Although there is no documented symbolism for the red stripe, its creator indicated that the selection of the colors red, white and blue were to mirror the color scheme of the flag of the United States of America.
The three white "bridges" across the flag symbolize the Grand, Locust, and Walnut Street bridges at the Des Moines River.
Starting September 19, 2016 the Grand Avenue bridge was closed for demolition then subsequent rebuilding due to structural deficiencies, and reopened at the end of 2017. The other bridges adjacent to the Grand Ave. bridge are scheduled for the same treatment in the following years. They will not be rebuilt in the same style and will not have functional arch supports. Construction will be standard square/rectangle design with facade arches painted on the side.
In the same pane of the flag as the bridges, the blue background symbolizes the water of the Des Moines River.