Southampton Village, NY Fence Regulations: Retaining Walls (2026)

Section 116-12I regulates retaining walls that change the grade of a property compared with its natural grade. It excludes walls supporting subsurface features such as stairwells, window wells, below-grade driveways or sunken tennis courts, and it excludes landscape design walls that do not change the profile of the property, which fall under the wall dimensions in § 116-18. The section was added on 1-25-2022 and amended 8-11-2022.

The core standards are numeric. No retaining wall can be located within the first 20 feet of any property line. No retaining wall can result in a change in grade of more than three feet. Walls cannot be less than 15 feet offset from one another. Every retaining wall must be designed by a licensed professional engineer. Between walls, a gradual change in grade not exceeding a 20% slope in any location is permitted, but that allowance does not extend to the strip between the property line and a retaining wall, where fill is prohibited. The increase in grade created by walls and fill cannot exceed the required base flood elevation (BFE) for the structure to comply with FEMA construction standards.

Where walls provide area and coverage for dry wells and a sanitary system, the design professional must illustrate the full system profile and identify the soil scour effect. If a wall cannot meet the 20-foot, three-foot, 15-foot, system-design or 20% slope standards because an innovative or alternative wastewater treatment system needs it, a special permit from the Village Board of Zoning Appeals is required, with referral to the Village Engineer. The applicant must show the minimum deviation needed to meet Suffolk County Department of Health Services guidance and submit an application form, a licensed surveyor's survey with test hole information, a site plan with cross section, engineer-prepared wall plans, and drainage calculations.