Certain corners of the internet have surfaced a technique for water preservation that is applicable in just such an instance. As long as the municipal water system is still intact, “tap water” can be run from a faucet into a storage vessel—a jug, if you will. A canteen or large bottle will also work, as will a food-grade watertight sack.

Factory-bottled water costs around 2,000 times as much as artisanal-bottled water. The former is usually not recommended to be stored for longer than two years, while the latter can be stored for up to six months.

“Well, I don’t have a jug!” some people might say.

The nice thing about jugs is that they are purchasable and reusable. They keep until whenever you need them, and they are environmentally less costly to ship than cases of bottled water. This means less burning of fossil fuel, and so less carbon flowing into the atmosphere, and so less warming of the oceans, and so less intensification of the very weather patterns that bring about the need for stockpiling water.

Disaster-preparedness experts recommend that people invest in quality vessels if possible. Choosing the optimal way to store gallons of water for any given home isn’t necessarily obvious, and it depends on geography. Sources in the San Francisco Bay Area have informed me that many households maintain full tanks of water for use after the next earthquake. Among the popular options are large, polyethylene barrels, some of which are equipped with taps (like kegs) and hold up to 55 gallons of water. Water can be safely stored in these kegs for years, according to some experts, when they’re well cleaned and sealed.

Of course, making space for a large sturdy barrel in a city where real estate costs something like $8,500 per square foot is a privilege not afforded to all. The same problem of space presents itself in New York, where some apartments are barely larger than bedrooms, and in my experience almost none have water barrels. Keeping a 55-gallon barrel of water on a high shelf to save space creates its own set of risks upon arrival of a natural disaster.

In cases where storage is limited, collapsible five-gallon containers can be purchased cheaply and easily stored in even a modest-sized crack in a wall. Hurricanes afford time for preparation that earthquakes do not, namely time to fill one’s vessels.

Even if the municipal water system does fail or become contaminated, as some did in Texas in the wake of Harvey, tap water can be made potable in various ways. The CDC advises adding a tiny bit of bleach, one teaspoon of 5.25-percent sodium hypochlorite per gallon of water. If anything, grocery stores should be selling out of bleach.