other measures to reduce sediment in the river.
Environmental Benefits
The drying up of the Mississippi River has significant short and long-term environmental effects. Most of the river’s wetlands, marshes and floodplains are fed by sedimentation and the natural migration of soils and plant material along the river. With reduced flows, this essential sedimentation is greatly diminished.
In the short term, reduced river flows lead to an increase in water temperatures, as well as the risk of algal bloom. Algal bloom is the result of an increase in nutrients – such as phosphates and nitrates – that find their way into the river when water levels are low. This, in turn, can lead to severe water pollution and endangerment of the local ecology.
In the longer term, the traditional habitats of fish and birds could also be adversely affected. This will place even more strain on the ecosystems downstream.
Economic and Social Costs
The drying up of the Mississippi River creates significant economic and social costs, not only for those living along the river, but with broader impacts to the economy and communities of the region. Commercial and recreational interests rely on water levels in the river for their activities, and a reduction in these water levels means a reduction in activity.
The decrease in river flow can put stress on the economic and social infrastructure of the region. Energy production and industry, essential for the economic development of the area, are reliant on the availability of ongoing and reliable river flows. Communities that depend on the river for drinking water and whose residents rely on the services provided by the river’s wetlands and ecosystems, such as fishing, boating and tourism, may also face diminished economic opportunities unless long-term measures are taken to restore river flows.
Mitigation Strategies
The Mississippi River is a vital resource to the communities along its banks. To sustain the river’s resources, such as drinking water, habitats, and recreational and commercial opportunities, politicians, industry and citizens need to work together.
There are many potential strategies to mitigate the effects of the drying of the Mississippi River. More effective freshwater management systems need to be implemented, with an eye towards balancing population growth, agricultural and industrial needs, and conservation. A focus on the environment could reduce pollution and conserve the habitats of the river’s species. Governments also need to better manage their resources to prevent over-exploitation of the river, as well as its tributaries and watersheds.
Environmental groups have been pushing for legal reforms and better management of river-based resources for years. Long-term risks such as climate change should also be taken into account to ensure that the river can continue to support the region for years to come.
Remediation Measures
Remediation measures for the Mississippi River should focus not just on its waters, but also on its tributaries and watersheds. This means the implementation of policies and incentives to encourage environmentally friendly agricultural practices and reduce pollution.
Upgrading existing dams and locks and building new ones should also be considered. This can help to conserve water and reduce sediment runoff. Additionally, wetland preservation and restoration efforts should focus on restoring the river’s wetlands.
At the same time, more investment needs to be made in R&D to develop technologies to desalinate saltwater and reduce water wastage. This can help to alleviate some of the water deficits that are causing the river’s flows to drop.
Finally, the effects of the current challenges need to be managed with firm yet fair regulations and incentives. Governments should step up and ensure that the economic, social and environmental benefits of the Mississippi River can be effectively conserved and managed for the benefit of future generations.
