23.8 Long-term water
A two-week reserve (chapter 2) is not enough for a month. For a prolonged collapse you need three things: a larger reserve, a way to replenish it, and a high- capacity purification method.
| Per day | 30 days | |
|---|---|---|
| Each person (1 gal / 3.8 L per person per day) | 1 gal (3.8 L) | 30 gal (114 L) |
| Each dog of ~15 lb (7 kg); adjust for your pets' weight | ~0.2 gal (0.75 L) | ~6 gal (22 L) |
| Minimum total | 1 gal (3.8 L) per person + water for pets | 30 gal (114 L) per person, plus your pets' water |
In extreme heat the need can double, and that figure does not include hygiene or toilet use. In an apartment you cannot fit it all in storage: store what you can (chapter 2) and plan how to replenish the rest.
Sources for replenishing
- Official distribution points. In large emergencies, the city, your water utility, FEMA, or the Red Cross hand out water. You need containers and a way to transport them (a cart or hand truck; 5 gallons weigh about 42 lb / 19 kg).
- Tap water under a boil advisory. As long as there is some pressure, keep filling up and treat it (chapter 3).
- Rain. According to state water management agencies, each inch of rain can yield about 600 gallons (2,270 L) per 1,000 square feet (93 m²) of roof. In an apartment you do not control the roof, but you can collect with buckets under the building's downspout (with permission), with a clean tarp in the yard, or with open containers during the rain.
High-capacity purification
Boiling several gallons a day uses a lot of fuel. For weeks, a large-capacity gravity filter (the kind you fill at the top and that drips into the lower reservoir), with its spare elements, and bleach or tablets as backup, is a good idea. Check what each filter removes: many do not remove viruses and must be combined with chemical disinfection. Comparison of methods and bleach doses in chapter 3.
