Study Sees Jump in South County Population

South Orange County’s population is expected to grow by nearly 800,000 people over the next 25 years, according to new figures released by the major regional planning group for six Southern California counties.

The increase would boost south Orange County’s population from 640,000 to 1,437,000--about 200,000 more than the Southern California Assn. of Governments projected in its last complete report, issued in 1985.

Exceed County Projections

The figures, which are preliminary and must be approved by SCAG’s executive committee, exceed projections made by the county and indicate that Orange County will be the fastest-growing of 24 subregions in the area studied, which includes Los Angeles, Ventura, Santa Barbara, Riverside, San Bernardino and Orange counties.

According to the figures, south Orange County--roughly, the area south of the Costa Mesa Freeway--would capture 13.6% of the nearly 6 million people expected to settle in the area by the year 2010. And, since all those people will need homes, an estimated 350,000 new housing units will be built in the area for them.

North Orange County, in contrast, is expected to add only about 260,000 people and 140,000 housing units in the same period.

The new SCAG figures for individual counties and subregions were derived from a study released last month that said the entire area’s population would jump 43% to a total of 18.3 million by 2010.

The study projects greater growth for Orange County and the region as a whole than did the previous SCAG report because it incorporates new assumptions on legal and illegal immigration flows and birth rates for different age and ethnic groups, SCAG senior planner John Oshimo said.

For example, Oshimo said, illegal immigration into the six-county area was projected to remain at about 46,000 people per year--85% of whom would be Latinos--with 64,000 more immigrants coming legally each year.

The earlier SCAG report projected a total Orange County population of 2,830,000 in the year 2010, about the same as the county’s own estimate, county demographer Bill Gayk said. The new projection brings Orange County’s population over the 3-million mark, to 3,097,000.

“They use a different methodology than we do, and a major chunk of the additional projected growth is due to the effects of immigration,” Gayk said. “We don’t make the same assumptions.”

The county’s projections have been “right on track” in recent years, Gayk said, adding that he saw no reason to believe that the new SCAG figures are more accurate than the county’s numbers.

The Board of Supervisors has asked SCAG to justify its higher forecasts and prepare a paper explaining the potential financial and planning impacts of the forecasts.

Want Hard-Core Figures

“We’re asking them for the hard-core figures behind the facts,” said Christie L. McDaniel, an aide to Supervisor Thomas F. Riley. “There is the perception that south Orange County is growing fast, and we don’t want to perpetuate that more than it is true.”

The figures will undoubtedly be revised as SCAG’s executive members, made up of elected officials from the counties and cities that make up the association, prepare the final report for 1987. The report will be the chief document the group will use in addressing regional planning issues that range from housing and transportation to air quality and social services, Oshimo said.