As the United States and the world contend with the ever-present threat of global warming and its effects, the Mississippi River has become one of the greatest indicators of human impact on the environment. To many, it is a stark reminder of the consequences of over-extraction, runoff and loose environmental regulations for rivers worldwide. This article will explore why the Mississippi River is experiencing such a drastic decline in water levels, and the prospects for its future.
At 4,300 miles, the Mississippi River is the second longest drainage system in the United States. Its watershed is almost the entire length and breadth of the nation, encompassing parts of 31 US states and two Canadian provinces. It discharges approximately 1.2 trillion gallons of fresh water into the Gulf of Mexico each day. This has made it a lifeblood for the communities along its banks.
Despite its importance, in the past year the river has been at an all-time low, dropping 12.3 feet between the months of June to August alone. This is the result of over-extraction, skyrocketing agricultural demand and the subsequent nutrient runoff from fertilizers. This runoff has created an abundance of algae in the river, reducing the oxygen necessary to sustain wildlife. The US Corps of Engineers is asking farmers to reduce fertilizer runoff and control the outflow of their dams thus maintaining water levels.
Excessive extraction and overconsumption of water is common throughout the river basin. Water that has been diverted for industrial and residential use is not being replenished sufficiently by the natural sources. Tributaries have also been greatly affected by this, leading to significant declines in the amount of water. In addition to this, the climate crisis has exacerbated the problem by producing hotter summers and producing less snowmelt and rainfall to replenish the river.
The US Corps of Engineers is an organization tasked with managing the Mississippi River. The Corps has taken numerous steps to address the declining water levels, including increasing water releases from dams, maintaining levees and increasing irrigation efficiency. Additionally, the Corps is working with local farmers and agricultural groups to reduce nutrients and sediment runoff into the river.
Environmental groups and activists are also working to raise awareness of the issue and to push for stricter regulations and better management of the river. Efforts are underway to increase buffer zones along the banks of the river and reduce flooding. The US EPA has developed a plan to reclaim wetlands and estuaries along the edges of the river and to introduce species to the river that are more tolerant of changing water levels.
Ultimately, it is up to people and businesses that live near the Mississippi River to reduce their water usage and make changes to their practices that will make the area more sustainable. Conservation efforts and better land management will go a long way toward preserving the river and allowing it to flourish for future generations.
Sediment Runoff
Sediment runoff is a major factor for why the Mississippi River has decreased in water levels. With rising global temperatures, land around the river basin has been subjected to drought-like conditions that result in less water for the river. During heavy rain or flooding, the runoff from agricultural fields, built-up areas, and water from the tributaries upstream combine with the water from the river, resulting in a decrease in volume. The sediment in the runoff blocks the fish passages, reduces nutrients, and changes the environment of the habitats.
The increase in amount of sedimentation has been attributed to poor land management, construction, and farming practices. As agricultural production has grown and large quantities of nutrients and sediment runoff, the sediment reduces the already depleted water levels. Poor agricultural practices such asplowing and tilling accelerate the runoff of sediment, leading to increased water levels in neighbouring wildlife reserves and the creation of large sediment dams downstream.
Furthermore, levees that make up the banks of the Mississippi River hurt its water crystal clearness. These levees aid in controlling floods, but due to their construction, large amounts of sediment are blocked from further traversing downstream. Hence, rather than replenishing its water flow, sedimentation piles up due to the structural changes along the Mississippi River.
The Army Corps of Engineers have acknowledged this sediment problem, and have implemented plans for the construction of new levees and the removal of existing hydraulic barriers. These steps will allow sediment to release freely, and the increased water flow should gradually offset the river’s water levels. The Division of Water Resources in the US is also exploring other methods of managing the sediment runoff in the Mississippi.
Drought
In addition to sediment runoff, another major contributor to decreased water levels in the Mississippi River is prolonged periods of drought. At various times during the year, the river can experience an extended dry spell, when the water is not replenished by the usual rain and snow melt. This water scarcity causes the water levels to drop, damaging aquatic ecosystems and other local businesses. The drought experienced in 2019 was one of the worst in the history of the river, with the water levels in St. Louis dropping to historic lows.
Furthermore, the longer periods of extreme heat due to climate change have exacerbated the situation and made the conditions of the river worse. The hotter climate with prolonged summers have increased the evaporation from the river, leading to greater water loss. Warmer temperatures also cause reduced mountain snowpack and diminished soil moisture, which further contribute to the river’s water shortage.
The US Department of the Interior has taken notice of this development, and has launched initiatives for the management and conservation of water, including the development of water storage, better flood control infrastructure, and efficient water use practices. Additionally, the EPA has tried to implement cross-border negotiations and arrangements between states at the basin which it has termed “water-pact negotiations”.
The EPA has also worked with local conservationists to raise awareness of the dwindling water levels. By emphasizing the importance of conservation and reducing water use, individuals and businesses can help to restore water levels of the Mississippi River.
Over development
Overdevelopment along the banks of the Mississippi River also contributes to the decreased water levels in the river. Human activities including development of the waterfronts, construction of homes, and various industrial activities strip the river of vital nutrients and oxygen, negatively affecting its water quality.
These activities lead to an imbalance of the chemical composition of the river, resulting in an unhealthy environment where pollutants are more prominent, oxygen levels decrease and dangerous microorganisms can infect native wildlife. Additionally, the overdevelopment of land often displaces wildlife and destroys their natural habitats, further decreasing the aesthetic value of the Mississippi and leading to a decrease in tourism.
In recent years, the municipal and state governments have made steps to reduce the impact development can have on the Mississippi River. Development projects and building plans have been restricted and stricter building codes have been implemented. Furthermore, the states and local governments have also formed task forces and committees dedicated to river preservation and promotion of green infrastructure practices.
Furthermore, the EPA is presently working on launching public outreach initiatives, which will explain the long-term environmental effects of improper development practices. These awareness campaigns will not only inform the public of the consequences of their actions, but also suggest ways of building that are more sustainable and benefit the environment.
Damming
Another factor contributing to the decreased water levels of the Mississippi River is the presence of dams. Man-built dams impede the natural flow of the river, reducing the water’s ability to replenish itself. Due to the number of dams built along the river, large amounts of water are unable to reach the parts of the river downstream, resulting in a decrease in water levels.
In recent years, the Army Corps of Engineers have invested heavily in improving the operation of dams and levees to increase the efficiency of water usage. Additionally, numerous conservation and environmental groups have organized campaigns that seek to restrict or eliminate the presence of dams on the river. By working together, the US government and these groups have made significant progress in reducing the number of dams and restoring the quality of the river.
In addition, the government has focused its efforts on improving the viability of the remaining dams. Repair and maintenance are necessary, as old and unsafe dams could potentially increase the risk of damage to other areas of the river, as well as reduce water levels further.
The health of the Mississippi River is a major concern for the US government and environmentalists alike. The river serves as a key source of hydropower and transportation, as well as an important resource for the people, plants and animals that rely on it abundantly. As such, it is essential that steps are taken on a local, regional and national scale in order to both preserve and restore the life of the river and ensure it is enjoyed by humans and by nature alike.
