When an existing drain is the service, not a new trench
Homeowner warning signs — change in how the yard recovers, a damaged outlet, settlement over a known line — are listed on Drainage Repair Signs. This page is the inspection: why the system failed, and whether repair or replacement is honest.
- An existing exterior French drain that used to work and no longer does
- Little or no flow at an outlet that used to run after rain
- Water backing up along the old trench line
- Landscape or hardscape work over or below the original drain
How French drain problems get diagnosed
The first step is locating the existing system: trench path, pipe, and outlet. If the outlet is buried or discharging into a new low spot, that alone can put water back in the yard.
Sediment can reduce the stone’s ability to accept water. Roots, collapsed pipe, or a broken connection can stop flow in one section while the rest of the trench still looks fine from above.
Sometimes the drain is intact but the yard around it has changed. Fill dirt, a new garden bed, or a downspout added later can send more water than the original line was meant to handle — or send it to a different place.
Repair might mean exposing and replacing a damaged run, clearing an outlet, or rebuilding a section of trench. Replacement is the conversation when the system is in the wrong place, undersized for the current yard, or damaged along most of its length.
Repair vs. replacement
Repair makes sense when the original layout is still the right layout: the trench is where water collects, the outlet is still viable, and the failure is localized.
Replacement is more likely when the drain was never given a real outlet, when it was installed too flat, or when the wet area has moved because the yard was regraded or rebuilt.
Flushing a line without finding the restriction can waste time. So can digging a new French drain next to a working one that only needed its outlet uncovered. The property decides which path is honest.
What to inspect on an existing drain
A repair visit should treat the old system as evidence, not assume a clog and stop there.
- Whether an outlet still exists and where it discharges
- Whether water is backing up along the original trench
- Visible pipe, stone, or fabric at any exposed point
- Grade changes, new hardscape, or planting over the drain
- Downspouts or surface water now feeding the same area
- Whether a repair can restore flow or the layout itself is the problem
Related drainage solutions
If the old drain cannot be saved, or never addressed the whole water problem, these are the usual next pages to read.