Sea water is making its way into the Mississippi River, posing a threat to water supplies in various parts of the United States. The ongoing drought and hot weather have caused the water level of the Mississippi River to reach near-record lows. As a result, seawater from the Gulf of Mexico has been intruding into the river for several months, and it is now approaching New Orleans and surrounding areas, putting their water supply systems at risk.
The Mississippi River is a crucial source of fresh water in southeastern Louisiana. Currently, seawater has reached a 70-mile stretch of the river and is expected to arrive at multiple water intakes in New Orleans by mid-to-late October. This could make the city’s drinking water unsafe within the next three months and pose a threat to farmland irrigation and infrastructure along the river. The affected population is estimated to exceed 800,000 by the end of October.
New Orleans Mayor LaToya Cantrell has reassured the public that the drinking water supply in the city is still safe at present, but relevant departments are closely monitoring the situation. Despite this, reports indicate that bottled water has been in high demand in many supermarkets in New Orleans in recent days.
Another concern is the potential impact on New Orleans’ water supply system, which consists of an old lead pipeline system. Seawater entering the system can corrode the infrastructure, releasing heavy metal substances that can be harmful to various organs in the human body. The extent of lead contamination will depend on factors such as salt concentration and the duration of the seawater flow. Corroded pipes may continue to release lead for months or even years.
In response to the crisis, both the state of Louisiana and the city of New Orleans have issued emergency declarations to mobilize resources. President Biden has approved federal agencies to provide emergency assistance to Louisiana. Proposed measures include the construction of fresh water pipelines in the affected areas and the installation of large-scale water purification reverse osmosis devices capable of removing salt from the water. Priority will be given to ensuring clean water in schools and hospitals.
The U.S. Army Corps of Engineers attempted to address the seawater intrusion by building an underwater levee in July. However, the levee was overturned by seawater last week. The Corps is now planning to expand and raise the height of the embankment to prevent further intrusion.
The backflow of seawater into the Mississippi River is a naturally occurring cyclical situation due to lower riverbeds in some parts of the river being below sea level. If the river flow drops to a certain level, denser seawater can flow upstream along the river bottom. The abnormal drought experienced in Louisiana and other states along the Mississippi River has caused river water levels to plummet. As a result, seawater has been slowly flowing northward along the riverbed for months.
Preventing further seawater intrusion necessitates a significant amount of rainfall in the area north of New Orleans to increase the freshwater in the Mississippi River. Unfortunately, the weather forecast for the region is not promising in terms of rainfall.
As the situation unfolds, various agencies and departments are working together to mitigate the impact of seawater intrusion on the Mississippi River and the water supply in New Orleans. The safety and well-being of affected residents remain a top priority.