French Drains Ellenwood GA | McDonough Drainage

French Drains and Drainage in Ellenwood, GA

French drains in Ellenwood, GA cost roughly $25 to $40 per linear foot outside a house, and most drainage projects come to $2,500 to $9,000. McDonough Drainage connects Ellenwood homeowners with a vetted local contractor. Two things set Ellenwood apart: hillside soils full of mica and rock, and no city hall, so the county your lot sits in writes the rules.

French Drains and Drainage on Ellenwood's Slopes

Much of the ground around Ellenwood is sloped and stony. USDA soil maps around the community include Madison and Pacolet soils on 10 to 25 percent slopes, and Ashlar sandy loam labelled "very rocky." On a hillside lot, rain runs down the slope through the topsoil, meets clay and keeps moving sideways until it hits a house, a patio or a retaining wall. That sideways seep is what a french drain cut across the slope intercepts.

Madison soil is the distinctive one. It formed from rock rich in mica, and every layer is full of fine mica flakes. The red clay layer runs from about 9 to 30 inches down, and below roughly 35 inches it turns into soft, crumbly weathered mica schist. That soft layer is easy to dig but can slough off the walls of a narrow trench, so the stone and fabric need to go in the same day the trench is opened.

Ashlar is the opposite problem: weathered granite 20 to 40 inches down. On those lots a contractor probes the route before quoting, and the design may run shallower or around a ledge rather than through it.

Black corrugated drain pipe on gravel at the foot of a stacked block retaining wall, with a round outlet cap at the wall's base — A french drain outlet at the foot of a block retaining wall. On cut hillside lots, the drain behind the wall carries off the water that would otherwise push on it. (Photo: Wikideas1, CC0)

Ellenwood French Drain Pricing

A Georgia contractor's published price guide puts exterior french drains at $25 to $40 a linear foot and interior perimeter systems at $40 to $55. In Ellenwood, slope works both ways. A steep lot gives a short, easy path to daylight, which keeps the outlet cheap, but rock, retaining walls and the hand work needed on a steep yard raise the per-foot labor.

Ask any bidder to state where rock would change the price and by how much. A quote with no rock clause on Ashlar ground isn't a low quote; it's a change order waiting to happen.

Example project

Seeping retaining wall on a DeKalb-side hillside lot

The lot: a house on the DeKalb County side of Ellenwood, built on a pad cut into a Madison-soil slope, with a block retaining wall holding the cut. The wall face stays wet after storms and the lawn at its foot never firms up.

The fix: about 40 feet of perforated pipe in washed stone wrapped in filter fabric, laid behind the base of the wall and outletting through the wall to daylight, with stone and fabric placed the same day the soft schist trench is opened.

Cost math: 40 feet at the sourced $25 to $40 per foot is $1,000 to $1,600 for the drain, before any wall work.

Paperwork: on this side of the county line the call goes to DeKalb's Land Development office, not Henry or Clayton. Its answer depends on project type and disturbed area.

What goes wrong: leaving a mica-schist trench open overnight before a storm. The walls slump, the bottom fills with silt, and the stone ends up bedded in mud.

An illustrative example of a typical job, not a specific customer's project.

Four Counties, No City Hall

French drains and drainage diagram for Ellenwood GA lots: a driveway culvert under compacted fill on a roadside ditch, with rip-rap at the outlet — Roadside ditches and driveway culverts are where yard drainage meets public land. In Ellenwood, which county owns that ditch depends on the address.

Ellenwood isn't a city. It's an unincorporated community spread across Clayton, Henry, Rockdale and DeKalb counties, strung along I-675 and GA 42 and named for the old Ellenwood Plantation. Neighbors on the same road can answer to different county offices, with different permit thresholds, inspection staff and stormwater billing.

Find your county first, then call its office: Henry County's Environmental Inspections and Compliance, DeKalb's Planning and Sustainability, Land Development, or Clayton County, where the Clayton County Water Authority runs stormwater for the unincorporated area.

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Ellenwood French Drain Questions

Does DeKalb County require a permit for a french drain in Ellenwood? +

It depends on the job. DeKalb's Land Development office says land disturbance permit requirements depend on the project type and the area disturbed, and asks applicants to call 404-371-2155 for guidance. It also publishes a water quality review checklist for single-family residential sites.

Does Henry County's 120-square-foot rule apply in Ellenwood? +

Only on the Henry County side. There, any clearing, grading or leveling over 120 square feet needs a county land disturbance permit, applied for through the SagesGov portal, and most french drain trenches cross that line. Clayton and DeKalb parcels follow their own county's rules.

Did Hurricane Helene flood Ellenwood? +

The South River did. DeKalb County took an estimated 10 to 12 inches of rain in September 2024, and the river gauge at Flakes Mill Road, a road with Ellenwood addresses, set a new record crest. Yards on low ground near the river are flood zone questions first and drainage questions second; check msc.fema.gov.

Who maintains the roadside ditch on an Ellenwood street? +

On the Clayton County side, the Clayton County Water Authority's Stormwater Utility handles ditches, pipes and inlets in the road right-of-way of unincorporated Clayton. On the DeKalb, Henry and Rockdale sides, ask that county. Either way, the ditch is public and the yard is yours.

How do I tell which county my Ellenwood house is in? +

Look at your property tax bill or search the address on a county tax assessor's site; the ZIP code, 30294, won't tell you. It matters for permits, stormwater fees and who to call about the street.