The county board of supervisors may annually levy a tax not to exceed six and three-fourths cents per thousand dollars of assessed value of all agricultural lands in the county, to be used for flood and erosion control, including acquisition of land or interests in land, and repair, alteration, maintenance, and operation of works of improvement on lands under the control or jurisdiction of the county as provided in this chapter.
Iowa Code § 161E.9
83 Acts, ch 123, §188, 209