Transboundary sediment loads and water quality in the Tijuana River Watershed
High sediment loads from Tijuana threaten ecosystems in the Tijuana Estuary by burying salt marsh vegetation and reducing the tidal prism, while cross-border sewage flows threaten human health. This work documents the processes generating sediment in Tijuana, including its interactions with socioeconomic status, differences by geology, and possibilities for mitigation. Field observations, remote sensing, and modeling are combined to construct a sediment budget and dynamic model of stream channel erosion. Win-win solutions are proposed that could mitigate sediment generation while improving the lives of residents. Ongoing work to document bacteria concentrations in the Tijuana Estuary in real time will also be described.