What is the purpose of an auxiliary water supply in a standpipe system?

The purpose of an auxiliary water supply in a standpipe system is to supplement the standpipe and/or sprinkler system. An auxiliary water supply provides additional water volume and pressure that may be required during a fire emergency when the primary water source may not be adequate. In high-rise buildings or during large-scale fires, the demand for water can exceed what the standpipe system is designed to deliver on its own. By having this supplemental supply, firefighters can ensure they have the necessary resources to effectively combat the fire and protect lives and property.

Choosing another option would not align with the intended function of the auxiliary water supply. For instance, it does not serve as the primary water source since the standpipe system is generally designed to operate with a primary source of water. Additionally, while the fire department connection may assist in bringing additional water into the system, the auxiliary water supply itself is not meant to replace it. Controlling water flow is more about the design of the system rather than the specific role of an auxiliary supply. Thus, the key function of an auxiliary supply is its role in enhancing the performance of existing fire protection systems during emergencies.