Story Spark: Saltwater Intrusion
A nearly invisible poison is creeping into coastal communities around the world — saltwater is moving inland, killing once fertile farmlands and contaminating previously reliable drinking water. Saltwater intrusion is turning freshwater sources brackish as seas rise, droughts deepen, and coastal flooding and tropical storm systems worsens — all driven by climate change.
Saltwater intrusion isn’t as flashy as other extreme climate events like wildfires, but the threat it poses is extensive. More than 40 countries are at risk of saltwater intrusion by 2050, with research suggesting that seawater will contaminate underground freshwater in roughly 75% of the world’s coastal areas by the end of the century. Even subtle changes in soil and water chemistry in these coastal regions can significantly damage crop yields, which we’re seeing across the world — for example, in Vietnam, the US, Gambia, and Indonesia. Increasing salinity in freshwater rivers and streams are creating more ideal conditions for invasive predators and destroying coastal forests.
Saltwater intrusion into freshwater sources carries a raft of health consequences. Drinking even marginally salty water increases the risk of kidney disease, raises blood pressure, and threatens reproductive health. Desalinatization is prohibitally expensive and energy-intensive for much of the world, making this yet another example of how climate change exacerbates existing inequalities. Examine the climate justice angle and investigate what measures are being taken to stem the ceaseless advance of saltwater.
– David Dickson, CCNow
Expert Tips
This edition’s tips come to you from Dr. Kate Tully, an associate professor at the University of Maryland whose research focuses on managing coastal agroecosystems in the face of climate change. She works on saltwater intrusion, precision sustainable agriculture, soil health, and urban agriculture and is also the co-founder of Farm the District, a Washington, D.C.–based nonprofit aiming aims to grow food and community in the nation’s capital.
Understand the main drivers of saltwater intrusion. Sea-level rise is just one of the handful of ways salt is moving further inland. Increasing frequency of storms, really high tides, sometimes called “king tides,” and drought are the main drivers of saltwater intrusion — as when brackish water evaporates, salt is left in and on the soil. The final two ways have less of a direct climate connection. When we extract freshwater water for agriculture it creates space for salty water to move in. Finally, in really low-lying landscapes, like the Chesapeake Bay, humans have created a lot of ways for salty water to get inland through ditches, canals, and levees.
Make the invisible visible. Saltwater intrusion is a less visible symptom of climate change than disasters like heatwaves. Thankfully, there are great visuals to help highlight this growing impact to coastal communities. Try using Google Earth to look for salt rings developing on the edges of fields or expanding salt marshes. For example, if you’re covering the Delmarva Peninsula, check out this interactive ArcGIS map we created to help people find saltwater intrusion. Also, be on the lookout for “ghost forests.” These haunting stretches of dead, sun-bleached trees paint a dramatic picture of the ecological changes resulting from saltwater intrusion.
Investigate adaptation measures and their limitations. For most areas at or near sea level, simply “washing the salt away” is not an option. Report on what actions are being considered locally to deal with saltwater intrusion. Where I work on the Eastern Shore of Maryland, I recommend three main strategies to landowners. First is protective measures; put in a tide gate or a berm. But as sea levels continue to rise, these barriers will only protect for a couple years. Second, consider switching to more salt-tolerant crops such as sorghum. Third, for areas that will inevitably become a marsh, learn about transition programs that may provide incentive payments to create wildlife habitats.
“Solution” vs. “strategy.” I never use the word “solution”; instead I use “strategy.” When I’m in a room full of farmers and stakeholders, I never want to give the impression that I am going to solve sea-level rise or saltwater flooding — because I’m not.
Stories We Like
- In Gambia, brackish water now moves more than 300 kilometers inland; the saltwater is choking crops, threatening farmers’ livelihoods and food security in the region, Inside Climate News reports.
- As their drinking water becomes saltier, women in Bangladesh face growing dangers to their reproductive health, including hypertension, preeclampsia, and infertility, Grist reports.
- Carolina Public Press examines how climate change is influencing the spread of “ghost forests,” which strain the economic, historic, and social fabric of North Carolina’s coastal communities.
- In Vietnam, infrastructure fixes to block saltwater and protect freshwater are failing. Mekong Eye explores the country’s history of preventing saltwater intrusion and highlights the challenges and uncertainties of future adaptation plans.
- With saltwater intrusion threatening the future of Florida’s aquifers, CBS Miami highlights this slow-onset crisis and speaks with experts about what can be done to protect the state’s water supply.
Resources
- Bookmark this NOAA page explaining the various acronyms and tidal data points that you’ll encounter when researching sea-level rise and flood events.
- Examine where ghost forests are spreading across the US Atlantic coast using this interactive map with more than 11 million points, each representing a once-living tree, in a region stretching from South Carolina to Maine.
- Head to the US Department of Agriculture’s website to learn how to identify the stage, cause, and progression of saltwater intrusion in coastal forests and farms.
- Use NOAA’s Sea Level Rise Viewer to visualize community-level impacts from coastal flooding made worse by climate change–caused sea-level rise.
Experts and Sources
- Aneire Khan, research associate in public health and engineering, Imperial College London
- Peter Regier, earth scientist, Pacific Northwest National Laboratory
- Emily Bernhardt, ecosystem ecologist and biochemist, Duke University
- Christopher Russoniello, professor, University of Rhode Island
- Resilience Implementations for Salt-INtruded Geographies (RISING) Mid-Atlantic
- Saltwater Intrusion and Sea Level Rise (SWISLR) Research Coordinating Network
Before We Go…
The next Locally Sourced will examine how climate change disrupts education. With the school year right around the corner, explore how worsening heat and weather disasters impact learning. Have you reported on this climate impact and possible solutions? Send them to us at local[at]coveringclimatenow[dot]org. We’d love to consider them for the next edition of Locally Sourced and our media trainings and social platforms.
Apply: Covering Climate Now Academy. We’re now accepting applications for our free three-month training program that runs from September to December 2026. With 40 slots available, become a part of a global community and learn climate science basics, how to practice solutions journalism, how to spot disinformation, and much more. Apply by August 11.
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Want more story ideas? Check out the Locally Sourced archive for more topics to explore, including AI data centers, coastal flooding, air transportation, and more.
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