Restoration of the Jocko River near Arlee
Client / Agency
Confederated Salish and Kootenai Tribes
Geum Environmental Consulting, Inc. and Westwater Consultants, Inc.
2003 to Present
The Jocko River is a major tributary to the Flathead River that provides important habitat for bull trout and westslope cutthroat trout. An interdisciplinary restoration team including technical staff from the Confederated Salish and Kootenai Tribes and consultants from Geum, Inc, River Design Group, Inc., and Westwater Consultants, Inc., prepared the Jocko River Master Plan, as a planning document designed to guide restoration activities in the lower 22 miles of the Jocko River. Following completion of the Master Plan, initial restoration efforts focused on restoring two miles of the Jocko River affected by channel straightening, vegetation removal and levee construction undertaken to achieve flood control objectives in the 1950s. Over time, these actions resulted in simplification of habitat, significant channel incision and sediment delivery from failing earthen levees. A two-phased demonstration project addressed the loss of floodplain connection and altered aquatic habitat conditions. Phase 1 of the project was completed in autumn of 2004 and included one mile of river and floodplain restoration. A 25-year flood event in the project area during spring 2005 provided the opportunity to collect valuable monitoring data and gain insight into how improvements could be made on channel design and construction techniques for Phase 2. Phase 2 of the project was implemented in 2008 and included one mile of river and floodplain restoration. Adaptive management measures undertaken prior to and during implementation of Phase 2 resulted in significantly less maintenance and improved project performance. Project elements included levee removal, nearly 2 miles of channel reconstruction, floodplain re-connection that elevated the river bed 1 to 6 ft above existing erosive conditions, 4,400 ft of side channel enhancement, and conversion of 2,000 ft of the existing channel into floodplain wetlands. The design and channel dimensions were based on properly functioning “reference reaches” of the Jocko River. Large wood structures, and vegetated soil lifts were the primary structures used for temporary bank stabilization while the near-bank and floodplain vegetation recovers. Project benefits include the reduction of fine sediment annually entering the stream and a healthy dynamic channel and floodplain system once again providing quality habitat for native trout. Ongoing monitoring continues to provide insights on the techniques used in restoration and this information is shared at www.jockoriver.net