DESCRIPTION
The Saxon Reach Restoration Design project is located on the South Fork Nooksack below the Saxon Road Bridge near River Mile 12.5 near Acme, Whatcom County. With consultants Cardno-Entrix, Lummi Natural Resources developed a feasibility analysis and 50% design with cost estimates. The objective of the project is to encourage flow away from the Saxon Road and split flow downstream of the bridge to increase habitat diversity and key habitat quantity (holding pools) in a groundwater influenced section of the reach. The project design addresses limiting factors for South Fork Chinook and other salmonids in the Lower South Fork Geographic Area. These factors include reduced habitat diversity, loss of key habitat quantity and lack of refuge from elevated temperatures. Logjams and other woody structures will increase the availability of diverse instream habitat and provide deep pools with complex woody cover in a reach associated with cool groundwater influence on channel temperature. In this reach of the river, wood continues to be the dominant pool-forming feature, with stable accumulations of wood creating deep scour pools with complex woody cover. However, bank protection projects, riparian harvest, and channel cleaning have left a legacy of small unstable wood accumulations in the channel that fail to persist through the frequent small flood events. The loss of wood has directly led to a reduction in the distribution of deep pools with complex cover in the reach. While the channel is still unconfined and able to migrate across most of its floodplain, it no longer has stable hard-points in the channel to moderate its movement. The Saxon Reach Project was designed to restore these woody hard-points as an interim measure until the upstream process of wood recruitment and transport can again provide the tools to the river that create and maintain high quality instream habitat.
The 50% designed project included 12 engineered wood structures to scour pools. Due to the proximity of several houses and a county road, the project design required extensive risk analysis (flooding, channel migration, channel avulsion) to ensure that the project meets habitat and public safety goals.
NOTES
Other WRIA 1 Limiting Factors Addressed with Saxon Reach Project:
Lack of habitat diversity
Loss of key habitat