U.S. Census Bureau estimates being released today offer a detailed snapshot of San Joaquin County's midsize cities - the first since 2000, when the region was in the midst of racing growth that didn't slow considerably until the middle years of this decade.

The figures - which cover a wide range of topics, from fertility to education, to poverty and housing to employment - reflect a county whose smaller towns are negotiating the same demographic shifts as much larger communities.

They also reveal some striking differences in the character of each city's growth, disparities that often are obscured in countywide averages.

The Census Bureau's statistical portrait of midsize counties, cities and towns - those with populations from 20,000 to 65,000 - is the first such analysis released since the decennial count. Figures for larger cities are updated annually.

Since 2000, San Joaquin County has grown by more than 19 percent, placing it among the fastest-growing counties in California.

That growth can be traced city by city - from just under 14 percent in Lodi to fully 43 percent in Tracy, where, according to estimates, 57 percent of the housing units have been built since 1990.

As of the 2000 census, the two cities were of roughly equal size. Tracy is now larger by nearly 17,000 residents.

Immigrants account for much of the county's growth, especially in Tracy, where foreign-born residents make up almost a quarter of the population. In 2000, they accounted for about 17 percent.

"It has had a great impact on the district," said Mercedes Silveira, who coordinates services for students learning English in Tracy Unified. "It has changed how we conduct business and education."

She said the largest growth has been among Spanish speakers, but Tracy also is serving growing numbers of children who speak Punjabi at home.

As part of its plan for working with those and other minority groups, the district has organized a database of parents, school staff members and community leaders who have second-language skills and who serve as translators.

"Especially during parent-teacher conference time ... there are some translators who are there all day," Silveira said. "Once in a while, we need someone who speaks Farsi or Hmong, and that's difficult to find."

Tracy's growth in the late '90s and the early part of this decade helped motivate the nonprofit group El Concilio to open a satellite office there.

"I think they'll continue to grow," said Angel Jimenez, a spokesman for the organization. "It's a pretty good blend of the Bay Area and the Central Valley. ... I think that's what makes Tracy so unique."

Demographically, Tracy does diverge from other San Joaquin County cities in significant ways.

About 6.7 percent of families with children are poor in Tracy, compared with nearly 12 percent in Manteca, 17 percent in Lodi and more than 19 percent in Stockton.

Similarly, median household incomes are higher in the south county: $77,911 in Tracy and $59,585 in Manteca, compared with $48,074 in Lodi and $46,298 in Stockton.

In another example of regional disparity, people with advanced degrees in San Joaquin seem to be concentrated at the edges of the county: In Lodi, 19 percent of residents have a bachelor's or graduate degree. In Tracy, 20 percent do.

Figures are lower in Stockton and Manteca.

Lodi, though, also has a high percentage of residents who haven't finished high school: 24 percent. That's second to Stockton, where 27 percent of residents 25 and older don't have a diploma. Meanwhile, for 14 percent of residents in the county seat, education didn't continue past ninth grade.

Contact reporter Jennifer Torres at (209) 546-8252 or jtorres@recordnet.com.

Reader reactions have moved These discussions and our forums are not moderated. We rely on users to police themselves, and flag inappropriate comments and behavior. You need not be registered to report abuse. In accordance with our Terms of Service, we reserve the right to remove any post at any time for any reason, and will restrict access of registered users who repeatedly violate our terms.