Typhoon preparation talk tends to focus entirely on power outages, but in Okinawa, a power outage can turn straight into a water outage — even when the water pipes themselves are undamaged. If you don’t understand this mechanism, you’ll get the amount you stockpile wrong.
Why a power outage stops the water — the pressure pump
Kin Town explains a water outage in apartment-style housing this way:
If you live in an apartment or condo building that uses a pressure pump (a machine that uses electricity to pressurize water and send it up to an elevated tank or to your tap), a typhoon power outage — or an earth-leakage breaker tripping — will stop the pressure pump from working, causing a water outage.
In other words, the water is arriving, but the equipment that pushes it up to the higher floors has stopped. If you live in apartment-style housing, it’s safer to prepare assuming that a power outage equals a water outage.
And importantly, the same thing happens even if only the earth-leakage breaker trips. If the water stops even though the building itself hasn’t lost power, that’s a reason to suspect the pump’s own breaker (check equipment operation with your management company or management association).
The same applies to a detached house if you use a pump because you’re on high ground or in an area with weak water pressure.
How much to store before a typhoon
The Okinawa Prefecture Enterprise Bureau calls on households to stockpile, in preparation for a prolonged power outage or damage to water facilities, and gives the following daily guideline per person:
| Use | Guideline per person per day | How to store it |
|---|---|---|
| Drinking water | 3 liters | Bottled water, etc. |
| Water for daily use | Roughly 20–30 liters | Bathtub, buckets, etc. |
Kin Town gives the same figures. What stands out is that water for daily use requires 7 to 10 times as much as drinking water. Miss this and prepare only drinking water, and your toilet will back up.
For a family of four, that’s 80–120 liters a day just for daily-use water. This is not an amount bottled water can cover. That’s exactly why the bathtub matters. Fill it once the typhoon’s track comes into view.
Things to watch when storing water
- Don’t drink bathtub water. It’s for daily use (toilet, dishes, handwashing)
- Households with small children should watch for drowning risk — pair this with measures like locking the bathroom door or keeping it shut
- If you have a water tank, the prefecture also recommends “keeping a tank filled with tap water on hand as a matter of routine”
- Buckets, pots, and empty bottles can all be pressed into service at the last minute
After the typhoon passes — why conserving water matters
It’s easy to overlook, but the period right after a typhoon is actually when a water outage becomes more likely. The Okinawa Prefecture Enterprise Bureau explains:
If everyone uses water at once for cleaning their homes and washing their cars, supply may not keep up with demand, and a water outage or similar issue can occur.
Once a typhoon passes, everyone starts cleaning up and washing their cars at the same time. As a result, the water can stop even though nothing about the water system itself is broken.
For non-urgent water use, Kin Town asks residents to cooperate by “spacing it out by roughly a day or two.”
It’s understandable to want to wash your car in the clear weather right after a typhoon, but wait a day. Just this can be enough to prevent a water outage across the whole area.
If the water stops, where do you look?
This is where the pitfall lies. The Okinawa Prefecture Enterprise Bureau states that its own role is treating water at the source and supplying it to municipalities, and that supply to individual households is managed by the municipality.
In other words:
- The Enterprise Bureau’s leak, outage, and water supply information — for wide-area outages across the prefecture
- Your municipality’s water utility office — for the individual case of “the water isn’t reaching my home”
You need to check both. “It’s not on the prefecture’s page, so it must be fine” does not follow. If you live in an apartment building, contacting your management company or management association may need to come first.
Always check official information for the latest water outage status — this site does not cover it.
Summary — what to do once a typhoon’s track comes into view
- Fill the bathtub (for daily use — 20–30 liters per person per day as a guideline)
- Check your drinking water (3 liters per person per day — go shopping if you’re short)
- If you live in apartment-style housing, decide your amount assuming power outage = water outage
Power outage preparedness itself is covered in Preparing for a Typhoon Power Outage, and shopping logistics in When to Go Shopping, and What to Buy.