What comes next for the Tolt Dam warning system?

The alarm has malfunctioned several times over the last year, concerning residents.

After the Tolt River Dam warning system failed a regular test for a third time in the last several months, the utility that owns the dam is exploring ways to upgrade its alerts.

The dam, located in northeast King County, is owned by Seattle Public Utilities. It provides water to some 1.5 million people in the region. But the city of Carnation lies downstream. If the dam were to break, residents would have to evacuate before a 30-foot wall of water descended on them.

A current alarm siren system exists, and is scheduled to run test alerts every Wednesday at noon. On Jan. 13, the alarm failed to sound after a severe windstorm ripped through Puget Sound. While the dam was not in danger of breaking, and Seattle Public Utilities informed the city that the alarm may not sound, residents were concerned about it. The alarm also failed to sound in September.

In July, a false alarm sent Carnation residents scrambling to reach higher ground.

Carnation Mayor Kim Lisk said the false alarm in July left residents on high alert. And with so many people working from home due to the coronavirus pandemic, she would like to see a rethinking of how Seattle Public Utilities communicates with her constituents. Others with hearing disabilities may not know sirens are going off.

“Our main concern is communication,” Lisk said. “How are you communicating with our community? Why are we not getting an alert on our phones just like we do when there’s flooding or power outages?”

King County Councilmember Kathy Lambert, who represents Carnation and eastern King County, said she was in lockstep with the rural city. She said Seattle Public Utilities did a good job apologizing for the mistakes and technical glitches, but she wants to see a full list of what the utility company is planning on doing to address the problems.

“I want to see now action to go with those apologies,” Lambert said.

Lisk and others voiced these concerns at a Carnation City Council meeting last week, attended by Seattle Public Utilities representatives, including Alex Chen, the utility’s water division director.

If the dam were to fail, Chen said an emergency alert would be relayed to their partners at the King County Office of Emergency Management, NORCOM and Snohomish County. These agencies have emergency communication tools like a reverse 911 call, or an Amber Alert style text message to quickly get the word out.

“The emergency action plan for the dam has several components, of which the sirens are one part,” Chen said.

But after the meeting with Carnation leaders, Chen said it was clear that the current alert system can make it difficult for residents to discern what is an emergency and what isn’t. Seattle Public Utilities representative are meeting with King County emergency staff and Carnation leaders on Jan. 29 to discuss ways to improve the system.

One possibility is a system run by the county, called Alert King County. Residents could sign up for alerts that would be delivered either by email or text message.

Any changes to the alert system will be in addition to the sirens. But those sirens are also getting an upgrade.

Seattle Public Utilities are designing upgrades to the siren system. This includes ordering replacement sirens, starting design work and getting the necessary permits. They hope to get the needed federal permits by the end of this year, and the sirens should be installed in the first half of 2022.

Throughout this year, the utility will be hosting public meetings with Carnation residents. The first will be scheduled for the end of February, although a date hasn’t been announced.