Seawest Granston (Middle Bear) Natural Area Rest.

Planting and installation of Habitat Pickets were installed at the Seawest Granston site over the fall and winter of 2022-2023. A total of 33 wooden posts were driven vertically into the streambed in 9 different locations within the project reach to study their effects on the channel and whether beaver would utilize them for dam-construction. These installations were monitored over the course of the winter of 2022-23 and through the following summer and fall.

In addition, 1850 potted plants and 6350 live stakes were installed on the site during February and March of 2023 over a total of 8.8 acres of riparian habitat. This included live staking of 4.8 acres of dense reed canayrgrass, some of which was treated with burlap mulch prior to installation, one acre of conifer underplanting, and 2.9 acres of shrub underplanting in and area previously planted with a monoculture of Douglas fir. These plantings were installed by Washington Conservation Corps crews. A property owner requested a modification of the planting plan, which we accommodated by moving about 0.9 acres worth of live stakes to another area of the site where they still provided riparian function.

Beaver activity in these reaches of Bear Creek increased dramatically as a result of the planting. Six new dams have been recorded in the reach since planting occurred, one of which was erected on an array of habitat pickets installed as part of this project. The result has been a dramatic rise in water surface elevations in the reach and extensive flooding of the broad floodplain adjacent to the channel. Beaver have constructed several large channels through the reed canarygrass and extending hundreds of feet into the floodplain and begun construction of dams of those channels. This is a significant and dramatic rehydration of the Bear Creek floodplain consistent with our most optimistic predictions. However, beaver harvested a majority of the live stakes installed to create these dams, again consistent with our predictions.

The project team continues to monitor the site and plans for subsequent planting phases, as well as possible large wood addition to the channel. Future challenges will include planting in a much wetter environment than existed prior to this first phase of planting.

The project goal is to enhance the quantity and quality of accessible juvenile salmon rearing habitat within a 2,400-foot reach of Bear Creek by leveraging existing beaver populations to raise baseflow water elevations. Establishment of woody vegetation communities in riparian areas will allow the existing beaver community to thrive, create and maintain more dams, and thereby provide channel structure and elevated water tables. These effects will, in turn, improve rearing habitat quantity and quality for juvenile coho and Chinook salmon, as well as steelhead and cutthroat trout.