What color top indicates a hydrant that flows under 500 gallons per minute?

A hydrant with a color-coded top serves as a quick visual indicator of the water flow rate it can provide, which is critical information for fire safety and response. When the top of a hydrant is red, it signifies that the hydrant has a flow rate of under 500 gallons per minute. This rating is important for firefighters as it helps them assess whether the hydrant is sufficient for fighting fires in a given area.

This color-coding system is designed to aid first responders in ensuring they have access to adequate water supply while managing time-sensitive operations during emergencies. The other colors in the system—blue, green, and yellow—represent higher flow rates, thus distinguishing the red top as indicative of the most limited capacity for hydrants.