Airport Overlay District (A) Regulations in the City of Concord
The Airport Overlay District (A) in the City of Concord is established to protect people and property on the ground and to shield Buchanan Field Airport from incompatible land uses. Land use applications within the designated airport influence area and safety zones are subject to review by the Contra Costa County Airport Land Use Commission (ALUC) to ensure consistency with the adopted airport land use compatibility plan.
Purpose and Applicability
The Airport Overlay District (A) applies to lands within the "airport influence area," defined as extending 14,000 feet from the ends of the primary surfaces for specified runways, as well as designated airport safety zones [Section 18.100.010, Section 18.100.020]. If a conflict arises between the regulations of the Airport Overlay District (A) and those found in the Contra Costa County airport land use compatibility plan (ALUCP), the ALUCP provisions prevail [Section 18.100.020].
ALUC Review Requirements
All land use applications within the airport influence area must be referred to the ALUC for review and recommendation [Section 18.100.030]. This includes the following types of actions:
- New Development: Any proposal for new development (including buildings, antennas, or other structures) exceeding 150 feet in height [Section 18.100.030(A)].
- Aviation Hazards: Any obstruction reviewed by the Federal Aviation Administration (FAA) that does not receive a "not a hazard" finding [Section 18.100.030(A)].
- Electrical/Visual Hazards: Projects with the potential to cause electrical interference with radio/navigational signals, lighting that could be mistaken for airport lighting, glare impacting pilots, or increased bird attraction [Section 18.100.030(A)].
- Residential and Large-Scale Projects: Within the 55 dB CNEL noise contour, proposed residential subdivisions consisting of 20 or more acres and five or more lots, or any discretionary project with 20,000 square feet or more of building floor area [Section 18.100.030(B)].
- Specific Safety Zone Proposals: Various height and usage restrictions apply specifically to Safety Zones 1 through 4 and Height Exception Overlay Zones [Section 18.100.030(C)].
Safety Zone Development Criteria
Development within the defined safety zones must adhere to the following criteria:
| Safety Zone | Use and Development Restrictions |
|---|---|
| Safety Zone 1 | No new structures permitted except for FAA-determined aeronautical facilities; fuel/hazardous material storage prohibited. |
| Safety Zone 2 | Limited to 30 people per acre; max two habitable floors above ground; K-12 schools, hospitals, and nursing homes prohibited; bulk storage of hazardous materials prohibited (with limited exceptions). |
| Safety Zone 3 | Limited to 125 people per acre; max three habitable floors above ground; K-12 schools, hospitals, and nursing homes prohibited; bulk storage of hazardous materials prohibited. |
| Safety Zone 4 | No land use intensity limit; max four habitable floors above ground; bulk storage of hazardous materials prohibited in residential/commercial areas. |
Note: Subject to ALUC review, higher intensity uses (up to 45 people per acre in Zone 2 and 250 in Zone 3) may be permitted if special risk-reduction design features (e.g., concrete walls, limited windows, upgraded roof strength, increased emergency exits) are incorporated [Section 18.100.040(B)(5)].
Nonconforming Uses
Existing uses not in conformance with the ALUCP may continue but are subject to strict limitations regarding expansion and reconstruction. Expansions in Safety Zone 1 are prohibited, with narrow exceptions for residential expansion (if not increasing unit count) and a one-time 10% floor area expansion for nonresidential uses if intensity does not increase by more than 10% [Section 18.100.050(A)]. Reconstruction of destroyed nonconforming structures within Safety Zone 1 is generally prohibited, while reconstruction outside of Zone 1 is permitted if the structure was only partially destroyed (less than 75% of assessed value) and intensity requirements are met [Section 18.100.050(B)].
Sections Cited
- Section 18.100.010: Purpose
- Section 18.100.020: Applicability
- Section 18.100.030: ALUC review required
- Section 18.100.040: Development standards
- Section 18.100.050: Nonconforming uses