Trending Topics

Responding to waterflow alarms: A step-by-step guide

Detailing alarm causes, actions to mitigate the incident and fire protection post-incident


Collins (Miss.) Fire Department Chief Pope details the riser and valve portions of the waterflow sytem to crews in 2017.

Photo/Collins (Miss.) Fire Department

By Bruce Moore

It’s 9:00 pm on a Friday night, and you are dispatched to a waterflow alarm in a large warehouse/industrial facility.

You arrive on the scene and give an initial report of nothing showing. You request a building representative, take the entrance key out of the lock box, and enter the building. What are your next steps?

Waterflow alarm basics

A waterflow alarm can be caused by a fire, an accidental sprinkler head discharge, an inspector’s test valve or main drain valve opened, a broken sprinkler pipe, testing, maintenance, a faulty/out-of-adjustment waterflow switch, or a minor surge in the system.

Our first action is to access the fire alarm panel to see what riser has activated. Most alarm systems have addressable “points.” A point is an alerting device within the alarm system that sends a signal to the alarm panel. It could be a pull station, smoke detector, waterflow alarm, trouble alarm or something similar. These alarm points are programable, which means information like the alerting device’s location (address) can be programmed into the fire alarm system for that alarm point. That way, when we check the alarm panel, this information will be displayed.

To make it easier to locate the riser in alarm, fire departments should require such facilities to have a map at the alarm panel showing the layout of the building, how the building is broken down in sections, and the location of the risers. An address of riser #10, @ section H-12, may not be that helpful if we do not have a map of the facility.

Step-by-step response

Once we have determined which riser’s waterflow alarm has been activated, we need to proceed to the affected riser. If there is an on-site fire pump, we will also need to send someone to the pump room/house to determine if the fire pump is running and to turn off the fire pump if there is not a fire. It is important to not turn off the fire pump until it is determined whether there is a fire or an accidental water flow.

When at the riser, check the water pressure gauges and listen for water flowing through the riser. The riser may also be cold to the touch. You can compare the upper riser gauge readings with an adjoining riser to see if they differ. If one riser has an upper gauge reading lower pressure than another riser, then there could be water discharging from that sprinkler system.


Main drain.

Photo/Bruce Moore

If a sprinkler head is discharging water, you may be able to see, hear and/or smell it. Because the sprinkler system is a closed system, the water does not move or change but rather becomes stagnant, and when it discharges, the water will be initially dirty, almost black, and smell like sewer gas.

If the sprinkler system is flowing water, then the first thing to check is whether there is a fire. If there is a fire, then we follow our standard operating guidelines (SOGs) for fires in sprinklered buildings and, if not, we need to stop the water flow, turn off the fire pump if running, and silence the building alarm. It is hard to think and communicate when an alarm keeps on sounding.

If the sprinkler head is accessible, we may be able to place a wooden wedge into the sprinkler head to stop the water flow. However, if the wedge does not work, or the sprinkler head is at a height we cannot access, then we need to turn off that riser’s water supply valve.

There are several different types of water supply valves, and we need to know how to turn off each type. Preplanning and conducting walk-throughs of these facilities will help us identify the location of the water shut off valves and how to close these valves. It is important that we do not shut off the fire protection water supply valves for the entire building, just the supply valve for the affected riser.

Once we close the water supply valve, we open the main drain valve on the riser. The main drain valve is a 2-inch valve pre-piped into a drain that will be the largest valve connected to the riser. It is located in the middle part of the riser, just above the face plate. Opening the main drain valve drains the water out of the sprinkler system. Once we have taken these steps, the water is not going to instantly stop flowing; there is still water in the sprinkler system piping that must drain out. Initially, you may not notice a change in the amount of water discharging from the sprinkler head, but after a few minutes, it will start to decrease.

Once the water supply valve has been closed and the facility’s fire protection’s system pressure has returned to normal, we can turn the fire pump controller back to the auto position. However, if the fire protection system has not yet returned to its normal pressure, the fire pump will sense a low pressure and can automatically start running again. If this happens, turn the pump controller to the off position until the pressure reaches its normal operating pressure, then turn the controller back to the auto position.

Maintaining fire protection

Our job involves reducing property loss. If there is water discharging and damaging property, we need to stop the flow of water. However, before we leave, we need to ensure that the building is placed back in a position where the building is still protected. Our role is not to repair or restore sprinkler systems; it is to protect the building.

The cause of the accidental alarm, whether it is a sprinkler head discharging or other issue, may not be repaired until a sprinkler system technician performs the repairs. Requesting a sprinkler technician to repair the system after hours or on weekends is more expensive than a repair during normal working hours, and the facility will not want to pay the afterhours costs. This means that the sprinkler system may be out of service for an extended period of time, many times not until the next day or longer.

In order to ensure the sprinkler system has been repaired, we need to require the facility to contact the fire department after the sprinkler system is repaired and restored. If the call is not made, someone from the fire department will need to follow up to ensure that the sprinkler system has been repaired and restored.

We think of fire detection systems as an alerting system (i.e., smoke detectors) and sprinkler systems as fire suppression systems. However, a sprinkler system is not just a suppression system; it is also an alerting system. In warehouse storage and industrial processing areas, the codes do not require smoke detectors or other automatic alerting devices. They rely on the waterflow alarm as the alerting device. If a sprinkler system is shut down, then the fire alerting device for the area the sprinkler system covers is also out of service. Then, if a fire starts in this area, and the area is unoccupied, there will not be any notification of the fire until the fire activates an adjoining sprinkler system.

Shutting down a fire suppression system and then just leaving causes an increased legal liability risk for the fire department. We need to make the facility responsible for the continued fire protection of that facility. There should be policies and procedures in place like an impairment process – steps a facility has to perform when a fire alarm/fire pump/suppression system is out of service, that we require the facility to follow.

A key component of the impairment process is a fire watch program that requires the facility to have someone on site, walking through the affected area on a timed basis (i.e., once every 30 minutes) to look for fires or other problems until the system is repaired. A requirement of the fire watch program should be for the facility to log the patrol times and the person conducting the patrol.

In sum

Whether it is a large or small facility, when responding to a waterflow alarm, these same steps apply. Responding to a waterflow and taking the appropriate action is not hard, but it is something we need to know how to do.

About the author

Bruce Moore is an adjunct fire science instructor and fire science program developer for Columbus State Community College in Ohio and an adjunct fire science instructor for Purdue University Global. He previously served as fire chief for the Sturgis (Michigan) Fire Department, the Worthington/Sharon Township Division of Fire and EMS in Ohio, and the Oshtemo Fire Department in Michigan. He also served as an industrial fire chief for Securitas Security Corporation.