The threat of saltwater intrusion, currently encroaching upon the drought-stricken Mississippi River and inching closer to New Orleans, is anticipated to become a growing concern for coastal cities across the United States, caution experts, according to The Guardian.
Louisiana has been proactively preparing for a potential crisis due to seawater infiltration from the Gulf of Mexico into the vulnerable Mississippi delta. Recently, the mayor of New Orleans declared a state of emergency, expressing concerns about the potential health hazards linked to the city's drinking water. In response, residents have had to rely on bottled water for cooking and cleaning.
The impact of rising saltwater levels has already affected thousands, particularly in lower Plaquemines Parish, downstream from New Orleans, where residents have been contending with contaminated drinking water since June.
The Army Corps announced a possible retreat of the saltwater before reaching New Orleans, but experts said to The Guardian that as seas continue to rise due to the climate crisis and weather events become more extreme, the threat of saltwater reaching other major U.S. cities is escalating.
Soni Pradhanang, a hydrologist from the University of Rhode Island, emphasizes the urgency of addressing this situation within the next five to ten years, as the acceleration of the threat is evident. The concern is widespread, but experts are particularly alarmed about cities in Louisiana, Florida, the Northeast, and California.
The Salt Line: Beneath the surface, the salt line delineates the boundary where freshwater from inland meets salty seawater along every coast. This line constantly shifts due to natural processes and can be influenced by weather events like floods and storms. However, rising seas are progressively pulling the salt line inward. For instance, in Miami, the salt line is encroaching inland at a rate of approximately 330 feet per year. Severe drought, as experienced by the Gulf coast and Midwest this year, exacerbates the inward shift of the salt line.
Coastal Louisiana is likely to be the first region in the U.S. to reach crisis levels, given its rapid sea-level rise, making it a vital area for immediate attention. The scorching summer witnessed record-breaking ocean surface temperatures globally, particularly in the Gulf waters.
