IOWA CITY — Johnson County Supervisors have decided not to challenge the new state law that removes from local officials any control of the minimum wage. The board determined after conferring with County Attorney Janet Lyness that the county didn’t have legal authority to sue over the legislation. It was finally passed by the Legislature and signed by Gov. Terry Branstad last month. In September 2015 Johnson County became the first in Iowa to approve a plan raising the local minimum wage.