waterBOB review: filling the bathtub with drinking water before the outage hits

This is a research-based review, based on manufacturer specs and published data. We do not test products. Specs come from the waterBOB order page and FAQ, checked November 1, 2026. Water guidance comes from the CDC and Ready.gov.

Many water systems need electricity to treat and pump water. In a long outage, pressure can drop and boil-water notices follow. The waterBOB solves one narrow problem: it lets you capture a large amount of clean tap water in the hours before that happens, in a container you already have room for. You lay the plastic liner in the tub, attach the fill sock to the faucet and let it run. The bladder closes, keeping out soap film and debris that would spoil water stored in an open tub.

The useful number is not the 100-gallon headline. The maker's own FAQ says most standard bathtubs hold about 60 to 70 gallons, and you must not fill above the tub's edge. Plan on 60.

Who should buy it

• Coastal and storm-belt households that get advance warning of hurricanes or ice storms. The CDC asks for at least 1 gallon per person per day for 3 days, and a 2-week supply if possible. A family of four needs 56 gallons for two weeks, which one filled tub roughly covers.
• Apartment dwellers with no room for barrels. The liner folds into a drawer until it is needed.
• Households on public water that is likely to go under a boil-water notice after a storm.
• Anyone who already keeps a 2-week supply in jugs and wants a cheap extra layer for flushing and washing.

Who should skip it

• People preparing for an outage with no warning. A waterBOB holds nothing until you fill it, and you cannot fill it once pressure is gone. Keep stored water in rigid containers year-round as well.
• Homes without a bathtub, or with a tub that is in poor condition or hard to reach.
• Anyone planning to keep water stored for months. The maker gives 16 weeks as the outer limit and recommends purification tablets for longer storage or well water.

Strengths

• Volume for the footprint. About 60 to 70 gallons in a space you are not using for anything else during an outage.
• Fast to fill. The maker lists about 20 to 30 minutes, which fits inside a typical storm-warning window.
• Closed bladder. Unlike an open tub, the liner keeps out soap residue, pet hair and debris, so the water stays drinkable.
• Pump included. The siphon pump moves water into a pitcher or jug, so you never dip cups into the reserve.
• Small to store. The packed liner weighs about 1 lb, so a household can keep two or three, one per tub or for a second storm.

Drawbacks

• One use. The maker designs it for one-time use. After an event you drain it, recycle it and buy another.
• Real capacity is lower than the label. Plan on the 60 to 70 gallons a standard tub holds, not 100.
• You lose the tub. No bathing or using the tub as a bucket-flush reservoir while it is full.
• Short shelf life for the water. Up to 16 weeks, and the maker says to keep direct sunlight off it with towels or a sheet.
• Supply gaps. The maker's own store listed it as temporarily out of stock with expected availability in early December when we checked; Amazon availability may differ, and storm season empties shelves fast.

How it compares

The alternatives trade speed for permanence: rigid containers you fill once and rotate, which work even when an outage arrives with no warning.

Using it in a long outage

When and how to fill it

1. 01Clean the tub so the outside of the liner sits on a clean surface. The bladder protects the water, but you will handle the fill area.
2. 02Fill as soon as a storm watch is issued, while the water supply is still normal. Do not wait for the warning to become an outage.
3. 03Stop below the rim of the tub. The maker warns against filling over the edge.
4. 04Cover the filled liner with towels or a sheet to keep light off it, as the maker advises.
5. 05Write the fill date on tape next to the tub. The 16-week limit starts that day.

Rationing the water

Sixty gallons is 15 person-days at the CDC's 1 gallon per person per day, which covers drinking and basic food prep and hygiene. For a family of four that is just under 4 days, so a waterBOB is a strong second layer behind stored jugs, not a full 2-week supply on its own. Drink and cook from the waterBOB first, because it has the shortest life, and keep sealed containers for later in the outage. Use gray water from washing to flush toilets rather than drawing on the drinking reserve.

Safety around the tub

A full tub is a drowning hazard for small children, liner or not. Keep the bathroom door shut and supervise children. Do not run a camp stove or heater in the bathroom to warm the water; the CDC says never use a portable gas camp stove indoors, because it produces carbon monoxide.

When the outage ends, pump out any remaining water for plants or flushing, remove the liner and recycle it. For storage that is ready before the next no-warning outage, pair the waterBOB with rigid containers and a filter for any water you collect later.