21-015 McNary Lock and Dam to resume use of laser, test acoustic device to deter birds and protect salmon

Walla Walla District Corps of Engineers
Published March 31, 2021
McNary Dam

McNary Dam

UMATILLA, Ore. – The US Army Corps of Engineers, Walla Walla District will resume use of bird deterring lasers, and will be testing a Long Range Acoustic Device (LRAD) to prevent birds from preying on endangered juvenile salmon passing through McNary Dam.

In a change from last year, McNary Dam will be utilizing two lasers simultaneously. Previously only one of the two lasers owned by the dam were operational at any given time. One laser will be positioned on the navigational lock wing wall on the downstream side. It will provide coverage of the fish outfall pipe and surrounding waters and facilities, including the dam itself. The other will be positioned directly on the outfall pipe and cover the water directly below it.

The lasers will run from dawn to dusk daily starting April 1 and will be in operation until approximately November.

The lasers emit a bright green light that creates a large dot. Birds interpret the dot as a solid object which they avoid as a potential threat. The lasers are programmed to move in random patterns within a predetermined area and have a range of approximately 950 feet to a mile, weather dependent.

The LRAD is scheduled to begin usage in late August. A small device, resembling a common speaker, it can broadcast preprogramed audio tracks over a large area. When activated, the tracks act as an audio deterrent for birds. Similar devices have garnered success at airports across the United States.

Currently, McNary’s LRAD is programmed with two audio tracks. The first is a computer-generated male voice that announces it is an LRAD device and performs a countdown. The second closely matches the noise emitted by a standard car alarm. When active it will be audible throughout the McNary Dam and Lake Wallua area.

The LRAD will run intermittently throughout the day from late August through October. This period will serve as a trial run for the device. If the trial is deemed successful, the device will resume operations in 2022.

Corps’ safety and operational managers have performed a variety of tests on both the lasers and LRAD systems and have confirmed they pose no adverse risk to humans or wildlife.



Release no. 21-015