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What to Do With Your Well After a Flood

A flooded well should be treated as contaminated until proven otherwise. Here’s the safe sequence: alternate water, inspect, disinfect, and test.

By Know Your Well Water Editorial TeamReviewed October 28, 20262 min read

Quick Answer

If flood water reached your wellhead or the well was submerged, assume the water is contaminated. Use a safe alternate water source for drinking, cooking, and brushing teeth; have the system inspected for damage; disinfect the well; and test for bacteria before returning to normal use. If the power or pump was affected, involve a professional before restarting.

Assume contamination

Flood water can carry bacteria, chemicals, and debris into a well. Do not drink or cook with the water until it has been disinfected and a bacteria test confirms it is safe. Boiling is only a short-term emergency measure for microorganisms and does nothing for chemicals.

Safe steps after a flood

  1. 1Switch to bottled or another safe water source immediately.
  2. 2Don’t turn on the pump if the pump or electrical system was submerged — have it checked first (electrocution and damage risk).
  3. 3Once it’s safe, inspect the wellhead and system for damage; a professional should evaluate submerged equipment.
  4. 4Disinfect the well (shock chlorination), ideally with professional help if the situation is unclear.
  5. 5After the chlorine clears, test for total coliform bacteria and E. coli — and retest a few weeks later.

Also consider

  • If chemicals or fuel may have entered the area, discuss additional testing with your health department.
  • Replace or service treatment equipment that was submerged.
  • Keep records of the event, inspection, and test results.

When in doubt, ask the experts

Your local health department can advise on flood-specific testing and whether local conditions warrant extra precautions. Accredited labs and licensed professionals handle the testing and repairs.

Frequently asked questions

Can I use my well water right after a flood?
No. Treat flooded well water as unsafe until the well is inspected, disinfected, and a bacteria test confirms it’s safe. Use an alternate source in the meantime, and don’t restart a submerged pump without a professional check.
Is boiling enough after a flood?
Boiling can kill microorganisms as a temporary measure, but it won’t remove chemicals that flooding may introduce and isn’t a substitute for inspecting, disinfecting, and testing the well.

Sources & references

This guide is documentary research and general information, not a laboratory analysis or professional assessment of your specific well. See our disclaimer.