Dam Basics
This term describes a barrier built across a river to control water flow.
What is a dam?
These fish rely on free‑flowing rivers to migrate and spawn.
What are salmon?
This Washington river is the site of the largest dam removal project in U.S. history.
What is the Elwha River?
Reservoirs behind dams often flood these, destroying wildlife habitat.
What are forests and riparian zones?
Dams often provide this type of water for cities and farms.
What is irrigation water?
The film argues that this type of energy, once seen as “clean,” has hidden ecological costs.
What is hydropower?
This term describes the journey salmon make from the ocean back to their birthplace.
What is migration?
After the Elwha dams were removed, this natural process resumed for the first time in over a century, rebuilding beaches and reshaping the river mouth.
What is sediment flow?
Decaying plants underwater release this greenhouse gas.
What is methane?
Dams can help prevent this natural disaster by controlling river flow.
What is flooding?
This is the primary purpose of most dams, storing water for later use.
What is water storage?
This term describes how dams increase death rates among young salmon trying to reach the ocean.
What is mortality?
This term describes the rapid return of natural river processes after dam removal.
What is river restoration?
Dams can change this, the natural rise and fall of river water levels.
What is the flow regime?
Large dam projects sometimes require this, the relocation of people.
What is displacement?
The lake that forms behind a dam is called this.
What is a reservoir?
This type of structure, often built to help fish bypass dams, is shown to be largely ineffective.
What is a fish ladder?
DamNation shows how sediment trapped for decades was released, rebuilding these coastal features.
What are beaches and river deltas?
This term describes the unnatural, human‑controlled water releases from dams.
What is regulated flow?
This federal law, passed in 1972, is considered as a major step in protecting U.S. waterways.
What is the Clean Water Act?
This is the process of removing a dam, often to restore natural river flow.
What is dam removal?
This major river in the Pacific Northwest is currently highlighted for its heavy damming and salmon struggles.
What is the Columbia River?
This smaller dam in Oregon became a symbol of the dam removal movement after its dramatic demolition footage.
What is the Marmot Dam?
The documentary argues that dams fragment these, preventing species from moving freely.
What are river ecosystems?
This U.S. agency manages many major dams, including Hoover Dam.
What is the Bureau of Reclamation?