How much water can be collected from a 1" rainfall on a 1,000 sq ft roof?

• A. 300 gallons
• B. 600 gallons
• C. 900 gallons
• D. 1,200 gallons

Answer: (B)

To determine how much water can be collected from a 1-inch rainfall on a 1,000 square foot roof, we can use the following calculation:

1 inch of rainfall over 1,000 square feet can be calculated in gallons using the formula:

• 1 inch of rain = 1/12 feet.

• Volume of water (in cubic feet) = area (in square feet) × height (in feet).

This results in:

1,000 sq ft × (1/12) ft = 83.33 cubic feet of water.

Next, to convert cubic feet into gallons, we use the conversion factor that 1 cubic foot is approximately 7.48 gallons. Thus:

83.33 cubic feet × 7.48 gallons/cubic foot = approximately 623.75 gallons.

Rounding this to a more practical figure would lead to the conclusion that approximately 600 gallons of water can be collected from a 1-inch rainfall on a 1,000 square foot roof. This is why 600 gallons is the correct answer.