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Fix a French drain that is clogged

We'll confirm the clog, flush the drain, and clear sediment or roots—or tell you when to call a drainage professional.

Troubleshooting · Home maintenance
30–90 min
What you'll need
  • Hose (high pressure)
  • Drain snake (if a cleanout exists)
  • Shovel (to expose inlet or outlet if buried)
Step 1 of 5

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Steps

Goal: Confirm the French drain is clogged, clear the outlet, and flush the drain to restore flow.

  • Check during or after rain. Water pools along the French drain line or backs up instead of draining away.
  • Good: Water pools or backs up—drain clogged. Proceed to Check outlet.
  • Bad: Drain appears clear but water still pools—check the outlet or dry well; see fix-dry-well-backs-up.

Check outlet

Goal: Clear blockage at the drain outlet so water can discharge.

  • Locate the inlet and outlet. Clear any debris or sediment at the outlet. If the outlet connects to a dry well, check that the dry well is not backed up.
  • Good: Outlet clear. Proceed to Flush drain.
  • Bad: Outlet inaccessible or buried—call a drainage professional.

Flush drain

Goal: Flush the pipe to push sediment through and restore flow.

  • Run a hose into the inlet at full pressure. Water should flow through and out the outlet. If the outlet is accessible, flush from that end too.
  • If a cleanout exists, use a drain snake to clear roots or stubborn sediment.
  • Good: Water flows to the outlet. Test after the next rain.
  • Bad: Flushing does not restore flow—call a drainage professional. The pipe may be collapsed or shifted.

When to get help

Call a drainage professional if:

  • The drain is deeply buried with no accessible inlet or outlet.
  • Flushing and snaking did not restore flow.
  • You suspect the pipe has collapsed or shifted.
  • The outlet connects to a system you cannot access.

Verification

  • Water flows through the drain to the outlet when you run a hose.
  • No pooling along the drain line after rain.
  • The outlet discharges water when the drain is flushed.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Confirm clog Verify water pools along the drain or backs up.
  2. Check outlet Clear blockage at the outlet.
  3. Flush drain Flush from inlet and outlet with a hose.
  4. Snake if cleanout exists Use a drain snake to clear roots or sediment.
  5. Call a pro Buried drain, no access, or flushing did not work—call a drainage professional.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Inlet and outlet locations
  • Whether the outlet is blocked
  • Flow after flushing
  • Steps already tried

Is the French drain clogged?

Water pools along the drain line or backs up instead of draining away.

Check during or after rain. Clogged: water pools or backs up. Clear: if water still pools, check grading or the outlet—the dry well may be backed up. Good: drain clogged—proceed. Bad: drain clear but water pools—check outlet or dry well.

Yes No

You can change your answer later.

Is the outlet accessible and clear?

The outlet is where the drain discharges. Debris or sediment can block it.

Check the French drain outlet. Blocked: clear debris and sediment. Clear: proceed to flush. Inaccessible: call a drainage professional.

Yes No

You can change your answer later.

Clear the outlet

Remove debris and sediment from the outlet. Run a hose from the inlet to test. If water flows, the fix is complete. If not, proceed to flush from both ends.

Done

Flush the drain

Run a hose into the inlet at full pressure. Flush from the outlet if accessible. If a cleanout exists, snake the pipe. Water should flow to the outlet. If flushing does not restore flow, call a drainage professional.

Done

Outlet or dry well may be the issue

The drain may be clear but the outlet or dry well is backed up. Check the outlet. If the drain feeds a dry well, see fix-dry-well-backs-up. If the outlet is inaccessible, call a drainage professional.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a French drain clog?
Sediment, silt, and soil wash into the drain over time and block the pipe. Roots can grow into perforated pipe. The outlet can get blocked by debris or soil. French drains need periodic flushing to stay clear.
Can I clear a clogged French drain myself?
Yes, for shallow drains with accessible inlets and outlets. Flush with a hose from the inlet. If there is a cleanout, use a drain snake. For buried drains with no access, or if flushing does not work, call a drainage professional.
When should I call a drainage professional?
Call a drainage professional if: the drain is deeply buried with no access, the outlet is inaccessible, flushing and snaking did not restore flow, or you suspect the pipe has collapsed or shifted.

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