New projections show that fast-growing Hamilton County in suburban Indianapolis could become Indiana's third most-populous county within about a decade, surpassing Fort Wayne's Allen County.
State population estimates prepared by Indiana University's Indiana Business Research Center show that Hamilton County has grown by 17 percent since 2010, to 323,000 people. Allen County has grown 5 percent, to 373,000.
Hamilton County, fueled by the booming cities of Carmel, Fishers, Noblesville and Westfield, is expected to surpass Allen County around 2030, research center demographer Matt Kinghorn told The Fort Wayne Journal Gazette .
The center's estimates for 2030 show that the state's largest two counties will continue to be Marion County, which includes Indianapolis, and Lake County, in the state's northwest. Marion County is expected to grow about 6 percent to just over 1 million residents, and Lake County is expected to shrink slightly, to 482,000 people.
Estimates through 2050 are that Lake County's population stagnation will continue as Hamilton County could see 70 percent growth by then.
"Our projections show that Hamilton County is expected to race past both Allen and Lake counties over the next few decades and become the state's second-largest county," Kinghorn said.
Indiana's population will increase by about 660,000 residents between 2015 and 2050, from an estimated 6.61 million residents to 7.27 million, according the center's projections.
Population growth is expected to be concentrated in central Indiana in the coming decades, with 59 of Indiana's 92 counties losing population by 2050. The 11-county Indianapolis metro region is expected to grow from 1.99 million residents in 2015 to 2.51 million in 2050 — a 26 percent increase.
"These projections suggest that most counties will continue to have a net out-migration, but as the population ages, fewer and fewer counties will have enough of a natural increase to make up the difference," the center's report said.