EWS Siren
EWS Siren

Sirens Tested Successfully

Author: Kelly Van Buren
Date: Saturday, August 26, 2017 7:22 PM

The Early Warning System sirens were tested successfully during the annual full-scale test. The sirens were sounded twice, once at 12pm and again at 12:30pm to test both the primary and backup activation points. During each test all 131 sirens sounded successfully.


On Saturday, August 26th the County of San Luis Obispo and Pacific Gas & Electric conducted the annual full-scale test of the Early Warning System sirens.  This test, which takes place on the fourth Saturday of August, allows emergency officials to activate the sirens from both the primary and backup activation points to ensure the system is operating as expected.  Although the siren system is tested continuously throughout the year, the annual test is the only time all year the sirens are activated simulataneously.   During this year's test, all 131 sirens sounded successfully.

The San Luis Obispo County Early Warning System sirens are located throughout the Diablo Canyon Power Plant Emergency Planning Zone (EPZ) which stretches from Cayucos in the north, throughout San Luis Obispo, and down to Willow Rd. in Nipomo.   Although the sirens were installed as a requirement of Diablo Canyon, they can be activated for any local emergency where there is a need for the public to take action such an evacuation or sheltering in place.   The sirens are an indication that the public should tune to a local radio or television station for emergency information and instructions.  For those at sea, these instructions will be broadcast on Marine channel 16.

During the siren system's tenure here in San Luis Obispo County since the mid 1980's, the sirens have never been activated during an emergency. That being said, the siren system is a valuable public alert and notification system for the county.  Not only is it able to rapidly alert over 150,000 residents, it has been preprogrammed for a wide range of different disasters from tsunami, to dam and levee failure, and even geographic specific emergencies.

Although the sirens do not cover the entire county, there is still a benefit to residents outside of the siren coverage area.  Should an emergency occur that would require alert and notification of large areas of the county, emergency officials could activate the siren system while focusing response resources and other alert and notification systems on those areas outside of siren coverage.

For more information on the Early Warning System sirens or on other public alert and notification systems, please call the County Office of Emergency Services at 781-5011.