Although the floodplain in the lower mainstem of the Nooksack River has not been degraded in recent years, the habitat is still a long way from meeting the Salmon Recovery Plan’s long-term goal of returning the floodplain to historic conditions.
From the State of Our Watersheds Report, released last year by treaty tribes:
Based on the most recent comprehensive wetland study, in 1880 there were approximately 4,754 acres of wetlands within the Nooksack River floodplain; by 1998, the floodplain wetlands had been reduced to less than 10% of that historical area.
There has been little change in floodplain wetland area since the late 1990s. There was an estimated 1.5% loss of wetland area in the floodplain between 1996 and 2006, and no further loss between 2006 and 2011.
The lower mainstem of the Nooksack River historically meandered through a complex of wetlands and beaver dams. Now, the lower mainstem floodplain is a single threaded river through cropland (raspberries, blueberries, silage corn, potatoes), hay fields and small municipalities. The lower mainstem has suffered the greatest loss of habitat area and function from historical conditions, and the losses have been especially costly for rearing juvenile Chinook salmon. In addition, the productivity of pre-spawning migrant, and over-winter and over-summer rearing life stages are all limited by the loss of historic off-channel wetland habitat in the lower mainstem.
While not the most limiting factor to Chinook recovery, all Nooksack stocks of Chinook are affected by conditions in the lower mainstem. Restoration of floodplain wetland conditions in the lower mainstem toward historic conditions remains a long-term goal of the WRIA salmon recovery plan.