has found that this phenomenon is causing increased corrosion and failure of critical infrastructure in cities with complex networks of buried and partially buried structures. This includes sewer lines, roadways, and building foundations. The study compiled research from experts worldwide to highlight the impact of rising sea levels on coastal groundwater. The interaction with the shallower and saltier groundwater is exacerbating corrosion and leading to the deterioration of essential systems in these urban areas.Research conducted at the University of Hawai’i (UH) at Manoa gathered data from experts around the world, indicating that in cities with intricate networks of buried and partially buried infrastructure, exposure to shallow and salty groundwater is causing increased corrosion and failure of vital systems such as sewer lines, roadways, and building foundations.
“It has been acknowledged that rising groundwater levels will lead to persistent flooding as it resurfaces. What is less understood is that it can begin causing issues decades before as the groundwater interacts with underground infrastructure,” explained Shellie Habel.The main author and coastal geologist at the School of Ocean and Earth Science and Technology (SOEST) at UH Manoa stated, “A lack of understanding on this subject often leads to coastal groundwater changes being completely disregarded in infrastructure planning.”
The research team’s goal was to raise awareness about these issues and provide guidance from global experts on how to manage them. Habel and his co-authors analyzed existing literature to investigate the various effects on different types of infrastructure. Additionally, they used global elevation data and geospatial data to determine the extent of urban development, identifying 1,546 low-lying coastal cities and towns.around the world, impacting approximately 1.42 billion people. According to Chip Fletcher, co-author of the study and interim Dean of SOEST at UH Manoa, the IPCC 6th Assessment Report emphasizes that sea level rise is an inevitable and long-lasting reality. Fletcher also emphasizes the importance of preparing for the challenges posed by this issue by creating more resilient and socially equitable communities. Sea-level rise affects the water table long before visible surface flooding occurs.The movement of saltwater towards land increases the corrosive nature of the subsurface environment, posing a threat to underground infrastructure such as drainage and sewage lines. This can lead to urban contamination and structural weakening of building foundations.
Extensive studies by the CRC have confirmed that essential infrastructure, including drainage systems and basements, is currently being impacted by flooding due to rising groundwater levels around the world.
“The harm caused by coastal groundwater influenced by rising sea levels is often hidden and not immediately obvious.le,” said Habel, who is based at the CRC and Hawai’i Sea Grant in SOEST. “As a result, it tends to be overlooked in infrastructure management and planning efforts.” Informing management strategies The study authors emphasize the importance of research efforts that can contribute to informed adaptation strategies. “Being aware of these hidden impacts of sea level rise is of significant importance for the State of Hawai’i due to the concentration of communities situated along low-lying coastal zones where groundwater is generally very shallow,” said Habel. The CRC actively collaborates with partnersThe goal is for infrastructure managers in Hawai’i to have a better understanding of how sea level rise influences coastal groundwater and its impact on vital infrastructure such as pipe networks, roadways, and buildings. This understanding will allow for more effective management and adaptation to the risks associated with sea level rise. The study titled “Hidden Threat: The Influence of Sea-Level Rise on Coastal Groundwater and the Convergence of Impacts on Municipal Infrastructure” by Shellie Habel, Charles H. Fletcher, Matthew M. Barbee, and Kyrstin L. Fornace is a valuable resource for gaining insight into this issue.The Annual Review of Marine Science for the year 2024, volume 16, issue 1, contains an article with the DOI number 10.1146/annurev-marine-020923-120737. You can access the article by following this link: http://dx.doi.org/10.1146/annurev-marine-020923-120737.