Missouri Floodplain Management — SEMA NFIP Coordination + MDNR 10 CSR 20-8 (MO)

Tracked preemption from the Missouri overlay bundle.

Overview

Effective
1973-12-31
Sunset
Authority
state
Scope
state:MO

Trigger predicate

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

OR
  • city.is_in_floodplain_management_community == True
  • parcel.geometry geographic match

Preempted fields

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

FieldOpValueNote
review_typerequirelocal_floodplain_development_permit_per_FEMA_44_CFR_60_3Communities participating in the NFIP must adopt floodplain management ordinances meeting 44 CFR §60.3 minimums; SEMA serves as the state NFIP coordinator and audits local adoption. Non-participation forfeits federal flood insurance availability and federal disaster assistance for individual flood damage.
base_districts[*].floodplain_construction_findingsrequirelowest_floor_at_or_above_BFE_plus_freeboardLowest floor (including basement) of any new residential construction must be at or above the base flood elevation; Missouri model floodplain ordinance recommends ≥1 ft freeboard; SEMA Community Assistance Visits enforce.
wastewater_treatment_facility.floodplain_construction_reviewrequireMDNR_construction_permit_10_CSR_20_810 CSR 20-8.020 (Engineering Reports) and related subchapters: MDNR Water Protection Program review for wastewater facilities in or near floodplains; treatment-facility siting in 100-year floodplain requires elevation/floodproofing per the design standards.

Citation

Authority source
Federal: National Flood Insurance Act (42 U.S.C. §4001 et seq.); 44 CFR Parts 59, 60. State coordination: Missouri State Emergency Management Agency (SEMA) NFIP coordinator role; Mo. Rev. Stat. ch. 44 (emergency management). Wastewater facility design in floodplain: 10 C.S.R. 20-8 (MDNR Water Protection Program design standards)
§ 44 CFR §60.3 (community floodplain management criteria); 10 CSR 20-8.020 (engineering reports)
https://sema.dps.mo.gov/programs/floodplain_mgmt/

Research notes

Task brief referenced 'Mo. Rev. Stat. § 89.330' as the floodplain anchor — verification shows §89.330 is the zoning-commission officer-rules provision, NOT a floodplain statute. Missouri does not have a standalone state floodplain management statute; floodplain regulation operates through (a) federal NFIP via 44 CFR §60.3 with SEMA as state coordinator, (b) local floodplain ordinances adopted under the general police power of Chapter 89 / Chapter 64, and (c) MDNR 10 CSR 20-8 for wastewater facility siting design. Federal conflict check flagged because the binding standards are federal (NFIP) and state regulations are implementing/coordinative. TIF carve-out: RSMo §99.847 restricts new TIF projects in floodplain areas — see MO_TIF_REDEVELOPMENT below.