Rockland County, NY Environmental Rules: Stormwater Management (2026)

The County Drainage Agency, chaired by the County Superintendent of Highways and advised by a five-member Drainage Board (one appointee per town), administers the Stream Maintenance Program adopted after Tropical Storm Floyd's 1999 flood damage under Rockland County Code Ch. 53, Art. II. The Legislature appropriated $5,600,000 to repair the county stream system plus another $5,000,000 in the 2000 capital budget, finding that regular planning and maintenance is essential to prevent flooding and avoid millions of dollars in future drainage repair costs. Section 53-5 defines a COUNTY STREAM as any watercourse identified on the Rockland County Official Map and sets CHANNEL LINES at the one-hundred-year frequency line, or, absent such a study, 100 feet in distance or three feet in elevation, whichever is greater, from the normal high water line.

Under the implementation provisions, the Agency must conduct on-site maintenance reviews twice yearly, in April-May and September-October, and must mail registered first-class notice to property owners at least seven days before an inspection. Inspectors check whether streams remain within their banks, note erosion, debris, fallen trees, or ponding that could breed mosquitoes, and coordinate with the Health Department on mosquito control. After every rainfall exceeding two inches, the Agency inspects the entire inventoried system and files a written damage report with the Clerk of the Legislature and the County Executive.

Regular maintenance identified during inspection must be completed within 30 days; larger construction projects go on a construction schedule to be completed as soon as possible to avoid further damage.