The San Francisco Bay Area is a globally recognized hub of innovation and culture, but defining its precise location is more complex than a simple map outline. Traditionally understood as the nine counties bordering the San Francisco Bay, this definition, while convenient, doesn’t fully capture the region’s expanding influence and interconnectedness. As the Bay Area evolves, especially with rapid growth in neighboring counties like Merced and San Joaquin, it’s crucial to reconsider “Where Is The Bay Area” to effectively address regional challenges.
SPUR, through its long-term Regional Strategy project, aims to develop a comprehensive vision for the Bay Area’s future. This initiative seeks to understand the appropriate scale for addressing critical issues such as job accessibility, housing affordability, and traffic congestion. Is the conventional nine-county definition sufficient, or should we broaden our scope to include more areas? Perhaps, instead of focusing solely on counties, we should consider the interconnected systems that define the region.
To answer these pivotal questions about where the Bay Area truly is, SPUR consulted with experts, examined various geographical definitions, and analyzed data and maps. This exploration seeks to determine the most effective scale for tackling the region’s most pressing challenges and to provide a clearer understanding of the Bay Area’s multifaceted boundaries.
The Enduring Nine-County Definition of the Bay Area
The nine-county definition of the Bay Area isn’t arbitrary; it’s rooted in history and reinforced by institutions. Its longevity has imbued it with significance, making it a valuable framework for understanding the region.
Historical and Cultural Significance
The concept of the San Francisco Bay Area as a distinct region has been developing for nearly a century. While maps of the San Francisco Bay exist from as far back as 1776, the term “San Francisco Bay Area” gained traction in the early 20th century. Interestingly, a 1914 report already referred to an eleven-county “San Francisco Bay Area,” encompassing Santa Cruz and San Joaquin counties in addition to the now-standard nine. However, it was during World War II that planners solidified the nine-county definition, and this has largely persisted.
Governmental Jurisdictions Reinforce the Nine Counties
Since the mid-20th century, numerous governmental agencies have operated across the nine counties, solidifying this geographical understanding. The Association of Bay Area Governments (ABAG) and the Metropolitan Transportation Commission (MTC), now with merged staffs, are prime examples. These agencies collaborate on Plan Bay Area, the comprehensive land use and transportation plan for these nine counties. Furthermore, agencies like the Bay Area Air Quality Management District, the Bay Conservation and Development Commission, and the San Francisco Bay Regional Water Quality Control Board also operate within roughly the same nine-county jurisdiction.
Bay Area Air Quality Management District Jurisdiction
Source: https://www.arb.ca.gov/ei/maps/basins/absfmap.htm
California Transportation Department District 4 Jurisdiction
Source: http://www.dot.ca.gov/dist4/images/d4map061803print.pdf
Metropolitan Transportation Commission Jurisdiction
Source: https://mtc.ca.gov/sites/default/files/0-Introduction.pdf
Given its historical roots, established precedence, widespread use, and the readily available data at this scale, SPUR acknowledges the continued relevance of the nine-county definition. Research, policy advocacy, and recommendations will continue to be conducted and promoted at this scale.
Expanding Horizons: Activity Beyond the Nine Counties
While the nine-county Bay Area is a significant entity, many regional patterns extend beyond these boundaries. It’s essential to consider these broader connections to fully grasp the region’s dynamics.
The Emergence of the Northern California Megaregion
The Bay Area doesn’t exist in isolation. Crucial factors shaping life here, such as water and energy systems, development patterns, housing costs, transportation networks, and economic forces, transcend the nine counties. Recognizing this larger context, SPUR published a groundbreaking report in 2007 on the Northern California megaregion. This report identified a 21-county core area, further surrounded by a 20-county sphere of influence stretching from the Bay Area to Fresno and Reno.
The Northern California megaregion concept better reflects the increasing interdependence between the Bay Area and surrounding regions. It encompasses the nine-county Bay Area, the six-county Sacramento region, the three-county Monterey Bay Area, and three counties in the northern San Joaquin Valley.
The Northern California Megaregion
Tracking Growth in the Megaregion
Analyzing trends within this larger megaregion is vital for addressing numerous regional issues. For instance, focusing solely on the nine-county Bay Area would obscure the fact that counties outside this traditional boundary are experiencing faster percentage growth in population. These new residents often commute into the nine-county core for work. While absolute population growth remains higher within the core cities, understanding these broader trends and offering more options for people to live closer to their workplaces are crucial policy considerations for the entire region.
Changes in Population
The fastest growing counties in recent years are just outside the nine-county Bay Area. Source: http://www.bayareaeconomy.org/files/pdf/The_Northern_California_Megaregion_2016c.pdf
However, simply expanding regional boundaries isn’t a panacea. As urban theorist Jane Jacobs noted, “A region is an area safely larger than the last one to whose problems we found no solution.” Enlarging the region doesn’t automatically solve problems. Any re-evaluation of regional boundaries must be approached cautiously and strategically, expanding the scale only when it’s genuinely necessary and likely to contribute to effective solutions.
System-Based Geographies: Defining Regions by Function
Beyond county lines and megaregions, understanding specific systems can offer alternative, and sometimes more relevant, geographical definitions of the Bay Area.
Commute Patterns and Economic Interdependence
Research and stakeholder discussions reveal that population and commute patterns are powerful indicators of human-based geographies. These patterns highlight economic interdependency, demonstrating how people’s lives connect their neighborhoods and workplaces. Analyzing commute flows over time can refine our understanding of economically linked regions and emphasize the importance of inter-regional collaboration.
Commute data has been used since 1948 to define core-based statistical areas across the United States. This approach identifies cities with a population core and analyzes surrounding counties based on commute patterns. Geographers utilize similar methods to project megaregion formation. As visualized in commute patterns across Northern California, intense exchange exists within the Bay Area’s urban core and between it and cities like Santa Cruz, Stockton, and Sacramento.
Commute Patterns in Northern California
A heat map of commutes in Northern California reveals the urbanized core of the Bay Area, Sacramento and Central Valley cities, as well as the workers who flow into and out of each. Source: Dash Nelson G, Rae A (2016) An Economic Geography of the United States: From Commutes to Megaregions. PLoS ONE 11(11): e0166083. https://doi.org/10.1371/journal.pone.0166083
Goods Movement and Industry Networks
The goods movement industry operates across geographical barriers, connecting producers, suppliers, and consumers. Analyzing goods movement corridors reveals industry-specific geographies. In Northern California, major goods movement routes highlight the Central Valley’s importance and the Bay Area’s connections to it and Sacramento for trade.
Goods Movement on Major Highways
The heavier truck traffic for goods movement occurs in the spine of the Central Valley, as well as in the areas that ring the Bay and connect it to other metro areas. Source: Metropolitan Transportation Commission
Shared Natural Resources and Environmental Systems
Natural resources and environmental challenges often disregard administrative boundaries. Water flow, sediment movement, and air currents are governed by natural processes, not county lines. Addressing critical issues like water supply, sea-level rise, and air pollution requires mapping and understanding these natural systems.
The San Francisco Bay watershed, for example, transcends county and even state lines. Understanding this system is crucial for managing water pollution and supply, essential for the health of the Bay Area and wider California.
The San Francisco Bay Watershed
The areas that drain into the San Francisco Bay reveal a large swath of the state that ignores all manmade boundaries. Source: http://www.spur.org/sites/default/files/publications_pdfs/SPUR_The_Northern_California_Megaregion.pdf
Conclusion: A Multifaceted Bay Area
The spatial patterns discussed reveal that the Bay Area’s geography is multifaceted and extends across various scales. These patterns represent regionally significant systems crucial to life in the Bay Area. Based on this understanding, SPUR has outlined its approach:
- Primary Focus: The nine-county Bay Area remains the central focus for SPUR’s Regional Strategy, recognizing its established identity, governance structures, and data availability.
- Megaregional Considerations: For key issues, the 21-county Northern California megaregion will be considered to address broader trends and interdependencies.
- System-Based Mapping: Systems like regional train networks, commute flows, and watersheds, whose boundaries differ from county or megaregion definitions, will be mapped to design solutions at the appropriate geographic scale.
Ultimately, defining “where is the Bay Area” requires flexibility. Researchers and policymakers should move beyond rigid adherence to city or county lines. Understanding the specific geography of each problem or system is paramount. Different regional scales may be relevant for sea-level rise, water management, housing markets, or commute patterns. The Bay Area’s political systems must adapt to work across these diverse geographies to effectively address the region’s complex challenges and ensure a thriving future.
