Local zoning · Hercules

Hercules — Overlay Districts

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

Last reviewed: July 2, 2026

Overview

Overlay districts in Hercules are special map- and text-based zoning layers that sit on top of the City's base zoning districts and add project‑level requirements (design, setbacks, environmental buffers, review triggers) for properties inside their boundaries. Overlays are established in Title 13 of the Hercules Municipal Code and are applied “in conjunction with” an underlying district: the overlay adds to (and where applicable, the more restrictive standard prevails over) the base zoning rules. See the City Zoning overview for where overlays fit into the code and how to find map designations.

Below I summarize the overlay districts actually in the Hercules Zoning Ordinance, show the key decision rules and numeric standards you will run into, and provide a checklist and practical guidance tied to the exact code sections.

How I use links on this page

First time each related topic is mentioned it is linked to the GoCodebook Hercules menu page for that topic (parking, design review, development standards, ADUs, historic preservation, California Building Standards Code, and zoning overview). Use those pages for operational details that live outside the overlay rules themselves: parking calculations, design review process, and building-code compliance.

Hercules zoning & planning overview: Hercules zoning & planning overview
Development Standards: Hercules Development Standards
Design review: Hercules Design Review
Parking: Hercules Parking
Historic preservation: Hercules Historic Preservation
ADUs: Hercules ADUs
California Building Standards Code: California Building Standards Code

(Links appear only on the first natural mention of each topic above.)

Overlay Districts — District-by-district breakdown

Each subsection below follows the ordinance text: purpose, typical permitted uses or use rules, key numerical/dimensional standards you will actually rely on in project planning, where the overlay applies, and the primary code citations.

Historic Overlay District — H

Purpose: Preserve and manage areas/buildings with unique historical character; review exterior architectural and other significant features proposed to be erected, relocated, improved, or demolished. H districts overlay other districts and carry additional review requirements and findings for establishment. § 13‑20.100 and § 13‑20.200 .
Typical permitted uses: Uses allowed by the underlying base zoning remain permitted; the overlay does not create wholesale new uses but imposes review and possible conditions on exterior changes. See § 13‑20.100 for the overlay purpose and applicability. .
Key standards and process:
- Establishment of an H district requires City Council findings and public hearings (owner application or Commission/Council initiation) § 13‑20.200–13‑20.800 .
- If established, the zoning map is changed and a notation of the ordinance is recorded § 13‑20.900 .
- Design review of exterior changes is central; the overlay’s regulatory text prevails where it conflicts with other zoning provisions. § 13‑20.200(2) .
Where it applies: Areas designated HTC or mapped as H on the Zoning Map; created only after the findings and hearings described above. § 13‑20.100–900 .

Practical guidance: expect mandatory public noticing, a Planning Commission recommendation and City Council decision, and conditions tailored to preserve historic fabric. Verify whether a property is mapped H on the City Zoning Map before planning exterior work. Verify with the jurisdiction for parcel-specific status.

Special Flood Hazard Area Overlay — F

Purpose: Manage development in FEMA 100‑year floodplain areas and coordinate with the City Flood Damage Prevention Ordinance (Title 10, Chapter 7). § 13‑21.100 .
Typical permitted uses: Uses permitted by the underlying zoning, but all are subject to Flood Damage Prevention rules; certain improvements require conditional use permit approval and Flood Ordinance compliance. § 13‑21.500 .
Key standards:
- The F overlay is defined by FEMA maps (100‑year floodplain). § 13‑21.200 .
- Projects in the F overlay must comply with the Flood Damage Prevention Ordinance; where conflicts exist, the Flood Ordinance (Title 10, Chapter 7) may prevail. § 13‑21.200 .
- New/expanded uses generally require an administrative or conditional use permit and plan review by Community Development Director and City Engineer. § 13‑21.400–13‑21.500 .
Where it applies: Properties mapped by FEMA and incorporated by reference into the overlay. § 13‑21.200 .

Practical guidance: a flood‑zone determination (FEMA FIRM) is primary — coordinate early with the City Engineer and expect additional technical submittals and possible mitigation conditions. See the Flood Damage Prevention Ordinance (Title 10, Chapter 7) for construction‑level rules. Verify with the jurisdiction on required elevations and permits.

Refugio Creek Overlay District — RCO

Purpose: Protect creek corridors and riparian habitat by establishing a 50‑foot buffer from the top of bank and preserving the trail/vegetated corridor character. § 13‑22.100 (purpose) .
Typical permitted uses: Underlying zoning uses may remain permitted but are subject to buffer/performance and review standards; many new/expanded uses require administrative or conditional use permit and design review. § 13‑22.300–13‑22.500 .
Key numerical standard: 50‑foot setback from the top of bank to development (the overlay boundary is by definition the creek corridor plus that setback). § 13‑22.100–13‑22.200 .
Where it applies: Land within 50 feet of top of bank of Refugio Creek and tributaries (overlay mapped/defined in the code). § 13‑22.200 .

Practical guidance: plan setbacks and open space/landscaping to meet the buffer; coordinate with design review (Chapter 13‑42) early because the overlay requires design review and permits for new/expanded uses. § 13‑22.300 .

School‑Park Overlay District — S‑P‑O

Purpose: Reserve centrally located parcels for development of an elementary school/neighborhood park and ensure new development funds park/school mitigation. § 13‑23.100 .
Typical permitted uses: Underlying zoning uses subject to overlay performance standards; the overlay focuses on mitigation conditions (park fees, dedications, school capacity measures). § 13‑23.500 .
Key rules:
- The overlay adds performance standards to the base zoning; conflicts resolved in favor of the more restrictive regulation. § 13‑23.200 & 13‑23.500 .
- Projects that increase demand for schools must either demonstrate adequate capacity or undertake measures (payments, land dedication, facilities) to address capacity. § 13‑23.400 .
Where it applies: The mapped parcels west of San Pablo Avenue designated in the General Plan and Zoning Map. § 13‑23.200 .

Practical guidance: landscape, subdivision or housing proposals inside S‑P‑O will be evaluated for school/park mitigation obligations; budget these off‑site obligations early and verify with the school district. Verify with the jurisdiction for parcel‑specific mitigation formulas.

Special Study Area Overlay District — SSA

Purpose: Manage and coordinate redevelopment of the Hercules Properties, Inc. parcels and other identified Special Study Area parcels (historic resources, bay frontage, remediation, transit opportunities) and to encourage joint planning and infrastructure coordination. § 13‑24.100 .
Typical permitted uses: Uses otherwise allowed by the underlying zoning, with overlay performance and density guidance for certain subareas (e.g., the southern slope planned development residential densities). § 13‑24.500 .
Key rules:
- The overlay adds requirements to whatever other zoning designation applies and is established for General Plan Special Study Area No. 1 and No. 2. § 13‑24.200 .
- Special performance rules include environmental/remediation verification (e.g., closure reports for remediated Hercules Properties Inc. sites) before planned development approvals. § 13‑24.400 .
- Conflicts resolved in favor of the most restrictive regulation. § 13‑24.600 .
Where it applies: Parcels identified in the General Plan as Special Study Area No. 1 and No. 2 (see Zoning Map and General Plan). § 13‑24.200 .

Practical guidance: redevelopment here commonly requires project‑level studies (remediation closure reports, hydrology, master circulation) and coordinated planned development review. Expect plan review tied to the underlying district plus overlay performance standards. § 13‑24.300–13‑24.400 .

Scenic Road and Highway Overlay District

Purpose: Protect visual quality along scenic routes by reviewing developments visible from the designated corridor and encouraging attractive architecture, landscaping, low-profile signage, clustering, and view protection. § 13‑25.100 .
Typical permitted uses: Uses consistent with underlying zoning; design/landscape and sign plan requirements are added. § 13‑25.500–13‑25.400 .
Key numerical/locational standard: The overlay applies to the right‑of‑way and land within 200 feet on both sides of a road designated scenic in the General Plan. § 13‑25.200 .
Review triggers: All new or expanded development within the corridor requires Design Review (Chapter 13‑42) and an administrative or conditional use permit. § 13‑25.300 .
Where it applies: Properties within 200 feet of a scenic road or highway designated by the General Plan. § 13‑25.200 .

Practical guidance: expect a required sign plan, landscape plan that considers water‑conserving planting, articulation of building mass, and avoidance of high‑glare materials. Early design review is recommended. § 13‑25.400–13‑25.500 .

Quick reference table — Decision‑relevant overlay standards and triggers

Overlay District	Most important numeric / trigger	What that affects on a project	Code Reference
Refugio Creek (RCO)	50‑foot setback from top of bank	Siting, building footprint, revegetation, trail buffers	§ 13‑22.100–13‑22.200
Scenic Road & Highway	200‑foot corridor from road right‑of‑way	Design review, sign/landscape standards, material restrictions	§ 13‑25.100–13‑25.200; §13‑25.300–13‑25.400
Special Flood Hazard Area (F)	FEMA 100‑year floodplain mapping	Elevation standards, Flood Ordinance compliance, use permit triggers	§ 13‑21.100–13‑21.200; §13‑21.400–13‑21.500
Historic (H)	Establishment requires Council findings & hearings	May restrict exterior alterations, demolition, and require special review	§ 13‑20.100–13‑20.200; §13‑20.700–13‑20.900
Special Study Area (SSA)	Remediation verification (closure reports) for some parcels	Condition precedent to planned development approvals; special performance standards	§ 13‑24.300–13‑24.400; §13‑24.500–13‑24.600
School‑Park (S‑P‑O)	School capacity / park mitigation required	Requires mitigation, dedications or fees tied to new development	§ 13‑23.100–13‑23.400; §13‑23.500

Checklist

For any property that may lie inside an overlay district, an applicant should at minimum plan to do the following (code basis cited):

Confirm overlay mapping and base zoning on the City Zoning Map. § 13‑5.210 .
Prepare and submit plans to the Community Development Director in accordance with plan‑submission rules (many overlay chapters require plan submission per Section 13‑40.300). § 13‑22.300; § 13‑24.300; § 13‑25.300 .
Determine whether Design Review (Chapter 13‑42) is required (explicit in RCO and Scenic overlays and in many overlay rules). § 13‑22.300; § 13‑25.300 . See the City Design Review page for procedure.
Check for required administrative or conditional use permits specific to the overlay (common in F, RCO, Scenic, SSA, etc.). § 13‑21.400; § 13‑22.300; § 13‑25.300; § 13‑24.300 .
For floodplain parcels, obtain FEMA map confirmation and coordinate with the City Engineer and the Flood Damage Prevention Ordinance (Title 10, Chapter 7). § 13‑21.200–13‑21.400 .
For Refugio Creek parcels, design the project to respect the 50‑foot top‑of‑bank buffer and riparian performance standards. § 13‑22.100–13‑22.400 .
For Special Study Area sites, obtain required environmental/remediation documentation (closure reports) where applicable before planned development approvals. § 13‑24.400 .
Budget for overlay‑triggered mitigation: park/school fees in S‑P‑O; signage or landscape plans in Scenic; possible historic mitigation in H districts. § 13‑23.100; § 13‑25.400; § 13‑20.100 .
Prepare for the fact that where overlay text conflicts with base district text, the more restrictive rule generally governs (but Flood Ordinance may prevail where noted). § 13‑22.200; § 13‑24.600; § 13‑21.200 .
Confirm building‑permit level compliance with the California Building Standards Code once entitlements are in place. See the State code. (Building‑code specifics are outside Title 13.)

Risks & Ambiguities

Issue	Why it matters	What to verify
Overlay boundary vs underlying zone boundaries	Overlays “add to” underlying rules and the overlay boundary may not coincide with base zones; that changes which overlay standards apply to a parcel.	Check the Zoning Map and the overlay definition that may be text‑defined (e.g., 50‑ft RCO buffer). § 13‑5.210; § 13‑22.200
Conflicting standards (which rule controls)	Some chapters state the more restrictive regulation prevails; the flood overlay explicitly defers to Flood Ordinance in some conflicts.	Verify which specific regulation is controlling for the parcel. See § 13‑24.600 and § 13‑21.200.
Parcel‑specific remediation requirements in SSA	The SSA contains remediation verification requirements that can block planned development approvals without closure reports.	Determine if your parcel is the Hercules Properties remediated site and whether closure reports are filed. § 13‑24.400
Historic overlay establishment criteria	No automatic H overlay — establishment requires findings and hearings; property owners may need to follow a formal process.	For properties near HTC/on the Zoning Map, confirm whether H applies and what specific restrictions apply. § 13‑20.200–13‑20.800
Technical flood requirements (elevations, mitigation)	Flood overlay ties into technical Flood Ordinance standards that impose elevation/foundation/mitigation requirements.	Coordinate with City Engineer and consult Title 10, Chapter 7 (Flood Damage Prevention). § 13‑21.200–13‑21.400
Question of design review triggers	Multiple overlays reference Chapter 13‑42 for design review but triggers and level (administrative vs. Planning Commission) can vary.	Verify the specific approval path in Chapter 13‑42 and the overlay chapter (e.g., § 13‑25.300, § 13‑22.300).

Plain‑English summary

Overlays in Hercules are extra zoning layers (Historic H, Flood F, Refugio Creek, School‑Park, Special Study Area, Scenic Corridor) that sit on top of your base zone and add review triggers, buffers (for example a 50‑ft creek buffer), or special findings (historic districts, remediation verification). They rarely change allowed uses wholesale, but they do add permit, design, landscape, and mitigation requirements that apply in addition to the underlying district. Confirm overlay status on the Zoning Map and expect design review, administrative/conditional use permits, or technical submittals depending on the overlay. § 13‑5.210; § 13‑22.100; § 13‑25.200; § 13‑21.200

Source References

Hercules Zoning Map and overlay mapping rules — § 13‑5.210
Historic Overlay District — § 13‑20.100–13‑20.900
Special Flood Hazard Area Overlay (F) — § 13‑21.100–13‑21.600
Refugio Creek Overlay District — § 13‑22.100–13‑22.500
School‑Park Overlay District — § 13‑23.100–13‑23.500
Special Study Area Overlay District — § 13‑24.100–13‑24.600
Scenic Road and Highway Overlay District — § 13‑25.100–13‑25.600
General overlay and ordinance interpretive rules (conflicts, sequencing) — § 13‑5.200; § 13‑1.400; § 2.400 (see ordinance preface and rules)
Hercules zoning and planning overview (GoCodebook) — Hercules zoning & planning overview
Design review procedure (GoCodebook) — Hercules Design Review
Parking rules (GoCodebook) — Hercules Parking
Development standards (GoCodebook) — Hercules Development Standards
Historic preservation guidance (GoCodebook) — Hercules Historic Preservation
ADU guidance (GoCodebook) — Hercules ADUs
California Building Standards Code (state) — California Building Standards Code

Sources

Retrieved passages

Hercules Zoning Code (§ 2) High relevance
Hercules Zoning Code (§ 2) High relevance
Hercules Zoning Code (§ 2) High relevance
Hercules Zoning Code (§ 2) High relevance
Hercules Zoning Code (§ 2) High relevance
Hercules Zoning Code (Section 13-5.200.) High relevance
Hercules Zoning Code (§ 2) High relevance
Hercules Zoning Code (Section 13-40.300) High relevance

Cited sections

Official Hercules code library

Frequently asked questions

What overlays could apply to my Hercules parcel?

Check the Zoning Map and overlay map definitions: overlays in Title 13 include H (Historic), F (Special Flood Hazard Area), RCO (Refugio Creek), S‑P‑O (School‑Park), SSA (Special Study Area) and the Scenic Road & Highway overlay. Confirm status on the Zoning Map; the code notes overlays may be mapped or defined by text. § 13‑5.210; § 13‑20.100; § 13‑21.100; § 13‑22.100; § 13‑23.100; § 13‑24.100; § 13‑25.100

Do overlays change what uses are allowed on my lot?

Generally, overlays do not create completely new base uses; they add performance, buffer, or review requirements to the uses allowed by the underlying zoning. The code repeats that allowed uses are per the underlying land use zoning designation but subject to the overlay’s conditions. § 13‑22.500; § 13‑23.500; § 13‑24.500; § 13‑25.500

What are the setback or buffer requirements I must respect in overlays?

Specific numeric buffers exist in some overlays: for example, the Refugio Creek overlay establishes a 50‑foot setback from the top of bank § 13‑22.100, and the Scenic overlay covers lands within 200 feet of designated scenic rights‑of‑way § 13‑25.200. Other overlays rely on FEMA maps (F overlay) or project‑level determination. § 13‑22.100; § 13‑25.200; § 13‑21.200

Does my project need design review because of an overlay?

Yes — several overlays explicitly require design review (Chapter 13‑42) for all new or expanded development in the overlay (for example Refugio Creek and Scenic Road & Highway overlays). Check the overlay chapter to confirm. § 13‑22.300; § 13‑25.300

Are administrative or conditional use permits commonly required in overlays?

Many overlays require either an administrative or conditional use permit for new or expanded uses (Scenic overlay § 13‑25.300, Refugio Creek § 13‑22.300, Flood overlay § 13‑21.400). Review the specific overlay chapter for permit triggers. § 13‑25.300; § 13‑22.300; § 13‑21.400

How does the Flood (F) overlay interact with the City Flood Damage Prevention Ordinance?

The Flood overlay is defined by FEMA maps and the overlay’s regulations are to be applied together with the Flood Damage Prevention Ordinance (Title 10, Chapter 7); where conflicts exist the Flood Ordinance provisions may prevail as stated in the overlay chapter. § 13‑21.200

What special documentation is required in the Special Study Area (SSA)?

For certain parcels (notably the Hercules Properties, Inc. remediated site), the code requires copies of remediation closure reports prepared by Cal‑EPA certifying remediation before approval of planned development plans. § 13‑24.400

If my property is in the Historic (H) overlay, what process creates the overlay and what should I expect?

An H overlay is established only after an application or motion, public hearings, Planning Commission recommendation, and City Council findings per the code; establishing an H district requires specific findings and public notice steps. Once established, H overlay rules and design review apply to exterior work. § 13‑20.200–13‑20.800; § 13‑20.900

Who do I contact in Hercules for overlay confirmation and file submittals?

The ordinance repeatedly directs plan submissions and preliminary review to the Community Development Director and, for flood matters, also to the City Engineer. Many overlay chapters cite the plan submission requirement “as per Section 13‑40.300.” § 13‑22.300; § 13‑24.300; § 13‑25.300 ---

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