2011 aerial view of the Wiley Slough Restoration Project.  Photo: Pictometry.
2011 aerial view of the Wiley Slough Restoration Project. Photo: Pictometry.

 

The Wiley Slough Estuary Restoration Project is located on the south fork of the Skagit River, near Conway, on lands owned and managed by the Washington Department of Fish & Wildlife (WDFW). The project objective was to rehabilitate natural processes at the Wiley Slough site to be largely self-sustaining and in turn support natural fish, wildlife and vegetative communities common to estuarine habitats in Puget Sound. To this end, the project design focused on restoring important physical processes (tidal and riverine flooding). The project was designed to protect interests of adjacent land owners, promote wildlife-oriented recreational activities consistent with the restoration objectives, and take into consideration the perspectives of stakeholders affected by the project. Restoration of estuarine functions to the Wiley Slough site provide significant benefits to Chinook, chum, coho, pink, sockeye, bull trout, steelhead and cutthroat by restoring important rearing habitat.

Restoration activities implemented during the summers of 2008 and 2009 were aimed at restoring tidal inundation and fish access to approximately 156 acres of estuarine wetlands by removing dikes around the project perimeter. This was accomplished through the removal of 6,500 lineal feet (LF) of dike, construction of 2,840 LF of set-back dikes along the pre-1956 levee footprint, and augmenting an addition 2,200 LF of previously existing dikes around the site perimeter. An existing tide gate on Wiley Slough was removed, and a new, larger tide gate was constructed at the new diked perimeter of the site. Lastly, 3,470 LF of borrow ditches were filled to promote sheet flow and drainage to historic channels. In 2009-2010, following the completion of major construction activities, native plants were installed on 3.8 acres in zones adjacent to areas impacted by tidal flows.

Wiley Slough at the former tidegate location during the first post-construction high tide.
Wiley Slough at the former tidegate location during the first post-construction high tide.

 

Project Status/Timeline
Project was constructed in summer 2010. Installation of native plants took place in winter 2010 – 2011. Project monitoring is ongoing.

Primary Project Contact
Steve Hinton – Director of Restoration

Funding Sources

Project Partners
WDFW – Washington Department of Fish and Wildlife
PSNERP – Puget Sound Nearshore Ecosystem Restoration Project
Ducks Unlimited
Skagit Dike and Drainage District #22
UWFWS – US Fish and Wildlife Service
NRCS – Natural Resources Conservation Service
NOAA Fisheries
SCL – Seattle City Light

References
Beamer, EM, and R Henderson, B Brown. 2015. Juvenile Chinook Salmon Utilization of Habitat Associated with the Wiley Slough Restoration Project, 2012-2013.

Hinton, S, J Blank, A McKain, G Hood, et al. 2005. Wiley Slough Estuarine Design Report.