A newly published study shows that California's largest lake, the Salton Sea, is experiencing accelerated shoreline retreat after policy changes diverted more Colorado River water to San Diego. As the lake bed dries up, the agricultural runoff left behind is producing increasing amounts of polluting dust, posing health risks to nearby communities, researchers warn.

Due to changes in water policy, the Salton Sea is shrinking and the risk of pollution is increasing. Researchers are using balloon mapping to track seawater retreat and support restoration efforts. Source: Loma Linda University

According to the study, the coastline on the northern shore of the Salton Sea is expected to retreat by 150 meters by 2030, and by a further 172 meters by 2041 if current rates of retreat continue.

Aerial photo of the Salton Sea showing the receding coastline. Source: Loma Linda University

Between 2002 and 2017, the average retreat rate increased from 12.5 meters per year to nearly 38.5 meters per year after 2018. "Without mitigation measures, expanding exposed depressions around the Salton Sea are expected to exacerbate local communities' exposure to pollutants," the study states.

The study is a community science project involving local youth and other residents, using balloon mapping to record images of the coastline.

Aerial images of the Salton Sea coastline show the coastline's gradual retreat over time. Source: Loma Linda University

"This study is a direct response to a request from a community that wants to engage in impactful research questions to understand shoreline loss," said Ryan Sinclair, Ph.D., associate professor of environmental microbiology at Loma Linda University School of Public Health and the study's principal investigator. "This community wants to be able to live next to the Salton Sea that they are proud of."

Researchers use balloon mapping to track the Salton Sea coastline. Source: Loma Linda University

Sinclair said balloon mapping can cover a larger area than drones that need to be recharged.

Sinclair and community members spent many days from 2019 to 2021 creating a series of maps using balloons equipped with cameras suspended 200 feet above the coast. The researchers compared their findings with satellite images from 2002. Now, they hope their findings can be part of efforts to restore the lake's capacity.

Compiled from /ScitechDaily