Geomorphic Assessment of Tualatin River Tributaries

Location: Tigard, OR
Client: City of Tigard

As part of the River Terrace Master Plan for the City of Tigard, Otak’s stream restoration and geomorphology professionals conducted extensive fieldwork documenting the existing condition and geomorphic trajectories of seven tributaries to the Tualatin River prior to development in a recently expanded area of the urban growth boundary. Reach-scale habitat data and geomorphic characteristic data were collected, including documentation of habitat complexity, riparian/bank conditions, substrate gradations, channel geometry measurements, and indicators of potential channel degradation. The field data was used to develop conceptual channel rehabilitation measures and sustainable management actions that are achievable for each sub-basin in this soon-to-be urban context.