Iowa Code § 468.383: Liability for damage.

In addition to all other penalties contained herein, any person, firm or corporation who shall construct, alter or maintain any building, other structure, or any ditch, or remove earth, in violation of this part, shall be liable to the drainage or levee district with pumping stations maintaining said levee, for all damage sustained by the drainage or levee district resulting from the violation, and in the event of flood, or other emergency so declared by resolution of the governing body, any building or other structure, or ditch so constructed without permission of the governing board, as required herein, and within three hundred feet of the center line of any levee, may be removed, or the ditch filled in, without prior notice thereof to the owner.