Middle Fork John Day Intensively Monitored Watershed: Lessons Learned from a Temperature Limited Watershed

The Middle Fork of the John Day River is one of the most active locations for stream restoration in the Pacific Northwest. In 2008, a local working group decided to take advantage of this activity and ongoing monitoring to develop an Intensively Monitored Watershed (IMW) for measuring restoration benefits to salmon and steelhead. A before-after-control-impact experimental design was adapted to measure watershed-scale fish responses. Temperature was identified as the main factor limiting freshwater production of salmon and steelhead in the watershed. Heat Source modelling has indicated that seven day average daily maximum temperatures can be effectively lowered through restoration actions, primarily through riparian vegetative shading. Restoration implementers have focused most restoration funds on restoring stream form and function together with large wood placements and riparian vegetation plantings. These actions have produced significant improvements in physical habitat quantity and quality. Vegetative shading however, is responding slowly. We also have yet to measure a significant temperature response, nor a fish productivity or abundance increase for the watershed. It appears unlikely that significant responses will become apparent within the ten-year funding window of the IMW.