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Getting Water From a Fire Hydrant in a Worst-Case Survival Situation
In certain situations, you may be able to obtain emergency drinking water from fire hydrants. Should you do so, and is this even legal, you may ask?
For the most part, opening a fire hydrant on a municipal water line is against the law and should never be attempted. Secondly, if the hydrant is still pressurized, the force of the unregulated water could cause injury or even death. Also, if citizens begin randomly opening fire hydrants, this may result in a loss of pressure when it is needed for actual firefighting.
Private Subdivision Water Systems
Only in the most dire of emergency situations—one in which your subdivision has its own private water supply, and where you have obtained permission from the system owner—can you begin to attempt to obtain drinking water from a fire hydrant. In disaster situations, when there is no power available for the main water station to operate pumps, or if there are no reserves left in overhead or gravity supply tanks, there may be thousands of gallons of potable water still left in the system.
Water supply systems often feature "low point drains," which are used by the water company to periodically drain sediment from lines. Often, there are fire hydrants at these low point drains. Even if the local water supply system has been de-pressurized, there may still be water available in hydrants at low spots, and it may still be under some amount of pressure. How much pressure remains on the line depends on the height and amount of remaining water in the lines above the low spot. A 4" pipe, for example, can hold .653 gallons of water per linear foot. See the chart below.
Note: Never trust the quality of water obtained from fire hydrants when the main water supply has been down for an extended period of time or after an earthquake. Following an earthquake, there may be breaks in the line which allow back-flow of sewage, and the entire line can be contaminated.
Opening the Cap
Fire hydrants feature a five-sided cap-end that requires a special wrench to open. Since no two sides of the cap end are parallel to each other, it's nearly impossible to use an adjustable or Crescent wrench. Using a common pipe wrench will damage the surface of the valve or cap end. For both the top hydrant valve and the caps, you'll need a special fire hydrant wrench, such as the adjustable one seen below.
Opening the Valve
With all persons cleared out of the way and one of the caps removed, the top hydrant valve can slowly and cautiously be opened using a fire hydrant wrench. Do not attempt this procedure on lines for which you have not obtained permission and never attempt this on lines that are pressurized. Have several buckets readily available to transfer the water to a portable tank.
If you are able to obtain a length of fire hose with the female connection to attach to the hydrant, you may be able to use this to fill barrels or tanks in the back of a truck or trailer.
Final Thoughts and Cautionary Statement
Opening a fire hydrant to obtain drinking water should be a measure of last resort and only performed under extreme and dire circumstances with the permission and oversight of the water system owner or an authorized person such as a firefighter.
Water obtained from unpressurized lines should always be treated as suspect and should be filtered and chlorinated as necessary. Never attempt this measure on lines for which you do not have permission to do so or without professional guidance.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2020 Nolen Hart
Danny from India on August 20, 2020:
Nice way to use hydrants for water use, but with caution :)
Thanks for the information Doodlebugs.