Riverbank Stabilization Program

Abstract

Erosion of riverbank property is a frequent occurrence along the dynamic river systems within Snohomish County. In the mid-1980s the County established a legal mechanism that allowed the county to cost-share bank stabilization projects with private landowners, where the project could also be demonstrated to have a public benefit. To date, the program has completed over 250 bank stabilization projects. Projects have evolved from historic bank stabilization techniques that relied largely on end dumping of large rock along eroded riverbanks to more technical and cost-effective methods that strive to work with the forces of a river as well as protect against those forces. These methods, often called bioengineering, combine engineering materials such as rock and geotextile matting with live native plants. Incorporating live native plants within these structures benefits riparian wildlife and improves salmon habitat. Recent flood-hazard–management planning efforts have produced additional recommendations to enhance the program.