Mesa Airfield Overlay District (AF) Modifications to Base Zoning
The Mesa Airfield Overlay District (AF) modifies base zoning standards by restricting specific land uses within designated flight paths and enforcing strict height limits to protect navigable airspace. In the most sensitive areas, such as the Runway Protection Zones, the City of Mesa prohibits all buildings, while in Overflight Areas, habitable structures must meet a 45 db noise attenuation standard and owners must grant avigation easements to the municipality.
Purpose and Applicability of the Mesa AF Overlay
The City of Mesa established the Airfield (AF) Overlay District to mitigate the hazards associated with aircraft operations near the Phoenix-Mesa Gateway Airport and the Mesa-Falcon Field Airport. This overlay is superimposed over base zoning districts to promote public safety and ensure that land development remains compatible with high noise levels and overflight activity [Section 11-19-1].
The AF Overlay is divided into four distinct sub-areas, each with varying levels of restriction based on their proximity to runways and noise contours.
| Sub-Area | Definition and Location |
|---|---|
| Runway Protection Zone (RPZ) | Areas designated to minimize public exposure to accident hazards near runways [Section 11-19-4]. |
| Airport Overflight Area One (AOA 1) | The area located within the 65 DNL (Day-Night Level) noise contour [Section 11-19-3]. |
| Airport Overflight Area Two (AOA 2) | The area between the 60 and 65 DNL noise contours, including an additional half-mile buffer [Section 11-19-3]. |
| Airport Overflight Area Three (AOA 3) | The area outside the 60 DNL contour that still falls within the broader airport influence area [Section 11-19-3]. |
Modifications to Land Use Standards
The Mesa Zoning Ordinance specifies that use limitations are most restrictive in the Runway Protection Zones (RPZ) and Airport Overflight Areas One and Two (AOA 1 and AOA 2). AOA 3 generally does not impose use limitations beyond those already required by the base zoning district [Section 11-19-4].
Runway Protection Zone (RPZ) Restrictions
In the RPZ, the City of Mesa prohibits the construction of any buildings. Permitted uses are limited to on-site improvements that do not involve human habitation or permanent assembly, such as:
- Vehicle parking.
- Stormwater retention basins.
- Landscaping (provided no element penetrates the defined runway protection zone slope or approach surface) [Section 11-19-4].
Overflight Area Use Limitations
Base zoning districts such as Agricultural (AG), Residential (RS, RSL, RM), and Employment (PEP, LI, GI, HI) are modified when they fall within AOA 1 or AOA 2. Common modifications include:
- Prohibited Uses: Certain noise-sensitive or high-density assembly uses are prohibited in AOA 1 and AOA 2 (e.g., specific residential or educational facilities depending on the base zone) [Tables 11-4-2, 11-5-2, 11-7-2].
- Council Use Permits (CUP): Some uses that are "permitted by right" in a base district may require a Council Use Permit when located within AOA 2 [Section 11-4-2, Table 11-5-2].
Modifications to Development and Performance Standards
Height Limits and Exceptions
The AF Overlay imposes stricter height regulations than standard Mesa zoning. While other districts may allow for minor height projections, Section 11-30-3 of the Mesa City Code explicitly states that there are no exceptions to the specified height limits within the AF Overlay Districts unless a Special Use Permit (SUP) is granted. Furthermore, items such as flagpoles, which often have no limit in other districts, are strictly capped or require a SUP if they exceed base district standards when located within the AF Overlay [Section 11-30-3].
Noise Level Reduction (NLR)
For any structure intended for human habitation within the Mesa AF Overlay, the building must be designed to achieve an interior noise level of no more than 45 decibels (db). A registered Professional Engineer or Architect must certify that the plans meet these attenuation requirements before the City of Mesa will issue a building permit [Section 11-19-5].
Mandatory Disclosures and Easements
The Mesa AF Overlay adds several administrative requirements to the development process:
- Avigation Easements: Property owners must execute an avigation easement in favor of the City of Mesa. This easement acknowledges the property will be subject to overflights and holds the municipality and the airports harmless from damages caused by aircraft noise or vibration [Section 11-19-5].
- Public Reports and Disclosures: All final subdivision plats and real estate sales/leasing offices within the overlay must provide formal notice to potential buyers regarding the proximity of the airport and the potential for objectionable aircraft noise [Section 11-19-5].
Sections Cited
- Section 11-4-2: Agricultural District Land Use Regulations
- Section 11-5-2: Residential Districts Land Use Regulations
- Section 11-7-2: Employment Districts Land Use Regulations
- Section 11-19-1: Purpose and Intent (Airfield Overlay)
- Section 11-19-2: Runway Protection Zones and Airport Overflight Areas
- Section 11-19-3: Definitions Specific to Airfield Overlay Districts
- Section 11-19-4: Land Use Regulations (Airfield Overlay)
- Section 11-19-5: Supplementary Provisions
- Section 11-30-3: Exceptions to Height Limits