Colusa — Land Use

Last reviewed: July 1, 2026

Overview

This page summarizes what the City of Colusa Zoning Ordinance (Title 17) actually says about land use: the districts the City uses, what each district permits or requires, and the key dimensional and programmatic controls you must check before proposing a project. For quick jurisdiction-level rules on parking, see the city's rules on parking; for the numeric development controls see development standards; for review triggers see design review. For overlays and special combining districts consult overlay districts. When the ordinance refers to building safety or code compliance, local permits still reference the California Building Standards Code.

All statements below are tied to the Colusa municipal code clauses cited (§ numbers) and the underlying ordinance excerpts retrieved from the City's Title 17 text. Where the ordinance excerpts did not include a specific provision, I note that as "Not found in retrieved materials." Verify parcel-specific rules with the Planning Department.

District-by-district breakdown

The Colusa Zoning Ordinance establishes the list of base zones in Sec. 2.01; the ordinance also uses several special combining districts (e.g., FP, H, P, AO) listed in § 2.02.

Below are the districts most commonly relevant to residential and commercial proposals in Colusa. Each subsection gives the district purpose, typical permitted uses, the most decision-relevant dimensional standards (where the ordinance provides them) and where you find the rule in the code.

Note: the bolded district name and the controlling § are highlighted in every subsection.

R-1 — Single-Family Residence (§ 5.01–§ 5.05)

Purpose: intended for single-family residential neighborhoods; general rules in Article 32 still apply.
Typical permitted uses: one-family dwellings, accessory buildings/garages, secondary dwelling units (ADUs) in compliance with ADU rules, small residential care facilities, certain public uses, limited agriculture (no sales structures) — § 5.02.
Key dimensional standards (decision-relevant): Lot area 8,000 sq ft; lot width 80' × depth 100'; max building coverage 35%; front setback 20 ft; interior side yards minimum 5 ft and a combination not exceeding 15 ft; rear yard = 20% of lot depth (≥15 ft, ≤30 ft); height limit 2.5 stories / 35 ft; off‑street parking: Article 29 applies. See § 5.05.
Where it applies: areas mapped R‑1 on the official Zoning Map; lands not otherwise zoned default to R‑1 unless remapped per § 3.02.

(If you are proposing an ADU, see the City ADU rules in Article 49 and cross‑check state ADU law; the city’s ADU standards are summarized in § 49.01–§ 49.08.)

R-2 — Two-Family Residence (listed in § 2.01)

Purpose/uses/dimensions: R-2 is identified in § 2.01 (the district list) but the detailed R‑2 article text was not found in the retrieved materials; specific permitted uses and dimensional rules for R‑2 (Article 6) are Not found in retrieved materials. Verify R‑2 details with the Planning Department and the full ordinance text.

R-3 — Neighborhood Apartment District (listed in § 2.01)

Purpose/uses/dimensions: the R‑3 label is in the district list but the explicit R‑3 article text was not retrieved. Note: several multi‑family standards are described in R‑4 and in other articles that reference R‑3; consult the full ordinance for Sec. 6 (R‑3) text. Not found in retrieved materials.

R-4 — General Apartment District (§ 8.01–§ 8.05)

Purpose: intended where multifamily dwellings are appropriate.
Typical permitted uses: all uses permitted in R‑1, R‑2, and R‑3 plus multifamily dwellings, accessory uses, limited signs, private garages, single room occupancy, and farmworker housing (some uses may require permits) — § 8.02–§ 8.03.
Key standards: lot area 6,000 sq ft (1,500 sq ft/unit for buildings ≥5 units); max building coverage 60%; front setback 20 ft (can be reduced to 10 ft in HD combining district); side/ rear setbacks described (rear reduced to 10 ft in High Density Combining District); height up to 4 stories / 50 ft; off‑street parking per Article 29 — § 8.05.

C-N — Neighborhood Business (§ 9.01–§ 9.03)

Purpose: convenience shopping and service for nearby residents.
Permitted uses: retail stores, professional offices, barber/beauty shops, drug stores, restaurants, laundries, service stations (with enclosure), public buildings, parking lots — § 9.02.
Standards: front setback 15 ft; rear setback 15 ft; building height 1 story / 30 ft; parking as required by Article 29 — § 9.03.

C-G — General Commercial (§ 10.01–§ 10.03)

Purpose: general commercial facilities for public convenience.
Permitted uses: broad range of commercial and service uses (see § 10.02), including hotels, auto sales, bakeries, restaurants, repair shops, wholesale/retail, funeral parlors, etc. Many uses require only standard permits; some (e.g., dwellings) may require use permits.
Standards: rear setback 5 ft; side setbacks none except as required by building code; height 2 stories / 35 ft; parking Article 29 — § 10.03.

C-H — Highway Service Commercial (§ 11.01–§ 11.04)

Purpose: highway/frontage commercial services for travelers.
Permitted uses: travel-related uses such as restaurants, motels, travel trailer parks, and other highway services; advertising sign regulations specific to frontage are present — § 11.02.
Standards: front setback 15 ft; rear 15 ft; height typically 1 story / 30 ft; parking Article 29 — § 11.04.

M-1 — Light Industrial (§ 12.01–§ 12.03)

Purpose: light industrial and manufacturing operations that do not produce objectionable impacts.
Permitted uses: uses permitted in C‑G (commercial) except dwellings/hotels unless with use permit, plus warehouses, feed/fuel yards, small manufacturing (with controls on fumes/noise); certain outdoor operations allowed only when enclosed or screened — § 12.02.
Standards: rear setback 5 ft; side setbacks none except as required by other regs; building height up to 100 ft in some cases; parking Article 29; loading area required — § 12.03.

M-2 / M-L — General Industrial / Limited Manufacturing (§ 13.01–§ 14.08)

Purpose: heavier industrial uses (M‑2) and limited clean manufacturing (M‑L).
Permitted/conditional uses: M‑2 permits many heavier industrial activities (lumberyards, concrete batch plants, junkyards under enclosure) — § 13.02–§ 13.03; M‑L permits research, light manufacturing, offices, and clean industrial uses with more yard/setback controls — § 14.03–§ 14.04.
Standards: M‑2: few lot area/coverage limits; height up to 100 ft; parking Article 29 (see § 13.04). M‑L: lot area 10,000 sq ft; yards 20 ft; height 2 stories / 35 ft — § 14.04.

P-D — Planned Development (§ 15.01–§ 15.08)

Purpose: allow project‑specific planned development with tailored standards; establishment requires an application package and approval of use permits for development within the P‑D — § 15.01–§ 15.03.
Standards/process: P‑D zones are unit‑specific: base required information includes maps, elevations, and a use permit; P‑D lot area, setbacks and heights are set in the approved P‑D plan or use permit — § 15.03–§ 15.07. Variances and adjustments are possible through the planning commission — § 15.08.

P-F — Public Facilities (§ 16.01–§ 16.02)

Purpose: public uses such as schools, parks, civic centers, utility facilities. Permitted uses include public schools, parks, reservoirs, public utility facilities; some public uses require a Major Use Permit (e.g., airports, sewage disposal) — § 16.01–§ 16.02.

O-S / F-W — Open Space / Floodway (Articles listing and overlay rules)

Purpose: open space and floodway protections; where combined with base zones they add specific allowances/restrictions (e.g., crop/tree farming exceptions in FP) — Article 23 FP and district listings § 2.01–§ 23.02.

Mixed‑Use Districts — M-U-B / M-U-D / M-U-M / M-U-R (Articles 44–47; Mixed Use Table Article 48)

Purpose: multiple mixed‑use designations tailored to Bridge St, Downtown, Main St and Residential mixed‑use. Uses and the P/C/NP designations are collected in the Mixed Use Table (Article 48); M‑U‑R includes specific dimensional rules for the core and remainder areas — § 47.01–§ 47.04 and Article 48.

• Example: in M‑U‑R, minimum lot areas range from 4,800 sq ft (core) to 9,600 sq ft (remainder); front setbacks 5–10 ft; side setbacks 0–5 ft; rear 5 ft; height 35 ft — § 47.03.

Quick reference table — most decision-relevant standards and where to read them

Checklist (what an applicant must satisfy before filing a discretionary request or building permit)

• Confirm the parcel's base zoning and any combining overlays on the official Zoning Map (Sec. 3.01–3.03)
• Confirm the proposed use is a permitted use or whether a Minor Use Permit / Major Use Permit / Special Use Permit is required (see relevant district §: e.g., § 5.02, § 8.02, § 9.02)
• Match project dimensions to district development standards (lot area, setbacks, height, coverage) found in the applicable district article (e.g., § 5.05, § 8.05, § 47.03)
• Calculate off‑street parking per Article 29 and determine if a parking combining district or reductions apply; if project is mixed‑use check Article 48 matrix for allowed use type and parking requirements; refer to parking for details.
• Check combining districts (e.g., FP, H, P, AO, HD) for additional restraints or permissions — § 2.02 and each combining article (e.g., Article 23 FP)
• For ADUs, follow Article 49 and cross‑check State ADU rules (California ADU law) — see § 49.01–§ 49.08.
• If subject to design review or site plan review, follow the City’s design review procedure and supply plans per the P‑D or site review checklists.
• Verify compliance with overlay requirements (e.g., floodplain, airport height) found under overlay districts and the specific combining article (e.g., Article 23 FP, Article 24 H)
• Confirm any required permits (use permits, conditional permits, cannabis permits, adult‑oriented permits) and CEQA triggers (some permits are defined as discretionary and CEQA applies) — see cannabis rules in Article 21.5 and adult rules in Article 27.

Risks & Ambiguities

Plain-English Summary

Colusa's Title 17 divides the city into familiar zones (R‑1 single‑family; R‑4 multi‑family; C‑N/C‑G commercial; M‑1/M‑2 industrial; P‑D planned; P‑F public facilities; several mixed‑use zones). For each zone the code lists permitted uses, which uses need a discretionary use permit, and the dimensional rules (lot area, setbacks, height, coverage) you must meet; see the district articles cited above (for example, § 5.02–§ 5.05 for R‑1 rules). Always confirm parcel-level zoning and overlays with the Planning Department because combining districts and map amendments can change what you may build.

Information Gaps

• Full text for the R-2 and R-3 district articles (Article 6 / Article 7) was not present in the retrieved excerpts — specific R‑2/R‑3 dimensional rules and permitted uses are Not found in retrieved materials. Verify with the City.
• The official, current Zoning Map image with parcel-level overlays was not included in the retrieved file excerpts; parcel‑specific verification is required. Not found in retrieved materials.

Source References

• Colusa Zoning Ordinance (Title 17 Zoning): district list and general provisions — Sec. 2.01 and related articles. (See § 2.01)
• R‑1 Single Family Residence: uses and development standards § 5.02 and § 5.05.
• R‑4 General Apartment District: uses and standards § 8.02–§ 8.05.
• C‑N Neighborhood Business: uses and standards § 9.02–§ 9.03.
• C‑G General Commercial: uses and standards § 10.02–§ 10.03.
• M‑1 / M‑2 / M‑L Industrial: § 12.02–§ 12.03, § 13.02–§ 13.04, § 14.03–§ 14.04.
• Planned Development (P‑D): application and use‑permit requirements § 15.01–§ 15.08.
• Public Facilities (P‑F): permitted public uses and conditional uses § 16.01–§ 16.02.
• Mixed‑Use / M‑U‑R: purposes, uses by table, and dimensional standards § 47.01–§ 47.04 and Article 48 Mixed Use Table.
• Off‑street parking (use‑by‑use parking table and reduction rules): Article 29 and Sec. 29.01–29.02.
• ADUs: Article 49 (Accessory Dwelling Units and JADUs) — § 49.01–§ 49.08 (City standards consistent with state ADU law).
• Cannabis: Article 21.5 (commercial cannabis facility caps and permit process).
• Adult‑oriented uses: Article 27 special combining provisions and distance buffers.

Retrieved passages

• Colusa Zoning Code (Section 32.01.) High relevance show source text
• California Building Code (Article 29.) High relevance show source text
• Colusa Zoning Code (§ 30) High relevance show source text
• Colusa Zoning Code (Article 29.) High relevance show source text
• Colusa Zoning Code (§ 26) High relevance show source text
• Colusa Zoning Code (Article 29) High relevance show source text
• Colusa Zoning Code (title shall) High relevance show source text
• Colusa Zoning Code (Article 23.) Medium relevance show source text
• Colusa Zoning Code (Article 32) Medium relevance show source text
• California Building Code (Article 29.) Medium relevance show source text
• Colusa Zoning Code (Article 2.) Medium relevance show source text
• Colusa Zoning Code (§ 4) Medium relevance show source text
• Colusa Zoning Code (Article 29.) Medium relevance show source text
• Colusa Zoning Code (§ 23) Medium relevance show source text
• Colusa Zoning Code (Article 29.) Medium relevance show source text
• Colusa Zoning Code (Article 32.) Medium relevance show source text
• California Building Code (Article 29.) Medium relevance show source text
• California Building Code (Article 29.) Medium relevance show source text

Cited sections

• Colusa Zoning Ordinance (Title 17 Zoning): district list and general provisions — Sec. 2.01 and related articles. **(See § 2.01)** (Title 17)
• **R‑1 Single Family Residence**: uses and development standards **§ 5.02** and **§ 5.05**. (§ 5.02)
• **R‑4 General Apartment District**: uses and standards **§ 8.02–§ 8.05**. (§ 8.02)
• **C‑N Neighborhood Business**: uses and standards **§ 9.02–§ 9.03**. (§ 9.02)
• **C‑G General Commercial**: uses and standards **§ 10.02–§ 10.03**. (§ 10.02)
• **M‑1 / M‑2 / M‑L Industrial**: **§ 12.02–§ 12.03**, **§ 13.02–§ 13.04**, **§ 14.03–§ 14.04**. (§ 12.02)
• **Planned Development (P‑D)**: application and use‑permit requirements **§ 15.01–§ 15.08**. (§ 15.01)
• **Public Facilities (P‑F)**: permitted public uses and conditional uses **§ 16.01–§ 16.02**. (§ 16.01)
• **Mixed‑Use / M‑U‑R**: purposes, uses by table, and dimensional standards **§ 47.01–§ 47.04** and Article 48 Mixed Use Table. (§ 47.01)
• **Off‑street parking** (use‑by‑use parking table and reduction rules): Article 29 and Sec. 29.01–29.02. (Article 29)
• **ADUs**: Article 49 (Accessory Dwelling Units and JADUs) — **§ 49.01–§ 49.08** (City standards consistent with state ADU law). (Article 49)
• **Cannabis**: Article 21.5 (commercial cannabis facility caps and permit process). (Article 21.5)
• **Adult‑oriented uses**: Article 27 special combining provisions and distance buffers. (Article 27)
• Colusa_ZoningCode.md

• Official Colusa code library