Sea level rise is an ever-pressing concern as climate change melts ice sheets. Coastal flooding is an unfortunate consequence, which can have a devastating impact on the local environment, including an unexpected toll on coastal tourism in North Carolina.

A new study, published in Water Resources Research, has identified a direct correlation between the quality of drinking water and the number of tourists staying overnight in accommodations in the area, highlighting increases in tap water salinity.

The elevated saltiness of drinking water is caused by the intrusion of saltwater into freshwater aquifers as sea water inundates low-lying areas (particularly the barrier islands), which makes the water undrinkable without processing. As most public water in the area is obtained through the desalinization of sea water and relies upon freshwater from these aquifers to aid the process, the supply of safe, clean drinking water may come under threat.

In particular, it is likely to increase the costs of potable water as more desalinization treatment would be required, plus it will impact the taste of water as the saltiness cannot be entirely eliminated. Across North Carolina, the sea level has risen by up to 5 mm per year and is predicted to continue this trend in the decades to come (even within the next eight years it could reach 5 cm), meaning the challenge will only continue.

Professor John Whitehead, of North Carolina's Appalachian State University, and colleagues used people's willingness to pay for overnight accommodation with low-salinity tap water to assess the impact of rising sea levels on sustainable freshwater supplies and coastal tourism. They conducted online surveys with more than 430 North Carolina residents who had taken trips to the coast within the preceding three years and posed the question of whether the increasingly salty taste of water in their chosen beach destination would dissuade them from visiting.

The team found that tap water that was slightly (barely noticeable compared to usual tap water), moderately (somewhat noticeable) or very (definitely noticeable) salty had a direct impact on the likelihood of tourists staying overnight in their chosen coastal resort, declining by 2%, 8% and 11% respectively.

Having said this, 21% of respondents noted that the salinity of drinking water would not be an issue for them and they would continue with their planned beach break, happy to pay additional costs associated with buying bottled water if necessary.

Projecting to 2040, the research team estimates that 13% of the 31 studied beaches in North Carolina would no longer have freshwater aquifers, with a further 42% suffering from salinity issues. Twenty years on, the number of beaches without viable aquifers rises to 32%, and by 2080 this could reach 55%, with only 6% of aquifers having no salty-tasting water.

Consequently, the researchers estimate that a staggering $232 million could be lost in annual consumer income by 2040 if the low quality of the drinking water continues. Therefore, this study highlights the importance of implementing strategies to help alleviate the degradation of tap water within North Carolina, including new drinking water regulations and technologies.

© 2025 Science X Network