Quick answer: 1 US gallon [3.8 L] per person per day for at least 3 days is the CDC emergency storage baseline. For four people, that is 12 US gallons [45.4 L]. Stored safe water works without the electric well pump. Remaining tank pressure is limited; manual pumping needs suitable equipment installed before the outage.
Plan well water during a power outage alongside your power outage checklist. For a home supplied by an electric well pump, the loss of power can also interrupt replenishment of household water. Here, “without a pump” means without the electric pump operating: storage avoids pumping, while a hand-operated alternative still uses a pump.
Plan well water during a power outage with a separate reserve
CDC recommends a minimum reserve for three days and suggests trying to store two weeks if possible. Its baseline covers drinking and sanitation. Extra needs, including pets or hot conditions, require a larger allowance. The figures below are household multiplication, not a prediction of what your family will actually consume.
Count the people the reserve must serve and choose a planning horizon. Keep the water budget separate from the electrical budget. A pump that can restart does not remove the need for stored water during equipment trouble or an interruption in the backup supply. Nor should an unlabeled tank be counted as a ready drinking-water reserve.
| People | Planning horizon | Stored amount at baseline | What the figure represents |
|---|---|---|---|
| 1 | 3 days | 3 US gal [11.4 L] | CDC minimum-duration baseline, multiplied for one person |
| 1 | 14 days | 14 US gal [53.0 L] | CDC longer preparation horizon, if possible |
| 4 | 3 days | 12 US gal [45.4 L] | Four-person scenario; additional needs may raise the amount |
| 4 | 14 days | 56 US gal [212.0 L] | Longer household scenario, not a pressure-tank rating |
CDC identifies unopened commercially bottled water as the safest and most reliable emergency source. For containers you fill, use food-grade storage containers and follow the agency’s container guidance. Never reuse a container that held toxic chemicals. Keep drinking-water storage distinct from water set aside for nonpotable purposes.
Treat the pressure tank as a limited buffer
Amtrol’s homeowner brochure describes a buffer of pressurized water, including a reserve during power failure. Its operating manual explains that pressure falls as water is used, normally triggering pump replenishment. With the electric pump stopped, that replenishment cannot be assumed. Water at a faucet immediately after the outage is not evidence of an unlimited supply.
The tank’s nameplate volume does not establish how much usable water remains when power fails. Its current fill state and the system’s operating conditions matter. Ask the well contractor to identify the actual arrangement and explain its reserve. Avoid promising a number of showers or hours of water from a generic tank size.
The Amtrol manual reserves precharge checks and adjustments for licensed professionals. Do not add air or alter pressure settings to create an outage reserve. If the system has lost pressure or water quality is in doubt, ask the local health department and well contractor what checks are needed. Mechanical availability and drinking-water safety are separate questions.
A hand pump depends on water level and discharge conditions
A manual option should be assessed and installed by a well contractor before an emergency. The examples below illustrate different pumping designs, not product recommendations. Have the contractor check water level, casing clearance, existing equipment, the intended discharge and local requirements. A maximum depth in a headline cannot confirm compatibility with your well.
| Documentary example | Stated limit | Reference point and conditions | What the contractor must resolve |
|---|---|---|---|
| Shallow suction: Bison Model 1900 | Specification says less than 25 vertical ft [7.6 m] | Static water level relative to pump; other manual sections say 25 ft or less | Actual lift, site conditions, plumbing compliance and freezing protection |
| Deep-well design: Simple Pump 100CA | Up to 325 ft [99.1 m] static water level | Hand operation to ground level at ambient pressure; not total drilled depth | Compatible cylinder and casing; pressure, elevation and piping losses reduce capability |
The Simple Pump manual describes clearance and freezing-related requirements; the Bison manual also covers winterization. An installed pump therefore still needs its documented operating conditions. Ask for a written operating and maintenance plan. This guide gives no well-cap removal, wiring, priming, valve-switching or household pressurization procedure.
An electrical backup restores pumping only if the complete system fits
Use the well pump running and starting power guide to understand the electrical sizing question. Then identify your own equipment through the appliance label and wattage guide. A published example is not the specification of your installed motor, controller or treatment equipment.
Give those documents to a licensed electrician and well contractor. The generator sizing guide separates running demand from startup needs. Use a professionally approved connection and account for the complete system. Avoid assuming a small household battery can supply a hardwired pump because its advertised energy capacity looks sufficient.
An engine backup also needs fuel, maintenance and planned interruptions. The generator continuous-operation guide explains those stops. Stored water provides a separate fallback while pumping is unavailable. The reserve calculation does not promise that a generator will operate throughout the outage or that a well damaged by the storm can safely restart.
Keep water access separate from water quality
EPA advises staying away from a flooded well pump and not drinking or washing with water from a flooded private well. Get help from a well or pump contractor and the local health or environmental department. The EPA flood guide requires professional electrical checks before flooded equipment is restarted.
EPA well-testing guidance calls for testing after nearby flooding or well-system repairs and using a state-certified laboratory. Follow local drinking and bathing advisories and use a known safe source while safety is unresolved. A working handle, flowing faucet or restored power cannot certify water quality. No homemade disinfection recipe is provided here.
We built the reserve table from an institutional storage baseline and compared complete manufacturer documents for pressure storage and manual-pump conditions. The graphic uses planning endpoints, not measured performance. We did not test a well, measure remaining drawdown or recommend a model. During a power cut, use the documents and local requirements for your actual system; these storage quantities use US gallons.
Protect the well system and keep engine exhaust outdoors
Leave well-system installation, pressure adjustments and electrical connections to qualified licensed professionals. Follow EPA flood precautions and local water-quality advice; do not restart flooded equipment or rely on its water simply because electricity returns.
Any engine generator stays outdoors. Follow the generator CO placement guidance, keep exhaust away from openings and maintain working CO alarms. Never backfeed household wiring. A water emergency does not justify improvised electrical or well-system work.
Frequently asked questions
Does well water not work when power is out?
For a system supplied by an electric well pump, loss of its power stops replenishment. The Amtrol brochure describes a limited pressurized reserve that may still be available. Existing storage or a suitable installed manual alternative changes the situation. Do not infer unlimited water from a faucet that briefly continues to run.
How to get water from your well in a power outage?
Use stored safe water while the electric pump is unavailable. A compatible manual pump installed beforehand or a professionally approved electrical backup can provide another route. The Simple Pump manual shows why casing and operating conditions matter. Keep extraction and water quality separate; neither a hand pump nor a generator certifies potability.
Can I take a shower if the power is out with well water?
Do not assume a normal shower is available. Remaining pressure does not establish its duration, and water quality must also be suitable. EPA says not to wash with water from a flooded private well. Use your stored reserve for priority needs and follow local health-department guidance when the well’s safety is uncertain.
How long will well water last without power?
There is no universal duration for well water during a power outage. The Amtrol manual distinguishes water delivered between pump cycles from general tank storage. Remaining reserve depends on the actual system and its state when power fails. Plan stored safe water separately rather than promising hours of household use from a nameplate volume.
This article is general information, not an installation guide and not a substitute for a licensed electrician. Electrical work on a service panel, a transfer switch or a utility connection is regulated in most jurisdictions and normally requires a permit and an inspection. Fuel-burning equipment produces carbon monoxide and must never be run indoors, in a garage or near an opening into the home.
