Johnson garnered 236 votes, or 54.76 percent, more than enough to avoid a runoff with second-place finisher Greg McClarin, who collected 172 votes, or 39.91 percent, of the 431 votes cast in the Democratic primary.
Incumbent District 3 County Commissioner Bob Gilreath had 23 votes, or 5.34 percent, of the vote.
Renew, running unopposed in the Republican Primary, had 317 votes, more than any of the Democratic candidates, but less than the 431 votes cast in the Democratic primary.
Johnson, 42, is a local State Farm insurance agent. She could not be reached for comment.