Iowa Code § 303.68: Conflict with other regulations.

If the regulations made under this chapter impose higher standards than are required in any other statute or local ordinance or regulation, the regulations made under this chapter govern. If any other statute or local ordinance or regulation imposes higher standards than are required by the regulations made under authority of this chapter, that statute or ordinance or regulation governs. If a regulation proposed or made under this chapter relates to a structure, building, dam, obstruction, deposit, or excavation in or on the floodplains of a river or stream, prior approval of the department of natural resources is required to establish, amend, supplement, change, or modify the regulation or to grant a variation or exception from it.