Douglas County Deploys Hi-Lo Sirens in Patrol Cars for Evacuations

Douglas County announced it has deployed Hi‑Lo sirens in patrol vehicles as a dedicated, audible evacuation notification tool for the county, with the Sheriff’s Office and the Douglas County Office of Emergency Management leading the rollout. County officials unveiled the system at a press conference March 4 and posted a “Demonstration Video of Hi Lo Sirens” on the Douglas County Sheriff’s Office social channels to let residents see and hear the new alert in action.

The system emits an alternating high-low tone from patrol cars followed by a standardized recorded message to prompt immediate movement away from danger. The county-prescribed recording reads: “A MANDATORY EVACUATION ORDER HAS BEEN ISSUED FOR THIS AREA. PLEASE EVACUATE IMMEDIATELY.” Sheriff’s Office posts and OEM materials specify the siren units and pre-recorded messages are being installed in patrol cars across Douglas County.

Officials described the Hi‑Lo deployment as an additional life-safety layer to be used only during extreme, life-threatening incidents that require immediate evacuation. County messaging states: “This critical warning system will only be used during extreme emergencies, such as wildfires, flash floods, major law enforcement incidents, or other life‑threatening events requiring immediate evacuation.” The county also instructed residents: “Remember: When you hear the Hi‑Lo, it’s time to go. Heed the warning and evacuate immediately.”

Douglas County and its OEM framed the change as redundancy for situations where digital and remote systems cannot keep pace. Dcsheriff materials cite recent catastrophic fires as rationale, listing the Palisades, Marshall, Lahaina, and Waldo fires as examples where evacuation needs outpaced digital systems. OEM Director Mike Alexander said, “These definitions are designed to eliminate ambiguity. Clear language leads to faster action, and faster action saves lives.”

At the March 4 press conference, a speaker identified only as “Curtis” described the challenge for fire response during fast-moving incidents and said, “For the fire service, one of the biggest challenges during fast-moving incidents is reaching people quickly. That is where tools like the [hi‑lo] siren become incredibly valuable.” Another speaker identified as “Weekly” pointed to a Highlands Ranch tornado response as an example and said, “If you got a patrol car on your street with this siren, you know it's a potentially deadly situation.”

County materials emphasize the Hi‑Lo is not a replacement for established alert channels. Officials state: “Hi‑Lo sirens are not a replacement for door knocks, DougCoAlert, IPAWS alerts, social media updates, or other emergency communication tools. They are an added layer of redundancy designed to ensure residents receive evacuation information, even when technology fails.” Douglas County is also promoting signups for the county alert system via DougCoAlert and is directing the public to the Sheriff’s Office Facebook page to view the demonstration video and hear sample audio.

The March 4 announcement did not include technical specifications such as manufacturer, decibel range, number of patrol vehicles equipped, or the exact activation authority and thresholds; those operational details remain to be confirmed by the Sheriff’s Office and OEM. Officials say the Hi‑Lo rollout is part of a broader regional push among Front Range agencies to add field-based evacuation tools to existing alert systems.