Perth Amboy, NJ Fence Regulations: Retaining Walls (2026)

Section 430-66, Clearing and grading, sits in the design standards of Perth Amboy's zoning and land development chapter. Its lot grading subsection sets the retaining wall rule. Retaining walls installed in slope control areas shall be constructed of heavy treated timber, reinforced concrete, other reinforced masonry or other construction acceptable to the Municipal Engineer, and adequately designed and detailed on the final plat to carry all earth pressures, including any surcharges. The height of retaining walls shall not exceed one-third (1/3) of the horizontal distance from the foundation wall of any building to the face of the retaining wall. If the municipality later adopts standard details for such construction, those govern. The same subsection sets a minimum lawn slope of two percent (2%), a minimum of three-fourths of one percent (3/4 of 1%) for smooth, hard-finished surfaces other than roadways, and a maximum grade of five percent (5%) for lawns within five (5) feet of a building.

The drainage section, § 430-79 G, prints a different fraction: the heights of retaining walls should not exceed one-half (1/2) of the horizontal distance from the foundation wall of any building to the face of the retaining wall, and walls must be adequately designed to carry all earth pressures.

On the building-permit side, the flat Building Subcode fees in § 184-2 price retaining walls by class: Class 3 Residential under 550 square feet is $160, Class 3 Residential over 550 square feet is $210, and all other use groups are priced by cost of construction as tabled in sections A and B. The minimum fee is $75. In a floodway, § 231-801.5 says retaining walls that involve placement of fill shall meet Section 231-105.3A(1) and N.J.A.C. 7:13. Under § 430-101 C(2) the Municipal Engineer enforces the subdivision, site plan and construction standards.