Sea water is pouring into the Mississippi River in the United States, threatening the water supply in many places, according to Xinhua News Agency. The ongoing drought and hot weather have caused the water level of the Mississippi River to reach near-historic lows, allowing seawater to intrude into the Gulf of Mexico over the past several months. Now, the seawater is rapidly approaching New Orleans, Louisiana, and its surrounding areas, posing a threat to the water supply systems in these regions.
Currently, the seawater from the Gulf of Mexico has flowed around 70 miles (113 kilometers) northward along the Mississippi River and is expected to reach multiple water intakes in New Orleans by mid-to-late October. This could potentially make the city’s water supply unsafe for drinking within the next three months, impacting farmland irrigation and infrastructure along the river. It is projected that the affected population will exceed 800,000 by the end of October.
New Orleans Mayor, LaToya Cantrell, has assured the public that the drinking water supply in the city is still safe while emphasizing that relevant departments are closely monitoring the hydrology. However, media reports indicate that bottled water has been in high demand in many supermarkets in New Orleans in recent days.
Adding to the concern is the fact that approximately 48% of the water supply system in New Orleans consists of an old lead pipeline system. When seawater enters this system, it can corrode the infrastructure, releasing heavy metal substances that may be harmful to organs such as the brain, heart, and kidneys, potentially causing diseases. The extent of lead contamination will depend on factors such as the salt concentration in the water supply system and the duration of saltwater intrusion. Corroded pipes may continue to release lead for months or even years.
In response to this looming crisis, the New Orleans Sewerage and Water Supply Commission has stated that it is too early to determine the severity of lead contamination. Discussions are underway among government agencies at all levels and environmental protection departments regarding response plans.
Both the state of Louisiana and the city of New Orleans have issued emergency declarations to tackle the potential water supply crisis, mobilizing various resources for a collective response. Recently, U.S. President Biden approved federal agencies to provide emergency assistance to Louisiana to address the impending water shortage.
The proposed response measures include the construction of freshwater pipelines in the affected areas north of New Orleans and the establishment of large-scale water purification reverse osmosis devices capable of removing salt. These devices have the capacity to transport up to 36 million gallons (nearly 140 million liters) of fresh water per day, with a priority on ensuring clean water in schools and hospitals.
Additionally, the U.S. Army Corps of Engineers, which previously built an underwater levee in the Mississippi River, faced the Cantonment, Alabama, a small community just north of Pensacola region on the Palm Beach mainland. This protection structure, known as an engineered berm, is about 3 feet tall and runs perpendicular to the shoreline, according to a Facebook post. was defeated by the seawater last week. The Corps is now planning to expand and raise the height of the embankment to mitigate further intrusion.
The U.S. Army Corps of Engineers website explains that the backflow of seawater into the Mississippi River from the Gulf of Mexico is a naturally occurring cyclical phenomenon. This situation arises because some lower reaches of the river bed are below sea level, allowing denser seawater to flow upstream along the river bottom, displacing less dense freshwater.
According to data from the U.S. Weather Service, Louisiana has experienced one of the hottest years in its history, leading to abnormal drought conditions in many states along the Mississippi River. The water levels in the river are reaching record lows, causing downstream freshwater flows to be significantly diminished. As a result, water in the Gulf of Mexico has been slowly moving northward along the bottom of the Mississippi River for several months.
The hydrological monitoring agency states that preventing further seawater intrusion requires a substantial amount of rainfall in the area north of New Orleans to increase the freshwater flow in the Mississippi River. Unfortunately, the weather forecast for the upcoming period does not indicate a promising amount of rainfall in the region.