Old Tolt Dam Early Warning System taken out of Carnation
Published 4:03 pm Wednesday, April 1, 2026
On March 17, a post on the official City of Carnation Facebook page informed residents that Seattle Public Utilities would be in the area to remove the old Tolt Dam Early Warning System equipment and signage.
Residents are attentive to work on the Tolt Dam and its warning system after multiple false alarms from 2020-2024. This Facebook post prompted questions, with one person commenting, “Does that imply we have a new Tolt Dam Early Warning System?”
The answer to that is, yes, there are new sirens in the Carnation area. This project began in 2020, and installation of the new sirens was completed in 2023.
The new Tolt Dam Early Warning System “is active and includes state-of-the-art technology, equipment and sirens that improve the resiliency, reliability and security of the system,” a SPU spokesperson said.
Seattle Public Utilities (SPU) is now working to remove the deactivated sirens, install landscaping and bollards around the new sirens and remove temporary project signage. These tasks are expected to be complete by the end of April, according to SPU.
From spring 2024 to fall 2025, the alarm system was turned off while the city of Carnation and SPU worked to come to an agreement on its operation.
The alarm was turned back on in November. It will be audibly tested once a year, as opposed to monthly, during Carnation’s “Be Dam Ready” event.
SPU recently told the Snoqualmie Valley Record that the Tolt Dam “has been and continues to be safe.”
“The city of Seattle monitors the dam 24/7, 365 days a year with around-the-clock system operators and daily in-person safety checks at the site,” a SPU spokesperson said. “Automated continuous monitoring of reservoir level, upstream and downstream river flows and dam safety sensors are also a part of the 24/7/365 dam safety watch.”
For a deeper dive into the Tolt Dam, read “A Tolt Dam failure is unlikely, but not impossible” from Nov. 14, 2025, at valleyrecord.com.
