Sunnyvale, California, the United States

Installed as part of a larger project to replace a car travel lane with a bicycle route and parking for an adjacent park,  Caribbean Avenue bioretention basins reduce stormwater pollution to the Bay. Together the basins provide 4,000 cubic feet of bioretention capacity and treat an upstream urban area of approximately 41,500 square feet. This Green Street provides a host of multiple benefits for the City, the general public, and native flora and fauna.  In addition to these benefits, the bioretention gardens are also removing contaminants such as PCBs and mercury from stormwater runoff.  We estimate that, on average, between 80% and 100% of PCBs in runoff will be captured and 32% to 54% of mercury will be captured per year.  Because of the location adjacent to the Baylands, the bioretention features were designed with a novel plant palette drawn largely from species native to the former alkali meadows. While significant portions of San Francisco Bay’s former tidal marshlands are being restored, it is more difficult to reestablish the now-developed alkali meadows that occupied the lowlands bordering the Bay in Silicon Valley. This distinctive, salt-tolerant ecosystem is one of the rarest in the region. In total, 100% of the plants in this project are California natives, and 77% are regionally native to South San Francisco Bay. Additional projects drawing on these grasses and flowering pollinator plants can establish a habitat zone complementing the Bayland habitats with missing elements of the terrestrial ecosystem. The approach is described and featured in prominent educational signage. Caribbean Avenue is the first green street in Sunnyvale, CA.

Learn more about this project here.

Key Elements: Habitat Diversity, Matrix Quality, Native Vegetation