This week, the Pilchuck River will be redirected to its original channel, after the removal of two dam structures that have held it back for more than 100 years. It’s a relatively small project , compared to the monumental dam removals on the Elwha River in 2014 or even this summer’s explosive demolition work on the Nooksack. But taking down this 10-by-60-foot barrier promises to dramatically improve critical habitat for salmon and steelhead.