Dallas County had the fifth fastest growing population in the U.S. from 2015 to 2016 according to new estimates provided by the U.S. Census Bureau. Dallas County’s population grew by 4.6 percent during that time, and the population has swelled by more than 27 percent since 2010.
“While the 2016 population estimates show that Iowa’s population continues to grow, that growth is occurring in only 23 of Iowa’s 99 counties,” said Gary Krob, coordinator of the State Data Center at the State Library of Iowa. “The Des Moines-West Des Moines Metropolitan area was our fastest growing metro area, increasing by 11.4 percent since 2010.”
Clinton County has had the largest decline in population since 2010, losing 1,807 people, while Adams County has declined at the highest rate, with a decrease of 8.3 percent of its population since 2010. Net migration losses occurred in 77 other counties, where more people moved out of the county than into it.
Other findings from the 2016 County population and Metropolitan Statistical Area population Estimates (all data compared to 2010 Census numbers):
- 26 counties gained population; 73 counties lost population.
- Largest county: Polk, 474,045 residents; smallest county: Adams, 3,693 residents
- Polk County saw the largest increase in population, a gain of 43,410 residents
- Dallas County had the fastest growing population (27.8 percent), followed by Johnson county (12.0 percent), and Polk county (10.1 percent)
- 51.8 percent of the total state population (3,134,693) lives in 10 counties: Polk, Linn, Scott, Johnson, Black Hawk, Woodbury, Story, Dubuque, Pottawattamie, and Dallas. All ten counties are part of an Iowa Metropolitan Statistical Area
- 78.8 percent of all the international migration in Iowa occurred in 10 counties: Polk, Johnson, Story, Linn, Jefferson, Black Hawk, Dallas, Woodbury, and Scott.
- Fastest growing metro areas in Iowa:
- Des Moines-West Des Moines Metro Area - 11.4 percent
- Iowa City Metro Area - 10.6 percent
- Ames Metro Area - 8.4 percent
The new county, metropolitan, and micropolitan population estimates, rankings, and maps are on the State Library’s State Data Center web site at www.IowaDataCenter.org.
The new estimates from the Census Bureau are based on administrative data for births and deaths and estimates of migration since the 2010 census. Caution is urged in making year-to-year comparisons of population estimates. When the Census Bureau releases new estimates for the current year it also revises estimates for previous years in the decade.
The U.S. Census Bureau Population Estimates Program prepared the latest population estimates in partnership with the Federal-State Cooperative Program for Population Estimates. The State Data Center is part of the State Library of Iowa, www.StateLibraryofIowa.org, and is a member of the Federal-State Cooperative Program for Population Estimates.