The State of Oregon has classed the Bear Creek Dam as a "High Hazard" dam. That is not because the dam might fail under ordinary circumstances. Bear Creek is just one of 122 dams in the state that are given this classification and in the case of Bear Creek it's because of the homes downstream in the Knappa-Swenson area that would be threatened if the dam were to fail. The main concern would come if a strong Cascadia Subduction Zone earthquake were to occur. While failure under normal conditions is unlikely, having an emergency plan in place is required by the Oregon Water Resouces Department for any dam classed as high hazard.
The City of Astoria owns the dam. The acres of city watershed comprised of lakes full of fresh water above the dam are the responsibility of the city. Astoria has just completed a new emergency action plan that lays out procedures in stepped degrees depending on the nature of the failure from possible to immediate which outlines the actions that would be taken to respond to the emergency. Included in the plan are maps that estimate the time it would take flood waters to reach different zones from the base of the dam all the way out to Highway 30 and Old Highway 30. The plan was devised in cooperation with Clatsop County Emergency Management along with first responders and city public works setting out the exact procedures to be followed from the time a problem is identified. The main thrust is to help ensure the safe evacuation of people who live downstream and to make sure they are sheltered properly if the worst scenerio is realized.
The Clatsop County Board of Commissioners will consider the plan at the next board meeting and authorizing the County Manager to sign a letter of concurrence with that plan. The Board meets November 7 at 10:00am in the Judge Guy Boyington Building in Astoria.