Client: Tualatin River Watershed Council

Waterways staff prepared engineering designs and specifications to improve passage for steelhead and cutthroat trout on a headwater tributary to the Tualatin River in Washington County, OR. The site consisted of a seasonal flashboard dam. Downstream of the flashboard dam the channel had incised 3-feet creating a fish passage barrier under most flow conditions. The design consisted of a series of five rock weirs to build the bed up downstream of the structure and provide fish passage under all flow conditions by creating a backwater condition at the dam. Waterways assisted the Tualatin River Watershed Council (TRWC) with the permitting and construction supervision. The project was constructed in Summer 2008.