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Carmen-Smith Educational Resources

You use electricity every day. You can’t see the electricity, but it makes important things work – like heaters, lights, TVs, and refrigerators. Have you ever wondered where electricity comes from? 

In Eugene, most electricity is created by using water. That is called hydropower. Hydropower is a renewable energy source that makes electricity from flowing water. 

Nearly 80 percent of Eugene's power comes from hydroelectric projects near Eugene or farther north in the Columbia River Basin. Check out this video from Bonneville Power Administration which follows the journey of hydropower from a water drop falling as snow in the mountains to an energy watt traveling on an electricity superhighway to your doorstep. 

How Does the Carmen-Smith Hydro-electric Project work?

A lot of the hydropower we use in Eugene comes from rivers far away. But some of the hydropower we use comes from rivers closer to us. One of those rivers is the McKenzie River, which is home to the Carmen-Smith Hydroelectric Project, not too far from Eugene. 

At the Carmen-Smith Hydroelectric Project, about a one-hour drive from Eugene, EWEB uses water from the Smith River and the McKenzie River to make electricity for your house and school, and all the other buildings in Eugene.

The Carmen-Smith Hydroelectric Project has many different parts. The most important parts are dams, reservoirs, tunnels, and power plant. All these parts work together to create hydropower.  

A dam is a large barrier in the river that blocks its flow, causing a lake to form. The lake is called a reservoir. On the other side of the reservoir, the river continues down the mountain. Tunnels move water between reservoirs.

Smith Dam   

Smith Dam on the Smith River

The Carmen-Smith Hydroelectric Project has three dams.  

  • The Carmen Dam 
  • The Smith Dam 
  • The Trail Bridge Dam 

It also has three reservoirs.  

  • Carmen Diversion Reservoir  
  • Smith Reservoir  
  • Trail Bridge Reservoir. 

It has two tunnels.  

  • The Diversion Tunnel  
  • The Power Tunnel.  

It has one power plant, the Carmen-Smith power plant.  

Water from Clear Lake moves down the McKenzie River until it reaches Carmen Reservoir. Then, it moves through the Diversion Tunnel to Smith Reservoir. Finally, it moves through the Power Tunnel to the Carmen Power Plant.  

The Smith Reservoir is 500 feet higher in elevation than the Carmen Power Plant. Have you been to the zoo? If you stacked 30 giraffes on top of one another, it would be 500 feet. Talk about a long way to fall! 

When water goes down through the power tunnel, it creates energy. At the Carmen Power Plant, water moves quickly through a turbine A turbine is a wheel with blades. The wheel connects to a machine that creates electricity. 

The Carmen Power Plant can generate 110 megawatts of electricity. That’s enough to power almost 4,000 homes for a day! This electricity runs through powerlines, and travels to houses, shops, and schools in Eugene.  

The Carmen Power Plant is unique. When people in Eugene need more electricity, EWEB opens the entrance to the power plant so more water can flow in and make more power. When people need less electricity, like in the middle of the night, EWEB closes the entrance to the power plant all or part of the way so less water flows in.  

Opening and closing a the power plant would change the amount of water flowing in the river if it wasn’t for the Trail Bridge Reservoir. Trail Bridge holds the water until it is needed in the river, keeping the McKenzie River at a steady flow. That’s good for fish and for people! 

Now you know that electricity can come from water! The Carmen-Smith Hydroelectric project is a machine that uses water from the McKenzie River to make electricity. It’s a cool way to power our homes and schools.

Rendering of carmen-smith hydro project

Download a PDF of this illustration of the Carmen-Smith project.

What is the history of the Carmen-Smith Hydroelectric Project? 

The Smith River and the McKenzie River flow down steep hills from the Cascade Mountains toward the Willamette Valley, where Eugene is located. Click here to learn more about the Willamette Valley.  

This region has a rich history. Before Europeans came to this area in the 1830s, Native Americans lived here. The Molalla tribe lived in the Cascade Mountains, and the Kalapuya tribe lived in the Willamette Valley. Click here to learn more about the Kalapuya people.  

The Molalla tribe may have lived in the Cascades for 10,000 years before Europeans arrived. They used spearheads made of stone to hunt animals like elk and deer. They also loved to eat camas bulbs, a relative of the asparagus, huckleberries, acorns and hazelnuts.  

The Molalla were often on the move. In the cold winters, extended families would live together in underground lodges. When it warmed up in spring, the family would break into groups. Each group would travel to a different part of the mountain to collect different resources.  

The Molalla traded with neighboring groups, like the Kalapuya. They would give away the resources from the mountains for new resources from the valley. The Molalla may have gone all the way to the Oregon coast to trade! 

When Europeans arrived, they brought disease and used a lot of resources. The Molalla signed the Dayton Treaty in 1855 and the United States took their land. Most Molalla people relocated to the Grand Ronde Reservation in the Western Willamette Valley. You can learn more about the Grande Ronde Reservation here.

The Europeans slowly moved in to settle the mountains. They created roads and cities. They used the land for hunting, livestock grazing, and recreation.  

When World War II started in the 1940s, so many people moved to Eugene that there was not enough electricity for all the new homes and businesses. Around 1947, EWEB started looking for places to build a hydroelectric project to provide more electricity. 

The first site EWEB found was called Beaver Marsh. EWEB received a license to build a hydroelectric project at Beaver Marsh in 1956, but the community did not like this idea. They worried that construction would change some of their favorite recreation spots forever and voted to stop the Beaver Marsh project. 

EWEB kept looking and decided that the Carmen-Smith Hydroelectric Project could generate enough electricity for Eugene, without destroying natural sites. The community supported the Carmen-Smith Hydroelectric Project.  

Historic image of land cleared for construction of the Carmen Smith hydro project

Land cleared to build the Carmen-Smith Hydroelectric Project 

Historic image of Smith Reservoir and Dam post-construction  

Smith Reservoir and Dam post-construction 

EWEB received a license from the federal government to build the Carmen-Smith Hydroelectric Project in 1958 and completed construction in 1963. The Carmen-Smith Hydroelectric Project has provided Eugene with reliable, carbon-free energy to this day! 

How does the Carmen-Smith Hydroelectric Project affect the forest? 

The Carmen-Smith Hydroelectric Project is located on the foothills of the Cascade Mountains. This land is covered in a thick forest. It is home to many animals, such as Spotted Owls, elk, and salmon.  

The Carmen-Smith Hydroelectric project provides Eugene with electricity. But sometimes, it causes problems for the forest creatures. When dams need to be repaired, EWEB employees bring loud tools to the forest. The dams also block rivers that the salmon need to swim. Finally, cars and trucks scare the animals. 

EWEB cares about the animals that live near the Carmen-Smith Hydroelectric Project and works hard to keep them safe while delivering reliable energy to Eugene.  

Spotted Owls 

Spotted owl

Spotted Owls live near the Carmen-Smith Hydroelectric Project. They are endangered. This means there aren’t many Spotted Owls left, and they may die out. When they are nesting, Spotted Owls do not like loud noise. If it’s too loud, they might abandon their young, or leave their home. Sometimes, they even push baby birds out of their nests! 

EWEB knows Spotted Owls don’t like noise. We keep track of where the owls build nests and when the babies hatch, and make sure the forest stays as quiet as possible.   



Another animal in the area is elk. Elk are large, deer-like animals. When cars and trucks drive by, elk get very nervous. When elk are nervous, they do not eat enough food. They also do not spend enough time with their babies.

In the fall and winter, elk go through a stressful time. There is less food to eat. They also need to migrate and reproduce. They don’t have energy to worry about cars! 

EWEB knows elk don’t like cars, so we close six roads where elk roam during the fall and winter. With fewer cars driving through the forest, elk feel much more comfortable! 


Salmon are also impacted by the Carmen-Smith Hydroelectric Project. Salmon are very important fish. They provide nutrients to the forest.

Salmon lay their eggs in rivers like the McKenzie River. Baby salmon hatch in late winter and travel to the ocean. After one to seven years in the ocean, salmon journey back to their home stream. When they finally make it home, salmon lay their eggs. Most salmon pass away just a few days after laying eggs.  

Animals and Native Americans rely on salmon for food. When salmon die, their bodies provide nutrients to the plants and the soil. Salmon help the land stay healthy and strong.  

Hydroelectric projects, such as the Carmen-Smith Project, make the lives of salmon harder. When they try to journey home, there are dams and reservoirs in the way.  

EWEB cares about salmon and all the people, plants and animals that rely on salmon. That’s why we created passageways for salmon to get home safely.  

You may be wondering: Why don’t the salmon just lay eggs in a different stream, and avoid the Carmen-Smith Hydroelectric Project? Well, salmon must always return to the exact stream they were born in. They follow the smell of home.  

EWEB created a spawning channel for the salmon leading up to the Carmen-Smith Hydroelectric Project. These are good places for the salmon to lay eggs. EWEB also makes sure that the water coming out of the project is not too fast and not too slow. It stays steady so salmon feel comfortable.  

Those travelling upstream must face the Trail Bridge Reservoir and Trail Bridge Dam. A dam is a blockade in the river, and a reservoir is all the water trapped behind the dam. The dam is very tall. It would be impossible for fish to get by on their own.  

EWEB uses a Trap and Haul system to move fish past the dam. Salmon will jump through a series of pools, one higher than the other. When they reach the top, an EWEB employee will help them into a large tank. EWEB will drive the tank to the other side of the dam. From there, the salmon will swim free and continue their journey.  

Here in Eugene, we rely on EWEB and the Carmen-Smith Hydroelectric Project for electricity. Sometimes, the things we need put animals at risk. EWEB works hard to minimize those effects so that people, plants, and animals can live in harmony.