Rialto — Overlay Districts

Last reviewed: July 2, 2026

Overview

Rialto’s municipal zoning title (Title 18) uses multiple overlay districts to add site‑ or corridor‑specific rules on top of the underlying zoning. Overlays in Rialto include corridor and downtown revitalization overlays, a Residential Overlay, hazard/airport overlays, and design/architectural overlays; each overlay defines where it applies, what extra uses or limits it allows or prohibits, and the discretionary approvals required. The summaries below synthesize the ordinance requirements and point to the controlling code sections so you can verify for a specific parcel.

How to read this page

• Bolded terms highlight the overlay or specific numbers you will look for on a parcel report (for example, Riverside Avenue Corridor Overlay or 15 ft front yard).
• Every requirement cites the Rialto code section with the § glyph and the file excerpt that contains it. Use the citations to read the ordinance text directly.
• When the ordinance delegates design control or site standards to a plan or director, expect a discretionary review (see Checklist and Risks).

Overlay districts — district‑by‑district

Residential Overlay (Chapter 18.116)

Purpose and where it applies

• The Residential Overlay aims to “allow for attractive high density residential development” while leaving the underlying zoning intact; it is explicitly optional for property owners and does not force redevelopment. § 18.116.010.
• The overlay is mapped to specific areas including properties near Baseline Road and Riverside Avenue, properties in the Gateway Specific Plan, Central Area Specific Plan, Foothill Boulevard Specific Plan, and other listed areas. § 18.116.020.

Typical permitted uses and approvals

• Multiple family dwellings of four or fewer units are allowed by right; developments of five or more units require a Conditional Development Permit (CDP) from the Planning Commission. § 18.116.040.
• Non‑residential development within the overlay continues to follow the underlying zone. § 18.116.010.

Key dimensional/approval notes

• The overlay’s regulations apply only to residential development within the mapped overlay; nonresidential uses remain subject to the underlying zone standards. § 18.116.020.
• For projects of five or more units the CDP process and findings set out in Chapter 18.66 apply. § 18.116.040 (cross‑references).

Practical guidance

• If you own property inside one of the mapped overlay areas, you can choose to pursue the overlay’s residential entitlements (to access higher density) or keep the current underlying use. Verify overlay map location before assuming residential entitlement. Verify with the jurisdiction. § 18.116.020.

Downtown Revitalization Overlay Zone (Chapter 18.49)

Purpose and where it applies

• The Downtown Revitalization Overlay implements the General Plan and the Rialto Central Area Specific Plan for properties fronting a portion of Riverside Avenue between identified railroad rights‑of‑way. § 18.49.010–18.49.020.

Permitted actions and design controls

• Most exterior changes, demolition, or material alterations visible from public streets require prior approval of a Precise Plan of Design by the Community Development Director; building permits that would effect exterior changes are withheld until that design approval is granted. § 18.49.030(A)(1).
• The overlay references the Rialto Central Area Specific Plan standards; unless stated otherwise those specific plan development standards control. § 18.49.030(C)(1).

Key standards

• The overlay commonly eliminates required building setbacks (no required setbacks from property lines), but the community development director may impose setbacks as a condition of the precise plan where they enhance project integrity and do not deprive reasonable use. § 18.49.030(C)(2).

Design review

• The Community Development Director is the primary reviewer and approves precise plans of design; approval is based on findings including compliance with city ordinances and compatibility with surrounding uses. § 18.49.040(A), (G).

Practical guidance

• Expect an emphasis on architectural continuity, preservation of historic resources, and pedestrian‑oriented elements. Link your submittal to the Precise Plan of Design requirements early; incomplete design submissions will delay building permit issuance. § 18.49.030–18.49.040.

Riverside Avenue Corridor Overlay Zone (Chapter 18.51)

Purpose and where it applies

• The Riverside Avenue Corridor Overlay applies to R-3 multiple family residential parcels fronting Riverside Avenue between Foothill Boulevard and Walnut Avenue, intended to allow administrative and professional office uses in place of residential where appropriate. § 18.51.010–18.51.020.

Permitted uses and permits

• Administrative and professional office uses are allowed only after a Conditional Development Permit (CDP) and a Planning Commission finding limiting retail activity and on‑site goods sales. § 18.51.030.

Development standards (selected)

• Front yard: 15 ft minimum (but not greater than 30 ft where neighboring front yards are deeper). § 18.51.040(A).
• Side yards: 5 ft minimum; exceptions include 15 ft street side for corner lots and 10 ft where adjacent to a residential dwelling. § 18.51.040(B).
• Rear yard: 15 ft. § 18.51.040(C).
• Building height: 2.5 stories / 35 ft maximum. § 18.51.040(E).
• Required street‑front setbacks must be landscaped and maintained. § 18.51.040(D).

Practical guidance

• Converting an R-3 property to offices is discretionary; prepare landscape plans and parking plans (off‑street parking is regulated in Chapter 18.58) to support the CDP. § 18.51.030–18.51.040.

(See the related design review and parking rules when preparing a submittal: link to parking and design review.)

Rialto Avenue–Cedar Avenue Corridor Commercial Overlay Zone (Chapter 18.43)

Purpose and where it applies

• This overlay allows C‑3 (general commercial) uses on selected M-1 and M-2 parcels fronting portions of Rialto Avenue (between Willow and Linden) and Cedar Avenue (between the former PE Railroad ROW and Merrill Ave), to enable conversion of certain industrial parcels to commercial uses. § 18.43.010–18.43.020.

Permitted uses and permits

• Commercial uses permitted under the C‑3 chapter may be allowed on qualifying M‑1/M‑2 parcels only after approval of a Conditional Development Permit with findings about site adequacy, utilities, compatibility with industrial character, and minimizing adverse effects. § 18.43.030(A–D).

Development standards

• Commercial conversions must conform to standards listed in § 18.43.040 (development standards for commercial uses on M‑1/M‑2 within the overlay); see the code for the full list and any parking cross‑references. § 18.43.040.

Practical guidance

• Expect rigorous CDP findings because the ordinance prioritizes compatibility with existing industrial operations. Prepare analysis of truck access, on‑site loading, noise, odors, and utilities to support the required findings. § 18.43.030.

Hazardous Waste (HW) Overlay Zone (Chapter 18.47)

Purpose and where it applies

• The Hazardous Waste Overlay governs siting, expansion, and operational controls for hazardous waste handling, treatment, storage, transfer, and disposal in the designated heavy industrial areas of the Agua Mansa Industrial Corridor Specific Plan. § 18.47.010–18.47.020.

Permitted and conditional uses

• Limited uses (e.g., household hazardous waste collection centers) may be permitted with distance and quantity limits; other hazardous waste facilities (on‑site treatment, off‑site storage, transfer stations, Class III disposal) require a CDP and completion of an Initial Environmental Study (to determine if an EIR and risk assessment are required). § 18.47.050–18.47.060.

Prohibitions

• The overlay explicitly prohibits certain high‑risk facilities (Class I and II disposal, cement kilns burning hazardous waste, etc.). § 18.47.070.

Practical guidance

• Hazardous waste uses are heavily conditioned and may trigger environmental review; plan for more extensive technical studies (risk assessment, traffic, air quality) and longer review timelines. § 18.47.060.

Architectural Design (D) Zone (Chapter 18.46)

Nature and function

• The D zone is an overlay classification that is combined with another zone (e.g., D‑C‑2). It adds mandatory design review: no change of use, structural alteration, or construction occurs until a detailed plan is submitted and approved by the Planning Commission. § 18.46.010–18.46.020.

Criteria reviewed

• The Planning Commission considers site plan, building height/bulk, parking/loading, landscape, setbacks, and signs when approving designs. § 18.46.020(A–F).

Practical guidance

• When your property carries a D designation, assume a discretionary design review step and include elevations, materials, landscape, and parking/loading plans. § 18.46.020.

Airport / Approach Area Overlay (Chapter 18.50) (airport‑related overlays)

Purpose and where it applies

• The airport overlay regulates development within approach/transition/horizontal/conical surfaces of the municipal airport. It requires avigation/noise easements and gives the director a role in review of building permits. § 18.50.120–18.50.140.

Key controls

• Conflicting regulations defer to the more stringent rule; avigation easements may be required prior to building permits in defined safety areas. § 18.50.120, § 18.50.140.

Practical guidance

• For properties near the airport, expect special permit conditions and easements; contact Planning and Building early. Verify with the jurisdiction. § 18.50.140.

Decision‑relevant quick table

Checklist

• Confirm whether the parcel is inside any overlay map (Residential, Downtown Revitalization, Riverside Corridor, Rialto/Cedar corridor, Hazardous Waste, D zone, Airport overlay). § 18.116.020; § 18.49.020; § 18.51.020; § 18.43.020; § 18.47.020; § 18.46.010; § 18.50.120.
• Identify the underlying base zone and compare its uses to the overlay’s allowed/required uses. (Overlays often preserve the underlying zoning; overlay adds uses or restrictions.) § 18.116.010; § 18.43.030.
• Determine whether a Conditional Development Permit (CDP), Precise Plan of Design, or other discretionary approval is required and prepare the applicable findings. § 18.66; overlay chapters. § 18.49.040; § 18.51.030; § 18.43.030; § 18.116.040.
• Prepare parking, landscape, and site plans consistent with overlay standards and cross‑referenced chapters (off‑street parking Chapter 18.58). § 18.49.040(B)(7).
• For hazardous activities, budget for environmental studies (initial study / EIR / risk assessment) per § 18.47.060.
• If property is in the downtown overlay, prepare façades, signage, lighting and pedestrian access information to meet the precise plan findings. § 18.49.040(B)(2–11).

(If you will submit plans, consult the city’s development checklist and the Development Services front counter for file completeness: Verify with the jurisdiction.)

Risks & Ambiguities

Plain‑English Summary

Rialto’s overlays are “layers” on top of the usual zoning: some let new uses (e.g., residential in mapped corridors), some require design approval (downtown, D zone), and some strictly control hazardous or airport‑area uses. If your parcel sits in an overlay, you must follow the overlay’s rules in addition to the base zone; many overlay changes require a Conditional Development Permit or a Precise Plan of Design and related studies. Always verify the overlay map and the required discretionary approvals with Planning. § 18.116.020; § 18.49.030; § 18.43.030; § 18.47.060.

Source References

• Rialto Municipal Code — Downtown Revitalization Overlay Zone, § 18.49.010–18.49.040.
• Rialto Municipal Code — Residential Overlay, § 18.116.010–18.116.040.
• Rialto Municipal Code — Riverside Avenue Corridor Overlay, § 18.51.010–18.51.040.
• Rialto Municipal Code — Rialto Avenue–Cedar Avenue Corridor Commercial Overlay, § 18.43.010–18.43.040.
• Rialto Municipal Code — Hazardous Waste Overlay Zone, § 18.47.010–18.47.070.
• Rialto Municipal Code — Architectural Design (D) Zone, § 18.46.010–18.46.020.
• Rialto Municipal Code — Airport / Approach Area (Chapter 18.50) (avigation easements, safety areas). § 18.50.120–18.50.140.

Helpful internal pages to consult while you prepare a submittal:

• Rialto zoning & planning overview: Rialto zoning & planning overview
• For base rules and mapping: Rialto Zoning
• For dimensional table cross‑checks: Rialto Development Standards
• For parking requirements referenced by overlays: Rialto Parking
• For precise plan and façade expectations: Rialto Design Review
• For historic resources in downtown overlay: Rialto Historic Preservation
• For signage controls in overlays: Rialto Signage
• For nonconforming and CDP rules: Rialto Nonconforming Uses and Rialto Variances and Exceptions
• For landscape and buffering expectations: Rialto Landscaping and Screening
• For accessory dwelling unit questions inside overlays, consult: Rialto ADUs and state law at California ADU law
• For building code matters (not covered by this page): California Building Standards Code

Retrieved passages

• Rialto Zoning Code (Title XII) High relevance show source text
• Rialto Zoning Code (section are) Medium relevance show source text
• Rialto Zoning Code (§ 8) Medium relevance show source text
• Rialto Zoning Code (§ 1) Medium relevance show source text
• Rialto Zoning Code (Title XII) Medium relevance show source text
• Rialto Zoning Code (§ 2) Medium relevance show source text
• Rialto Zoning Code (Chapter 18.72) Medium relevance show source text
• Rialto Zoning Code (Title XII) Medium relevance show source text

Cited sections

• Rialto Municipal Code — **Downtown Revitalization Overlay Zone**, **§ 18.49.010–18.49.040**. (§ 18.49.010)
• Rialto Municipal Code — **Residential Overlay**, **§ 18.116.010–18.116.040**. (§ 18.116.010)
• Rialto Municipal Code — **Riverside Avenue Corridor Overlay**, **§ 18.51.010–18.51.040**. (§ 18.51.010)
• Rialto Municipal Code — **Rialto Avenue–Cedar Avenue Corridor Commercial Overlay**, **§ 18.43.010–18.43.040**. (§ 18.43.010)
• Rialto Municipal Code — **Hazardous Waste Overlay Zone**, **§ 18.47.010–18.47.070**. (§ 18.47.010)
• Rialto Municipal Code — **Architectural Design (D) Zone**, **§ 18.46.010–18.46.020**. (§ 18.46.010)
• Rialto Municipal Code — **Airport / Approach Area (Chapter 18.50)** (avigation easements, safety areas). **§ 18.50.120–18.50.140**. (Chapter 18.50)
• Rialto zoning & planning overview: Rialto zoning & planning overview
• For base rules and mapping: Rialto Zoning
• For dimensional table cross‑checks: Rialto Development Standards
• For parking requirements referenced by overlays: Rialto Parking
• For precise plan and façade expectations: Rialto Design Review
• For historic resources in downtown overlay: Rialto Historic Preservation
• For signage controls in overlays: Rialto Signage
• For nonconforming and CDP rules: Rialto Nonconforming Uses and Rialto Variances and Exceptions
• For landscape and buffering expectations: Rialto Landscaping and Screening
• For accessory dwelling unit questions inside overlays, consult: Rialto ADUs and state law at California ADU law
• For building code matters (not covered by this page): California Building Standards Code
• Rialto_ZoningCode.md

• Official Rialto code library