OAKLAND — The Bay Area will need to find room to build more than 635,000 homes in the next 25 years to accommodate an added 1.7 million people, a regional agency said Friday.
As more people enter the region, opportunities are dwindling to effectively plan for the growth in a way that reduces traffic, energy costs and environmental damage, said planners with the Association of Bay Area Governments.
"It's rethinking how we travel, rethinking how we live," planner Christy Riviere said. "It's a whole slew of things we have to consider."
San Jose will lead the pack with an estimated 412,200 more people by 2035, followed by San Francisco with 159,000 and Oakland with 141,100.
The planners forecast that Santa Clara County, already the most populous, will grow by 33 percent, Alameda County by 27 percent, San Mateo County by 22 percent and Contra Costa by 21 percent.
That would mark a shift from years past, when Contra Costa was the fastest-growing of the Bay Area's nine counties.
Adding 1.7 million people is roughly equivalent to squeezing into the region two more cities the size of San Francisco.
The projections show that after decades of rapid growth in suburbs at the region's edges, population growth over the next 25 years will speed up in the cities. Almost 75 percent of the growth is expected to happen in the horseshoe-shaped urban perimeter circling the Bay from Richmond to San Francisco.
The planners presented their figures — some dire, others hopeful — to more than 100 local leaders and others Friday morning in downtown Oakland.
The new estimates override earlier targets for curtailing congestion and environmental degradation, planners said.
Carbon dioxide emissions will drop, but not by enough. The average Bay Area resident will be driving 20 miles a day in 2035 — a mile more than now — and particulate emissions, including road dust, will keep rising.
Among the worries were whether the region's roads and transit systems are equipped to handle the growth. The $222 billion programmed for Bay Area transportation in the coming years is mostly for repair.
"We're having a harder time being able to operate what we built," said Doug Kimsey, planning director of the Metropolitan Transportation Commission. "We have to get much, much, much more efficient."
The association releases its projections every two years. This year it also offered alternative scenarios with different outcomes.
Regional planners are pushing for denser growth near transit, a move they acknowledge has drawn resistance of local leaders who have a different vision for their communities.
In the Tri-Valley region that includes Livermore, Pleasanton and Dublin, less than a quarter of population growth in the next 25 years will happen in the kind of dense, transit-oriented communities that regional planners consider a priority for improving the region's environmental health.
In East Contra Costa, once-rapid population growth has subsided but will increase enough for the area to number 330,000 people in 2035 — more than all of Marin County. Jobs will more than double in Oakley and Pittsburg.
But because those areas have some of the highest per-capita emissions and worst traffic, planners have laid out scenarios that sharply reduce suburban growth in ways that would not happen without significant policy changes.
"It essentially looks like we're emptying out eastern Contra Costa County," Riviere said of one scenario. "We did this to be provocative. ... That is an extremely difficult dialogue to have."
Mayors, city council members and others who attended the meeting said the population projections are a wake-up call but not something the Bay Area cannot handle.
"I don't think it's a cause for hand-wringing," said Union City Mayor Mark Green, vice president of the association. "There's ample opportunity for us to accommodate the growth."
Source: Association of Bay Area Governments
Coming to the Bay Area
n Time people spend waiting in traffic: 46 hours a year (up from 39)
n Share of income spent on housing and transportation: 59 percent (down from 61)
n People with access to transit: 75 percent (up from 74)