Zoning › State preemptions › Iowa

Iowa Code Ch. 455B + 567 IAC 71 — Floodplain Development Approval (DNR Flood Plain Program) (IA)

Tracked preemption from the Iowa overlay bundle.

Overview

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Effective
1972-07-01
Sunset
—
Authority
state
Scope
state:IA
Other Iowa preemptions
Iowa SF 592 (2025) — Statewide Accessory Dwelling Unit By-Right MandateIowa Code §414.1(2) — Short-Term Rental Preemption (Residential Use Classification)Iowa Code §459.310 — Master Matrix CAFO Siting ScorecardIowa Code Ch. 161D — Loess Hills Development and Conservation Authority + AllianceIowa Code §414.28 / §335.30 — Manufactured Home Zoning Parity MandateIowa Code Ch. 303 — State Historical Society / SHPO Review + Local Historic Preservation CommissionsIowa Code §352.6 — Agricultural Area Designation + Right-to-Farm Nuisance ProtectionIowa Code Ch. 461A + 571 IAC 13 — Sovereign Lands Construction Permits

Trigger predicate

When this evaluates true for a parcel, the law's preempted fields take precedence over base zoning.

OR
  • parcel.geometry geographic match
  • parcel.geometry geographic match

Preempted fields

2 fields on the base district schema are rewritten when the trigger fires.

FieldOpValueNote
review_typerequireIADNR_floodplain_development_permitConstruction, dam, obstruction, deposit, or excavation in or on a regulated floodplain/floodway requires DNR Flood Plain Program approval. Rural threshold: projects in a floodplain of any stream draining ≥10 sq mi at the downstream end of the project site (567 IAC 71). Urban threshold: streams draining ≥2 sq mi at the downstream end. Approval criteria at 567 IAC 72.
county_zoning.floodplain_carveoutpermitsection_335_2_floodplain_exceptionCounty zoning §335.2 ag exemption does NOT bar floodplain zoning — counties may regulate structures/excavations in/on the floodplain regardless of agricultural character.

Citation

Authority source
Iowa Code §§455B.261–455B.281 (Flood Plain Management); 567 Iowa Administrative Code ch. 70 (Title V, Flood Plain Development), ch. 71 (When Approval is Required), ch. 72 (Criteria for Approval)
§ Iowa Code §§455B.261–.281; 567 IAC 70, 71, 72
https://www.legis.iowa.gov/docs/iac/chapter/567.71.pdf

Research notes

Per-parcel geographic predicate against DNR-mapped regulatory floodplains/floodways. Federal conflict check flagged because the Iowa floodplain program runs alongside FEMA NFIP regulations (44 CFR Part 60) and may intersect U.S. Army Corps §404 jurisdiction on adjacent waters. Applications are processed through the DNR PERMT system. Mississippi River and Missouri River corridors are the marquee floodplain interfaces — both are federally-managed flood-control channels with USACE permit overlays on top of state §455B authority.