
The Masonry Dam at the Cedar Falls watershed.
Seattle City Light will begin testing March 2 for a safety warning system being installed at the Masonry Dam in the Cedar Falls watershed to warn people in the unlikely event of a dam failure.
Replacement of a safety siren at the Cedar Falls Powerhouse started in January. Additionally, pole-mounted safety sirens will be installed near Rattlesnake Lake and near the Masonry Dam. Siren testing will take place before and after the installations are complete.
“Safety is always a top priority for Seattle City Light,” Power Production Officer Mike Jones said. “Installing this warning system will enhance safety for the community, visitors and our employees in the unlikely event of a dam failure.”
Seattle City Light selected a digital warning system made by Whelen. The system will deliver an emergency warning sound followed by a voice message alert.
“Whelen is proud to partner with Seattle City Light to upgrade and advance the emergency warning capabilities at their Cedar Falls facility,” Whelen District Manager Ed White said. “This digital system not only provides broad area coverage with warning tones, but also provides clear, easily understood voice commands appropriate to the emergency at hand.”

An example of a test siren like those that will be used to identify the best locations for installing sirens near the Masonry Dam.
The sirens will alert Seattle Public Utilities and Seattle City Light personnel working near the structures at Cedar Falls and people in the surrounding areas. Testing is being conducted to determine the best locations for the sirens to provide coverage for recreation areas, the Watershed Education Center and wilderness areas near the Masonry Dam.
Bruce Muir says
We in one of the intended neighborhoods, definitely heard it today.
Considering that the engineers the city hired before the dam was built, twice warned the city not to build in that location, and the fact that the dam is now over 100 years old, it’s about time and Thank you.
Lenard Stoltman says
I live in the ~650 home development 1 mile from Rattlesnake Lake and listened for the tests on 3/2/2016. The siren was audible inside my home once it had a chance to build the reverberations between the valley walls, but the voice commands were unintelligible due to the echos created. Fewer words spaced 5 seconds apart would be more effective in this area. Thank you for saving lives.
thomses says
Thank you for your feedback. It will help the team that is determining the best locations for the warning sirens.
thomses says
You’re welcome and thank you for letting us know the test was successful.