Issaquah, WA Noise Ordinances: Aircraft Noise (2026)

The only aircraft noise provision in the staged Issaquah code is the heliport section, LUC 18.508.040. It applies to all heliports, including hospital transport and business or public use transport heliports that are an accessory use. The requirements can be modified only in special circumstances, on the written technical evaluation and recommendation of the Federal Aviation Administration (FAA) Airport District Office or the Washington State Department of Transportation, Division of Aeronautics Office.

Subsection (B) is the noise tool. To limit noise impacts, the City can impose conditions restricting the type of aircraft permitted to land at an approved heliport and conditions that limit the number of daily takeoffs and landings and hours of operation. The City can also impose a periodic review requirement on heliport approvals so it can consider additional conditions to mitigate adverse impacts from new aircraft technology.

Subsection (C) sets location and design rules that bear on noise. An application to construct a heliport must include the results of the appropriate FAA review, and a determination of negative impact on navigable airspace results in denial of a City land use permit unless the applicant agrees to comply with the FAA recommendations. The facility must participate in a noise reduction program, such as Fly Neighborly. A heliport site must have flight path access directly to the interstate highway system that does not require flight over any residentially zoned properties. Flight paths and altitude requirements are required to minimize noise and echoing within Central Issaquah and Olde Town. Landing areas must be at least one and one-half times the overall length of the largest helicopter expected to use the facility, and access to landing areas, except water surfaces, must be controlled by physical restraints, with a minimum height of 42 inches where fences, walls or parapets are used.

Public use heliports face stricter rules under subsection (D): traffic patterns must be over freeway paths only, and use at night, if permitted, must be limited, with exact hours of operation set as a condition of the land use permit. The permitted locations and review level for a heliport come from the table of permitted uses in IMC 18.402.020 and the review levels in IMC 18.204.020.