Flood Plain Management Rules Review



Summary of Rules: Iowa Administrative Code 567 Chapters 70, 71, 72, 73 and 75


Below is a summary of relevant chapters of Iowa Administrative Code that regulate flood plain development.  Following each summary is a link to the full text of the chapter.  

These rules are intended to implement Iowa Code Sections 17A.3, 455B.105, 459.102, and 481A.15 and Iowa Code chapter 455B, division III, part 4.  Definitions for flood plain management and dam safety terms are included in this chapter as well as the process for requesting approval of a flood plain development permit.  This chapter discusses procedures for review of applications and the administrative process for approving or denying a project.



These rules are intended to implement Iowa Code chapter 455B, division III, part 4; and Iowa Code sections 459.102, 459.301 and 481.15.  While Iowa Code 455B states that the Iowa DNR has authority over all flood plains in the state of Iowa, this chapter contains and clarifies the administrative thresholds for when approval from the Iowa DNR is obtained for work in the flood plain or floodway.  There are different administrative thresholds for different project types:  Bridges, culverts, temporary stream crossings, road embankments, channel changes, dams, levees, dikes, waster or water treatment facilities, sanitary landfills, buildings, fill pipeline crossings, stream bank protective devices, boat docks, excavations, and miscellaneous structures, obstructions or deposits.



These rules are intended to implement Iowa Code sections 455B.261, 455B.262, 455B.263, 455B.264, 455B.275, 455B.277, 459.102 and 459.301.  This chapter contains the specific requirements that must be met for approval of a project or activity in a flood plain or floodway for the entire list of project types in 567-71.



The rules in this chapter are intended to implement Iowa Code sections 109.15, 455B.275, 455B.277, 455B.264 and 17A.12.  This chapter covers approval procedures for dam operating plans, raising or lowering of impoundment levels, abandonment of dams, and removal of dams.  Also covered are the scope, purposes and procedures for a dam safety inspection program.



This chapter is currently unused.
These rules are intended to implement Iowa Code sections 455B.262, 455B.263, 455B.264, 455B.275 to 455B.279(2).  The Iowa DNR has jurisdiction over all flood plains and floodways in the state to promote the protection of life and property from floods and to promote the orderly development and wise use of the flood plains of the state.  This chapter discusses 3 different types of regulation including issuance of department flood plain management orders, approval of locally adopted flood plain management ordinances, and approval of development on a case-by-case basis.  Flooding characteristics, establishment of a floodway, minimum standards for flood plain and floodway uses and preexisting nonconforming development and associated uses are covered.  The process for the delegation of authority to local governments by approval of local regulations and the review and approval of variances from local regulations is covered.




Rulemaking Actions


The Administrative Procedures Act, Iowa Code chapter 17A, requires all state agencies to promulgate rules for the operation of their programs. The rulemaking process increases agencies’ accountability to the public, allows public participation in the formulation of rules, and provides legislative oversight for program operations.

Below are the recent rulemaking activities that are being considered, have been proposed, or are in the process of being adopted by the DNR for the chapters administered by the Flood Plain Management & Dam Safety section. Many of these proposals are a direct result of the comprehensive five year rule review required by 17A.7(2).

There are no active rulemakings underway.

Changes to Bridge Design Standards and Enumerating Exemptions

Chapter(s) involved: 567 IAC 70, 567 IAC 71, and 567 IAC 72

Effective date: November 16, 2016

Major provisions:

These rule changes streamline certain development within Iowa’s flood plains. The changes can be grouped into three different categories:

  1. Rescinded or changed rules to which a waiver or variance was routinely sought by stakeholders;
  2. Enumerated exemptions from permit requirements for certain development in a flood plain; and
  3. Minor changes to update definitions, references to Iowa Code sections, forms, and DNR contact information and to replace a subrule which was inconsistent with the Iowa Code. 

Rescinded or Changed Rules

The rule changes rescind the Q50 backwater criterion (567 IAC 72.1(1)“a”).  The Q50 backwater criterion regulated the amount of pooled surface water allowed during a 2-percent-annual-chance flood event.  This criterion was difficult for those constructing bridges to meet, including IDOT.  In addition, the criterion provided little to no benefit to landowners and was not required by any federal law. 

The changed rules also provide an alternative means to satisfy the minimum freeboard requirement (567 IAC 72.1(1)“b”).  Freeboard, in the context of the flood plain rules, is space between the lowest part of a bridge and the water surface.  The rule change provides an exception to the minimum criterion for freeboard; so long as a licensed engineer provides certification that the bridge is properly designed to withstand the relevant forces of water during flood conditions.


The finalized rulemaking also added exemptions to DNR’s flood plain development permit requirements for certain activities such as excavations installed for conservation practices (567 IAC 71.11(1)”e”) and for the installation of signs, utility poles and other similar structures (567 IAC 71.12(3)).  DNR developed these exemptions in cooperation with stakeholders such as electric generating utilities and the NRCS.

Minor Changes

In 2000, the Iowa legislature established minimum criteria which must be met in order to receive a waiver or variance from any executive branch rule.  These are found at Iowa Code section 17A.9A.  To implement this statutory provision, the DNR adopted 561 IAC Chapter 10 in 2001.  However, the DNR never modified the agency’s waiver and variance provision for flood plains (567 IAC 72.31), which was promulgated years before the enactment of Iowa Code section 17A.9A and is inconsistent with the Iowa Code.  For that reason, 567 IAC 72.31 was changed to reference 561 IAC Chapter 10.  This will alleviate confusion as to what criteria must be met in order to receive a waiver or variance, and it will ensure that any waiver or variance granted by the DNR is compliant with the Iowa Code. 


The rule changes were adopted and filed by the Environmental Protection Commission (EPC) on September 20, 2016. Final approval was granted at the November 14, 2016 Administrative Rules Review Committee (ARRC) meeting.  

Links to additional information or documents: