The Mississippi River is the second longest river in North America and is responsible for supplying water to much of the U.S. As a major waterway and essential resource, the Mississippi River’s quality and quantity of water is highly dependent on its feeding sources. Rivers, lakes and aquifers in the Mississippi’s watershed contribute their excess water that adds to the volume of the Mississippi River. These sources also influence the water quality along with other factors such as land use and industrial development.
The Missouri-Mississippi river system which forms the largest river in the United States feeds into the Mississippi River. Other major rivers which contribute to the Mississippi River include the Minnesota, Illinois, Ohio, Wisconsin, and Pearl Rivers. Further north, numerous smaller rivers, creeks and lakes drain into the Mississippi from Minnesota, Wisconsin, Iowa, and Illinois. In addition, many other rivers and streams connected to bayous, swamps, and other aquatic systems also feed into the Mississippi. Because the Mississippi River receives its water from numerous sources in its watershed, it is important that any pollution or other forms of contamination be monitored regularly from as many of these sources as possible.
The amount of water in the Mississippi River is determined by the amount of rainfall and snowfall in the watershed. In times of drought, it may be less, while during floods, it may be more. Human influences also affect the amount of water coming into the river. For example, the increased use of reservoir water can reduce the amount of water the Mississippi River receives. On the other hand, increased irrigation further up the river in its tributaries can also increase the amount of water in the Mississippi.
In order to maintain healthy water quality, it is important to reduce or prevent water contaminants from entering the river. Wastewater treatment plants are designed to mitigate human contamination in the river, and technologies exist to reduce agricultural runoff too. It is also crucial to promote other agricultural practices such as filter strips and cover crops to minimize nutrient and sediment runoff.
Geographically speaking, the limited flow of water from the hills in the Midwest and agricultural activities in the Southeast contribute to mitigating events of high water volume caused by heavy rains in the Midwest. On the other hand, heavy rains in the Southeast, combined with storms from the Gulf, can cause high levels of volume and pressure on the Mississippi River. The Upper Mississippi River has more floodplains that can absorb excess water and alter the amount of water entering the main channel.
Climate change is impacting the Mississippi River, and it is predicted that the amount of water in the river, as well as its water quality, will be affected by rising temperatures, changing rainfall, and other consequences of climate change. Extreme weather events, such as droughts and floods, are also expected to increase in frequency and intensity, leading to further changes in the water quantity and quality.
Groundwater
Groundwater is a major source of water for the Mississippi River. In the Midwest and the Upper Mississippi, much of the water in the river comes from underground aquifers, which store and transport water beneath the surface. There are numerous aquifers associated with the Mississippi, including the Ozark Plateaus, Central Iowa, and Saginaw aquifers. All of these help to feed the river from below the surface.
Groundwater becomes available to the Mississippi River in a few different ways. Groundwater runs off into surface drainage systems, such as rivers and creeks, and eventually finds its way into the Mississippi. Groundwater also flows directly through water-filled networks beneath the river bed, known as “groundwater conduits”. These conduits can account for a significant portion of the water in the Mississippi River.
Groundwater also contributes to the health of the Mississippi River in other ways. It helps to buffer seasonal fluctuations in the water level, meaning that during dry periods, groundwater can help to keep the river at an appropriate level. Additionally, it helps to dilute any contamination that occurs due to runoff or local water use, making the water healthier and more suitable for human use or aquatic life.
Agricultural Runoff
Another major source of water for the Mississippi River is agricultural runoff. Rainwater runs off of fields and farms, where it collects any chemicals and compounds sprayed on the fields, as well as any animal waste. It picks up more contaminants as it runs into streams, rivers, and even wetlands, and eventually makes its way to the Mississippi.
The chemicals and compounds found in agricultural runoff can change the water quality of the Mississippi River. This water often contains excessive amounts of nutrient and sediment, which can increase the rate of eutrophication in the river. Additionally, the presence of chemicals such as fertilizers and pesticides can be harmful to both human health and aquatic life.
Agricultural runoff is impossible to totally eliminate, but its impacts can be reduced. Farmers can use techniques such as cover crops and buffer strips to reduce the amount of runoff entering the Mississippi. Additionally, proper management of animal waste and careful application of fertilizers and pesticides can also help to reduce runoff contamination.
Impervious Surfaces
Urban development is another major source of runoff that feeds into the Mississippi River. Buildings, roads, and other impervious surfaces, such as parking lots or sidewalks, prevent rainwater from soaking into the ground. Instead, it runs off directly into drainage systems, eventually finding its way to the Mississippi River.
Urban runoff carries a variety of chemicals and contaminants, including motor oil, antifreeze, fertilizers, and heavy metals. These substances can increase the amount of suspended solids in the river, leading to the death of aquatic life and creating a less hospitable environment for humans and other species. Urban runoff can also carry trash and sewage into the river, further polluting the environment.
Reducing the impact of urban runoff is an important task for maintaining the quality of the Mississippi River. Best management practices, such as rain gardens and green roofs, can help to slow the flow of runoff into the river and reduce the amount of suspended solids. Additionally, ecologically-minded urban designs can help to limit the amount of impervious surfaces in the city, and lead to better runoff management.
Aquatic Invasive Species
Aquatic invasive species, such as mussels and algae, can also contribute to changes in water quality along the Mississippi River. These species can disrupt the natural ecology of a river and its tributaries, leading to changes in species composition, nutrient cycling, and water chemistry. This can further affect the river’s water quality, leading to poor conditions for both aquatic life and human recreation.
Invasive species are often transported to different rivers and lakes through ships and recreational water vessels, where they can quickly spread and become established. Additionally, untreated wastewater, ballast water, and other sources of pollution can provide the perfect environment for invasive species to mature and thrive.
Controlling invasive species is a challenging task, and can require the cooperation of many different stakeholders. Early detection of invasive species is key, as it is much easier to remove established populations. Physical, chemical, and biological methods of control can also be used to reduce the presence of invasive species.
Water Management Strategies
Cities, states, and the federal government all have a role to play when it comes to managing and protecting the Mississippi River. Several strategies exist to ensure the conservation of the river’s water quality and volume, as well as its long-term viability as a natural resource. These include creating buffer zones and fish refuges, developing water management plans, and implementation of water-saving strategies.
Creating buffer zones and refuges along the Mississippi River can help to protect important habitats, create corridors for species migration, and provide sources of clean water. Additionally, water management plans can help ensure that water use is sustainable, and that its quality is maintained in the long term. Water-saving strategies, such as water reuse and conservation, can also reduce the amount of water entering the Mississippi River and help to maintain its water levels.
The Mississippi River is a major source of drinking water, recreation, and environmental health. The sources that feed into the river are key to its long-term viability and quality, and it is important that these be monitored and managed in conjunction with the river itself. By taking steps to protect the Mississippi River, cities, states, and the federal government can ensure the river’s long-term health for future generations.
