For continuous flow of a fixture into a storm drain, each GPM shall equal what area in square feet?

The correct relationship between gallons per minute (GPM) of continuous flow from a fixture and the corresponding drainage area in square feet is established in plumbing codes to ensure that storm drains can effectively handle runoff without overflowing. Specifically, each GPM of continuous flow is assigned an area of 24 square feet.

This ratio is based on the design principles that dictate how much water can be safely collected and channeled through a storm drain system. By designating 24 square feet per GPM, the plumbing code ensures that even under sustained flow conditions, the drainage system has adequate capacity to prevent potential backflow and flooding.

This allocation takes into consideration factors such as rainfall intensity, runoff characteristics, and sedimentation, providing a calculated approach to maintaining efficient drainage functionality. Therefore, for every gallon of water flowing per minute into the storm drain, the system is designed to efficiently manage the water corresponding to an area of 24 square feet.