Local zoning · Grand Terrace

Grand Terrace — Overlay Districts

Q: What must I do to use the R3‑24 overlay for a multi‑family project?

A property owner may elect the R3‑24 overlay only on parcels with that overlay on the map and only if the project commits to the required affordable set‑aside (at least 5% very‑low or 10% lower‑income units) and records an affordable housing covenant; development follows R3‑24 standards in Chapter 18.10 and is processed administratively per § 18.48.020–050 .

Q: If an overlay requires a covenant (like R3‑24), when is it recorded?

For the R3‑24 overlay , the affordable housing agreement and recorded covenant must be in place prior to issuance of any building permit for a development exercising the overlay; the code also requires reimbursement of City processing costs § 18.48.050–060 .

Overlay Districts under the Grand Terrace local zoning and planning code, with the controlling citations.

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Last reviewed: July 2, 2026

Overview

Overlay districts in Grand Terrace are special zoning layers that modify or add to the rules of underlying base zones for specific purposes (flood management, agriculture, adult-business location, or housing-density incentives). The official zoning map shows where overlays apply and the overlay rules either supplement or, in limited cases, supersede the base-zone rules. See the City’s zoning map and base-zone rules before planning a project; overlay rules are codified throughout Title 18. Zoning designations and map rules are established in § 18.09.020 and § 18.09.030 . Overlay-related projects frequently touch design standards and review procedures, so expect coordination with the City’s site and architectural review process and the development standards (see design review and development standards) Grand Terrace Zoning Grand Terrace Design Review Grand Terrace Development Standards.

How this page is scoped

This page covers only overlay districts that appear in Grand Terrace Title 18 (zoning ordinance) as retrieved: FP (Floodplain Overlay), AG (Agricultural Overlay), AG-2 (Agricultural-2 Overlay), R3-24 (High Density Residential Overlay / R3-24 overlay), and the Adult Business (AB) overlay. All references below are tied to specific code sections; verify parcel-specific designations on the official zoning map before acting (§ 18.09.030) .

Overlay districts — district-by-district

FP — Floodplain Overlay District

Purpose: The FP overlay identifies FEMA-designated flood hazard areas and imposes floodplain management rules in addition to the underlying district, and where conflicts exist the FP overlay rules prevail for flood matters § 18.50.010 .
Typical permitted uses: Flood control channels, levees, spreading grounds/basins, roads, bridges and diversion drains with county flood-control approval § 18.50.020 .
Conditional uses: Agriculture and other uses permitted in the underlying district (subject to a conditional use permit) § 18.50.030 .
Key compliance notes: All uses and structures must be reviewed for FEMA regulations; FP regulations are expressly “in addition to” the underlying district; where conflict exists FP controls flood-related rules § 18.50.040 .
Where it applies: Parcels shown with the FP designation on the official zoning map § 18.09.030 .

Practical guidance: If your lot is in the FP overlay, expect additional submittal items (flood elevations, FEMA compliance, and possibly engineered floodproofing) and confirm whether the FP overlay imposes any building/lowest-floor elevation or mitigation conditions (verify with the City’s planning/engineering staff).

AG — Agricultural Overlay District

Purpose: The AG overlay permits limited agricultural uses in areas that historically contained such uses and where parcel sizes can support a compatible relationship between agriculture and nearby residential uses § 18.53.010 .
Typical permitted uses and standards: Table 18.53.020 lays out animal density and site-area minimums (e.g., horses, small animals, birds) including permitted vs. conditionally permitted categories — see TABLE 18.53.020 § 18.53.020 .
Key dimensional/operational standards: Minimum site area per animal and maximum numbers are specified in the table; temporary seasonal sale stands are subject to Director approval and County health-code compliance § 18.53.020, § 18.53.070 .
Where it applies: Parcels mapped as AG on the official zoning map § 18.09.020 .

Practical guidance: Use Table 18.53.020 as the first screen for whether an animal or small horticultural operation is allowed; if you plan sales or food service, check County health department requirements and obtain any temporary-stand permits § 18.53.080 .

AG-2 — Agricultural-2 Overlay District

Purpose: The AG-2 overlay allows limited commercial agricultural uses with single-family residential as accessory to support commercial ag operations; it sets rules to protect health, safety and community welfare § 18.56.010 .
Typical permitted uses: Limited commercial agricultural activities and accessory residential uses tied to the operation (detailed operational limits are in Chapter 18.56) § 18.56.010 .
Key standards: The chapter establishes operational restrictions, sizes and uses intended to maintain compatibility with residential neighbors (see Chapter 18.56 for specifics) § 18.56.010 .
Where it applies: Parcels mapped as AG-2 on the official zoning map § 18.09.020 .

Practical guidance: Commercial ag uses in AG-2 often require coordination with the Planning Director for operational conditions; check for specific lot-size and buffering requirements that may be in Chapter 18.56.

R3-24 Overlay District (High Density Residential Overlay)

Purpose: The R3-24 overlay allows property owners an optional alternative to the base zone to permit multi‑family housing at 20–24 units/acre to facilitate affordable housing production § 18.48.010 .
Applicability and affordability requirements: The overlay applies only at the property owner’s request for sites that carry the R3-24 overlay on the official zoning map, and only when the development makes a legally binding commitment to provide either at least 5% of units affordable to very‑low‑income households or 10% affordable to lower‑income households (Health & Safety Code references) § 18.48.020.A .
Design and unit distribution rules: Affordable units must be dispersed and comparable in design, and constructed concurrently with market-rate units unless the affordable housing agreement provides a different schedule § 18.48.020.B–C .
Development regulations & standards: Projects exercising the overlay must comply with the same regulations that apply to the R3-24 district as established in Chapter 18.10 (i.e., base R3-24 development standards apply) § 18.48.030 .
Review & approvals: Applications in the R3-24 overlay are processed as administrative site and architectural review per Subsection 18.63.020.C and 18.48.040. Developers must enter an affordable housing agreement and record a covenant before building permits are issued § 18.48.040–050 .
CEQA note: Developments within the R3-24 and R3-24 overlay are listed as not constituting a “project” for purposes of Division 13 (PRC § 21000) under Subsection 18.63.020.C (i.e., the code treats certain R3-24 projects as ministerial for CEQA triggers; see the code for exact scope) § 18.63.020.C.5 .
Where it applies: Parcels mapped as R3-24 or carrying the R3-24 overlay on the official zoning map § 18.09.020–030 .

Practical guidance: The R3-24 overlay is an owner‑opt‑in density incentive tied to enforceable affordability covenants (traceable to Government Code requirements). Expect an affordable housing agreement, recorded covenant, and administrative site/architectural review; check Chapter 18.10 for the numerical development standards that will apply § 18.48.030–050 .

AB — Adult Business Overlay

Purpose/Scope: The City created an Adult Business (AB) overlay to identify where adult businesses may locate; the AB overlay is attached to the ordinance as Exhibit A and is on file with the City Clerk § 18.70.050.A .
How it interacts with base zones: The AB overlay’s regulations apply in addition to the underlying zone; where AB overlay rules differ from the base zone, the AB overlay governs matters pertaining to adult-business planning and zoning § 18.70.050.A .
Separation and location standards: Required separation distances include 500 ft from parks, schools, churches, or day care centers, and 1,000 ft from residential zone districts and from other adult businesses; separation measurement rules are specified and must be certified by a licensed surveyor or civil engineer § 18.70.050.B–C .
Where it applies: Parcels within the mapped AB overlay on the City’s AB map (Exhibit A on file) § 18.70.050.A .

Practical guidance: If a property falls inside the AB overlay, adult-business entitlement requires compliance with both the AB overlay rules and any applicable conditional use permit and separation measurements certified by a professional surveyor § 18.70.050.B–C .

Overlay quick-reference table

Overlay district	Core purpose / key standards	Typical permit outcome	Code Reference
FP (Floodplain Overlay)	Manage FEMA flood hazard areas; FP rules are additional and prevail for flood matters	Uses like flood control works permitted; other uses may be conditional per FEMA review	§ 18.50.010–040
AG (Agricultural Overlay)	Allow limited agricultural uses where historically present; animal/site-area minimums	Small-scale ag and animal keeping (P or C by table)	TABLE 18.53.020, § 18.53.010
AG-2 (Agricultural‑2)	Permit limited commercial agricultural uses with accessory residential	Commercial ag with operational conditions	§ 18.56.010
R3-24 Overlay	Optional 20–24 du/acre incentive for projects committing minimum affordable units (5% very‑low or 10% lower)	Administrative site & architectural review; recorded affordable covenant required	§ 18.48.010–060
AB (Adult Business Overlay)	Define where adult businesses may operate and impose separation standards	Adult business allowed in AB-mapped areas subject to separation and permits	§ 18.70.050

Checklist

Confirm whether the parcel is mapped with the overlay on the official zoning map (§ 18.09.030) .
For R3-24 overlay projects: prepare an affordable housing commitment showing 5% very‑low or 10% lower‑income unit set‑aside and plan to record an affordable housing covenant; budget processing fee § 18.48.020, § 18.48.050–060 .
For FP parcels: provide FEMA-related documentation, engineered flood elevations and show compliance with floodplain controls; confirm whether overlay rules alter base-zone building elevations § 18.50.010–040 .
For AG/AG‑2: use TABLE 18.53.020 to size animal totals and site area; secure any County health approvals for farm sales § 18.53.020, § 18.53.080 .
For AB overlay proposals: prepare separation-distance measurements certified by a licensed surveyor/engineer and confirm Exhibit A mapping § 18.70.050.B–C .
Plan for site and architectural review (administrative or public hearing) per Chapter 18.63 and confirm whether the project qualifies for administrative review or requires full review § 18.63.010–020 .
Coordinate parking and circulation requirements with the City early; overlay projects still must meet off-street parking rules in Chapter 18.60 (see parking) Grand Terrace Parking.
Verify whether applicable variance or exception processes are necessary and follow § 18.86 (variances) if standards cannot be met Grand Terrace Variances and Exceptions.

Risks & Ambiguities

Issue	Why it matters	What to verify
Map designation ambiguity	Overlay rules only apply where the zoning map shows them — wrong map read can lead to incorrect entitlements	Confirm parcel overlay(s) with the Planning Department and the official map § 18.09.030
Conflict between overlay and base zone	Some overlays (FP) explicitly prevail for flood matters; other overlays may be additive or optionally supersede base standards	For the FP overlay the code says FP rules prevail for flood matters § 18.50.010; for other overlays (R3-24) check the specific chapter for whether overlay supersedes base rules § 18.48.010–030
Affordable-housing covenant scope	R3-24 requires an enforceable covenant and references state law; the length/specifics must match Government Code requirements	Verify the required minimum duration of affordability and exact covenant language per § 18.48.050 and Government Code § 65915(c)(1) § 18.48.050
CEQA applicability for R3-24	Title 18 contains a statement about “not constituting a project” for certain R3-24 projects — this affects environmental review	Confirm with Planning staff whether your R3-24 proposal is ministerial or requires environmental review per § 18.63.020.C.5
Separation measurement for AB overlay	Separation distances must be measured and certified; incorrect measurement can invalidate a permit	Measurements must be certified by a licensed surveyor or engineer and follow § 18.70.050.C
Parcel-specific technical standards (elevations, drainage)	Overlay chapters sometimes require engineering or public‑works conditions not spelled out in zoning text	Verify with City Engineer or Planning Director and check applicable chapters for required submittals (FEMA, drainage, parking) § 18.50.040, § 18.63.010

Plain-English Summary

Grand Terrace overlay districts are special zoning layers that add rules for parcels shown on the official zoning map — for example, floodplain controls (FP), limited agricultural uses (AG/AG‑2), a mapped adult-business zone (AB), and a density/affordability option for multi‑family housing (R3‑24 overlay). Each overlay chapter sets permitted uses, special standards, and review steps; check the parcel’s map designation and the specific § for that overlay before applying (verify with the Planning Department).

Source References

§ 18.48.010–060 (R3‑24 Overlay — purpose, applicability, development regs, review, affordable housing agreement) — see R3‑24 overlay rules and affordable-covenant requirements.
§ 18.50.010–040 (FP Floodplain Overlay — purpose, permitted/conditional uses, FEMA regs) .
§ 18.53.010–090 and TABLE 18.53.020 (AG Agricultural Overlay — purpose, animal/site-area standards, temporary stands) .
§ 18.56.010 (AG‑2 Agricultural‑2 Overlay — purpose) .
§ 18.70.030–050 (Adult Business/AB overlay — conditional use and overlay map, separation standards, measurement) .
§ 18.09.020–030 (Districts established and zoning map designation/adoption) .
Chapter 18.63 (Site and architectural review; administrative vs. public review; CEQA note listing R3‑24 items) § 18.63.010–020 and § 18.63.020.C.5 .
Grand Terrace zoning & planning overview for navigation and related topics Grand Terrace zoning & planning overview.
For related topics referenced on this page: Grand Terrace Parking, Grand Terrace Design Review, Grand Terrace Development Standards, Grand Terrace ADUs, Grand Terrace Variances and Exceptions, California Building Standards Code.

Sources

Retrieved passages

Grand Terrace Zoning Code (Chapter 18.63) High relevance
CBC § 12 (§ 12) High relevance
Grand Terrace Zoning Code (title in) Medium relevance
Grand Terrace Zoning Code (§ 11) Medium relevance
Grand Terrace Zoning Code (§ 2) Medium relevance
Grand Terrace Zoning Code (Chapter 18.73.070) Medium relevance
Grand Terrace Zoning Code (Chapter 18.03) Medium relevance
Grand Terrace Zoning Code Medium relevance

Cited sections

Official Grand Terrace code library

Frequently asked questions

What overlays exist in Grand Terrace and where are they mapped?

Grand Terrace’s zoning code lists several overlays on the official zoning map, including FP (Floodplain Overlay), AG (Agricultural Overlay), AG‑2 (Agricultural‑2 Overlay), the R3‑24 overlay (high‑density residential option), and the AB (Adult Business Overlay); the map designations are on file with the Planning Department and described in § 18.09.020–030 .

What must I do to use the R3‑24 overlay for a multi‑family project?

A property owner may elect the R3‑24 overlay only on parcels with that overlay on the map and only if the project commits to the required affordable set‑aside (at least 5% very‑low or 10% lower‑income units) and records an affordable housing covenant; development follows R3‑24 standards in Chapter 18.10 and is processed administratively per § 18.48.020–050 .

Does the Floodplain (FP) overlay override the base zone?

For flood-related regulations the FP overlay explicitly governs where there is a conflict: the FP rules are in addition to the base district and FP provisions prevail for flood matters § 18.50.010 . Verify parcel-specific FEMA requirements with the City Engineer.

What uses are allowed in the Agricultural (AG) overlay?

Small-scale agricultural and animal‑keeping uses are allowed consistent with TABLE 18.53.020, which specifies minimum site areas and maximum animals; some uses are permitted and others are conditional — see § 18.53.020 for the full table and categories .

If my property is in an overlay, do I still need site and architectural review?

Yes — overlay projects still fall under the City’s site and architectural review rules in Chapter 18.63; some overlays (for example R3‑24 developments) are specifically processed administratively under Chapter 18.63 § 18.63.020.C and § 18.48.040 .

How are separation distances measured for an adult business in the AB overlay?

Separation distances in the AB overlay (500 ft or 1,000 ft, depending on the type of use being separated) are measured in a straight line from the nearest point of the structure containing the adult business to the nearest property line of the protected use, and measurements must be certified by a licensed surveyor or engineer § 18.70.050.B–C .

Are there CEQA benefits for R3‑24 overlay projects?

Title 18 includes a provision that certain developments within the R3‑24 and R3‑24 overlay “shall not constitute a ‘project’ for purposes of Division 13 (PRC § 21000)” (see § 18.63.020.C.5). That language affects environmental review but is project‑specific — verify with Planning staff whether your proposal qualifies for ministerial treatment or requires environmental review § 18.63.020.C.5 .

Where do I confirm exactly which overlays apply to my parcel?

Confirm overlays on the official zoning map on file with the Planning Department; the code states the zoning map designations and boundaries are part of Title 18 and are adopted by reference § 18.09.030 .

Do overlays change parking or setback numbers?

Overlays modify or add to underlying zoning standards where the overlay chapter says so. Unless the overlay chapter specifically changes parking or setbacks, the base‑zone development standards and the City’s parking chapter apply; confirm required parking per Chapter 18.60 and development standards per the district’s chapter § 18.43.060, § 18.48.030 .

If an overlay requires a covenant (like R3‑24), when is it recorded?

For the R3‑24 overlay, the affordable housing agreement and recorded covenant must be in place prior to issuance of any building permit for a development exercising the overlay; the code also requires reimbursement of City processing costs § 18.48.050–060 .

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