The Ten-Minute Drainage Check to Do While It Is Actually Raining
Almost everybody looks at their drainage the day after a storm, when there is a puddle in the low spot and the evidence of how it got there has already drained away.
The useful information exists only while it is raining. This week, with 1 to 1.5 inches forecast across several days, there will be more opportunity to collect it than there has been since spring.
This is the walk we do on a first visit, minus the parts that need equipment. It takes ten minutes. Wear a coat and take your phone.
1. Start at the roof, not the yard
Stand where you can see a downspout discharging. Watch the volume. Most people have never actually looked at this and are surprised by it — a roof concentrates a very large amount of water into three or four points in a short time.
Follow where it goes. Onto a splash block and then across the lawn? Into a buried pipe? If buried, walk to where that pipe is supposed to come out and confirm water is coming out of it. A buried line that discharges nothing during a two-inch rain is blocked, crushed, or was never connected to anything.
2. Find the seams
Walk the perimeter of the house and look at where water meets hard edges — the driveway, the patio, walkways, the foundation. Water travelling along a hard edge is water that has been redirected by something, and the redirect is usually the thing worth fixing.
Look specifically for water moving toward the house rather than away. On a two-inch rain it is obvious; on a normal shower it is invisible.
3. Photograph the sheet, not the puddle
Puddles are where water ends. Sheet flow is where it travels, and it only exists while it is raining. Take video rather than stills — direction and speed matter and a photo shows neither.
Stand at the high corner of the property and film downhill. Then do it from the low corner looking back. Those two clips are worth more than any description either of us could write, and if you do call somebody, they are the first thing worth sending.
4. Check the second hour, not the first
This is the one almost nobody knows, and it is the reason to go out twice.
Early in a storm, dry clay takes water fast — down shrinkage cracks, which is bypass rather than absorption. Everything looks like it drains. Later in the same storm, the surface seals and water begins moving across rather than in.
Where water stands in the second hour is your actual drainage problem. Where it stands in the first ten minutes is just where it is lowest.
5. Note what leaves the property, and where
Walk the downhill boundary. Water leaving in a concentrated stream at one point is a different situation from water leaving as a broad sheet — different in what it does to your soil, and different in what it does to your neighbour's.
Note whether it carries visible sediment. Brown water leaving your property is your topsoil leaving your property.
What to do with the ten minutes
Write down, the same day: where water entered the yard, where it travelled, where it stood after an hour, and where it left. Four answers. That sequence is the diagnosis; the puddle is only the last frame of it.
It also means that if you do eventually call somebody — us or anyone else — you are describing a system rather than a symptom, and you will get a better and cheaper answer for it. A contractor who has to guess at the sequence prices the guess.
Worth knowing before you make that call: the eight questions worth asking, and why perforated and solid pipe do opposite jobs.
If you want a hand with it
Carolina Terrain works in Waxhaw, Weddington, Marvin, Wesley Chapel, Matthews, Indian Trail, Monroe and south Charlotte. Request a consultation or call 980-280-7638. The printable version, with the four questions laid out as a form you fill in while standing outside, is the Yard Drainage Diagnostic Worksheet. Everything we have published is indexed on the Start Here page, sorted by the problem rather than the date.
Where these numbers come from
Drought classifications, reservoir levels and streamflow records: NC DEQ press release, 17 September 2026.
County-level precipitation departure and drought coverage: NIDIS / U.S. Drought Monitor, Union County.
Rainfall forecast for 18-23 September 2026: WBTV, 18 September 2026.
Tall fescue seeding guidance: NC State Extension TurfFiles.
Soil texture and compaction: NC State Extension Gardener Handbook, chapter 1.
Written by Alex Purdy, owner-operator of Carolina Terrain LLC in Waxhaw. NC Landscape Contractor Licence CL.1872, NCSU Stormwater Control Measure Inspection & Maintenance Certification #5970, NDS Certified Drainage Contractor. Not a Professional Engineer and not a Registered Landscape Architect — nothing here is an engineered design, and work requiring either of those licences should go to somebody who holds it.
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