Published: March 27, 2013

Boulder County and the City of Boulder will begin testing the countywide emergency sirens at 10 a.m. on Monday, April 1. The test is the first of the annual season of monthly emergency siren tests, and marks the beginning of flood awareness efforts countywide.

During an emergency, the sirens are used to alert residents to potential danger from a flood or other immediate threat. Siren tests ensure that all systems and procedures are working properly during the season of peak flood danger. The tests also promote public awareness of the warning sirens located throughout Boulder County.

 “Flash flooding can occur in the city of Boulder rain or shine,” said Lacey Croco, University of Colorado Boulder director of emergency management. “Boulder has the highest risk of flash flooding in Colorado because of its location at the mouth of Boulder Canyon, the number of people who live and work within the Boulder Creek floodplain, and the numerous other drainage basins running through the city.”

The siren tests will occur twice on each testing day, at 10 a.m. and 7 p.m., on April 1, May 6, June 3, July 1 and Aug. 5.

Should Boulder County experience severe weather during a one of the planned audible tests, the siren tests for that day may be cancelled. For updated information, visit

Severe weather and flash flooding alerts will also be distributed via the new nationwide Wireless Emergency Alert (WEA) system, launched in 2012. WEA-enabled smartphones that are in the geographic area of an alert will receive the localized messages of imminent threats. More information on the WEA program can be found on the Federal Emergency Management Agency (FEMA) website.

The CU-Boulder Emergency Management Division will begin on-campus flood awareness activities to coincide with the testing. Select east campus buildings will receive door hangers with flood safety and campus procedure information. Additional resources will be shared with the campus community throughout the flood season.