Bolthole Index

Mercer County, Illinois

Zoning, building permits and septic rules in Keithsburg, Illinois

Keithsburg is a city in Mercer County, Illinois. Keithsburg adopts its own zoning, so inside its limits Keithsburg’s rules apply, not the county’s. 9 rules below are quoted from official sources and independently re-checked, most recently on November 2, 2026. Rules for unincorporated land are on the Mercer County page.

Answers from the rulebook for Keithsburg

Keithsburg’s own rules

  • Building permitRequired

    New dwellings and buildings inside Keithsburg city; placement of preconstructed buildings and advertising signs also requires permits.

    • The zoning enforcer must deny a permit for a new dwelling or building unless the application provides for sewage connection (see utility_connection claim).
    • Permit fee schedule was not located in the pages opened.
    “the zoning enforcer shall deny a permit for any new dwelling or building, unless the application makes provision for connection to sewage handling facilities”
  • Local zoningPresent

    All land inside Keithsburg city limits (Keithsburg, Mercer County, Illinois). The city's own official site links its zoning regulations and zoning application, and names its zoning enforcer.

    • The ordinance is Title 10 (Zoning), cited in the text as Ord. 2017-12 dated 12-11-2017; no separate effective date was stated, so effective_at is left null.
    • Zoning map is kept on file in the office of the zoning enforcer (10-3-2) and was not reviewed.
    • The American Legal code library page for Keithsburg returned HTTP 403 when opened, so the current consolidated code and later amendments were not verified; the PDF text references an amendment to the 2018 code.
    “zoning regulations can be read by clicking the link above.”
  • Zoning districtsPartial

    All land inside Keithsburg city limits

    • Districts named in the text: a residential district, e recreational district, b business district, cd industrial district (the letters are OCR-garbled in the PDF).
    • The zoning map itself is kept on file in the zoning enforcer's office and was not reviewed; newly annexed land is classed a residential district until amended (10-3-4).
    “for purposes of this title, the city is hereby divided into districts designated as follows: • a residential district e recreational district b business district cd industrial district”
  • Minimum dwelling sizeSpecified

    New dwellings in the a residential district (Chapter 5, Section 10-5-3) inside Keithsburg city

    • Minimum floor area depends on story count (one story or two-plus stories).

    minimum floor area, one-story dwelling: >= 500 square feet · minimum floor area, dwelling with two or more stories: >= 750 square feet

    “one story dwellings shall be constructed with not less than five hundred (500) square feet of floor area.”
  • Minimum lot sizeSpecified

    Lots in the a residential district (Chapter 5, Section 10-5-2) inside Keithsburg city, for a single-family dwelling; the two-family lot rule is in the same section.

    • Applies to lots on which a single-family dwelling is to be constructed.
    • No agricultural or rural-residential district was identified in the zoning text; the recreational and business districts were not treated as residential lot-size rules.

    minimum lot area, single-family dwelling: >= 3000 square feet · minimum lot width, single-family dwelling: >= 30 feet · minimum lot area, two-family dwelling: >= 5000 square feet (applies to two-family dwelling lots only; minimum width 50 feet)

    “every lot or tract of land upon which a single-family dwelling is to be constructed shall have an area of not less than three thousand (3,000) square feet and a minimum width of thirty feet (30').”
  • SetbacksSpecified

    Lots in the a residential district inside Keithsburg city (front from road right-of-way; side and rear from adjoining lines)

    • Front setback applies to buildings, walls, fences and similar improvements that cannot be viewed through; a fence that can be viewed through may sit within the 25-foot line.
    • Side rule applies to residential and industrial districts.
    • Rear rule (Section 10-5-4, text partly captured): 5 feet where the rear lot line abuts an alley; 30 percent of lot depth otherwise.
    • Block-average exception exists (75 percent of frontage already nonconforming) per 10-4-4 a.2 and was not analyzed.

    front setback from road right-of-way: >= 25 feet (a block-average exception applies where 75 percent or more of frontage is nonconforming) · side setback from adjoining private property: >= 5 feet · rear setback, lot not adjacent to alley: >= 30 percent of lot depth (rear setback of 5 feet where rear lot line is adjacent to an alley)

    “rear yard depth shall be a minimum of five feet (5') for lots whose rear property line is adjacent to an alley and a minimum of thirty percent (30%) of the lot depth for lots whose rear property line is not adjacent to an alley.”
  • Camping on your landLimited

    Campgrounds for recreational vehicles in the e recreational district of Keithsburg city only; not a rule for the residential district

    • Each RV parking site must be graveled or otherwise improved, have access from an improved roadway, and provide one motor vehicle parking area off the public right-of-way per nonmotorized RV.
    • Campground is a permitted use in the e recreational district only.

    RV parking site area: >= 750 square feet (per recreational vehicle site in an e recreational district campground)

    “campground for recreational vehicles; provided, that a graveled or otherwise improved parking site of at least seven hundred fifty (750) square feet shall be provided for each recreational vehicle and that each such parking site shall have access from a graveled or otherwise improved roadway, and in the case of nonmotorized vehicles, a parking area off the public right-of-way shall be provided for one motor vehicle per nonmotorized recreational vehicle.”
  • Mandatory utility hookupConditional

    A new dwelling or building inside Keithsburg city that can connect to the public sanitary sewer

    • Connection is required when the public sanitary sewer is reachable with a lateral of 200 feet or less.
    • Sewage handling facilities must be connected and in operating condition before occupancy of the dwelling or building (same section).
    • No water-main availability rule was located in the text opened; water connection is not stated.

    public sewer lateral distance threshold: <= 200 feet (Connection not required where the lateral is longer than 200 feet)

    “and if said dwelling or building can be connected to the public sanitary sewer and if such connection can be done with two hundred feet (200') or less of the lateral sewer line, then the zoning enforcer shall deny a permit unless such connection is provided.”
  • Permit processPartial

    Zoning permits for construction inside Keithsburg city

    • The city site links a zoning application form and names the zoning enforcer; the application's submittal steps and review timeline were not read.
    • Zoning board variance procedure is in Chapter 2 of Title 10 and was not opened.
    “zoning regulations can be read by clicking the link above. to learn more about mobile homes and mobile home parks, click here. click here for a zoning application.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Keithsburg or Mercer County directly.

  • Owner-builder exemption — Owner-builders in Keithsburg city
  • Building code adopted — New construction inside Keithsburg city
  • Inspections — New construction inside Keithsburg city
  • Certificate of occupancy — New dwellings inside Keithsburg city
  • Lot coverage — Lot coverage in Keithsburg city
15 more unanswered
  • Building height
  • Tiny homes
  • Manufactured homes
  • Accessory dwellings
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Agricultural exemption
  • Subdividing land
  • Driveway access
  • Building in a floodplain
  • Short-term rentals
  • Permit fees

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Unanswered questions are usually a sign that Keithsburg publishes no rule on the point, not that none exists. Mercer County’s page lists the county offices to call.

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