O'Fallon, MO Right to Farm: Agricultural Zoning Protection (2026)
Key Facts
- Minimum AG lot
- 2 acres (§ 400.155(D)(1))
- Livestock-keeping lot minimum
- 10 acres
- Max lot coverage
- 10 percent
- Livestock/manure buffer
- 100 feet from property line
- Front/rear setback
- 50 feet each
- Farm building height cap
- 50 feet
Summary
O'Fallon protects farming through its "AG" Agricultural District, zoned for lots at least two acres (ten acres to keep livestock) with a hundred-foot buffer around hay, feed or manure storage. City Code § 400.155 sets the district's purpose "to conserve, stabilize, enhance, and develop farming," shielding agricultural land from denser encroachment nearby.
D. Regulations And Performance Standards. The following regulations shall apply in all "AG" Agricultural Districts. 1. Lot Area. No building or structure shall be established on any lot less than two (2) acres. The minimum lot area for the raising and keeping of livestock shall be ten (10) acres. ... 4. Yard And Setback Requirements. a. Front Yard. Not less than fifty (50) feet from the right-of-way. b. Side Yards. Least width of either yard shall not be less than thirty (30) feet except in the case of a corner lot where the side yard on the street side shall not be less than fifty (50) feet. c. Rear Yard. Not less than fifty (50) feet. d. The above requirements shall apply to every lot, building, or structure; provided, further, that where livestock is raised or kept, no structure or storage of hay, feed, or manure, shall be located less than one hundred (100) feet from a property line.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4860992; v58 updated 2026-05-14; through 05-14-2026).
Full Breakdown
155(A)). 155(D)(1)). Minimum lot width is one hundred fifty (150) feet, and maximum lot coverage by structures is capped at ten percent (10%), far below the thirty-five percent (35%) allowed in the R-1 residential district, keeping AG parcels predominantly open. 155(D)(4)). 155(D)(4)(d) adds a further protection: no structure or storage of hay, feed, or manure may sit closer than one hundred (100) feet to a property line, insulating neighbors from farm operations. 155(D)(5)), recognizing that barns and grain structures need more vertical room than a house. Off-street parking and other performance standards otherwise track Articles XII and XIII of the Zoning Code.
Violations & Fines
Using AG-zoned land or structures in a way that conflicts with § 400.155, such as keeping livestock on fewer than ten acres or building inside the required setbacks, is a zoning violation under Chapter 400. The City's general penalty, § 100.010(A)(4), applies the RSMo §§ 89.120/89.490 zoning-violation fine schedule: up to $200 for a first offense in twelve months, rising to $450 for a fourth.
Frequently Asked Questions
What is O'Fallon's AG Agricultural District for?
How much land do I need to keep livestock in O'Fallon?
Are AG District setbacks bigger than residential setbacks?
Can farm buildings be taller than houses in the AG District?
Sources & Official References
Other rules in O'Fallon
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