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Oregon -- Population -- Statistics, Demographic surveys -- Oregon, Population forecasting -- Oregon -- Benton County


Different parts of the county experience different growth patterns. Local trends within UGBs and the area outside them collectively influence population growth rates for the county as a whole.

Benton County’s total population has grown slowly since 2000, with an average annual growth rate of less than one percent between 2000 and 2010 (Figure 1); however, some of its sub-areas experienced more rapid population growth during the 2000s. The Benton County portion of Albany and Adair Village posted the highest average annual growth rates at 2.4 and 4.7 percent, respectively, during the 2000 to 2010 period while all other sub-areas experienced average annual growth rates at or below that of the county as a whole.

Benton County’s positive population growth in the 2000s was largely the result of substantial net in-migration. An aging population not only led to an increase in deaths but also resulted in a smaller proportion of women in their childbearing years. This, along with more women choosing to have fewer children and have them at older ages has led to fewer births in recent years. A larger number of births relative to deaths caused natural increase (more births than deaths) in every year from 2000 to 2015. While natural increase outweighed net in-migration during the early and late years of the last decade, in more recent years (2012-15) net in-migration has increased, far outpacing births (Figure 12).

Total population in Benton County as a whole as well as within its sub-areas will likely grow at a faster pace in the near-term (2017 to 2035) compared to the long-term (Figure 1). The tapering of growth rates is largely driven by an aging population—a demographic trend which is expected to contribute to natural decrease (more deaths than births). As natural decrease occurs, population growth will become increasingly reliant on net in-migration.

Even so, Benton County’s total population is forecast to increase by nearly 18,000 over the next 18 years (2017-2035) and by more than 33,000 over the entire 50 year forecast period (2017-2067). Sub-areas that showed strong population growth during the 2000s are expected to continue experiencing relatively strong growth rates during the forecast period.


This report is published by the Population Research Center at Portland State University, and is a product of the Oregon Population Forecast Program.

The introductory presentation, preliminary forecast presentation, and Benton County final forecast tables are attached to this document as supplemental files.

Persistent Identifier

Benton_prelim_presentaton.pdf (1660 kB)
Preliminary forecast presentation

regional forecast presentation.pdf (8173 kB)
Introductory presentation

Benton_County_Final_Forecast_Tables.xlsx (130 kB)