UGA and Savannah State University Research Grant Funded by the US Coastal Research Program (USCRP)

Assessing Compound Flood Impacts on Groundwater Levels in Coastal Urban Communities

Researchers:

• Felix Santiago-Collazo (PI), University of Georgia
• Adam Milewski (Co-PI), University of Georgia
• Jessica Brown (Co-PI), University of Georgia
• Carol Pride (Co-PI), Savannah State University
• Alan Roberts (Collaborator), City of Tybee Island
• Doug Haymas (Collaborator), Georgia Department of Natural Resources, Coastal Resource Division

Project:

High tidal events co-occurring with intense rainfall can produce substantial flooding in coastal urban communities, such as Tybee Island (GA). To mitigate this flooding impact on the community, engineers design flood resiliency measures that could include traditional structures (culver, pipes, pumps), as well as natural infrastructure (rain gardens, bio-swales, and bio-retention). These structures have been well studied and designed for inland communities with no risk of coastal flooding. However, tides and rising sea levels could influence the groundwater levels around coastal communities, reducing natural infrastructure capacity to soak the rainfall-runoff. Therefore, this proposal seeks to study the relationship between sea-level rise, tides, rainfall, and groundwater levels to improve natural infrastructure guidelines and implementation along GA coastal communities. To achieve this, we will use data collected from different groundwater wells around the GA coast, with a special emphasis on Tybee Island due to its data availability and relevance to the community, as well as numerical models, including hydrodynamic models and machine learning. Furthermore, community engagement activities will center around Tybee Island’s residents (and surrounding communities) to tailor the research outcomes to their needs. The outcomes of this proposal will greatly help Tybee Island’s Natural Infrastructure plan by providing specific recommendations for the design of their rain gardens for the current and future climate, as well as to the other GA coastal communities with similar threats.

_{Photo Description: Drone image of Tybee Island and its back marsh looking towards the east (Photo Credit: Daniel Buhr)}