Rising sea levels and changing water quality pose a growing threat to the coastal communities of the San Francisco Bay. Innovative nature-based solutions, such as the horizontal levee, offer the opportunity to reduce the impact of rising sea levels alongside multiple ecosystem services. A gradual incline of vegetation abutting traditional levee infrastructure, the horizontal levee naturally protects against flooding while also providing native ecosystem habitat and improving water quality in the region.
Observations from the demonstration-scale horizontal levee at the Oro Loma Sanitary District (referred to as the Oro Loma Horizontal Levee) have illustrated the horizontal levee’s ability to remove excess nutrients and contaminants from secondary wastewater effluent. Research to-date at the Oro Loma Horizontal Levee has sought to describe the physical and chemical perspectives of nutrient cycling and pharmaceutical transformations. However, there have been no investigations into the microbial interactions that are fundamental to driving biogeochemical processes. An incomplete understanding of how these systems function hinders the widespread implementation of horizontal levees and similar technologies in the San Francisco Bay area.
This project will use advanced environmental genetics techniques to clarify the microbial role in nutrient cycling and contaminant transformation within the horizontal levee. The insights gained from this project will offer a more complete understanding of the mechanisms responsible for improving water quality in the horizontal levee, promoting broader acceptance of horizontal levees as an adaptive management tool for designing a more resilient California coastline.