Sea level rise makes us think of coastal flooding and erosion, affecting coastal cities and ecosystems, but it can also have a major impact on freshwater supplies, due to saltwater intrusion into coastal aquifers.
Researchers at the University of Pennsylvania are working to identify water systems that are vulnerable to saltwater intrusion along the U.S. Atlantic and Gulf coasts, with the aim of developing strategies that will help utilities be more resilient to this type of risk, reports Scientific American.
Coastal flooding is already causing damage to homes, businesses and infrastructure in coastal cities, but “People are less often considering the potential impacts on drinking water,” notes principal investigator Allison Lassiter, Assistant Professor of city and regional planning at Penn.
Saltwater intrusion is not a new problem, and it has occurred to some degree in many coastal aquifers in the U.S, according to the USGS. Excessive groundwater pumping can reduce freshwater flow toward coastal areas and lead saltwater toward the freshwater zones of an aquifer. Sea-level rise is expected to exacerbate it. Salinized water is unpleasant to drink and can be harmful to vulnerable people. Moreover, it can corrode pipes and reduce the lifespan of water infrastructure, with increased maintenance and replacement costs.
Current approaches to tackle intruding seawater include dikes and desalination plants, which can be resource intensive. Lassiter and her team are looking into more novel and less costly methods to deal with saltwater intrusion risks, involving distributed water systems that do not rely on a single water source, and advanced smart water solutions that identify increases in salinity, in which case system managers can turn to other sources of water. The approach follows a “safe-to-fail” principle, meaning there is a backup plan in case of contingencies, and would be part of an overall climate adaptation strategy.
Lassiter’s team will study the coast stretching from New Jersey to Texas, focusing on rural and low-income areas. She hopes the research will help small water utilities improve their infrastructure through the use of smart technology: “We still have a lot of research to do on what is realistic and affordable and useful to water agencies”.