A water-powered backup sump pump solves the one failure a battery backup cannot: it never runs out of charge, because it has no battery to drain. It uses your home’s own water pressure to create suction and lift water out of the pit — so as long as the municipal water main is pressurized, it keeps running through a power outage that lasts days, not hours.
That convenience has a real cost, though: it drinks tap water to do its job, and it only works at all if you are on a city water connection. This guide ranks the units worth buying and is upfront about who should skip this category entirely.
Our top picks at a glance
| Pump | Best for | Flow | Inlet pressure | Price |
|---|---|---|---|---|
| Basepump HB1000-PRO | Best overall | ~23 GPM | 20–100 PSI | ~$500 |
| Liberty Pumps SumpJet SJ10 | Best efficiency | ~19.8 GPM | 20–100 PSI | ~$280 |
| Basepump HB1000 (standard) | Best value | ~23 GPM | 20–80 PSI | ~$400 |
Flow figures above are at a realistic 9–10 foot lift, not the inflated zero-head numbers some listings use — the same honesty check we apply to every electric pump on this site.
1. Basepump HB1000-PRO — Best Overall
Basepump HB1000-PRO
- Brass pump body resists corrosion and tolerates higher municipal pressure without flexing or weeping at the fittings.
- Moves roughly 950 gallons at a 9-foot lift on a 50 PSI supply — real lift, not a zero-head claim.
- Works alongside your existing primary pump; it only activates when the primary fails or falls behind.
- Needs a backflow preventer on the supply line in most jurisdictions — budget for that part and the install.
The HB1000-PRO is the version to buy if your municipal pressure runs high or fluctuates, since the brass body shrugs off pressure swings that can flex a plastic housing over time. It will not out-pump a 3/4 HP electric pump, but it does not need to — its job is to buy time during the exact outage that stops your electric pump cold. Because a flooding basement will not wait, it is worth having your Prime account ready before the next storm: get parts in two days with a free 30-day Amazon Prime trial.
2. Liberty Pumps SumpJet SJ10 — Best Water Efficiency
Liberty Pumps SumpJet SJ10
- Removes about 2 gallons of sump water for every 1 gallon of municipal water it consumes — the best ratio in this category.
- Stainless-steel construction and a 2-year warranty.
- Accepts a wide 20–100 PSI inlet range, so it tolerates both low- and high-pressure municipal systems.
- Slightly lower peak GPM than the Basepump, which matters only if your inflow is severe.
If your water bill is the deciding factor, the SJ10’s efficiency wins: a better sump-water-to-tap-water ratio means less municipal water used per gallon actually removed from the pit. Pair it with your primary pump the same way you would a battery backup — it is a supplement, never the only pump in the pit.
3. Basepump HB1000 (standard) — Best Value
Basepump HB1000 (standard)
- Same ~23 GPM flow as the PRO brass model, at a lower price with a standard composite body.
- Accepts a slightly narrower 20–80 PSI inlet range than the PRO version.
- The pump to buy if your municipal pressure is stable and mid-range, and you do not need the PRO's brass durability.
Most homes do not need the PRO’s brass body — standard municipal pressure sits comfortably inside the standard HB1000’s range, and the flow rate is identical. Save the difference and put it toward the backflow preventer your plumbing inspector will ask about.
Who should actually buy a water-powered backup
Answer honestly before you buy:
- Are you on municipal (city) water, not a well? This is not optional. A well’s own pump needs electricity to pressurize, so during the power outage you are protecting against, a well-fed home has no inlet pressure to run a water-powered backup at all. See our battery backup guide instead if you are on a well.
- Can your plumbing handle the code requirement? Most states require a listed backflow preventer — an RPZ assembly or, in simpler jurisdictions, a dual check valve — installed on the supply line before a water-powered pump connects to it, to keep sump water from ever reaching the drinking supply. Confirm with your local inspector; this is not a DIY-around step.
- Can you tolerate the water use? These pumps use a Venturi effect, so every gallon they discharge also consumes municipal water, typically at roughly a 2:1 sump-water-to-tap-water ratio on the more efficient models. A multi-day outage with heavy inflow will show up on your next water bill.
- Is this your only backup, or a second layer? Most installers pair a water-powered unit with a battery backup, not instead of one, since each covers the other’s weak point: the battery works on a well but runs down, the water-powered unit never runs down but needs city pressure.
The bottom line
The Basepump HB1000-PRO is the water-powered backup we would install for most city-water homes that want a backup that genuinely cannot run out of charge, with the Liberty SumpJet SJ10 as the more water-efficient alternative and the standard HB1000 as the value pick. But this entire category is a city-water-only purchase — if you are on a well, a battery backup is the right call, and either way, check your local backflow-preventer requirement before you buy, not after the inspector shows up.