Nearshore Restoration of the Elwha River Through Removal of the Elwha and Glines Canyon Dams: An Overview

摘要

Removal of two dams from the Elwha River is a unique restoration opportunity. In place for over 95 years, the dams have contributed to changes in the river, its estuary, and marine areas off shore from the river mouth, largely through reductions in sediment supply and salmon populations. Impending removals of both dams will only restore part of the severely degraded Elwha nearshore, where additional large scale anthropogenic impacts will remain. The effects of lower river levees, marine bluff hardening including significant riprapping of the marine shoreline, among other lesser habitat alterations, will continue beyond dam removal. Understanding the relationship of dam removal to the adjacent nearshore area is critical to the design of additional work necessary for successful ecosystem recovery. We provide an overview of the Elwha nearshore and collaborative efforts underway to understand it, and the role it plays in ecosystem restoration. Dam removal is slated to begin in the next 3 to 5 years making timing of this sorely needed nearshore work critical.