Dieckman Slough Restoration

This project removed heavy infestations of nonnative blackberry thickets, scotch broom, yellow flag iris and other nonnative invasive species on 24 riparian-floodplain acres. A native grass seed mix was spread throughout the disturbed areas after site prep to help prevent soil erosion. Once the invasive plants were treated, over 70,700 native trees and shrubs were planted on both sides of Dieckman Slough, a tributary/side channel located in the Lower North Santiam Subbasin. This work supplemented the ‘regular’ plant restoration conducted under the FSA CREP program which involved taking several acres out of crop production to help enlarge the riparian/floodplain restoration area. The original grant proposal had an instream large wood component to improve fish habitat. However, liability issues raised by the local water control district resulted in the landowner not moving forward with placement of large wood structures. A plant establishment grant associated with this project was funded by OWEB (215-3005-11570) to conduct plant maintenance activities.

The North Santiam is one of the core recovery basins for Upper Willamette spring Chinook salmon and winter steelhead. Restoring tributaries and side channels where these species can readily access and utilize during all phases of their life is a priority, Adding large wood will make instream habitat more diverse and provide protective cover, refuge, and rearing habitat for juveniles during high flows. Additionally, large wood increases the diversity of a channels physical properties by creating pools and depositional areas. Restoring floodplain forests will perhaps offer the greatest benefits in the long-term by providing shade, biological inputs of organic matter, pollution filtration, and future large wood recruitment, and ultimately, become a driver of channel dynamism.