Iowa Code Ch. 161A — Soil and Water Conservation Districts (Soil Loss Limits + Cost-Share) (IA)
Tracked preemption from the Iowa overlay bundle.
Overview
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Effective
1939-07-01
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. 455B + 567 IAC 71 — Floodplain Development Approval (DNR Flood Plain Program)
Trigger predicate
When this evaluates true for a parcel, the law's preempted fields take precedence over base zoning.
OR
parcel.is_agricultural_land==Trueproject.disturbs_more_than_one_acre==True
Preempted fields
3 fields on the base district schema are rewritten when the trigger fires.
| Field | Op | Value | Note |
|---|---|---|---|
review_type | advisory | soil_and_water_conservation_district_consultation | Iowa's 100 Soil and Water Conservation Districts (governed by elected commissioners) administer soil-loss limits and water-quality programs under Ch. 161A in cooperation with the Soil Conservation and Water Quality Division of the Iowa Department of Agriculture and Land Stewardship (IDALS). |
redevelopment.cost_share_eligibility | permit | ch_161A_voluntary_cost_share | Cost-share incentive payments are available to landowners voluntarily installing soil/water conservation practices designed to control erosion below the district's soil-loss limit and conserve water resources. |
county_zoning.335_2_ag_exemption_extension | extend | conservation_program_enrolled_parcels | Per 2020 amendments to §335.2 (HF 2403 / SF 2195), the county zoning ag exemption extends to parcels enrolled in a soil or water conservation program — even without active agricultural production. Ch. 161A is the principal program-enrollment statute that triggers this exemption-extension. |
Citation
Authority source
Iowa Code ch. 161A (Soil and Water Conservation); §161A.5 (districts); 27 IAC ch. 102 (Rules of Practice — Soil Conservation Division). Note: companion Ch. 466A (Watershed Improvement Review Board) was repealed effective 2017-12-31; that funding stream no longer exists.
§ Iowa Code §§161A.1–161A.80; 27 IAC ch. 102
Research notes
Voluntary-program + ag-exemption-extension overlay. Ch. 161A is principally a conservation-funding and soil-loss-standard framework — it does NOT directly preempt local zoning, but enrolled status under a Ch. 161A program materially extends the §335.2 county-zoning farm exemption beyond active production. Note for downstream consumers: the prior Watershed Improvement Review Board (Iowa Code ch. 466A) — sometimes referenced as a separate watershed-improvement overlay — was REPEALED by 2017 legislation effective 2017-12-31; that grant program no longer exists and should not be cited as a current authority. Soil-loss limits and water-quality work in Iowa run through Ch. 161A + the Nutrient Reduction Strategy (non-statutory framework) as of 2026-05-18.