Meanwhile, the Growth Goes On . . . : For the fourth straight year, the Santa Clarita Valley was the fastest growing region in

Los Angeles County, narrowly outpacing the rapidly developing Antelope Valley in 1988, according to a new report.

Palmdale was the county’s fastest growing city, registering a whopping 229% rate of growth between 1980 and 1988, said a report released last week by the county Department of Regional Planning.

Between 1980 and 1988, the total population of Los Angeles County grew by 930,000 residents to reach 8.4 million, an increase of 12.4%. That was the largest population gain of any county in the United States during the 1980s, the report said.

The San Fernando Valley grew by 12.7% during the same period to 1.2 million residents.

The Santa Clarita Valley’s population jumped from 79,015 residents to 132,700. That’s an increase of 68%, comparable to the combined populations of the cities of San Fernando and San Gabriel.

The Antelope Valley grew 65.7%, from 107,079 residents in 1980 to 177,500 last year, the report said.

Palmdale, with 12,277 residents eight years ago, had 40,419 residents last year. During the last half of 1988 alone, Palmdale gained 11,800 residents, the report said.

The rapid growth in the Santa Clarita and Antelope valleys did not surprise county statisticians, said Terry Bills, a research analyst with the regional planning department. Santa Clarita has led the county since 1985, he said.

But what has changed in the Santa Clarita Valley is the intensity of growth, Bills said. In the two-year period 1986-87, the valley’s population rose 34% over the 1980 figure. By last year, its population had grown by 68% since 1980.

Single-family homes, duplexes and mobile-home parks dominate the housing market in the Santa Clarita Valley, making up 78.8% of the dwellings there, Bills said.

Apartments account for 21.2% of the residential units in the valley. Conversely, apartments made up 42% of the residential units in the entire county.