LEWISBURG -- Since 1940, the population of Union County has doubled, and it seems likely the trend will continue.

"We've had double-digit percentage gains in population in every decade but two," said Shawn McLaughlin, Union County Planning Commission director, "and I expect that to continue."

McLaughlin spoke Tuesday about the update of the county's comprehensive plan during a luncheon forum of the League of Women Voters of the Lewisburg Area. The program was held in La Primavera.

McLaughlin said the updated document is intended to reflect residents' values and aspirations for the future.

"What you want your community to look like 10, 15, 20 years from now," he said. "It's a direct investment in Union County, both private and public, to meet those citizen goals that we determined."

The update of the comprehensive plan was started in March 2006 and kicked off publicly in September.

Through advisory teams, talks with municipal leaders, household surveys, public forums and student research, the group gathered data and determined some of the main concerns, such as land use, transportation, economic development and implementation.

"Union County, you all know it, it's an attractive place. A place that is probably going to continue to grow at a moderate rate," McLaughlin said.

It was the second fastest-growing county in this region between 1990 and 2000, second to Centre County.

About 60 percent of new development from 2001 to 2007 occurred in and around existing towns and villages, McLaughlin said, and 40 percent in the outlying areas, consuming farmland, forests and open space.

"Between now and 2050," he said, "if the current growth trends continue to project into the future and we have a moderate growth rate, we expect we're going to need about 8,000 housing units to be added to this county to support the population growth. And we expect that would consume about 10,600 acres if we continue the same style of development we've had recently."

McLaughlin said primary growth areas, or town centers, where the majority of new development is being encouraged, are in and around the existing communities of Lewisburg, Mifflinburg and Hartleton. New Berlin also is a possible area.

The idea is to have a greater density of development with smaller lots, multi-units, townhouses and condominiums.

Village growth areas, or secondary areas, would focus on Laurelton, Buffalo Crossroads, Kelly Crossroads, New Columbia, Winfield and Millmont. Those areas wouldn't have as much density, but more of an acre-lot size, he said.

"The whole entire goal is to try to get 80 percent of all new development within these growth areas," McLaughlin said, "and then preserve the rest of the county as farmland, working agriculture, open space and forests."