Emergency Public Alert System

While the county already has emergency alert capabilities, County Executive Ball wants the businesses, residents, and visitors of Ellicott City to have as much warning and direction as possible during severe weather events. As such, the county executive directed his Office of Emergency Management to develop a comprehensive plan to bolster the county’s Emergency Public Alert System, with new technology and elements to enhance capabilities during extreme weather situations. 

As part of EC Safe and Sound, an outdoor tone-based alert system was implemented to complement existing alert and warning tools.  The mobile, trailer-based speaker arrays (pictured) provide tone alerts to historic Ellicott City when flash flood conditions are imminent. The units  produce a very loud tone (technically rated at 120 decibels within a 100 ft radius) warning individuals in outdoor spaces. These sound levels are equal to an ambulance or emergency services siren at full volume. The temporary units are currently in place and operational. 


A permanent solution is being developed in parallel with this effort.  The permanent solution will have additional units for enhanced coverage and may add voice capabilities for better direction during emergencies.

Public Meetings

On February 25, 2019, County Executive Ball, in coordination with the Office of Emergency Management, hosted a public meetings to provide additional information about the temporary speaker arrays and to solicit feedback regarding a permanent speaker system. The presentation from that meeting can be found here.

Frequently Asked Questions

What activates the outdoor emergency tone alerts?

The units can be triggered by the National Weather Service through the IPAWS system for Flash Flood Warnings, and by officials in Howard County, as necessary.

Can I hear the audio alerts inside my house or when sleeping?

The intent of the interim outdoor alert system is to notify those outside in immediate danger. While the audio alert may be heard inside buildings, it is not intended to alert those inside.

How will visitors know what an audio alert means?

The alert is intended to notify individuals in imminent danger to find a safe location and tune in to local news, news/weather apps, a weather radio, or official government notices for more information. This system will be part of the broader campaign for Historic Ellicott City to inform residents and visitors of the ongoing risks of flooding and details about the alerts. Last year, signs were installed in various locations throughout Ellicott City explaining the alert system so visitors understand what to do if and when the tones go off.

What am I supposed to do when it goes off?

If you hear a Flash Flood tone alert:

  • Do not walk or drive through moving water
  • Do not go to your car
  • Look for HIGH GROUND access signs to lead you out of the floodplain
  • If it is necessary to remain in a building, go to higher floor
When tones sound, seek higher ground.

How much time do I have when I hear the tone alert?

Take immediate action once an alert is heard. There may only be minutes or seconds before conditions worsen.

How else will I get the notification?

The tone alerts are part of a network of alerting systems. Other emergency messaging may be displayed on cell phones, NOAA weather radios, and television using the Integrated Public Alert and Warning System (IPAWS). Weather alerts are available through a variety of mobile applications which can be found at The County's Office of Emergency Management (OEM) also recommends that every home and business have a NOAA all-hazards radio for watches and warnings related to weather.

Who do I contact if I have questions or concerns about the system?

Please contact the Howard County Office of Emergency Management via phone (410-313-6030) or email (

Will the tone alerts be used for other things besides flooding?

In the initial stages of the outdoor tone alert system, flooding will be the primary hazard to which alerts are focused. Future expansion of the system to include additional hazards may be assessed and discussed as the system develops.

Will there be tests of the tone alerts?

​​​​​​There are several scheduled tests to ensure the system remains operational:

  • Silent Test- High pitched short burst (under 2 seconds). This type of test will be scheduled for every Thursday at 10 am.
  • System Test- A voice alert announcement of the test, and short single tone. This type of alert will be once a month and on the second Thursday at 10am in place of the silent test.
  • Annual Test- A full alert of a pulsed tone (Flash Flood Warning Alert Tone) for under 2 mins. This test will be held once a year in December.

A System or Annual Test will not occur if there is a Flash Flood WATCH in effect during the test date/time. However, if a Flash Flood WATCH is issued for Ellicott City a silent test may be done to ensure the system is properly operating.

Are there other audio alerting systems in HoCo?

There are several other entities that use outdoor audio alerts for various reasons, to include lightning warnings and fire department operations. Howard County OEM will use a unique tone that does not currently mimic any other area outdoor alerts.

What does it sound like and how loud is it?

The units will produce an alert at 120db at a 100 feet radius. This is equal to a emergency services vehicle’s siren at peak volume. A Flash Flood alert produces a sound that is described as a continued pulsed tone over a 3 min period.

How many speaker arrays will there be?

The interim alerting system is comprised of three mobile speaker arrays situated in strategic locations on Main Street, including the Ellicott City Colored School, the Visit Howard County Welcome Center, and the B & O Ellicott City Station Museum. This provides for coverage in both the western end of Historic Ellicott City and Lower Main Street.

Where will I hear the tone alerts?

The tone coverage is focused on providing clear outdoor alerts to those that are next to or in the vicinity of the Tiber-Hudson river. A map of the estimated tone coverage area is located here. The outline on the linked maps is associated with maintaining a 70 decibel sound level, similar noise levels to a vacuum cleaner.