https://www.nwp.usace.army.mil Portland District News RSS Feed en-us Thu, 17 Jun 2021 19:13:29 GMT Sat, 13 Jun 2026 13:05:24 GMT https://www.nwp.usace.army.mil/Media/Feature-Stories/Article/2662388/that-sounds-fishy-twisting-traps-troll-tributaries-in-the-willamette/ The bulky contraptions float listlessly downstream of three dams in Oregon’s Willamette Valley. The buoyant, metal devices hold large screws that the water flow turns. This twist of the screw – creating a creaking, rasping, scraping sound – generates enough hydraulics to keep small fish from escaping the slowly spinning, cone-shaped collectors – or, screw traps.<br/> <img src='https://media.defense.gov/2021/Jun/17/2002744399/115/75/0/210528-A-EZ675-0014.JPG' alt='Corps contractors monitor screw traps downstream of Cougar Dam, May 28, 2021. The water flow turns a large screw creating hydraulics, which keeps small fish from escaping the trap. These traps are collecting juvenile salmon after they pass through Lookout Point, Cougar and Big Cliff dams. We’ve changed operations at these dams to help with downstream fish passage – or that’s the goal. These traps will give us insight into how well we’re doing.' /> <br /> Thu, 17 Jun 2021 19:13:29 GMT Tom Conning, Public Affairs Office https://www.nwp.usace.army.mil/Media/Feature-Stories/Article/2662388/that-sounds-fishy-twisting-traps-troll-tributaries-in-the-willamette/ Cougar Environmental Research Willamette U.S. Army Corps of Engineers Northwestern Division