Alaska Electric Light and power will test the Salmon Creek emergency sirens Thursday morning at 9 o’clock.
The high-pitched siren will last about three minutes and be heard in the 30-acre flood plain downhill from the dam. The evacuation area extends from Bartlett Regional Hospital to Jack’s Plumbing on Glacier Highway along Twin Lakes.
AELP has two sirens and is required to test them periodically to ensure adequate sound levels. Spokeswoman Debbie Driscoll says the company needs to know if businesses and residents in the area do not hear the noise.
“The biggest concern at this stage obviously when we’re dealing with the evacuation area is that everyone within the area can hear the sirens,” she says.
In an emergency, the company also would called every business and residence in the area, and notify local radio stations, “but there really is a small window if the dam ever failed to get people out of that area quickly,” she says, “so the sirens are the thing we rely on most.”
The concrete dam has never failed.
The Federal Energy Regulatory Commission requires the power company test its emergency and communications systems on a regular basis. Every five years, an actual evacuation drill is required.
The dam itself is inspected monthly by the company.
“FERC comes out and inspects the dam once a year and makes sure that our emergency evacuation plan is complete and acceptable to them. And then every five years we have to have an independent source come and do a complete inspection outside of FERC and ourselves. So it’s a very well-monitored system,” she says.
Thursday’s test will be heard only in the immediate area of the dam. It is an audible test, not a drill, so evacuation is not necessary.