Chatham County, GA Environmental Rules: Stormwater Management (2026)

Sec. 24-705 applies the Storm Water Management Ordinance throughout Chatham County, including drainage systems the county maintains under intergovernmental agreements with municipalities, and puts the Department in charge of the county's MS4, its municipal separate storm sewer system, and of carrying out the storm water program required under the county's NPDES permit. Sec. 24-708's prohibition list follows: dumping trash, landscape debris or other material into any stream, channel, ditch or storm water facility is unlawful outright, as is tampering with, damaging, or defacing any storm water structure or equipment, or altering, rerouting, deepening, widening, enlarging, filling or obstructing any part of the system without the Director's prior written authorization, including fencing across a drainage easement in a way that blocks maintenance access.

A short list of discharges is exempted: water line flushing by a government agency, unpolluted groundwater, foundation drains, air conditioning condensate, irrigation and lawn watering runoff, and firefighting flows. Anyone responsible for an accidental discharge into the county's MS4 must notify the Department within two hours and take immediate steps to contain it. Sec. 24-710 makes property owners responsible for maintaining any private storm water facility serving their own lot, and larger development is separately required under Sec. 2 inches of rainfall and remove 80 percent of the average annual sediment load before discharge.