A commercial, industrial and retail building spree is transforming Santa Clarita from a bedroom community into a truly suburban city with its share of familiar suburban gripes.

Four major commercial and industrial parks are now under construction three inside the city of Santa Clarita and one just outside that the city is seeking to annex. Several retail shopping centers with major big-box stores are also being built.

It’s a coming of age for a city whose population has grown by nearly 40 percent since 1990, in a pattern more commonly seen in Orange County or the Inland Empire than in greater Los Angeles.

“When I first moved into the area 36 years ago, there were just a couple of stoplights, one or two restaurants and miles and miles of open fields,” said retiree Sharon Welch. “Now there are so many projects springing up everywhere it’s a just like the big city.”

One of those projects is Valencia Town Center Corporate Park, within earshot of the roller coasters at Six Flags Magic Mountain. To the north is another office/industrial facility, Rye Canyon Business park, and to the northwest, at the 1,600-acre Valencia Commerce Center.

On the other side of town, 1.5 million square feet of light industrial space is going up at Center Pointe Business Park.

Much of the new construction is scheduled for completion within the next 12 to 18 months.

Next to the Valencia Town Center and elsewhere, several long-planned retail centers have sprung to life, with tenants that include Kohl’s, Home Depot and Wal-Mart.

Some longtime residents bemoan the loss of open space and mountain vistas.

“I moved here 12 years ago in large part because I loved the views of the mountains,” said Karen Forte, who lives nearby. “I can’t even see most of the mountains anymore.”

The growth has brought L.A.-style traffic jams to once-quiet neighborhood streets. Only a few years ago, most people living in Santa Clarita had to commute into Los Angeles for work. Now, said Bert Abel, senior vice president of retail for Grubb & Ellis.

“Now, almost as many people come into the Santa Clarita area to work as leave and increasing numbers of local residents also work here,” he said. As a result, it can take 20 minutes to go two miles through the center of town on a weekday afternoon.

“Traffic has now become our top concern,” said Larry Mankin, president and chief executive of the Santa Clarita Valley Chamber of Commerce. The chamber has been pushing for a project known as the “cross-valley connector” an east-west thoroughfare to relieve the congestion.

Environmentalists are also concerned about commercial growth encroaching on the ecologically sensitive Santa Clara River.

Lynne Plambeck, president of the Santa Clarita Organization for Planning and the Environment, points out that a new BMW dealership has been built in the river’s flood plain. “There’s too much growth occurring in the watershed,” she said.

It was the Santa Clara River that first brought farmers and ranchers to the region in the early 19th century. Decades later, a Southern Pacific rail stop at the small village of Newhall served to bring further growth. That was followed in the 1960s by the completion of Interstate 5.

Much of the land in the Santa Clarita Valley had been accumulated under the control of the Newhall Land and Farming Co., which last year was bought by Florida-based Lennar Corp. In the early 1960s, Newhall Land executives crafted a master plan for growth that involved selling off portions of the company’s holdings to major residential developers.

In 1986, voters approved the creation of the new city of Santa Clarita, comprised of all or portions of the communities of Valencia, Newhall, Saugus and Canyon Country. With a population of 165,000 (up from 120,000 in 1990), Santa Clarita is now the county’s fourth-largest city, behind Los Angeles, Long Beach and Glendale. The entire Santa Clarita Valley now is home to about 240,000.

For most of this time, much of the building has been residential. Commercial growth was confined mainly to the area of the Valencia Town Center, where Princess Cruises is a well-known tenant, and at the Valencia Industrial Center a couple of miles to the north and west.

But in the last five years, the pace has picked up as the next phase of the master plan was launched. In addition to the planned growth, tightening office and industrial vacancy rates much lower than in many other areas of the city have also driven new construction.

“These office and industrial parks are central to our strategy of keeping people here in the Santa Clarita Valley,” said Carrie Rodgers, Santa Clarita’s new economic development director.