Rising Seas, Salty Rivers: A Growing Threat To Our Water Supplies

As the planet warms, salt is sneaking into the places we least expect it—our rivers. A new study warns that salt contamination of drinking water in tidal rivers is becoming a serious and global problem. Robert Chant, professor in the Department of Marine and Coastal Sciences and affiliate of the Rutgers Climate and Energy Institute, is a co-author on the study, which was published in the journal, Environmental Science & Technology Letters.

The authors explain that rising sea levels, longer droughts, and human changes to river channels are letting more seawater move inland into rivers that many people rely on for drinking water, farming, and power generation.

The salt from the ocean—especially chloride and sodium—is dangerous in high amounts. It can corrode pipes, damage crops, and even impact health, especially for young children and people with high blood pressure. Cities like New Orleans and Bangkok have already had to take emergency steps to protect their water.

This problem isn’t limited to just a few places. Rivers on nearly every continent are affected—from the Mississippi and Hudson in the U.S. to rivers in Europe, Asia, and Africa. Climate change is making things worse by driving sea-level rise and causing more frequent dry spells, which reduce the freshwater flow that usually keeps salt out.

The study’s authors say we need better tools to track salt in rivers and smarter planning for the future. They suggest using artificial intelligence and building detailed models to help water managers make decisions—like when to release water from reservoirs to push salt back toward the sea.