Exploring solutions to mitigate flooding in urban estuaries

Estuaries are vital ecological and economic hubs, but they are increasingly vulnerable to flooding from rising sea levels, stronger storms and human alterations that have removed natural flood buffers. In the San Francisco Estuary, decades of landfilling and shoreline hardening have heightened these risks by amplifying tidal levels and reducing the system’s natural ability to absorb storm surges.

New research shows that nature-based solutions such as wetland restoration can significantly reduce extreme water levels, while hard structures like seawalls can worsen them. Using advanced hydrodynamic modeling, the study finds that a balanced combination of soft measures, hard infrastructure and targeted floodgates offers the most effective path for managing future flood risks in urban estuaries.