Do You Need a Permit for Drainage Work in Henry County, Georgia?

Henry County Land Disturbance Permit (LDP)

Henry County requires a residential land disturbance permit (LDP) for any activity that involves clearing, grading, or leveling over 120 square feet of land. This is one of the lowest thresholds in the metro Atlanta area. For perspective: 120 square feet is roughly a 10-foot by 12-foot area. A typical residential french drain trench is 50 to 200 linear feet. Most drainage projects easily exceed this threshold.

The low threshold reflects Henry County's concern about stormwater runoff from the rapid development occurring throughout the county. With nearly 7,000 new homes being built per year, the county has put in place permit requirements that capture even small residential grading projects.

Applications are submitted through the SagesGov permitting portal at sagesgov.com/henrycounty-ga. The reviewing department is Henry County Environmental Inspections and Compliance. For questions before submitting, contact the Henry County Environmental Inspections department directly.

Which Drainage Projects Actually Trigger the LDP

The arithmetic on 120 square feet is worth doing once, because most homeowners picture a large excavation and assume a narrow trench is exempt. It is not. A trench 18 inches wide has to run only 80 feet to hit 120 square feet, and that is before any spoil storage, staging, or equipment tracking alongside it. A 24-inch-wide trench hits the threshold at 60 feet. Since a typical Henry County residential french drain runs 50 to 200 linear feet, the overwhelming majority of real drainage work is over the line.

Roughly how common project types fall out in practice:

• Surface downspout extension, no digging: no land disturbed, generally outside the requirement
• Buried downspout run of 20 to 30 feet: usually under the threshold on its own, over it if combined with other work on the same site
• Single catch basin with a short pipe to a daylight point: borderline, depends on trench width and run length
• Exterior french drain, 50 to 200 linear feet: over the threshold, assume an LDP is required
• Interior basement perimeter drain: no land disturbed inside, but the exterior discharge line often is
• Regrading a swale or reshaping a low area: over the threshold almost immediately, since graded area adds up faster than trench area

One point that trips people up: the threshold applies to the total area disturbed on the site, not to each item of work separately. Three separate 40-foot runs on the same property are one 120-foot project as far as the county is concerned. Phasing the work across a few weekends does not reset the count either. When a project sits genuinely near the line, a call to Environmental Inspections before starting costs nothing and settles it.

Stream Buffers Around Drainage Outlets

A creek at the bottom of the yard looks like the obvious outlet, and on plenty of Henry County lots it is exactly where the water wants to go. Georgia state law puts a limit on how close you can work to it. The Erosion and Sedimentation Act requires a 25-foot undisturbed vegetative buffer along the banks of state waters, measured from the point of wrested vegetation, and 50 feet along designated trout streams. Trout streams are not a Henry County issue, but the 25-foot buffer is, on every lot backing onto a tributary of Cotton Indian Creek, the South River, Walnut Creek, or the Towaliga.

In practice that means planning the outlet to stop short of the buffer rather than running pipe to the bank. Disturbing inside the buffer requires a variance, which is a slower and more expensive process than most residential drainage budgets allow for. It is also the single most common reason a drainage plan that looked simple on a walk-through has to be redesigned. Establish where the buffer line sits before anyone prices the collection system, not after.

Georgia EPD Stormwater Permits

The Georgia Environmental Protection Division (EPD) administers NPDES General Permits for construction activities. These apply when land disturbance involves one acre or more, or when the project is part of a larger common plan of development that collectively disturbs one acre or more.

For most residential french drain installations in McDonough or Henry County, the disturbed area is well under one acre, so Georgia EPD NPDES permits typically do not apply. However, if your property is being re-graded on a larger scale, or if the drainage project is part of a broader site improvement, confirm the total disturbed area before proceeding.

The Georgia EPD NPDES General Permit series for construction includes:

• GAR100001: General permit for land disturbing activities (standard residential/commercial)
• GAR100002: General permit for residential construction in sensitive watersheds
• GAR100003: General permit for linear construction projects

Applications requiring EPD permits must submit a Notice of Intent (NOI) to EPD before work begins. Henry County requires applicants to provide a copy of the NOI when the EPD permit applies. More information at the Georgia EPD NPDES Construction permits page.

FEMA Flood Zone Considerations

Properties in FEMA-designated Special Flood Hazard Areas (SFHA) in Henry County may have additional restrictions on grading and drainage work. Before starting any drainage project near a creek, stream, or low-lying area, check whether your property is in a flood zone using the FEMA Flood Map Service Center. Henry County flood zone information is searchable by address.

If your property is in an SFHA, a floodplain development permit from Henry County may also be required in addition to the land disturbance permit. Contact the county's Building and Plan Review Department for guidance on floodplain permit requirements.

Who Is Responsible for the Permit?

In Henry County, the property owner is ultimately responsible for obtaining required permits before work begins. Some drainage contractors will apply for permits on behalf of the homeowner; others require the homeowner to pull the permit themselves. Confirm with your contractor before signing any contract.

Settle it in writing before signing anything. If the contract is silent on who files, the usual reality is that nobody has, and the owner is the one holding the exposure. Ask for the permit number before the crew shows up, the same way you would ask for proof of insurance.

Working without a required permit in Henry County can result in stop-work orders, fines, and requirements to remove and reinstall the drainage system after proper permits are obtained. That last remedy is the one that hurts, because it means paying for the same trench twice with restoration in between, on a property where the original water problem is still unsolved while it plays out. Set against a permit fee and a short review, it is not a close call. The county is enforcing on the back of real pressure too: Henry County has absorbed roughly 6,900 new homes a year for over a decade, and the cumulative runoff from that growth is why McDonough is now budgeting for work like the Blacksville Community Drainage Improvements project. The 120-square-foot threshold is low on purpose.

Frequently Asked Questions