Plumas County Overlay Districts — Zoning Ordinance

Last reviewed: July 6, 2026

Overview

In unincorporated Plumas County, overlay districts (called combining zones) layer additional rules on top of a parcel’s base zoning. The County’s zoning maps show both the base zone and any overlay(s); where an overlay applies, its standards control in addition to the base zone. The combining zones established in Title 9 include the Flood Plain (FP), Special Plan (SP), Manufactured Home (MH), Business Exclusion (BX), Farm Animal (F), and Limited (Ltd) overlays, each with its own purpose and procedures under the County’s Plumas County Zoning regulations. The County maintains official zoning maps and applies zone boundary rules to determine exactly where an overlay lies on the ground (§ 9-2.302; § 9-2.304) .

No physical aspect of a property in a Special Plan Area may be altered without special plan review—this overlay adds a separate design/historic review layer to any underlying zone (§ 9-2.3703(a)) .

The following combining zones are explicitly listed as part of Plumas County’s zoning framework (§ 9-2.301) :

Flood Plain Combining (FP)
Special Plan Combining (SP) — includes Design Review Areas (DRA), Scenic Areas (ScA), Scenic Roads (ScR), Historical Areas (HA), Historical Buildings (HB)
Manufactured Home Combining (MH)
Business Exclusion Combining (BX)
Farm Animal Combining (F)
Limited Combining (Ltd)

The County also adopts wildfire hazard mapping in a separate chapter for Local Responsibility Area Fire Hazard Severity Zones (moderate, high, very high), which functions as a mapped constraint layer used in planning decisions (§ 9-9.5.101–102) . Always confirm whether an overlay applies to unincorporated property by checking the official zoning plan map and any adopted special plan documents (§ 9-2.302; § 9-2.3702) .

FP — Flood Plain Combining Zone (FP)

Purpose: Ensure reasonable safety from flood hazards (§ 9-2.3501) .
Typical permitted uses:
- In primary flood hazard areas: no buildings; flood control works allowed (alterations, channelization, diversion, fill) for the protection of existing uses, subject to Title 8, Chapter 17 (§ 9-2.3502(a)) .
- In secondary flood hazard areas: no habitable structures; nonhabitable structures allowed where they won’t adversely alter off-site historic flood patterns (§ 9-2.3502(b)) .
- In mapped 100‑year flood areas that are not primary/secondary: the base zone’s uses are permitted (§ 9-2.3502(c)) .
Key dimensional/placement standards: Express prohibitions (no buildings; no habitable structures) substitute for typical dimensional controls in the most hazardous areas (§ 9-2.3502) .
Where it applies: Areas designated as primary/secondary/100-year flood hazard on County floodplain maps; implementation cross-references the County’s flood regulations (Title 8, Ch. 17) (§ 9-2.3502) . Coordinate base-zone setbacks through Plumas County Development Standards.

SP — Special Plan Combining Zone (SP) (DRA, ScA, ScR, HA, HB)

Purpose: Administer design review areas; protect scenic resources; and manage historical areas/buildings with tailored standards and community-specific guidelines (§ 9-2.3701) .
Typical permitted uses: Same as the base zone, but any physical changes are subject to Special Plan Review; demolition of designated historical buildings requires a public‑interest evaluation (§ 9-2.3703) .
Key process/standards:
- No alteration of a site/building without Special Plan Review (§ 9-2.3703(a)) .
- A Special Plan Review Committee (appointed by the Board) may set and apply review standards; decisions are appealable per Article 10 (§ 9-2.3704) .
- The requirements for each Special Plan Area are adopted into the General Plan (§ 9-2.3703(b)(2)) .
Where it applies: Areas identified in the General Plan as DRA, ScA, ScR, HA, or HB (§ 9-2.3702) . Expect coordination with Plumas County Design Review and Plumas County Historic Preservation. Note: other standards sometimes reference SP areas; for example, siting of certain telecom facilities must avoid adverse impacts in SP-ScA/ScR/HA/HB (§ 9-2.4108(a)(3)(ii)) .

MH — Manufactured Home Combining Zone (MH)

Purpose: Allow installation of manufactured homes and commercial coaches on support systems (§ 9-2.3801) .
Typical permitted uses: Manufactured homes and commercial coaches, subject to the provisions of the base zone; undersides must be skirted/obscured (decks or landscaping) (§ 9-2.3802(a)) .
Key dimensional standards: Follows the base zone’s yards, height, and coverage; MH adds installation and screening requirements (§ 9-2.3802(a)(2)) .
Where it applies: Parcels designated with MH on the zoning plan map (§ 9-2.302) . For accessory units, see County ADU provisions and California ADU law.

BX — Business Exclusion Combining Zone (BX)

Purpose: Preclude or exclude businesses (§ 9-2.3901) .
Typical permitted uses: Residential dwelling and appurtenant residential uses only, with limited exceptions for small-scale residentially compatible uses (child day care homes, limited day care, limited home businesses, limited residential community care) (§ 9-2.3902(a)) .
Key dimensional standards: Follows the base zone; BX functions as a categorical use limitation overlay (§ 9-2.3902(a)) .
Where it applies: Parcels shown with BX on the zoning plan map (§ 9-2.302) . Coordinate other controls like Plumas County Signage and Plumas County Parking at time of review.

F — Farm Animal Combining Zone (F)

Purpose: Provide for animal husbandry (§ 9-2.4001) .
Typical permitted uses: Small and large animal husbandry (§ 9-2.4002(a)) .
Key dimensional standards: F follows the base zone; the overlay ensures animal uses are permitted notwithstanding base-zone ambiguity (§ 9-2.4002) .
Where it applies: Parcels mapped with F (§ 9-2.302) . Check any related yard/setback, fencing, or screening expectations in Plumas County Landscaping and Screening and development standards.

Ltd — Limited Combining Zone (Ltd)

Purpose: Permit and mitigate uses with potential for significant adverse social, economic, or environmental effects; used to implement the General Plan’s Limited Industrial areas (§ 9-2.2701) .
Typical permitted uses: Uses allowed by the base zone are permitted but become subject to site development review; all other uses track the base zone’s requirements (§ 9-2.2702) .
Key dimensional standards: Follows base zone; the overlay adds a site development review step to address specified potential impacts (§ 9-2.2702) .
Where it applies: Parcels zoned with the Ltd combining designation in accordance with the General Plan mapping and zoning ordinance (§ 9-2.2701–2702) .

Most decision-relevant rules at a glance

Overlay	Core effect	Typical limits/permissions	Added process	Code Reference
FP	Flood hazard safety	No buildings in primary FP; no habitable structures in secondary FP; base-zone uses OK in other 100-year areas	Coordinate with Title 8 flood regs	§ 9-2.3501–3502
SP	Design/scenic/historic controls	Base-zone uses allowed; physical changes require review; historic demo requires public-interest test	Special Plan Review Committee; appealable	§ 9-2.3701–3704
MH	Manufactured homes allowed	Manufactured homes/commercial coaches on supports; skirting/landscape screening	Admin review per base zone	§ 9-2.3801–3802
BX	Business uses excluded	Dwelling + appurtenant residential uses only; limited care/home business exceptions	Tracks base zone	§ 9-2.3901–3902
F	Animal husbandry allowed	Small and large animal husbandry	Tracks base zone	§ 9-2.4001–4002
Ltd	Impact-mitigation overlay	Base-zone uses OK but subject to site development review; others per base zone	Site development review required	§ 9-2.2701–2702

How overlays interact with base zoning and other rules

Overlays add to the base zone; parcels must comply with both (§ 9-2.303) . See the Plumas County Land Use and Plumas County Development Standards pages for base-zone use lists and dimensional controls.
Zoning plan maps govern where an overlay applies (§ 9-2.302). If a zone boundary is uncertain, staff determine it; the Board can decide appeals (§ 9-2.304(d)) .
Special Plan (SP) areas are also adopted into the General Plan (§ 9-2.3703(b)(2)); SP review is in addition to any other approvals and can influence design elements you’d otherwise address via Plumas County Design Review or Plumas County Historic Preservation .
Some topic-specific standards point back to overlays; e.g., certain telecom facilities cannot undermine SP scenic or historic purposes (§ 9-2.4108(a)(3)(ii)) .
The County’s LRA Fire Hazard Severity Zones are adopted by ordinance and can affect review and mitigation in mapped areas, separate from the repealed “Potential High Fire Hazard Combining Zone” (§ 9-9.5.101–102; Article 36 repealed note) .

Checklist

Confirm the parcel is in the unincorporated area (these rules do not apply inside incorporated cities).
Identify the base zone and any overlays on the County zoning plan map (§ 9-2.302) .
If mapped in the FP overlay, determine whether the site is in a primary or secondary flood hazard area and plan uses accordingly (§ 9-2.3502) .
If within an SP area, assemble plans and materials for Special Plan Review; verify applicable design/historic guidelines (§ 9-2.3703–3704) .
For MH, confirm base-zone allowance for residential placement and provide required skirting/landscaping (§ 9-2.3802) .
For BX, limit the program to residential and the listed small-scale exceptions (§ 9-2.3902) .
For F, confirm husbandry type and check any related yard/screening expectations in development standards.
For Ltd, prepare for site development review even if the base zone permits the use (§ 9-2.2702) .
Cross-check project compliance with Plumas County Parking, Plumas County Signage, and other applicable Plumas County Development Standards.
If you rely on prior rights, consult Plumas County Nonconforming Uses. For relief, see Plumas County Variances and Exceptions. Verify with the jurisdiction.

Risks & Ambiguities

Issue	Why it matters	What to verify
Flood hazard tier (primary vs. secondary)	Primary/secondary tiers control whether buildings or habitable structures are allowed	How the site is classified under County flood maps; applicable FP allowances (§ 9-2.3502)
Whether a parcel is in an SP area	Triggers Special Plan Review and tailored design/historic standards	The General Plan SP designation and any adopted guidelines; role of the SP Review Committee (§ 9-2.3702–3704)
Scope of BX exceptions	BX sharply restricts non-residential activity	That the intended use fits “dwelling appurtenant” or the listed limited exceptions (§ 9-2.3902(a))
Overlay boundary location	Small shifts can change what’s allowed	Official zoning plan map and, if uncertain, staff/Board boundary determinations (§ 9-2.302; § 9-2.304(d))
Wildfire hazard mapping (LRA FHSZ)	Can add mitigation/conditions beyond base zoning	Whether the parcel lies in mapped moderate/high/very high LRA FHSZ and related code triggers (§ 9-9.5.101–102)
Interaction with other topic codes	Parking/signage/design controls can shape project feasibility	Project conformance with Development Standards, Parking, Signage, and any SP-specific guidelines

Plain-English Summary

Overlays in unincorporated Plumas County add special rules to your base zoning. Floodplain overlays limit buildings in the most flood‑prone areas; Special Plan overlays require a separate design/historic review; Manufactured Home and Farm Animal overlays confirm those uses are allowed; the Business Exclusion overlay blocks business uses; and the Limited overlay requires site development review. Always check the County zoning map for overlays and be ready to meet any added review or restrictions in addition to your base zone.

Source References

Zoning plan maps; zone list and overlay categories; conformance; zone boundaries: § 9-2.301–304
Flood Plain Combining Zone (FP): § 9-2.3501–3502
Special Plan Combining Zone (SP): § 9-2.3701–3704
Manufactured Home Combining Zone (MH): § 9-2.3801–3802
Business Exclusion Combining Zone (BX): § 9-2.3901–3902
Farm Animal Combining Zone (F): § 9-2.4001–4002
Limited Combining Zone (Ltd): § 9-2.2701–2702
Telecommunications cross-reference to SP: § 9-2.4108(a)(3)(ii)
LRA Fire Hazard Severity Zones (LRA FHSZ) mapping: § 9-9.5.101–102
General planning context: Plumas County zoning & planning overview

Sources

Retrieved passages

CBC § 1 (Section 9-4.348.) Medium relevance
Plumas County Zoning Code (Article 30) Medium relevance
CBC § G103 (SECTION G103) Medium relevance
Plumas County Zoning Code (chapter and) Medium relevance
Plumas County Zoning Code (Article 11.5) Medium relevance
Plumas County Zoning Code (Article 18) Medium relevance
Plumas County Zoning Code (§ 61204) Medium relevance
Plumas County Zoning Code (§ 2) Medium relevance
Plumas County Zoning Code (§ 3) Medium relevance
Plumas County Zoning Code (§ 3) Medium relevance
Plumas County Zoning Code (§ 3) Medium relevance
Plumas County Zoning Code (§ 3) Medium relevance
Plumas County Zoning Code (§ 3) Medium relevance
Plumas County Zoning Code (Article 5) Medium relevance
Plumas County Zoning Code (§ 3) Medium relevance
Plumas County Zoning Code (Section 9-9.202) Medium relevance
Plumas County Zoning Code (§ 3) Medium relevance
Plumas County Zoning Code (§ 1) Medium relevance

Cited sections

Zoning plan maps; zone list and overlay categories; conformance; zone boundaries: § 9-2.301–304 (§ 9-2.301)
Flood Plain Combining Zone (FP): § 9-2.3501–3502 (§ 9-2.3501)
Special Plan Combining Zone (SP): § 9-2.3701–3704 (§ 9-2.3701)
Manufactured Home Combining Zone (MH): § 9-2.3801–3802 (§ 9-2.3801)
Business Exclusion Combining Zone (BX): § 9-2.3901–3902 (§ 9-2.3901)
Farm Animal Combining Zone (F): § 9-2.4001–4002 (§ 9-2.4001)
Limited Combining Zone (Ltd): § 9-2.2701–2702 (§ 9-2.2701)
Telecommunications cross-reference to SP: § 9-2.4108(a)(3)(ii) (§ 9-2.4108)
LRA Fire Hazard Severity Zones (LRA FHSZ) mapping: § 9-9.5.101–102 (§ 9-9.5.101)
General planning context: Plumas County zoning & planning overview
PlumasCounty_ZoningCode.md

Official Plumas County code library

Frequently asked questions

What overlays does Plumas County use in unincorporated areas?

The code establishes Flood Plain (FP), Special Plan (SP), Manufactured Home (MH), Business Exclusion (BX), Farm Animal (F), and Limited (Ltd) combining zones, which layer over base zoning (§ 9-2.301) . Each overlay adds special permissions or review on top of the underlying zone.

What does the Flood Plain (FP) overlay allow me to build?

In primary flood hazard areas, no buildings are permitted; in secondary areas, no habitable structures are allowed. In other 100‑year flood areas, you may build what the base zone allows, subject to flood regulations (§ 9-2.3502) . Verify your site’s flood tier with the County before designing.

Do I need design review in a Special Plan (SP) overlay?

Yes. No physical aspect of a property in an SP area can be altered without Special Plan Review. A committee applies adopted guidelines; demolition of historic buildings must be weighed against the public interest (§ 9-2.3703–3704) .

Can I install a manufactured home if I’m in the MH overlay?

Generally yes—manufactured homes and commercial coaches are allowed on support systems, with skirting/landscape screening, and still must meet the base zone’s standards (§ 9-2.3801–3802) . Confirm any setbacks and height from your base zone.

What does the Business Exclusion (BX) overlay prohibit?

BX limits parcels to residential and appurtenant residential uses, with small exceptions (e.g., child day care homes, limited home businesses) (§ 9-2.3902(a)) . If you’re planning any commercial activity, expect denial in BX areas.

How do I know if my property is inside an overlay?

Check the County zoning plan map; overlays are mapped like base zones (§ 9-2.302). If a boundary is unclear, staff make a determination, and you can appeal to the Board (§ 9-2.304(d)) .

Does the SP overlay affect other permits like telecom facilities?

Yes. Other codes must respect SP purposes; for example, telecom siting cannot adversely impact SP scenic/historic areas (§ 9-2.4108(a)(3)(ii)) . Expect added design conditions within SP overlays.

Is there a wildfire hazard overlay I should check?

The County adopts LRA Fire Hazard Severity Zones (moderate/high/very high) that can shape planning decisions (§ 9-9.5.101–102) . This is separate from zoning but can affect feasible design and mitigation.

Plumas County — Overlay Districts