What does NAS North Island's AICUZ mean in Coronado?

If you’re buying or selling in Coronado, you’ve probably heard someone mention North Island and a study with an acronym in the same breath, then move on before saying what it actually requires of you. Two different documents are usually behind that mention: the Navy’s own AICUZ study, and the county’s Airport Land Use Compatibility Plan built on top of it. They do different jobs, and neither one does what most people assume.

What the Navy’s AICUZ study actually is

AICUZ stands for Air Installations Compatible Use Zones. It is a Department of Defense program, established in the early 1970s and directed by DOD Instruction 4165.57, that maps aircraft noise and accident potential around military airfields so the Navy can work with surrounding communities on compatible land use. For Naval Air Station North Island, the current version is the 2011 AICUZ study, prepared for the Navy and covering both NAS North Island and the Naval Outlying Landing Field in Imperial Beach.

The study itself is not a land use law. It is the technical foundation, noise contours and safety zone maps, that the county then has to build a compatibility plan around. If the Navy issues an updated AICUZ for North Island, state law requires the county to update its plan to match.

Clear zones, accident potential zones, and noise contours

The AICUZ maps three accident potential zones off each end of an active runway, plus a set of aircraft noise contours. The Clear Zone sits closest to the runway, where most land uses are considered incompatible with flight operations. Beyond that come Accident Potential Zone I and Accident Potential Zone II, areas of progressively lower but still real risk. The Navy’s guidance is that a range of uses can exist in APZ I and APZ II, but people-intensive uses such as schools, apartments, and churches should be restricted there because of the added safety exposure.

Noise gets measured separately, in CNEL, the Community Noise Equivalent Level used across California for aircraft noise around an airport. It is a weighted daily average that counts evening and nighttime flights more heavily than midday ones. The compatibility plan for North Island maps contour lines at 65, 70, 75, and 80 decibels CNEL, layered over the same area as the safety zones along Coronado’s north shore.

What the Airport Land Use Compatibility Plan does, and mostly does not do

The San Diego County Regional Airport Authority, acting as the county’s Airport Land Use Commission, adopted the Airport Land Use Compatibility Plan for Naval Air Station North Island on October 1, 2020. Its own stated purpose is to promote compatibility between the airfield and surrounding land uses, consistent with the safety and noise standards in the Navy’s 2011 AICUZ study.

Read past the purpose statement and the plan is careful about its own limits. It has no authority over NASNI’s operations, layout, or expansion. It does not apply to property owned by the federal government, the state, or a Native American tribe. And for private land, its review process is built around proposed land use actions, meaning new construction, zoning changes, and discretionary permits, not homes that already exist and are simply changing hands.

The plan’s own exemption table spells this out. An existing use that stays the same size and height, with no added dwelling unit, does not need to go through Airport Land Use Commission review at all. Repair, maintenance, and remodeling within the existing footprint is exempt. Reconstruction of less than half the home’s existing habitable space, with no increase in height and no new unit, is exempt too. If a past owner tore a house down and rebuilt one that is larger or taller, that project went through review at the time. Buying or selling the house as it sits today does not reopen that question.

Which part of Coronado actually sits inside the zones

The Clear Zone, APZ I, and APZ II for North Island are not citywide. They sit along Coronado’s north end, closest to the airfield, and extend across parts of the neighborhood between Sunset Park and Glorietta Bay before tapering out near the Naval Amphibious Base. The plan’s own noise contour maps run further, with the 65 decibel CNEL line reaching into a wider band of north Coronado.

The airport influence area, the boundary that actually triggers the state disclosure requirement, is larger still. It runs along San Diego Bay, through Coronado, National City, Chula Vista, and Imperial Beach, following flight paths and overflight patterns rather than a tight ring around the runway. Being outside the Clear Zone or the safety zones does not automatically mean you are outside the disclosure boundary. The two maps answer different questions.

Zarko Maletin, the Realtor behind this site, is also an InterNACHI certified home inspector, and the reason these maps matter to a resale is the same reason a foundation or a roof matters: what a buyer’s agent asks about is rarely what you’d guess from the street.

The airport-in-vicinity disclosure you’ll sign in escrow

If your property falls inside the airport influence area, California law requires a specific written notice. Under Civil Code section 1103.4, the required language is close to this: the property is presently located in the vicinity of an airport, within what is known as an airport influence area, and for that reason it may be subject to some of the annoyances or inconveniences associated with airport operations, such as noise, vibration, or odors.

This notice travels separately from the Natural Hazard Disclosure statement most sellers already know about. The standard NHD form covers flood, fire, and seismic zones, and airport proximity is not one of the six items on it. It is its own document, usually prepared by the same company that handles your NHD report. The guide to NHD reports walks through what that six-hazard form does cover, if you want the fuller picture of what else gets disclosed alongside it.

Overflight notification versus the state disclosure

The compatibility plan for North Island also has its own overflight notification policy, aimed at new or completely reconstructed housing built within a mapped overflight notification area that stretches well beyond Coronado, through the South Bay and out toward the county’s eastern edge. That policy calls for buyers of new construction to be told about potential aircraft overflight effects, through a recorded agreement, a notice at permitting, or similar means.

For an existing home changing hands, the plan states plainly that the state law requiring disclosure of airport proximity is adequate to satisfy this overflight notification policy on its own. In practical terms, the one disclosure you are required to give a buyer at resale, the Civil Code 1103.4 notice, does the job both requirements are asking for.

What this means if you’re buying

If you’re shopping in Coronado near North Island, take the airport-in-vicinity notice seriously without assuming it means more than it does. Visit at different times of day if flight noise matters to your decision, since a quiet midday showing tells you little about flight schedules earlier or later in the day. Ask whether the address sits inside the mapped Clear Zone or accident potential zones, which is a different and narrower question than whether it sits inside the disclosure boundary. And if aircraft noise genuinely affects what you’re willing to pay, price it the way you would any other real, ordinary feature of the location.

How to check a specific address

Do not guess this from how close a street feels to the runway. The current Airport Land Use Compatibility Plan for NAS North Island, including its safety zone and noise contour maps, is published by the San Diego County Regional Airport Authority at san.org. The Navy’s AICUZ study for North Island is the technical document behind it. If you are mid-transaction, your escrow company or NHD provider will typically make the determination for your specific parcel as part of preparing your disclosure package.

The short version

North Island creates one real, non-negotiable requirement for homes inside the mapped airport influence area: the Civil Code 1103.4 disclosure. It does not mean the Airport Land Use Compatibility Plan is reopening decisions about a house that already exists, and it does not mean every property near the base sits inside the tighter safety zones. Know which map actually applies to your address before you assume either extreme. The Palomar Airport guide for Carlsbad walks through the same kind of question for a civilian airport, if you want to see how the pattern holds outside a military base, and the seller disclosure guide for California covers how this fits alongside everything else you’re required to tell a buyer.

If you’re getting ready to buy or sell near North Island and want a clear-eyed read on a Coronado property before you price it, start with the home value tool.