Development, loss of affordable housing and natural migration patterns are some of the reasons linked to Arlington County's drop in Hispanic population, county officials say.

Arlington has 31,000 Hispanic residents, 11 percent fewer than in 2000, according to U.S. Census Bureau data released last week. Hispanic population doubled in Prince William County and tripled in Loudoun County, the data show.

Asians and non-Hispanic whites are making gains in Arlington, with 21 percent and 16 percent more people than in 2000. The number of non-Hispanic blacks has remained steady for 20 years, with an average of 17,250 residents.

Of Arlington's 207,600 residents, 64 percent are non-Hispanic whites and 15 percent are Hispanic.

Arlington County Board Chairman Chris Zimmerman said Virginia's diversity began in Arlington in the 1980s. Calling it "patterns of human migration, in general," Zimmerman said people who start off in Arlington's garden apartments eventually gain wealth or families, for example, and make their way farther into Virginia's suburbs.

In 1990, Arlington was home to 14 percent of the state's Hispanic population. That number decreased to 11 percent a decade ago and 5 percent today, the Census data show.

The Long Branch Creek community's Hispanic population declined significantly over the past 10 years, as the number of residents of all other races and ethnicities continued to grow.

Demolition for construction of new properties began in 2000 and construction continued in the years following, said Elizabeth Rodgers, a county demographer.

As developments opened and rental units such as the Park were renovated, the units became too expensive for low-income families, Zimmerman said. People who then moved into those properties were mostly "people with smaller household sizes," he said.

The number of Hispanic families nearly tripled in Douglas Park and almost doubled in Barcroft and Buckingham in 2000, but all three communities had large declines in 2010.

As it did in Long Branch Creek, redevelopment happened in Douglas Park, Rodgers said. In 2000, the area had 3.14 people per unit, and in the recent census data, the number drops to 2.14, she said.

In Buckingham, townhouses replaced some garden apartments, and others will be replaced by affordable housing units under construction, Zimmerman said.

Single-family homes in Arlington cost on average about $225,000 in 1990, according to a study by real estate firm Rufus S. Lusk and Son. That number increased to $305,000 in 2000 and $660,000 in 2010, according to the the George Mason University Center for Regional Analysis, based on Metropolitan Regional Information Systems statistics.

Density increased along the Rosslyn-Ballston corridor and surrounding the Pentagon City and Crystal City Metro stations. County officials have been working toward this, with a goal of making more walkable communities.

Despite the general growth, the area around the Rosslyn and Courthouse Metro stations lost Hispanic population. Gains were made among residents of all races and ethnicities in the areas around the Clarendon, Virginia Square and Ballston Metro stations. Population tripled in the Clarendon neighborhood and nearly quintupled in Virginia Square and Ballston communities.

"That development has become the most desirable stuff in America. Naturally, the cost is a higher end. Is all of this stuff a pressure on people of lower to moderate income? Yes," said Zimmerman, who added that the county's efforts to preserve more than 6,000 units of housing prevented the pressure from being "far more significant."

The county is building a plan for development along Columbia Pike that has a goal of preserving all of the area's affordable units, Zimmerman said.

Arlington officials will continue to monitor and analyze the census data as more become available throughout the year, Rodgers said.

"This is our first glimpse at the data," she said. "It is hard to pull out trends until the full data set is available."