This project is funded by the State of Oregon through the Department of Land Conservation and Development (DLCD).
Oregon -- Population -- Statistics, Demographic surveys -- Oregon, Population forecasting -- Oregon -- Washington County
Different parts of the county experience differing growth patterns. Local trends within the UGBs and the area outside them collectively influence population growth rates for the county as a whole.
Washington County’s total population has grown strongly during the 2000s, with an average annual growth rate of 1.8 percent between 2000 and 2010. However, some of its sub-areas experienced more rapid population growth during the 2000s. North Plains, the most populous UGB in Washington County outside of the Metro boundary, and Banks, posted the highest average annual growth rates at 2.0 and 3.0 percent, respectively, during the 2000 to 2010 period.
Washington County’s population growth during the 2000s was largely the result of natural increase. However, 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. The larger number of births relative to deaths caused a natural increase (more births than deaths) in every year from 2000 to 2015. While natural increase outweighed net in-migration for the majority of the 2000s (except for 2006 and 2007); net in-migration has risen in recent years (2013 to 2015), outpacing natural increase in both 2014 and 2015 (Figure 12).
Total population in Washington County and its sub-areas outside of the county’s Metro boundary will likely grow at a faster pace in the near-term (2017 to 2035) compared to the long-term. North Plains, with the second strongest population growth in the 2000s after Banks, is expected to experience faster rates of population growth, while Banks is expected to experience a slower growth during the forecast period. The Washington County portion of Gaston experienced slower growth rates it is expected to maintain (Figure 1). The tapering of growth rates is largely driven by an aging population—a demographic trend which is expected to contribute to a diminishing natural increase (more births than deaths). As natural increase lessens population growth will become increasingly reliant on net in-migration.
Portland State University. Population Research Center; Jurjevich, Jason R.; Chun, Nicholas; Rancik, Kevin; Proehl, Risa; MIchel, Julia; Harada, Matt; Rynerson, Charles; and Morris, Randy, "Coordinated Population Forecast for Washington County, its Urban Growth Boundaries (UGB), and Area Outside UGBs 2017-2067" (2017). Oregon Population Forecast Program. 34.