Local zoning · Modoc County

Modoc County — Development Standards

Development Standards under the Modoc County local zoning and planning code, with the controlling citations.

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Last reviewed: July 6, 2026

Overview

This page distills how Title 18 (Zoning) in Modoc County sets the dimensional and site-development rules for projects in unincorporated areas—things like minimum lot sizes, setbacks, height limits, and lot coverage. The ordinance applies only in the county’s unincorporated areas; incorporated cities within the county have their own codes (see § 18.02.060) . Modoc’s districts and overlays are enumerated in § 18.02.030 and implemented via district-specific chapters plus general standards in Chapter 18.110 .

Key take-away: Before you draw a site plan, identify the base zone and any overlay on the parcel; your setbacks, height, and even minimum lot size can change with utilities and adjoining districts (§ 18.02.030; § 18.02.060) .

For broader context and process, start at the Modoc County zoning & planning overview, then drill into Modoc County Zoning, confirm any overlays under Modoc County Overlay Districts, and line up required Modoc County Design Review and Modoc County Parking standards. Variations and relief are handled through Modoc County Variances and Exceptions. If you are exploring ADUs, see California ADU law. Where the ordinance defers to construction rules, consult the California Building Standards Code.

Countywide framework

  • Districts. Principal districts include resource/ag zones (TP, OFG, RC, AE, AG, LIC, LI), residential/commercial/industrial zones (RR, RL, RH, RT, C, IL, I, PF, PD, U). Overlays include FH (Flood Hazard), EP (Environmental Protection), MP (Migration Protection), M (Minimum Lot Size), AR (Animal Restrictions), and AH (Airport Hazard) (§ 18.02.030) .
  • Applicability. Zoning applies to unincorporated areas and to state/local public lands to the extent allowed by law; federal reservations are excluded (§ 18.02.060) .
  • General compliance. Yard/open space provided for one building cannot satisfy another; buildings must conform to the height and yard rules of the zone they’re in (§ 18.02.050(D)–(E)) .
  • Measurement. Building height is measured from grade to the highest point (definition in § 18.06.160) .

Snapshot table — common dimensional standards

These are the most decision-relevant baseline standards by zone. Always verify adjacency rules (many standards tighten when abutting residential zones) and overlays.

District Min. Lot Size (utilities note) Min. Yards (front/side street; side/rear) Max Height Max Lot Coverage Code Reference
RH (Residential High) 6,000 sf (w/ sewer), 15,000 sf (water only), 3 acres (no utilities) 20 ft; 5 ft 2 stories, ≤50 ft 60% § 18.36.060
RL (Residential Low) 10,000 sf (w/ sewer), 15,000 sf (water only), 3 acres (no utilities) 20 ft; 5 ft ≤50 ft 60% § 18.32.060
RR (Rural Residential) 1–15 acres (e.g., RR‑5 = 5 acres); no lot <2 acres unless public sewer 20 ft; 30 ft Not specified in chapter Not specified in chapter § 18.30.060
RT (Rural Town) 6,000 sf (w/ sewer), 15,000 sf (water only), 3 acres (no utilities) 20 ft; 5 ft (10 ft+ when abutting res./RT dwellings) 2 stories, ≤50 ft 60% when any residential use § 18.40.060; § 18.40.010
C (Commercial) 6,000 sf; 60 ft width (residential lots must meet RH min lot) 5 ft; 5 ft (10 ft when abutting RH/RL/RR or RT with dwelling) Not set in § 18.44.060 Not set in § 18.44.060 § 18.44.060
IL (Industrial–Light) 6,000 sf; 60 ft width 10 ft; 5 ft (20 ft+ when abutting RH/RL/RR/RT) ≤75 ft (reduced when abutting res./RT) Not listed § 18.50.050
I (Industrial) 3 acres; 100 ft width 10 ft; 0 ft (50 ft+ when abutting RH/RL/RR/RT; no activity in that yard) ≤100 ft (reduced when abutting res./RT) Not listed § 18.54.050
PF (Public Facilities) None 20 ft; 0 ft (10 ft+ when abutting RH/RL/RR/RT) ≤100 ft (reduced when abutting res./RT) Not listed § 18.62.050
AG (Agricultural General) 3 acres (15 acres where adjacent to AE lands) 20/10 ft; 5 ft (20 ft farm bldgs abutting RH/RL/RR; 50 ft dwellings abutting AE) Not listed 10% (excludes lots <5 acres) § 18.24.060
AE (Agricultural Exclusive) 80 acres typical; limited 1‑acre or 5‑acre splits allowed by criteria with “M” overlay 20/10 ft; 50 ft (dwellings) Not listed 10% (≤5 acre parcels exempt) § 18.18.060–.070
LI (Low Intensity) 20 acres 20/10 ft; 10 ft Not listed Not listed § 18.28.060
RC (Resource Conservation) 80 acres 20/10 ft; 30 ft Not listed Not listed § 18.16.060
OFG (Open Space, Forestry & Grazing) No minimum to apply zone; no future division <80 acres 20/10 ft; 30 ft Not listed Not listed § 18.14.070
TP (Timberland Production) 80 acres (or one quarter section) See Ch. 18.110 for general limits Not listed Not listed § 18.10.060
PD (Planned Development) Min development area 1 acre; standards adopted by PD ordinance Yards/setbacks are plan‑driven; zero‑lot lines may be allowed Plan‑driven Plan‑driven § 18.60.060
U (Unclassified) 3 acres (may require more to mitigate impacts) 20/10 ft; 5 ft (20 ft farm bldgs abutting RH/RL/RR; 50 ft dwellings abutting AE) Not listed 10% (excludes lots <5 acres) § 18.66.060

Notes:

  • Where a standard is “not listed,” the chapter either defers to Chapter 18.110 or does not set a numeric figure (verify with staff). Many zones include adjacency rules that increase yards or reduce height when abutting residential districts (e.g., RH/RL/RR) or RT with an existing or approved dwelling (see examples in §§ 18.40.060, 18.44.060, 18.50.050, 18.54.050) .

District-by-district detail (unincorporated areas)

RH — Residential High Density

  • Purpose/typical uses: Neighborhood-scale housing; single- and two-family by right; broader residential and community uses often by permit (§ 18.36.010; § 18.36.030–.050) .
  • Dimensional highlights: 6,000–15,000 sf lots where served by utilities; 3 acres without; 20 ft front; 5 ft sides/rear; ≤50 ft building height; 60% coverage (§ 18.36.060) .
  • Where applied: Urban residential areas consistent with the General Plan (§ 18.36.010) .

RL — Residential Low Density

  • Purpose/typical uses: Lower density residential than RH, with similar accessory/community allowances (§ 18.32.010–.050) .
  • Dimensional highlights: 10,000–15,000 sf lots with utilities; 3 acres without; 20 ft front; 5 ft sides/rear; ≤50 ft building height; 60% coverage (§ 18.32.060) .
  • Where applied: Urban and rural residential plan designations (§ 18.32.010) .

RR — Rural Residential

  • Purpose/typical uses: Large-lot rural living (1–15 acres), low-intensity recreation and incidental ag (§ 18.30.010, .030) .
  • Dimensional highlights: Zone suffix sets minimum lot (e.g., RR‑5 = 5 acres); no lots <2 acres unless public sewer; 20 ft front; 30 ft sides/rear; height not specified in chapter (§ 18.30.060) .
  • Where applied: Rural residential areas consistent with the General Plan (§ 18.30.010) .

RT — Rural Town

  • Purpose/typical uses: Mixed low-density “main street” communities with residential, commercial, and some ag (§ 18.40.010) .
  • Dimensional highlights: 6,000–15,000 sf lots where served; 3 acres without; 20 ft front; 5 ft sides/rear; when abutting residential/RT dwellings, some yards increase to 10 ft; ≤50 ft height; 60% lot coverage when there’s a residential use (§ 18.40.060) .
  • Where applied: Established unincorporated communities or new mixed-use consistent with the General Plan (§ 18.40.010) .

C — Commercial

  • Purpose/typical uses: Wide range of retail, services, offices; outdoor components by permit (§ 18.44.010–.050) .
  • Dimensional highlights: 6,000 sf/60 ft width; 5 ft front/side street; 5 ft sides/rear (increase to 10 ft next to RH/RL/RR or RT with dwellings); height not specified in this section; access/parking per Chapter 18.110 (§ 18.44.060) .
  • Where applied: Urban/commercial plan designations or supportive locations without plan conflicts (§ 18.44.010) .

IL — Industrial–Light

  • Purpose/typical uses: Light manufacturing, storage, logistics; select commercial and caretaker housing by permit (§ 18.50.030–.040) .
  • Dimensional highlights: 6,000 sf minimum lot; 10 ft front; 5 ft sides/rear; when abutting residential/RT, yards increase and max height steps down from 75 ft (§ 18.50.050) .
  • Where applied: Industrial/service corridors consistent with the General Plan.

I — Industrial (heavy)

  • Purpose/typical uses: Heavy industry, processing, high-impact operations (§ 18.54.030–.040) .
  • Dimensional highlights: 3 acres; 10 ft front; 0 ft sides/rear (but 50 ft+ next to RH/RL/RR/RT and no activity in that yard); ≤100 ft height (reduced when abutting residential/RT) (§ 18.54.050) .

PF — Public Facilities

  • Purpose/typical uses: Public utilities, parks, schools, government facilities (§ 18.62.010–.040) .
  • Dimensional highlights: No minimum lot size; 20 ft front; 0 ft sides/rear (10 ft+ when abutting RH/RL/RR/RT); ≤100 ft height (reduced when abutting residential/RT) (§ 18.62.050) .

AG — Agricultural General

  • Purpose/typical uses: Broad agricultural production, support services by permit (§ 18.24.030–.050) .
  • Dimensional highlights: 3 acres minimum; 15 acres if adjacent to AE lands that meet certain criteria; 20/10 ft front; 5 ft sides/rear (with notable adjacency exceptions); 10% lot coverage (lots <5 acres excluded) (§ 18.24.060) .

AE — Agricultural Exclusive

  • Purpose/typical uses: Protect high-value agriculture; very limited non-ag uses (§ 18.18.010–.050) .
  • Dimensional highlights: 80 acres typical minimum; tightly controlled one-time 1‑acre or limited 5‑acre splits only if stringent criteria are met and the M overlay is applied to prohibit further splits; 20/10 ft front; 50 ft sides/rear for dwellings; 10% coverage (≤5-acre parcels exempt) (§ 18.18.060–.070) .

LI — Low Intensity (rural transition)

  • Purpose/typical uses: Transitional resource/rural areas; limited recreation and a single dwelling (§ 18.28.010–.050) .
  • Dimensional highlights: 20 acres minimum; 20/10 ft front; 10 ft sides/rear (§ 18.28.060) .

LIC — Low Intensity Conservation

  • Purpose: Very limited development where environmental constraints (slope/soil) exist (§ 18.20.010) .
  • Dimensional standards: Not found in retrieved materials. Verify with the jurisdiction.

RC — Resource Conservation

  • Purpose: Conserve wildlife/natural resources; very limited development (§ 18.16.010) .
  • Dimensional highlights: 80 acres; 20/10 ft front; 30 ft sides/rear (§ 18.16.060) .

OFG — Open Space, Forestry and Grazing

  • Purpose: Large open-space/forestry/grazing lands (§ 18.14.010–.060) .
  • Dimensional highlights: May be applied to any parcel size, but future divisions cannot create parcels under 80 acres; 20/10 ft front; 30 ft sides/rear (§ 18.14.070) .

TP — Timberland Production

  • Purpose: Managed timber production under the state Timberland Productivity Act (§ 18.10.060–.080) .
  • Dimensional highlights: 80 acres (or quarter-section) minimum; other development aspects rely on general standards (§ 18.10.060) .

PD — Planned Development

  • Purpose: Custom, plan-driven projects mixing uses and lot sizes under unified control (§ 18.60.010–.040) .
  • Dimensional highlights: 1 acre minimum development area; setbacks, open space, and circulation are set through the PD permit and ordinance; zero-lot lines may be allowed (§ 18.60.060) .

U — Unclassified

  • Purpose: Interim “holding” zone before precise zoning is adopted (§ 18.66.010–.030) .
  • Dimensional highlights: 3 acres minimum (may require more for resource/service constraints); 20/10 ft front; 5 ft sides/rear with adjacency exceptions; 10% coverage (≤5-acre parcels exempt) (§ 18.66.060) .

Overlays that change development standards

  • FH — Flood Hazard: Additional siting/elevation, encroachment, and floodway provisions; prohibits or conditions new development in mapped flood areas (§§ 18.71.170–.220) .
  • EP — Environmental Protection: Establishes restricted areas and allows density to shift to less-sensitive areas; ties to the M (Minimum Lot Size) overlay for future divisions (§§ 18.74.030–.050) .
  • M — Minimum Lot Size: Used in AE/AG/EP contexts to lock in minimums after limited splits (§ 18.18.070; § 18.74.030) .
  • AH/AR/MP: Airport/animal/migration protections—standards not fully retrieved; see Modoc County Overlay Districts.

Special residential design standards

  • Multifamily projects must meet objective site/coverage and design criteria (e.g., ≤70% building/impervious coverage, 10% improved landscape, parking placement, and certain architectural features) (§ 18.110.080) .

Practical tips

  • Utility availability matters. Several zones let you use smaller lots if you are on public water and/or sewer (e.g., RH, RL, RT)—confirm utility status early (§§ 18.36.060; 18.32.060; 18.40.060) .
  • Adjacency rules can re-shape your layout. Industrial/PF yards and heights shrink when next to RH/RL/RR or RT dwellings (§§ 18.50.050; 18.54.050; 18.62.050) .
  • Overlays trump. In FH, your building placement and elevation may be more constrained than base-zone setbacks would suggest (§§ 18.71.170–.220) .
  • Definitions matter. Height and lot coverage follow the definitions in Chapter 18.06; for example, building height per § 18.06.160 and lot coverage per § 18.06.565 .

Checklist

  • Confirm parcel zoning and any overlays on the county map (§ 18.02.030–.040) .
  • Verify public water/sewer availability; apply the correct minimum lot size (§§ 18.36.060; 18.32.060; 18.40.060) .
  • Lay out setbacks for your district; check if adjacency to RH/RL/RR/RT increases yards (§§ 18.44.060; 18.50.050; 18.54.050) .
  • Confirm max building height and any adjacency reductions (§§ 18.50.050; 18.54.050; 18.62.050) .
  • If multifamily, meet the objective design standards in § 18.110.080 .
  • If within FH/EP or similar overlays, add overlay-specific requirements (§§ 18.71.170–.220; 18.74.030) .
  • Align access, parking, and sign plans to Chapter 18.110 cross-references in your zone.
  • Determine if design review or a use permit applies; if standards are infeasible, consider a variance.

Risks & Ambiguities

Issue Why it matters What to verify
Utility-dependent lot sizes RH/RL/RT minimums change with water/sewer; misclassifying utilities can cause noncompliance Utility provider confirmation; apply the correct table in §§ 18.36.060; 18.32.060; 18.40.060
Abutting residential/RT Triggers larger yards and lower heights for C/IL/I/PF Site context; apply adjacency clauses in §§ 18.44.060; 18.50.050; 18.54.050; 18.62.050
Overlays (FH/EP/M) Can override base-zone allowances; flood or resource constraints can limit buildable area FEMA mapping and county overlay maps; apply §§ 18.71.170–.220; 18.74.030–.050; 18.18.070
Height methodology Height is measured by definition, not always to a fixed number in every zone Use § 18.06.160 and any district cap; document grade references on plans
FAR limits FAR is not specified in retrieved zoning chapters Not found in retrieved materials; consult planning staff
LIC standards LIC development metrics not surfaced in the excerpts Not found in retrieved materials; verify before design

Plain-English Summary

In unincorporated Modoc County, what you can build—and how big or tall it can be—depends first on your base zone and whether overlays like flood hazard apply. Residential zones set minimum lot sizes that shrink with public utilities, while commercial/industrial districts have small front yards but larger buffers and lower heights next to homes. Many details (parking, signs, multifamily design) point to common standards in Chapter 18.110; confirm these early so your site plan passes on the first submittal.

Source References

  • Title 18 Zoning: districts and applicability — §§ 18.02.030–.040, 18.02.060
  • Definitions (height, coverage, lot): §§ 18.06.160, 18.06.565, 18.06.640–.650
  • RH standards — § 18.36.060; RL standards — § 18.32.060; RR standards — § 18.30.060
  • RT purpose/standards — §§ 18.40.010, 18.40.060
  • C standards — § 18.44.060; IL standards — § 18.50.050; I standards — § 18.54.050; PF standards — § 18.62.050
  • AG standards — § 18.24.060; AE standards — §§ 18.18.060–.070; LI standards — § 18.28.060; RC standards — § 18.16.060; OFG standards — § 18.14.070; TP standards — § 18.10.060; U standards — § 18.66.060
  • Multifamily objective design — § 18.110.080
  • Overlays — FH flood provisions §§ 18.71.170–.220; EP density/lot framework § 18.74.030–.050

Sources

Retrieved passages

  • Modoc County Zoning Code (section may) High relevance
  • Modoc County Zoning Code (Section 18) High relevance
  • Modoc County Zoning Code (Chapter 18.110) High relevance
  • Modoc County Zoning Code (chapter 18.110) High relevance
  • Modoc County Zoning Code (Chapter 18.110.) Medium relevance
  • Modoc County Zoning Code (Chapter 18.20) Medium relevance
  • Modoc County Zoning Code (§ 65595) Medium relevance
  • Modoc County Zoning Code (§ 17958.1) Medium relevance
  • Modoc County Zoning Code (Chapter 18.110.) High relevance
  • Modoc County Zoning Code (Chapter 18.100.) Medium relevance
  • Modoc County Zoning Code (Chapter 18.110.) Medium relevance
  • Modoc County Zoning Code (Chapter 18.110) Medium relevance
  • Modoc County Zoning Code (Section 18.100.030) Medium relevance
  • Modoc County Zoning Code (Section 18.100.030) Medium relevance
  • Modoc County Zoning Code (Chapter 18.110.) Medium relevance
  • Modoc County Zoning Code (section 18.100.020) Medium relevance
  • Modoc County Zoning Code (Section 18.100.030) Medium relevance
  • Modoc County Zoning Code (Chapter 18.144.) Medium relevance
  • Modoc County Zoning Code (section shall) Medium relevance
  • Modoc County Zoning Code (section 18.100.030) Medium relevance
  • Modoc County Zoning Code (chapter shall) Medium relevance
  • Modoc County Zoning Code (Section 18.74.040.) Medium relevance
  • Modoc County Zoning Code (Chapter 18.110) Medium relevance
  • Modoc County Zoning Code (Chapter 18.110.) High relevance
  • Modoc County Zoning Code (Section 18.62.030) Medium relevance
  • Modoc County Zoning Code (Section 18.100.010) Medium relevance

Cited sections

Frequently asked questions

What can I build on an RR lot in unincorporated Modoc County?

The RR district allows one single-family home, with large rural lots from 1 to 15 acres (e.g., RR‑5 = 5 acres). Minimum yards are 20 ft front/side street and 30 ft side/rear; no lot under 2 acres may be created unless public sewer is available (§ 18.30.030; § 18.30.060) .

What are the standard residential setbacks and heights for RH and RL?

In RH: front 20 ft, side/rear 5 ft, up to two stories but not exceeding 50 ft. In RL: the same setbacks and height cap. Lot coverage is 60% in both (§ 18.36.060; § 18.32.060) .

How do commercial or industrial projects handle buffers next to housing?

Commercial and industrial zones increase side/rear yards and/or reduce heights when abutting RH/RL/RR—or RT with existing/approved dwellings (e.g., IL yards jump to 20 ft and height may step down). Check the specific adjacency clauses in your zone (§§ 18.44.060; 18.50.050; 18.54.050; 18.62.050) .

Do utilities change minimum lot sizes?

Yes. Several zones scale minimum lot size by utility availability. For example, RH and RT allow 6,000 sf lots on public sewer, 15,000 sf on public water only, and 3 acres with neither. RL starts at 10,000 sf when sewer is available (§§ 18.36.060; 18.40.060; 18.32.060) .

Are there special design rules for multifamily housing?

Yes. Objective standards cap building/impervious coverage at 70% of the site, require at least 10% improved landscaping, specify parking placement away from street fronts, and call for certain architectural features (§ 18.110.080) .

How does the Flood Hazard overlay affect setbacks and building placement?

Within mapped flood hazard areas, projects must meet elevation, floodproofing, and encroachment controls. These can supersede base-zone siting flexibility, including where you can place fill or build in floodways (§§ 18.71.170–.220) .

Can I split an AE (Agricultural Exclusive) parcel to carve out a homesite?

Possibly, but AE splits are tightly limited. A one-time 1‑acre or a limited 5‑acre split may be allowed only if strict findings are met and the M overlay is applied to preclude further splits; otherwise AE remains at 80 acres (§ 18.18.070) .

Where do I find the exact definition of building height?

Height is defined in § 18.06.160 as the vertical distance from grade to the top of the structure, with roof-type specifics. Apply this definition along with any zone height caps (§ 18.06.160) .

Do Rural Town (RT) lots have the same residential coverage as RH/RL?

RT allows up to 60% lot coverage when a dwelling or residential use is on the lot, with 20 ft front and 5 ft side/rear yards (subject to increases at residential edges). Max building height is two stories, not exceeding 50 ft (§ 18.40.060) .

Is floor area ratio (FAR) used in Modoc County zoning?

FAR standards were not found in the retrieved zoning chapters. Verify with the planning department if a project or overlay imposes an FAR limit. Not found in retrieved materials.

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