Hennepin County is moving ahead with the county's newly drawn commissioner districts, using population data that surprised county and state officials.

Since the last redistricting for the seven board districts a decade ago, population growth across Minnesota's most populous county has been evenly dispersed. The state demographer told commissioners that was unusual for an urban county over such a long period of time.

In the Second, Third and Fourth districts — which encompass Minneapolis — the population shift since 2010 has been greater than 5%, which would ordinarily trigger a new election. However, the commissioners representing those districts — Irene Fernando, Marion Greene and Angela Conley — were already up for reelection this year.

If a significant population shift had occurred in the county's other four districts, newly elected commissioners would have had to face re-election before their terms had ended.

"Because of the even growth, there were only tiny changes around the edges of the districts," said Mark Chapin, the county's director of residential and real estate services.

Since the 2010 census, Hennepin County's population grew from 1.15 million to 1.28 million. The Seventh District, which includes 17 cities in the northwestern half of the county, had the largest population with 196,922 residents, while the Fifth District — Bloomington, Richfield and parts of Eden Prairie — recorded the lowest number of residents with 174,954.

The difference in population between the largest and smallest districts was nearly 22,000, resulting in noncompliance with the standards set by state law and triggering the need to redistrict. County officials had to wait until each of the county's 421 city precincts had completed their redistricting maps.

"We are the caboose on the bullet train," Chapin joked.

The County Board then had 80 days to approve its redistricting plan. It held several public hearings, something the county had never done in the past, Greene said. Three citizens, including one representing an immigrant group, submitted proposals.

"We wanted this process to be very transparent to the public," she said. "This reflects the values of this board and what the public has come to expect."

The most significant mapping change came in Greene's district, which covers St. Louis Park and parts of southwest Minneapolis. She now has a larger piece of downtown Minneapolis. Though Conley had raised concerns about downtown being split among three districts, no changes were made.

Before the start of the redistricting process, the board drew up a set of principles to guide their decisions. Commissioners said they took into account the voting rights of citizens on account of race, ethnicity or membership in a minority language group, and maintaining historical alignments of communities of interest.

The public input helped shape the board's decisions, along with the recommendations of consultants hired by the county.

"We do this every ten years," Chapin said. "I will now print up all the documents, bind them up and hand it to our law library. I do this because we don't know what the electronic future will bring."