Hillside Lot Gutter Drainage in Buckhead & West Atlanta

Sources: gallons and flow computed as roof sq ft x inches x 0.623 (x 0.0104 for gallons a minute) using NOAA Atlas 14, Douglasville, 2-year 60-minute; pipe pitch and spacing from the U.S. Department of Energy Building America Solution Center.

Retaining walls hold soil, not runoff

A retaining wall on a sloped lot is built to hold back earth. Empty a downspout behind it or over its top and the soil it holds gets wetter and heavier, and water working through the joints leaves stains and carries backfill out with it. Empty one at its base and the water undercuts the footing. So we route roof water around retaining walls and let it out below them, where the ground can take it.

More on what clay does with a downpour: our summer storm and red clay drainage guide.

Start up top, on the tall side

On a walkout or basement lot the back of the house can stand two or three stories tall, so the downspouts there run long and land hard. A gutter packed with oak leaves and pine straw overflows from that height and pounds a hole in the ground below, whatever drainage waits at the bottom. So the roof edge comes first: a gutter cleaning and flush of every run, repairs on sections that have lost their pitch, and BroGuard fine mesh guards so debris never reaches a buried line.

Distances: U.S. Department of Energy Building America Solution Center, “Gutters and Downspouts”: 5 feet out at the surface, 10 feet for underground systems, onto ground that slopes away.

How our crews handle it

A Solutionist walks the lot with you, uphill side first, follows every downspout to where it empties and plans a route for each one in writing. Gutters and downspouts are our work. New buried lines go in with our drainage partners, and existing underground drains get checked on the same visit. Matthew Prewett’s Lithia Springs team stays your one contact from the estimate to the final water test.

On a slope the pieces depend on each other. Gutters sized for the roof keep water from jumping the edge on a tall back wall, a mesh guard keeps oak leaves and pine straw out of the pipe, and the buried line carries the water to lower ground. Leave out the guard and the clog ends up underground, the hardest place to reach it.

• Water pooling against the uphill wall, or soaking the lawn just above it.
• A gully or bare channel running down the slope from a downspout or extension.
• Mulch, pine straw and red silt washed onto the driveway, sidewalk or street.
• Stains, seepage or a lean in a retaining wall below a downspout.
• Water sheeting off the gutter on the tall back side of the house.
• Dampness, a musty smell or water lines low in a basement or walkout lower level.
• An outlet that empties onto a neighbor’s yard or straight across a sidewalk.
• Soft or rotted fascia high on the back of the house where a gutter spills.

When the slope itself is the problem

Some hillside water has nothing to do with the roof. Springs and groundwater, a yard graded the wrong way, runoff from the street or the lot above, or a failing foundation drain can all wet a lower level. If that is what we find, a Solutionist will tell you plainly and point you to the right trade. Nobody here sells pipe a house does not need. What we can do is take the roof water out of the picture, which makes the rest easier to judge.

If rot shows up on the fascia while we are on the ladder, fascia board replacement can happen with the gutter work, and if a tall roof is too much for your gutters, 6 inch gutters with larger downspouts move it faster.

Soaking days come every year. Atlanta averaged about 3 days a year with 2 inches of rain or more from 1991 to 2020, and each one sends roughly 2,490 gallons off a 2,000 square foot roof. Short storms hit harder: NOAA Atlas 14 puts the two-year, one-hour rain at Douglasville at 1.55 inches, about 32 gallons a minute off the same roof, all of it looking for the fastest way downhill.

September 2009 showed the extreme. After days of rain that began September 15, the heaviest burst came overnight September 20 to 21. The Douglas County Water and Sewer Authority measured 21.03 inches in 24 hours, and the Weather Service put the chance of that much rain in a day at any Atlanta location at less than 0.01% a year. Sweetwater Creek near Austell crested 20 feet above flood stage. On a 2,000 square foot roof, 21.03 inches is about 26,200 gallons.

The U.S. Geological Survey found the peak flow on Sweetwater Creek near Austell went well past the 500-year flood level and closed Interstate 20, and it counted eleven deaths from the flooding across north Georgia.

Sources: 2 inch days counted from NOAA ACIS daily data for Hartsfield-Jackson, 1991 to 2020; NOAA Atlas 14, Douglasville; National Weather Service Peachtree City, 2009 Atlanta floodsand The Epic Floods of 2009; USGS Fact Sheet 2010-3061 .

What about the neighbors?

On a hillside, your water becomes someone else’s water fast. A downspout aimed at the property line can soak the yard below, and one aimed at the curb sends silt into the street and the storm drains. We place outlets on your own ground, low enough to drain and far enough back from the line for the flow to spread out, so the water soaks in or moves on gently instead of arriving at a neighbor’s fence as a stream. If the work touches a shared swale, a ditch or a storm drain, check with your HOA or your city or county before anything is trenched.

Rules differ from city to city and county to county, so we keep outlets on your property.