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After the Flood: Is Your Water Safe to Drink?

After a flood, drinking water sources may be contaminated - - be safe before you drink the water.


Regardless of whether you have your own water supply, get water from a public water system, or operate a public water system, you might have to take special steps to ensure that your drinking water is safe after the well or water treatment plant has been flooded.

These links will take you to information that can help you ensure that your water supply is safe:

Much of this information is in PDF format. (Help with PDF.)

Checklist for operators of PWSs

If your drinking water distribution system has lost operating pressure, be sure to follow these steps, as outlined in the flowchart Adobe Acrobat PDF Document found in the rules for public drinking water systems:

  1. Notify your customers immediately to boil water they use in cooking, for drinking, or for making ice. Be sure to issue the boil-water notice in both English and Spanish.
  2. Notify our regional office that serves your county or call the Water Supply Division in our central office at 512/239-4691.
  3. Take the measures needed to flush your distribution system, disinfect it, and ensure its integrity.
  4. Take samples as needed to ensure that clean water is available in all parts of your system. To have your water samples analyzed, see our list of labs certified to test drinking water Adobe Acrobat PDF Document .
  5. Once you have confirmed that your distribution system is capable of producing a stable supply of clean water, you may lift the boil-water notice.

The complete rules for public water systems are found in Title 30, Texas Administrative Code, Chapter 290. Two subchapters of these rules are available for reference:

If you have other questions, contact either our regional office or the Water Supply Division in our central office (512/239-4691) for advice.

Advice for customers of PWSs

To disinfect water by boiling, bring it to a full boil, continue to boil for two minutes, and then let the water cool before using it. For more information see After a Disaster: Is your Drinking Water Safe? Adobe Acrobat PDF Document and the EPA’s Web page on the emergency disinfection of drinking waterExit the TCEQ.

If you have not been told to boil your water, ask yourself these questions:

  1. Did my home flood? If yes, see "Flooding on Your Property." If no, go to question 2.
  2. Did the flood cover any part of the water line between my water meter and my house? If yes, see "Flooding on Your Property." If no, go to question 3.
  3. When I opened a faucet, did a typically strong stream of water come out? If yes, you are probably fine. If the faucet produced no water or only a weak stream, see Reporting a Water Outage.

Flooding on Your Property

If your home or any part of your property above your water lines was flooded, it would be a good precaution to flush your service line and household plumbing as follows:

  • Starting with the outside faucet farthest from your meter, run water through the faucet until you notice a change in water temperature. Then shut the faucet off.
  • Working back towards the water meter, continue flushing one faucet or water fixture at a time. Remove the aerator before you flush kitchen or bathroom faucets. At each faucet, this flushing procedure should take five minutes or less.
  • Be sure to drain and refill your water heater also.

Flushing should remove any air or contaminants that may have entered your plumbing system when the service was interrupted.

Reporting a Water Outage

If your faucet produces no water or only a weak stream and you have not already been told to boil your water, call your water system immediately to report a possible outage in your neighborhood.

Then boil or disinfect your waterExit the TCEQ above.

Be alert for water leaks and outages after a flood, too. If the flood washed soil away from a water main, the main could break days or weeks later. Report leaking mains or outages to your water system immediately.

Advice for disinfecting your own well

If your well has been flooded, disinfect your well and have a water sample analyzed by a lab certified to test drinking water.Adobe Acrobat PDF Document