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Washington population growth remains slow in 2011


OLYMPIA –Washington state’s population continues to grow, but at a slower rate. The 2011 population estimate prepared by the Office of Financial Management (OFM) places Washington’s population at 6,767,900 as of April 1, 2011. This represents an increase of 43,360, or a growth rate of just 0.64 percent from the state’s official 2010 census count.

This unexpected slowdown in population growth is due to the slower than expected economic recovery, which affects two components of population change: natural increase (the number of births minus deaths) and migration.

The total number of births in Washington declined from 88,200 last year to 84,800 this year. With the second “echo” of baby boomers reaching childbearing age, births had been steadily increasing from 81,800 in 2005 to 89,800 in 2009. This upward trend would likely have continued if not for the recession and the slow pace of economic recovery.

Migration to Washington, largely driven by economic opportunity, is a major component of the state’s growth. This year’s net migration is estimated at 6,600, the lowest level in more than two decades. Worker mobility remains low nationwide because of difficulties with both selling homes and finding work. Part of the overall decrease in migration is due to a decline in international migration.

State population and migration continue to slow in 2011

Chart showing state population and migration in 2011

Statewide, 57 percent of population growth between 2010 and 2011 took place in the Puget Sound region counties of King (11,400), Kitsap (2,800), Pierce (6,900) and Snohomish (3,700).

Four of the five counties experiencing the highest percentage of population growth are located in Eastern Washington. Franklin County gained nearly 3 percent after a decade of strong growth. Benton County grew 1.6 percent and Adams County grew 1.2 percent. Kitsap and Grant counties each had a growth rate of 1.1 percent. Consequently, the total percentage growth for Eastern Washington is at 0.70 percent, which is slightly higher than the 0.63 percent growth rate for the western portion of the state.

The population of Washington's cities and towns totaled 4,313,267 on April 1, 2011, a growth of 67,050 people since the federal census count. Nine of the top 10 cities with the largest numeric population growth are located in King County or the Tri-City area. In order of descending rank, they are Kent, Burien, Seattle, Renton, Pasco, Sammamish, Bremerton, Bellevue, Richland and Redmond. Sixty-two percent of the population growth in incorporated areas is due to annexation activity. A substantial portion of the growth in Kent, Burien and Sammamish in King County can be attributed to annexations which occurred this year.

Slow population growth affects new housing construction. The state added 18,200 new units this year, in contrast to 28,200 units during the same time period last year. This is the lowest amount of housing growth in two decades. King County has added 6,100 housing units, approximately one-third of the state total.

OFM's 2011 population determinations were benchmarked to the 2010 decennial census conducted by the U.S. Census Bureau. In some cases, adjustments were made by OFM to account for annexations occurring between January 1 and April 1, 2010. In other cases, OFM-certified 2010 city censuses were used.

OFM's official April 1, 2010, population estimates were interim numbers and have been officially replaced by OFM's adjusted 2010 census counts. The latter should be used when calculating annual growth.

Information on OFM's April 1, 2011, population estimates for cities, towns and counties is available at Information on the 2010 census is available at

Contact: Yi Zhao, 360-902-0592