City folks lose lights in a blackout. Well owners lose lights and every drop of water in the house — drinking, flushing, washing, livestock. The moment the grid drops, your pump is a paperweight, and the only water you own is whatever's sitting in the pressure tank.
How much is that? Less than you think: a typical "30-gallon" pressure tank holds about 6–9 usable gallons — drawdown, not total volume. A family burns through that in a couple of toilet flushes and a hand-washing session. Here's how to be the house that still has water on day three: what you've already got, the storage that costs almost nothing, and the honest generator math.
Hidden Water You Already Own
The moment the power fails, you have three reserves:
- The pressure tank: 6–9 usable gallons on a typical tank. Use it deliberately — that's drinking water, not toilet water.
- The water heater: 40–80 gallons of clean water. The unsung emergency tank. Power off, let it cool, connect a hose to the bottom drain valve, open a hot tap somewhere to break vacuum, and drain what you need. (This is one more reason to flush your heater yearly — sediment-free water when it counts.)
- Toilet tanks (not bowls): a couple of gallons each — fine for pets in a pinch, better as flush water.
Flush protocol: don't flush with stored pressure. Pour a bucket of any water (pond, pool, rain barrel) directly into the bowl — one bucket, one flush.
The $50 Storage Plan (Do This Before Any Storm)
FEMA's floor is 1 gallon per person per day; a realistic rural target is 2 (you have animals, gardens, and no corner store). For a family of four, a 3-day kit is 12–24 gallons; a week is 50+.
- Stackable water storage containers (5–7 gal jugs): fill from your own tap, add nothing if you'll rotate every 6 months, store cool and dark.
- A 55-gallon water barrel with pump and treatment drops: one barrel ≈ a week for a family, ~$100.
- Storm warning ritual: fill bathtubs (a tub liner bladder keeps 60–100 gallons clean instead of tub-grimy), every stock pot, and top off the jugs.
- Livestock: whatever your animals drink per day × 3, minimum, in barrels near the barn.
The Generator Math (Where Most Guides Get It Wrong)
A well pump is a motor, and motors need a starting surge of roughly 2–3× their running watts. Skip this and you buy a generator that hums along until the pressure switch clicks — then stalls.
| Pump | Running watts | Starting surge | Generator minimum (pump + fridge + lights) |
|---|---|---|---|
| ½ HP | ~750–1,000 W | ~1,500–3,000 W | 4,000+ W starting |
| ¾ HP | ~1,000–1,500 W | ~2,500–4,000 W | 5,000+ W starting |
| 1 HP | ~1,500–2,000 W | ~3,000–6,000 W | 6,500+ W starting |
Three non-negotiables:
- Voltage: most submersibles are 240V. Many small inverter generators are 120V-only — they cannot run your pump at any wattage. Check before buying.
- A transfer switch (or interlock kit), professionally installed. It's how the pump circuit legally and safely receives generator power. Backfeeding through a dryer outlet with a suicide cord can kill the lineworker fixing your grid — don't.
- Fuel reality: a 6,500W generator drinks 12–18 gallons of gasoline per day run continuously. A dual-fuel generator on propane sidesteps stale-gas carburetor problems and stores indefinitely — and you don't run it continuously anyway. The smart cycle: run the generator 2–3 times a day, pressurize the tank, fill jugs and buckets, top the water heater, power the fridge — then shut it down. A day's water in 90 minutes of fuel.
Off-grid alternative worth knowing: a hand pump or well bucket that installs alongside the submersible in the same casing — zero fuel, works forever, beloved by homesteaders as the backup's backup.
When the Power Returns
Don't just walk away when the lights blink on: check that the pressure switch cut in and the tank reached full pressure; if the outage involved flooding, treat the well as contaminated; brief brown/cloudy water after restart is stirred sediment — run outside spigots until clear. Repeated outages that end with a tripping pump breaker deserve an electrician's look — brownout restarts are hard on motor windings.
Your Action Plan
- This week: compute your pump's surge watts (nameplate HP → table above). Confirm 120 vs 240V.
- Buy storage first — jugs and a barrel beat a generator on dollars-per-crisis for short outages.
- If you generator up: dual-fuel, sized to starting watts, with a transfer switch installed properly.
- Storm ritual: tubs, jugs, charge, fuel.
- Twice a year: run the generator under load, rotate stored water, check fuel.
Item 5 is where preparedness quietly dies — the generator that won't start in February was last run in May. Put the rotation schedule in the WellKept app: stored-water swap every 6 months, generator exercise quarterly, fuel check before storm season. It also holds your pump's nameplate numbers (HP, volts, amps), so when you're standing in the generator aisle — or on the phone with an electrician — the answer is in your pocket, not on a label 200 feet down the well.
Frequently Asked Questions
Will my well work without electricity? No — the pump needs power, so water stops when the grid does. You'll have only the pressure tank's stored drawdown (typically 6–9 usable gallons) plus the 40–80 clean gallons sitting in your water heater. After that it's stored water or generator power.
What size generator do I need to run a well pump? Match the starting surge, not running watts: a ½ HP pump needs roughly 1,500–3,000 starting watts, a 1 HP pump 3,000–6,000. With a fridge and lights on top, a 5,000–6,500W starting-capacity generator covers most homes — and it must supply 240V for a standard submersible pump.
Can I plug my well pump directly into a generator? Not practically or safely for hardwired submersibles — pump circuits should receive generator power through a professionally installed transfer switch or interlock. Never backfeed through a wall outlet: it's illegal, it risks electrocuting utility line workers, and it can fry the pump when grid power returns.
How do I flush toilets during a power outage on a well? Pour a bucket of water — any water: pool, pond, rain barrel, tub-stored — directly into the bowl; gravity does the flush. Reserve your pressure-tank and water-heater water for drinking and hygiene, and fill bathtubs before a storm arrives for exactly this purpose.
How much water should I store if I have a well? Minimum 1 gallon per person per day for 3 days; a realistic rural target is 2 gallons per person per day for a week, plus livestock needs. A few 5-gallon jugs plus one 55-gallon barrel covers a family of four for a week for around $150, rotated twice a year.