Local zoning · Imperial County

Imperial County — Nonconforming Uses

Nonconforming Uses under the Imperial County local zoning and planning code, with the controlling citations.

Last reviewed: July 6, 2026

Overview

This page explains how Imperial County’s Land Use Ordinance governs nonconforming uses, structures, lots, setbacks, and signs in the unincorporated areas. Rules live primarily in Chapter 5 of Title 9 and apply across all base zones and overlay districts. Where a use or structure was legal before a change in the ordinance or map but does not meet current standards, the County sharply limits expansion, regulates rebuilding after damage, and sets abandonment timelines. Zoning maps maintained by the Planning and Development Services Department define where each zone applies in the unincorporated areas (§ 90501.04; maps are part of Title 9) .

The core rule in unincorporated areas: you generally may continue a legal nonconforming use or structure, but you may not enlarge it—and if you abandon it for one year, you lose it (§§ 90105.01(B)–(C), 90105.02(A)–(C), 90105.03(A)–(C)) .

What “nonconforming” means in Imperial County

The ordinance defines a nonconforming building, nonconforming lot, and nonconforming use as those that were lawful before adoption or amendment of Title 9 but fail to meet present district requirements (§ 91401.13 “N.”) .
Chapter 5’s stated policy is not to allow enlargement/expansion of incompatible nonconformities (§ 90105.00) .

Countywide nonconforming rules (unincorporated areas)

Nonconforming structures: May continue with maintenance/repair; no enlargement; 1-year vacancy bars re-use for a nonconforming use; rebuilding after damage allowed only if repair/reconstruction expense does not exceed 50% of the building’s assessed value at the time of damage and starts within one year; front-yard-setback changes allow like-for-like siting without greater nonconformity; condemned nonconforming structures may not be rebuilt (§ 90105.01(A)–(G)) .
Nonconforming use of structures: May continue without increase in area/volume; once changed to a conforming use, cannot revert; 1-year abandonment ends rights; may change to a similar or lesser-intensity nonconforming use if no structural alteration and no amortization extension (§ 90105.02(A)–(D)) .
Nonconforming uses of land (no main building): No expansion; no change to other uses except a conforming one; 1-year abandonment ends rights; stand‑alone land uses must be discontinued within five years of the effective date of Title 9 (§ 90105.03(A)–(D)) .
Nonconforming lots: A legally recorded lot may be used for permitted uses in its zone only if all yard/setback requirements can be met and necessary health/safety facilities can be accommodated (e.g., septic, well) (§ 90105.04) .
Nonconforming setbacks: A permitted use that exists with nonconforming setbacks may be replaced on the same location if damaged/destroyed—regardless of cost—so long as no new portion encroaches into the nonconforming setback (§ 90105.05) .
Nonconforming signs: 5-year amortization from the effective date of Title 9 or a later amendment; after that, remaining signs are illegal/public nuisances; only like-for-like structural repairs and routine maintenance allowed during the 5-year period; removal/alteration may be conditioned on discretionary approvals (§ 90105.06(A)–(D)) .
Proving status: When there is doubt, documentation must be submitted to the Planning Director to establish legal nonconforming status (§ 90105.07) .
No mixing uses on a lot with a nonconforming use: While a nonconforming use exists on a lot, the County will not permit any other new use unless the nonconforming use is removed or the owner signs a County-approved abatement agreement (§ 90501.06(A)(3)) .

Telecommunications—specific nonconforming allowances

Modifying a nonconforming telecommunication facility is not deemed an “expansion” if the type, height, and location aren’t changed and intensity is not substantially altered; determination is by the Planning Director (§ 92413.02(A)–(B)) .
Damaged/destroyed nonconforming telecom facilities may be rebuilt to the same type/height/location without discretionary approval; building permits must meet the California Building Standards Code and be pulled within 180 days (§ 92413.03(A)–(B)) .
Time extensions for a nonconforming telecom facility can be granted by the Planning Commission after a noticed hearing when specific findings are met (§ 92413.04(A)–(C)) .

The “PE” overlay for pre-existing operations

The PE (Pre-Existing Allowed/Restricted) overlay can be applied in addition to a base zone to allow an identified pre-existing, otherwise nonconforming operation to continue, maintain, and modify structural facilities required under Health & Safety regulations; it may be enlarged by no more than 30% of its current assessed value and replaced if destroyed by fire, flood, or act of God (§ 90501.09) .

Decision guide: key nonconforming standards (unincorporated areas)

Topic	What the code allows/prohibits	Code Reference
Continue a nonconforming structure	Allowed; routine maintenance/repair only; no enlargement	§ 90105.01(A), § 90105.01(B)
Vacancy/abandonment	1 year of vacancy/abandonment ends ability to use/occupy nonconformingly	§ 90105.01(C), § 90105.02(C), § 90105.03(C)
Rebuild after damage (nonconforming structure)	Allowed if cost ≤ 50% of assessed value; no area expansion; start within 1 year	§ 90105.01(D)
Rebuild with nonconforming setback	Allowed regardless of cost; no new portion within the setback	§ 90105.05
Change to conforming use	Once changed, cannot revert to a nonconforming use	§ 90105.02(B)
Change between nonconforming uses	Only to similar or lesser intensity; no structural alterations; no amortization extension	§ 90105.02(D)
Nonconforming uses of land w/o buildings	Must cease within 5 years of Title 9’s effective date	§ 90105.03(D)
Nonconforming lots	May be used if yards/setbacks and health/safety facilities can be met	§ 90105.04
Nonconforming signs	5-year amortization; then illegal and a nuisance	§ 90105.06(A)–(B)
New conforming use on lot with nonconforming use	Prohibited unless nonconforming use is removed or abated by agreement	§ 90501.06(A)(3)
Telecom exceptions	Limited modifications not an “expansion”; rebuild if destroyed; time extensions possible	§§ 92413.02–.04

How these rules play out by district (unincorporated areas)

Zoning applies per the officially maintained maps and map notes (§ 90501.04; § 90501.05) . Nonconforming rules above apply in every zone listed below; the purpose and key standards here help you evaluate feasibility in your specific district alongside Imperial County Zoning and Imperial County Development Standards.

A-2 (General Agriculture)

Purpose/use character: Agricultural production; additional agricultural-related uses occur subject to Title 9 Chapter 90508.* (Selected CUP/use lists appear in § 90508.02; prohibited uses are in § 90508.03) .
Key dimensional standards:
- Minimum lot size: 40 acres gross (§ 90508.04) .
- Structure separation: 10 ft house–accessory; 15 ft between dwellings; 50 ft house–animal structures; 100 ft animal structures or septic–well (§ 90508.08(A)–(E)) .
- Parking: Provided per countywide standards (§ 90508.09; see also Imperial County Parking) .
- Signs: Limited temporary and CUP-approved signs (§ 90508.10; see Imperial County Signage) .
- Landscaping: Mirrors M-1 for nonresidential; R-1 for residential (§ 90508.11; see Imperial County Landscaping and Screening) .
Where it applies: Per official zoning maps (§ 90501.04) .

AM-1 (Agricultural-Related Light Industrial)

Purpose: Provide limited, agriculturally compatible industrial uses and a path for existing M-1/M-1-N to align with the General Plan without becoming nonconforming (§ 90510.00(A)–(C)) .
Typical permitted uses: Agricultural accessory structures, cold storage, farm implement manufacturing/repair (under employee thresholds), feed stores, fuel (bulk) sales, and more (§ 90510.01) .
Key standards: Commercial/industrial developments comply with countywide development standards (street dedications, paved parking areas, utility undergrounding, screening, etc.) (§ 90301.02) .
Where it applies: As zoned on official maps (§ 90501.04) .

AM-2 (Agricultural-Related Medium Industrial)

Purpose: Support medium-intensity, ag-related industry; provide a path to keep certain existing industrial areas consistent with the General Plan without rendering them pre-existing nonconformities (§ 90511.00(B)–(D)) .
Typical permitted uses: From farm-labor housing to processing, packaging, creamery/dairy processing, cotton gins, composting, and more (§ 90511.01) .
CUP uses: E.g., asphalt/concrete batch plants; communication towers; certain manufacturing (§ 90511.02) .
Key standards: See commercial/industrial development standards (§ 90301.02) .
Where it applies: As zoned on official maps (§ 90501.04) .

M-2 (Medium Industrial)

Purpose/use character: Heavier industrial activities than M-1; many uses require a CUP.
CUP uses: Animal slaughter/stock yards, wrecking yards, major electrical facilities, recycling, smelting, surface mining, trucking yards, etc. (§ 90516.02) .
Key standards: Follow commercial/industrial development standards (§ 90301.02) .
Where it applies: As zoned on official maps (§ 90501.04) .

R-1 (Low Density Residential)

Purpose/use character: Low-density residential (base permitted uses not found in retrieved materials).
Key dimensional standards: Detached accessory buildings—max 35 ft height; siting restrictions relative to front yards and interior lines (§ 90501.12(A)–(F)) .
Where it applies: As zoned on official maps (§ 90501.04) .

R-2 (Medium Density Residential)

Purpose/use character: Medium density residential (base permitted uses not found in retrieved materials).
Key dimensional standards: Follows the same detached accessory building controls cited in § 90501.12(A)–(F) .
Where it applies: Per official maps (§ 90501.04) .

R-3 (High Density Residential)

Purpose/use character: High-density residential (base permitted uses not found in retrieved materials).
Key dimensional standards: Detached accessory building limits per § 90501.12(A)–(F) .
Where it applies: Per official maps (§ 90501.04) .

R-4 (High Density Residential and Mobile Home Park/Subdivision)

Purpose/use character: Higher-density residential and MH parks/subdivisions (base permitted uses not found in retrieved materials).
Key dimensional standards: Detached accessory building limits per § 90501.12(A)–(F) .
Where it applies: Per official maps (§ 90501.04) .

MU (Mixed-Use Overlay)

Purpose: Encourage integrated residential/commercial on the same parcel; overlay may be established over C-1 or C-2 base zones; site plan review is required (§ 90501.11(A)–(B)). Nonconforming rules still apply to pre-existing conditions within the overlay .
Where it applies: As adopted on official maps (§ 90501.04) .

U (Urban Areas Overlay)

Purpose: Identify lands within or adjacent to incorporated urban areas; in these areas, the County intends to adhere to the standards of the applicable urban jurisdiction to the extent feasible. Nonconforming status is still judged under County Title 9 in the unincorporated areas (§ 90501.08) .

H (Airport Height Restriction Zone)

Purpose: Limit structure height near airports; may influence whether a nonconforming structure can be reconstructed to prior height (§ 90501.10) .
Where it applies: Properties placed in “H” by application and covenant, per § 90501.10 .

Practical relationships to other reviews

A project that modifies or replaces structures also triggers relevant development standards and may need site-level approvals (e.g., MU overlay site plan review). For discretionary entitlements, the County can condition removal of nonconforming signs (§ 90105.06(D))—coordinate early with Imperial County Design Review and Imperial County Signage where applicable.
Nonconforming constraints are distinct from Imperial County Variances and Exceptions. A variance does not legalize an illegal nonconforming use; you must establish legal nonconforming status (§ 90105.07) .
State ADU law separately limits when a local agency can force correction of certain nonconforming zoning conditions as part of ADU permitting; see California ADU law for state-specific rules (context: HCD 2025 ADU Handbook) .

Checklist

Confirm the use/structure/lot/sign was lawful when established and lies in the unincorporated area (§ 90105.00; § 91401.13) .
Assemble documentation for the Planning Director to verify legal nonconforming status (§ 90105.07) .
Show no enlargement of the nonconforming structure/use is proposed (§§ 90105.01(B), 90105.02(A)) .
If rebuilding after damage, provide cost and assessor data to demonstrate ≤ 50% assessed value, and plan to start within one year (§ 90105.01(D)) .
If replacing a use with a nonconforming setback, keep all new work out of the setback (§ 90105.05) .
Confirm the nonconforming use has not been abandoned for one year (§§ 90105.02(C), 90105.03(C)) .
Do not add any other new use on the lot while the nonconforming use remains, unless you enter a County abatement agreement (§ 90501.06(A)(3)) .
For nonconforming signs, track the 5-year amortization and maintenance-only limits (§ 90105.06(A)–(C)) .
Check your zone’s base standards (e.g., A-2 setbacks/lot size; M‑zones site improvements) and parking to ensure any replacement work conforms (§§ 90508.*, 90301.02) .
If a telecom facility, consider the special modification/rebuild/time-extension allowances (§§ 92413.02–.04) .

Risks & Ambiguities

Issue	Why it matters	What to verify
One-year “abandonment” clock	Rights terminate after 12 months of nonuse	Document continuous use or permissible interruptions (§§ 90105.02(C), 90105.03(C))
50% assessed value cap vs. setbacks exception	Rebuild cap for nonconforming structures contrasts with unlimited-cost replacement for nonconforming setbacks	Apply the right standard for your case (§ 90105.01(D) vs. § 90105.05); consult the County
“Enlargement” interpretation	Minor changes can be viewed as expansion	Scope drawings to show no area/volume increase (§§ 90105.01(B), 90105.02(A))
Adding a new conforming use to a site	Code bars any new use while a nonconforming use remains	Either remove the nonconforming use or secure a written abatement agreement (§ 90501.06(A)(3))
Proving legal status	Burden is on the owner to show legality at inception	Provide permits, assessor records, historic aerials (§ 90105.07)
Telecom exceptions are discretionary	Director/Commission decide if a modification is not an “expansion”; time extensions need findings	Pre-application with staff; align with § 92413.02–.04 criteria
Interaction with overlays	PE/U/MU/H overlays can alter feasibility	Confirm overlay status on the official map (§ 90501.04; § 90501.09; § 90501.11; § 90501.08; § 90501.10)

Plain-English Summary

In the unincorporated areas, Imperial County lets you keep using a legal nonconforming building or use, but you cannot enlarge it. If you stop the nonconforming use for a year, or if a structure is too badly damaged (over 50% of assessed value), nonconforming rights end—except that permitted uses with old, nonconforming setbacks can be rebuilt in place if no new work encroaches. Special exceptions exist for telecom facilities and some pre-existing operations with the PE overlay, but most projects should plan to comply with current zoning, development standards, and signage rules going forward.

Information Gaps

Base permitted uses and dimensional standards for R-1, R-2, R-3, R-4 beyond accessory building limits: Not found in retrieved materials. Verify with the jurisdiction.
Complete permitted/CUP use lists for A-2 (90508.01/.02 headers): Not found in retrieved materials. Verify with the jurisdiction.
Any County-adopted amortization schedules for nonconforming uses (not signs): Not found in retrieved materials.
Procedures for determining assessed value for § 90105.01(D) rebuilds (appraisal method/timing): Not found in retrieved materials.

Source References

§ 90105.00–90105.01 (Purpose; Nonconforming structures) — Title 9, Chapter 5 (Nonconforming)
§ 90105.02–90105.06 (Nonconforming uses; land; lots; setbacks; signs) — Title 9, Chapter 5
§ 90105.07 (Determination of status) — Title 9, Chapter 5
§ 90501.04–90501.06 (Zoning maps; regulations in zones) — Title 9, Division 5
§ 90501.08–90501.11 (U overlay; PE overlay; H zone; MU overlay) — Title 9, Division 5
§ 90501.12 (Accessory buildings in R-1–R-4) — Title 9, Division 5
§ 90301.02 (Commercial/industrial development standards) — Title 9, Division 3
§ 90508.* (A-2 standards: lot size, separations, parking, signs, landscaping) — Title 9, Chapter 8 A‑2 zone
§ 90510.00–90510.01 (AM-1 purpose; permitted uses) — Title 9, Chapter 10 AM‑1
§ 90511.00–90511.02 (AM-2 purpose; permitted and CUP uses) — Title 9, Chapter 11 AM‑2
§ 90516.02 (M-2 CUP uses) — Title 9, Chapter 16 M‑2
§ 91401.13 (Definitions—nonconforming) — Title 9, Division 14
§§ 92413.02–92413.04 (Telecommunications—nonconforming modifications, rebuilds, extensions) — Title 9, Division 24
State context: HCD 2025 ADU Handbook excerpts (nonconforming zoning conditions and ADUs)

Sources

Retrieved passages

Imperial County Zoning Code (§ 90105.02) High relevance
Imperial County Zoning Code (§ 24) High relevance
Imperial County Zoning Code (§ 3) High relevance
Imperial County Zoning Code (§ 90105.01) High relevance
Imperial County Zoning Code (§ 11) High relevance
Imperial County Zoning Code (§ 90104.06) High relevance
Imperial County Zoning Code (§ 11) Medium relevance
Imperial County Zoning Code (Chapter 5) Medium relevance
Imperial County Zoning Code (§ 3) Medium relevance
Imperial County Zoning Code (§ 3) Medium relevance
Imperial County Zoning Code (§ 1) Medium relevance
Imperial County Zoning Code (§ 3) Medium relevance
Imperial County Zoning Code (§ 3) Medium relevance
Imperial County Zoning Code (§ 1) Medium relevance

Cited sections

Official Imperial County code library

Frequently asked questions

Can I enlarge or add to a nonconforming building in the unincorporated areas?

No. You may maintain and repair it, but any enlargement in area, space, or volume is prohibited (§ 90105.01(B)). If the structure was condemned, you may not rebuild it if it’s nonconforming (§ 90105.01(G)) .

If my nonconforming building is damaged in a storm, can I rebuild it?

Yes, but only if the reconstruction expense is 50% or less of the building’s assessed value at the time of damage, with no expansion, and you start within one year (§ 90105.01(D)). A special rule lets permitted uses with nonconforming setbacks be replaced at the same spot regardless of cost, so long as no new work encroaches in the setback (§ 90105.05) .

How long can I stop using a site before I lose nonconforming rights?

One year. Abandonment for a period of one year or more ends nonconforming rights for uses in structures and uses of land (§§ 90105.02(C), 90105.03(C)) .

Can I add a new, conforming use on a lot that already has a nonconforming use?

Not unless you remove the nonconforming use or sign a written abatement agreement with the County. While a nonconforming use exists on a lot, no other new use is permitted (§ 90501.06(A)(3)) .

What proof do I need to show something is legally nonconforming?

Provide documentation to the Planning Director showing the use/structure/lot/sign was lawful when established (e.g., permits, approvals, records). The code requires documentation in cases of doubt (§ 90105.07) .

Do the nonconforming rules treat telecommunications differently?

Yes. Modifying a nonconforming telecom facility (without changing type, height, or location) is not considered an expansion; damaged/destroyed facilities may be rebuilt to the same specs without discretionary approval. Time extensions can be granted by the Planning Commission (§§ 92413.02–.04) .

What happens to nonconforming signs in the unincorporated areas?

They can continue for five years from the effective date of Title 9 (or of a later amendment that made them nonconforming). After five years they become illegal and a public nuisance; only same-size/shape repairs and routine maintenance are allowed during the amortization period (§ 90105.06(A)–(C)) .

Can a legally recorded, undersized lot be used?

Yes—only if you can still meet all yard/setback requirements and provide necessary health/safety facilities (e.g., septic, well) for the permitted use in that zone (§ 90105.04). If not, a variance may be a separate question, but it does not itself create nonconforming rights .

Are there overlays that help a pre-existing operation continue?

Yes. The PE overlay can allow a specifically identified pre-existing use to keep operating, make health-and-safety-required modifications, expand facilities up to 30% of assessed value, and replace after certain disasters (§ 90501.09) .

Where do I find which zone I’m in?

Check the official County zoning maps kept by Planning and Development Services; only a signed and embossed copy is official (§ 90501.04). If a boundary is uncertain, Planning Commission determines location (§ 90501.05) .

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