Brookhaven, GA Environmental Rules: Stormwater Management (2026)

Article IV of Chapter 14 in the Code of the City of Brookhaven, Georgia covers post-construction stormwater management, and Section 14-79 requires compliance with the design standards of the Georgia Stormwater Management Manual (GSMM). Section 14-81 sets when the article applies: new development adding 5,000 square feet or greater of impervious surface or disturbing one acre or more; redevelopment creating, adding or replacing 5,000 square feet or more or disturbing one acre or more; any commercial or industrial hotspot land use regardless of size; any project that raises peak runoff by more than one cubic foot per second for a ten-year frequency storm; and single-family lot work creating, adding or replacing at least 3,000 square feet of impervious cover, which must provide storage and controlled release of the water quality volume or runoff reduction volume.

New development adding between 1,000 and 5,000 square feet needs only runoff reduction and water quality. Section 14-82 exempts emergency work by public agencies, utility trenches, ADA installations, and agricultural and silvicultural activities in zoned areas, among others. Section 14-83 sets the standards. The system must retain the first 1.2-inch of rainfall through runoff reduction to the maximum extent practicable, and where that is infeasible it must remove at least 80 percent of the average annual post-development total suspended solids load. Stream channel protection requires 24-hour extended detention of the one-year, 24-hour storm, and overbank flood protection holds the post-development peak discharge to the pre-development rate for the 25-year, 24-hour storm.

Live detention is sized on the 100-year rainfall. A downstream analysis runs to the point where the site is ten percent of the total drainage area. Facilities with a temporary water storage depth greater than four feet need permanent fencing at least four feet high with a maintenance gate, and detention facilities cannot sit in floodplains, wetlands, stream buffer zones, state buffer zones or transitional buffer zones. The city manager appoints the administrator under Section 14-80.