Most people call us about a wet yard with a solution already in mind. They want a french drain. Sometimes that is right. Often the water is not asking for a pipe at all, and the cheaper fix is to change the shape of the ground it is sitting on.
The difference matters because the two jobs fail in different ways. A drain put in the wrong place keeps working perfectly and the puddle stays. Regrading where a drain was needed moves the water three feet and leaves it there. Before anybody quotes you anything, the question worth answering is where the water enters the yard, not where it ends up.
Start at the top of the slope, not at the puddle
The puddle is the last thing that happens. Walk uphill from it instead. On a quarter-acre lot in Dunwoody or Brookhaven, water arriving at a low spot out back has usually come off the roof, the driveway, the patio, and whatever the neighbour’s grade sends across the line. Each of those has its own fix, and most of them are not a drain.
There is a lot of water to work with. The National Weather Service office in Peachtree City puts a normal year here at 49.71 inches, much of it landing on ground that is dormant through winter, when the grass has stopped taking anything up.
The six inches almost nobody has
Georgia’s mandatory residential code is the International Residential Code with state amendments, adopted by the Department of Community Affairs. Its drainage section, R401.3, sets a number worth knowing as a homeowner: the ground should fall six inches within the first ten feet away from the foundation wall. Where a lot line, a wall or a slope makes that impossible, the code accepts a steeper short run, and asks that swales and any paving within ten feet of the house slope at least two percent away from it.
Take a four-foot level and a tape into your own side yard and check it. A great many houses here are a long way off, and the reason is rarely a builder cutting corners. Topsoil was stripped, the hole was dug, the backfill went in loose and settled over the following decade. Ground that had six inches of fall in 1998 now has one, or slopes back toward the brick.
If that is what you find, you do not have a drainage problem. You have a grading problem, and a pipe buried in it will not raise the dirt back up.
Our clay gets blamed for the wrong thing
Nearly every wet-yard conversation in north Atlanta arrives at the clay sooner or later, usually with the idea that it swells up and holds water like a bathtub. The soil under most of these yards is the Cecil series, and the USDA’s official description classes it as well drained with moderately high conductivity. Its clay is kaolinite, a low-activity mineral, so it does not swell and shrink the way the clays of central Texas do.
What it does instead is compact. Driven on with a loaded truck while wet, or graded with a machine during construction, Cecil subsoil packs down hard and stays that way. Water then runs across it rather than into it. The soil is not naturally bad at drinking; it has been pressed shut. That distinction changes the fix, because loosening and planting compacted ground is sometimes the whole job.
When regrading is the answer
Reshaping the ground is the right call when the water is moving across the surface and simply has nowhere better to go. The signs are a yard that drains eventually but slowly, a wet strip that follows a line rather than sitting in a bowl, mulch washed into a fan shape after a storm, and a foundation that the ground slopes toward.
The work is soil, a machine and a rake: cut the high side, build the fall, shape a shallow swale with enough pitch to keep water moving, then sod or seed it so it holds. It is the option we push hardest for, and not only because it costs less to look after. There is nothing buried to clog, no fabric to fail, no pipe to dig up in fifteen years, and the swale keeps growing grass that takes up part of the water itself.
When a french drain is the answer
A drain earns its place when the water is already below the surface, or when there is no route across the top. That means a yard holding water in a true low spot with higher ground on every side, a slope feeding a basement wall, a spring or seep that runs days after the rain stops, or a retaining wall that needs the water behind it taken somewhere.
Done properly it is a trench, washed stone, perforated pipe laid to a steady fall, non-woven filter fabric around the stone, and a real outfall at daylight or into a basin. The fabric is its own decision, covered in our guide to woven and non-woven geotextile. The outfall matters most: a drain with nowhere to put the water is a long thin hole that fills up.
The yards that need both, and the order
Plenty of properties need both, and the order is not negotiable. Grade first, drain second. If you put the pipe in before you fix the shape of the ground, you have committed to a line through a yard that is about to change elevation, and the surface water you could have steered away for less is now the drain’s problem for the rest of its life.
The one exception is a house actively taking water against the foundation. There, getting the water off the wall comes first and the finish grading follows.
Two mistakes we see most
The first is downspouts. A yard can be graded correctly and still flood a bed because four roof planes discharge two feet from the brick. Carrying that water past the drip line is the cheapest drainage work there is, and it is where we would start on almost any house. There is more on where downspouts should put the water in its own write-up.
The second is sending everything to the street. A drain that collects the whole back yard and fires it into the gutter solves one property and adds to what the next storm does downhill. Where the lot allows it, we would rather put that water into a planted low area or a basin where it can soak in over a day. It keeps the water doing something useful on the property it fell on.
What we would do on our own house
Extend the downspouts. Take the level around the foundation and fix any run short of the code’s six inches in ten feet, because that one is about the building rather than the lawn. Then watch the yard through two or three real storms before deciding on a pipe. Most yards that look like they need a drain in January do not need one once those two jobs are done, and the ones that still hold water have told you exactly where the drain should go.
If you want somebody to walk it with you, that is what our drainage and grading page is for, and the deeper detail on installation sits on our french drain page. More of these write-ups are collected in our guides.
