The Tijuana River, located on the border between California and Mexico, flows into the Pacific Ocean through the Tijuana River Estuary, one of Southern California’s largest remaining coastal wetland systems. The river drains a 1,700-square-mile binational watershed, with most of its flow originating in Mexico. The region experiences an average annual rainfall of 10 to 12 inches, with episodic storm events delivering significant freshwater and sediment to the estuary. Seasonal sandbar closures at the river mouth create a dynamic environment, influencing water levels and salinity.

The Tijuana River Estuary supports critical habitats, including salt marshes, mudflats, and riparian zones, which are home to endangered species like the light-footed Ridgway’s rail and the Pacific green sea turtle. However, the system faces significant challenges from urbanization, cross-border pollution, sedimentation, and flooding. Storm events often deliver large amounts of debris, sewage, and sediment, impacting water quality and threatening sensitive habitats and nearby communities.

Real-time water level monitoring in the Tijuana River Estuary tracks tidal dynamics, flood risks, and the impacts of sediment and pollution inputs. This data is essential for managing cross-border environmental issues, informing habitat restoration efforts, and developing strategies to enhance the resilience of this vital and heavily impacted coastal system.