Iowa Code § 277.25: Directors in new districts.

At the first election in newly organized districts the directors shall be elected as follows:

1. In districts having three directors, two directors shall be elected for two years, and one for four years.

2. In districts having five directors, three shall be elected for two years, and two for four years.

3. In districts having seven directors, four shall be elected for two years, and three for four years.