Drainage and Erosion Control in Sandy Springs

What the scope covers

• Where the water starts, mapped before anything is dug: roof area, driveway, neighbouring lots upslope, and the point at which sheet flow becomes a channel
• French drains built as a graded trench with washed stone, a perforated pipe and a filter fabric wrap, rather than a stone-filled ditch that silts up in three seasons
• Catch basins and solid pipe where volume is high, with clean-outs at direction changes so the run can be jetted rather than dug up
• Downspout collection taken well away from the foundation instead of ending in a splash block at the wall
• Regraded swales and dry creek beds shaped to carry storm flow slowly and to look like part of the garden between storms
• Bed and slope stabilisation with deep-rooted planting, jute or coir matting, and a mulch that stays put on a grade
• Discharge points chosen with the city stream buffer and river corridor rules in mind, and land disturbance permitting handled as part of scope where the work triggers it

To have this priced on your own property, call (404) 737-3568 or use the quote form. Someone walks the yard, takes measurements, and leaves a written scope with a price on it. No charge for any of that.

Read next

• The Sandy Springs landscaping guide
• What landscaping costs here
• Working with Georgia red clay
• The glossary, for the words that turn up on a quote

On drainage, specifically

Why does my yard flood when the soil drains fine on paper?

Because infiltration rate and total capacity are different things. The Cecil-type soils across the Georgia Piedmont are described in the USDA soil survey as well drained with moderately high saturated conductivity, yet the same descriptions record medium surface runoff, and the Metro Water District puts practical clay absorption at about half an inch per hour. An afternoon storm here can drop that in fifteen minutes. The water is not sitting because the soil is bad. It is sitting because it arrived faster than any soil could take it.

Can I run the drain out to the street or into the creek behind me?

Sometimes, and it depends on what the water crosses to get there. Sandy Springs protects designated streams and water bodies with a 75-foot stream buffer, of which the inner 50 feet must stay undisturbed and the outer 25 feet is an impervious setback, and construction inside those areas generally needs an approved variance. Properties within 2,000 feet of the Chattahoochee sit inside the state River Corridor as well. The city publishes a map layer that shows whether either applies to a given address, and that check comes before the pipe layout, not after it.

Does drainage work need a permit?

Often. Sandy Springs generally requires a land disturbance permit once 1,000 square feet or more of ground will be disturbed, and the city notes that work under that figure can still need one if it requires erosion control measures or changes topography or drainage patterns, which is exactly what a drainage job does. Residential land disturbance fees run to a $25 administrative fee, a $50 certificate fee, a $100 review fee and $200 per lot, plus a technology fee. The contractor pulls it as part of standard scope.

Is a French drain or a surface swale the better answer?

They solve different problems. A swale moves surface water that is already running across the ground, and it handles large volumes cheaply. A French drain intercepts water moving through the soil and lowers a wet zone, and it moves far less volume than most people assume. A yard that puddles after a storm and dries in a day usually wants grading and a swale. A yard that stays soft for a week wants subsurface interception. Plenty of properties here need both, in that order.

What about erosion on a bare slope?

Cover is the whole answer, and speed matters more than species. Bare Piedmont clay on a grade sheds soil in the first storm after it is exposed, which is why the city requires erosion control measures and a final inspection only after landscape stabilisation is complete. In practice that means matting the slope, planting through it with something deep-rooted, and keeping the mulch coarse enough that it interlocks instead of floating away.