Operational Landscape Units (OLUs) are a practical way to manage the physical and jurisdictional complexity of the Bay shoreline. Home to beaches, wetlands, marinas, ports, landfills, lifeline infrastructure, residential neighborhoods and more, San Francisco Bay’s 650-kilometer (400-mile) shoreline is diverse, which means there is no one-size-fits-all solution to rising sea levels. The OLU framework divides the Bay shoreline into 30 distinct OLUs, geographic areas that share common physical characteristics. OLUs cross traditional jurisdictional boundaries of cities and counties, but adhere to the boundaries of natural processes like tides, waves, and sediment movement. Taken as a whole, OLUs encompass the entire Bay shoreline, cover the region’s land area potentially vulnerable to future sea level rise, and represent areas along and adjacent to the shore for which geographically specific and science-based sea level rise adaptation strategies can be developed.
A key purpose of the OLU framework is to identify where natural and nature-based approaches, such as beaches, marshes, and subtidal reefs, can help create a resilient shoreline with multiple benefits. Nature-based approaches and hybrid measures that integrate nature with engineered structural approaches, may perform better than traditional engineered infrastructure, while costing less and providing co-benefits like new recreational opportunities and habitat for native species. Adaptation in each OLU will most likely require a combination of nature-based measures, traditional engineering, and non-structural or policy strategies.
Within the next few decades, flood events signaling sea level rise will likely trigger more efforts around the Bay to plan for adaptation, to control flooding, and to modify the shoreline. Using OLUs as a planning framework and prioritizing appropriate nature-based solutions within them, can help ensure that future adaptation actions are sustainable and confer the most benefits per dollar spent.
The San Francisco Bay Shoreline Adaptation Atlas report, presents information about OLUs in four major chapters that summarize both the process of developing the OLUs and how the OLUs might be applied.