JCPL Teens

How do you take apart a 210 foot tall dam?  One chip at a time.  The Elwah River Dam located in Olympic National Park is being removed in order to restore the river for salmon spawning.  A large barge mounted caterpillar notches out 13 foot wide and 6 food deep sections of the dam wall.  These notches then let 580 cubic feet of water per second out of the reservoir.  In the end around 800 acres of land will be exposed in the former reservoir.  Already the damn is half as tall as it used to be.  There is a lot to consider in damn removal, how to replant the newly exposed earth, how to account for the amount of silt added to the rivers from the deconstruction and also how the increased flow will impact communities and ecosystems downriver of the damn. 

Want to know more? 

Check out our online database Science in Context

Check out the National Park blog about the Elwha Dam Removal