Islip, NY Environmental Rules: Flood Zones (2026)

Article XL's development permit applies to any 'man-made change to improved or unimproved real estate' inside an area of special flood hazard, as § 68-439 defines 'development': building, mining, dredging, filling, paving, excavating or storing equipment or materials all qualify. Applications go to the local administrator, the Commissioner of Planning and Development, on Town-furnished forms showing the nature, location, dimensions and elevation of the work under § 68-441B(1), plus an application fee set by the Town Board and a deposit of up to $500 for the Town's extra review, inspection and approval costs under § 68-441B(2).

Depending on the flood zone, the applicant must submit the proposed lowest-floor or lowest-structural-member elevation relative to mean sea level, certified as-built once the floor is complete by a licensed professional engineer or surveyor, per § 68-441B(3)(a)-(b). The local administrator reviews every application for completeness and for compliance with the Article's construction standards at § 68-442 before granting a permit, and determines whether the project could physically damage neighboring property under § 68-441C(1). A subdivision or other development greater than 50 lots or five acres in Zone A without existing base flood elevation data must supply its own elevation study under § 68-441B(3)(h).

A property owner who believes the permit standards work an unnecessary hardship can seek a variance from the Board of Appeals under § 68-443, but only on a showing of good cause and no increased flood risk to others.