Queens County, NY Environmental Rules: Grading & Drainage (2026)

The NYC Building Code regulates grading and drainage across Queens under Chapter 18 for Soils and Foundations and Appendix J for Site Grading. Finished grade must slope away from the foundation at least 6 inches within the first 10 feet, or, where physical obstructions or lot lines prevent this, an alternative drainage system must be designed by a licensed engineer and approved by DOB. Surface water cannot be directed onto adjacent private property or public right-of-way without approval. All new construction and major alterations in Queens require a DEP House or Site Connection Proposal that specifies how sanitary sewage and stormwater will be discharged, and separate combined, storm, or sanitary sewer connections may be required depending on the street where the property is located. Many Queens neighborhoods, including Southeast Queens (St. Albans, Hollis, Hollis Hills, Cambria Heights, Laurelton) and parts of the Rockaways and College Point, have combined sewer systems prone to surcharge during heavy storms, leading to basement flooding. New construction in these areas typically requires a backwater valve under NYC Plumbing Code Section 715.1. Properties in FEMA Special Flood Hazard Areas must have lowest floor elevations that meet or exceed the Base Flood Elevation plus NYC freeboard requirements. Dry wells, detention systems, and green infrastructure such as bioswales or rain gardens may be required by DEP for on-site stormwater management on larger lots.