What is the approximate area that will produce 1 gpm of rainfall at a rate of 4 in/hr?

To determine the area that will produce 1 gallon per minute (gpm) of rainfall at a rate of 4 inches per hour, we need to convert the rainfall rate into a volume of water.

First, let's break this down:

• Rainfall Rate: 4 inches/hour means in one hour, there are 4 inches of water.

• Conversion of Inches to Feet: Since 12 inches make 1 foot, 4 inches equals ( \frac{4}{12} ) feet, or approximately 0.333 feet.

Next, we calculate the volume of water that falls on a certain area in one hour. The volume can be expressed as:

[ \text{Volume} = \text{Area} \times \text{Height of Rainfall} ]

We are looking for the area in square feet, knowing that 1 gpm is equivalent to 60 gallons per hour.

Since 1 gallon of water is approximately 231 cubic inches, we can convert 60 gallons to cubic inches:

[ 60 \text{ gallons} = 60 \times 231 \text{ cubic inches} = 13860 \text{ cubic inches} ]

To convert cubic inches to cubic