19.52.030   Airport overflight (-AO) overlay zones.
   A.   Purpose. This section establishes five -AO overlay zones, which provide height limits for structures, use limitations, intensity limitations, and other development standards on and adjacent to the site of the Chico Municipal and Ranchero Airports, based upon specific zones or surfaces defined in the air space above each airport and its surroundings, in compliance with the Butte County ALUCP, State law, and the federal aviation regulations.
   B.   Findings. The Council hereby finds that a structure or other ground feature which obstructs air space near the Chico Municipal Airport or Ranchero Airport has the potential for endangering the lives and property of users of each airport, and property or occupants on land in each airport’s vicinity, and that an obstruction may reduce the size of areas available for aircraft takeoff, landing, and maneuvers, thereby tending to impair the usability of each airport and the economic investment in each facility.
   C.   Applicability. The -AO overlay zones may be combined with any residential, commercial, manufacturing/industrial, or special purpose zoning district established by Section 19.40.010. Unless otherwise noted, the -AO overlay zones are intended to implement the land use restrictions and development standards contained in the Butte County ALUCP. The -AO overlay zones are established, and shall be applied and shown on the Airport Zoning Map within 50,000 feet of the landing area of the airport, as follows.
      1.   -AOA, Runway Protection Zone. Includes airport runways and immediately adjacent areas wherein uses are restricted to aeronautical functions in accordance with Federal Aviation Administration standards. Encompasses the area of highest risk and noise levels. Implements Compatibility Zone A of the ALUCP.
      2.   -AOB1, Approach/Departure Zone and Sideline Zone. Generally surrounds zone - AOA, including areas both immediately beyond the runway protection zones and lateral to the runways. Noise levels and risks are both high. Implements Compatibility Zone B1 of the ALUCP.
      3.   -AOB2, Extended Approach/Departure Zone. The extended approach/departure zone for each airport also may include some land lateral to the runways. The area encompasses areas with moderate degrees of both noise and risk. Implements Compatibility Zone B2 of the ALUCP.
      4.   -AOC. Traffic Pattern. The area commonly overflown by aircraft at an altitude of 1,000 feet or less above ground level, including locations beneath the traffic pattern and pattern entry points. Annoyance associated with aircraft overflights is the major concern. Implements Compatibility Zone C of the ALUCP.
      5.   -AO, Other Airport Environs. Other areas within the airport vicinity which are overflown less frequently or at a higher altitude by aircraft arriving and departing the airport. The outer edge of this zone mostly coincides with the outer boundary of the FAR Part 77 conical zone. Implements Compatibility Zone D of the ALUCP.
   D.   Allowed Land Uses. Any land use normally allowed in the primary zoning district by this division may be allowed within the -AO overlay zone, except as set forth in Table 4-14 below.
TABLE 4-14
ALLOWED AND PROHIBITED LAND USES IN -AO OVERLAY ZONES
 
Zone
Permitted Residential density
Other uses - maximum people/acre
Prohibited uses
-AOA
0 - residential use not allowed
0
All structures except aeronautical facilities
Assemblages of people
Objects exceeding FAR Part 77 height limits
Aboveground bulk storage of hazardous materials
Hazards to flight
Other uses identified by the Airport Land Use Compatibility Plan
-AOB1
0.1 average site width (units/acre)
4.0 max single-acre (units/acre)
 
40 avg.
80 max. on a single acre
Children’s schools, day care centers, libraries
Hospitals, nursing homes
Highly noise sensitive uses (e.g. outdoor theaters)
Aboveground bulk storage of hazardous materials
Hazards to flight
Other uses identified by the Airport Land Use Compatibility Plan
-AOB2
0.2 average site wide max (units/acre)
4.0 single- acre max (units/acre)
 
100 avg.
300 max. on a single acre
Children’s schools, day care centers, libraries
Hospitals, nursing homes
Highly noise sensitive uses (e.g. outdoor theaters)
Hazards to flight
Other uses identified by the Airport Land Use Compatibility Plan
-AOC
Less than or equal to 0.2 units/acre or greater than or equal to 4.0 units/acre
200 avg.
600 max. on a single acre
Children’s schools, day care centers, libraries
Hospitals, nursing homes
Hazards to flight
Other uses identified by the Airport Land Use Compatibility Plan
-AOD
Limit set by primary zoning district
No limit
Hazards to flight
Other uses identified by the Airport Land Use Compatibility Plan
 
   Notwithstanding the above, designated infill properties in the -AOB2 overlay zone may develop at densities no greater than surrounding residential development, as set forth in the ALUCP and the accompanying map and list of parcels.
   In addition, no use shall be allowed under or within any -AO overlay zone that may:
      1.   Create electrical interference with aircraft communications;
      2.   Make it difficult for pilots to distinguish between airport lights and other lights;
      3.   Result in glare in the eyes of the pilots using the airport;
      4.   Impair visibility in the vicinity of the airport; or
      5.   Otherwise endanger the landing, takeoff, or maneuvering of aircraft.
   E.   Permit Requirements. Development and new land uses within the -AO overlay zones shall obtain the land use entitlements as required by this division in the primary zoning district. New development or land uses that are inconsistent with the standards contained in this chapter shall nonetheless be deemed consistent if the proposal is found by the Butte County Airport Land Use Commission to be consistent with the ALUCP.
   F.   Development Standards. Development and new land uses within the -AO overlay zones shall comply with all applicable requirements of the primary zoning district, and the following requirements.
TABLE 4-15
DEVELOPMENT STANDARDS IN -AO OVERLAY ZONES
 
Zone
Required Open Land
Development Standards and Conditions
-AOA
All remaining
Avigation easement dedication required
-AOB1
30% cumulative in zone
Locate structures maximum distance from extended runway centerline
Minimum Noise Level Reduction of 25 dB in residences and buildings with noise-sensitive uses
Airspace review required for objects over 35 feet tall
Avigation easement dedication required
-AOB2
20% cumulative in zone
Minimum Noise Level Reduction of 20 dB in residences and buildings with noise-sensitive uses
Airspace review required for objects over 70 feet tall
Recorded notice of airport operations required
-AOC
10% cumulative in zone
Airspace review required for objects over100 feet tall
Recorded notice of airport operations required
-AOD
No requirement
Airspace review required for objects over100 feet tall
 
      1.   Height Limits. No structure or tree shall be erected, altered, allowed to grow, encroach, protrude, extend into, or be maintained in any -AO overlay zone in excess of the height limits established in Table 4-15 above. The measurement of tree and structure height shall be based upon the United States Geodetic Survey (U.S.G.S.) mean sea level datum.
      2.   Nonconformities. Before any nonconforming use, structure, or tree may be replaced, substantially altered, or repaired, rebuilt, allowed to become higher, or replanted, a use permit shall be obtained in compliance with Chapter 19.24 (Use Permits). No use permit shall be granted that would allow the creation of an airport hazard or permit a nonconforming use, structure, or tree to be higher or become a greater hazard to air navigation than it was when the applicable regulation was adopted or when the use permit application was filed. No use permit shall be required for repairs or the replacement of parts of existing structures which do not enlarge or increase the height of the existing structure.
      3.   Hazard Marking and Lighting. Where determined to be necessary by the Airport Commission and where required by FAA regulations, any use permit or variance granted within an -AO overlay zone may be conditioned to require the owner of the use, structure, or tree:
         a.   At their expense, to install on the structure or tree and operate and maintain markers and lights as necessary to alert pilots to the presence of an airport hazard; or
         b.   To allow the City, at its expense, to install, operate, and maintain markers and lights as necessary to alert pilots to the presence of an airport hazard.
(Ord. 2185, Ord. 2427 §38, Ord. 2494 §30, Ord. 2519 §20)