Population and Land Area

The San Francisco Bay Area, located in Northern California, consists of nine counties, 101 cities, and comprises 7,000 square miles. All of the region's nine counties share the San Francisco Bay. With 7.1 million residents, the San Francisco Bay Area is the fifth most populous metropolitan area in the United States.

The Bay Area has a land area of 4.4 million acres (excluding bay waters and large lakes). In 2000, approximately 16 percent (or about 700,000 acres) of the region's total acreage was developed for urban use. Of those developed acres, 61 percent are residential and 42 percent are non-residential (e.g., employment, government, schools, and major infrastructure).

San Francisco is the most urbanized county, with 82 percent of its land developed and Napa is the most rural county with less than 4 percent of its land area developed. The remaining counties have developed land areas ranging from 7 percent to 28 percent.

Like many large urban centers, the Bay Area will continue to grow over the foreseeable future. Over the next 25 years, the nine counties of the region are expected to add a total of 1,655,400 new residents, or 66,000 new residents per year. Most people will live in San Francisco, the East Bay (including eastern Contra Costa County), and the South Bay (in both San Mateo and Santa Clara counties).

Santa Clara County is projected to continue to be the most populous county in the region and will also experience the greatest amount of growth, or nearly 23 percent over the next 25 years. San Francisco will see the least amount of growth of these high population counties, or almost 14 percent to 924,600 residents by 2030.

Though not as populous as the above areas in the region, the fastest growing county in the Bay Area will be Solano County. Today, Solano County is home to over 423,800 people. By 2030, Solano will see a 27 percent increase in its population, to 581,800 residents by 2030.

The region faces the challenges of serving this growth with an efficient transportation system and balancing it with the conservation of open space and agricultural lands.

More details about population growth by county: