Quick Answer
A sufficient cistern size for emergency preparedness depends on the household's water needs, climate, and storage duration, aiming for at least 1 gallon per person per day. A general guideline is a 1-2 month supply, which translates to 1,000-2,000 gallons for a four-person household. This estimate may vary based on specific circumstances.
Factors Affecting Cistern Size
When determining the size of a cistern for emergency preparedness, several factors must be considered. The household’s water needs, including drinking, cooking, hygiene, and other essential uses, must be calculated. A general rule of thumb is to estimate 1 gallon per person per day for drinking, cooking, and hygiene, while accounting for additional water needs for washing clothes, cleaning, and other non-potable purposes.
Calculating Cistern Size
To calculate the required cistern size, multiply the household’s daily water needs by the desired storage duration. For example, a four-person household with a daily water need of 10 gallons may require a 40-gallon cistern for a one-day supply or a 2,000-gallon cistern for a 50-day supply. Consider the following factors when adjusting the calculation: climate, seasonality, and the number of people in the household.
Cistern Size Guidelines
Typical cistern sizes for emergency preparedness range from 1,000 to 5,000 gallons. A more detailed guideline is to aim for the following cistern sizes based on household size: 1,000 gallons for a single person, 2,000 gallons for a four-person household, and 3,000-5,000 gallons for larger households.
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