Abstract Title

Session S-05F: Ecosystem Restoration: Geomorphic Context, Design Considerations, and Success Stories

Proposed Abstract Title

Emerging changes in a newly constructed salt marsh restoration project at Union River, Hood Canal

Presenter/Author Information

Doris SmallFollow

Keywords

Restoration

Location

Room 6C

Start Date

1-5-2014 5:00 PM

End Date

1-5-2014 6:30 PM

Description

Tidal influence was restored to former estuarine marsh habitat in August 2013 to re-establish salt marsh in a 32 acre site associated with the Union River in Hood Canal. The former salt marsh was cut off from the river and estuary by a dike built in the early 1900’s, and used predominantly as pasture and to grow hay. The Washington Department of Fish and Wildlife worked in partnership with the Hood Canal Salmon Enhancement Group to design and construct the estuary restoration site as part of a larger initiative which has protected over 500 acres of salt marsh and tidelands in the Lynch Cove estuary near Belfair, Washington. The restoration site provides habitat connectivity with Lynch Cove and the Union River, a key watershed within the ESU of federally listed Hood Canal summer chum salmon (Oncorhynchus keta). The summer chum recovery plan identifies “degraded nearshore/marine and estuarine conditions” as a limiting factor, emphasizing the role of estuarine marshes for feeding/rearing, refuge from predation and as a transitional habitat as the juvenile salmon move from freshwater to saltwater. The Union River estuary restoration project was designed to support habitat objectives and community values. In addition to restoration of tidal influence to the former salt marsh, we prioritized re-establishment of high salt marsh and tidal channels as indicated in the 1884 T-sheet. Strong community demand to maintain the dike top trail precluded full dike removal, since the existing dike is part of a popular trail system (Theler Wetlands) with over 200,000 user days/year. The final design included two pedestrian bridges located over 100 and 300 foot dike breaches, excavation of over 35,000 cubic yards for 10,000 feet of tidal channels and associated marsh elevations, and construction of a 2300 foot setback dike with new trail, forming a trail loop around the restoration site. Monitoring of the salt marsh development is currently underway to describe and quantify vegetation colonization, physical changes and fish use. The section of the trail system with the new bridges re-opened in mid-September, allowing the public an opportunity to view the transformation of the construction site to newly developed salt marsh habitat.

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May 1st, 5:00 PM May 1st, 6:30 PM

Emerging changes in a newly constructed salt marsh restoration project at Union River, Hood Canal

Room 6C

Tidal influence was restored to former estuarine marsh habitat in August 2013 to re-establish salt marsh in a 32 acre site associated with the Union River in Hood Canal. The former salt marsh was cut off from the river and estuary by a dike built in the early 1900’s, and used predominantly as pasture and to grow hay. The Washington Department of Fish and Wildlife worked in partnership with the Hood Canal Salmon Enhancement Group to design and construct the estuary restoration site as part of a larger initiative which has protected over 500 acres of salt marsh and tidelands in the Lynch Cove estuary near Belfair, Washington. The restoration site provides habitat connectivity with Lynch Cove and the Union River, a key watershed within the ESU of federally listed Hood Canal summer chum salmon (Oncorhynchus keta). The summer chum recovery plan identifies “degraded nearshore/marine and estuarine conditions” as a limiting factor, emphasizing the role of estuarine marshes for feeding/rearing, refuge from predation and as a transitional habitat as the juvenile salmon move from freshwater to saltwater. The Union River estuary restoration project was designed to support habitat objectives and community values. In addition to restoration of tidal influence to the former salt marsh, we prioritized re-establishment of high salt marsh and tidal channels as indicated in the 1884 T-sheet. Strong community demand to maintain the dike top trail precluded full dike removal, since the existing dike is part of a popular trail system (Theler Wetlands) with over 200,000 user days/year. The final design included two pedestrian bridges located over 100 and 300 foot dike breaches, excavation of over 35,000 cubic yards for 10,000 feet of tidal channels and associated marsh elevations, and construction of a 2300 foot setback dike with new trail, forming a trail loop around the restoration site. Monitoring of the salt marsh development is currently underway to describe and quantify vegetation colonization, physical changes and fish use. The section of the trail system with the new bridges re-opened in mid-September, allowing the public an opportunity to view the transformation of the construction site to newly developed salt marsh habitat.