Oroville Dam

The Oroville Dam is a giant wall.

It holds back a big lake. This dam helps give people water. It also makes power for our homes. It keeps the river from flooding.

Building the dam was hard work. Workers had to move lots of dirt. They used many trains to do this.

Some accidents happened during the work.

The dam is very tall. It is the tallest in the land. It sits on the Feather River. It helps farms get water too.

Sometimes, heavy rain causes trouble. The water can wash away parts of the dam.

People had to leave their homes to stay safe.

Workers fixed the dam to make it strong. Now it can hold the water safely. The dam is a very important tool.

The Oroville Dam is a giant wall of earth and rock.

It sits on the Feather River in California. At 770 feet tall, it is the tallest dam in the United States. The dam holds back Lake Oroville. This lake is a huge reservoir, which is a place that stores water.

The dam does three main jobs. It provides water for cities and farms. It also makes electricity at a power plant. Finally, it helps prevent floods. To make power, it uses the Edward Hyatt Power Plant. This is a large station hidden underground.

Building the dam was a very long task. It began in 1961 and finished in 1968. Workers used many trains to move dirt and rocks. In 2017, heavy rains caused a big problem. The spillway is a path that lets extra water out. The main spillway began to break. This meant many people had to leave their homes to stay safe. Workers later fixed the spillway to make it strong again.

The Oroville Dam is a massive earthfill embankment dam.

It sits on the Feather River in California. This dam is 770 feet tall. That makes it the tallest dam in the United States. It holds back Lake Oroville, which is a huge reservoir. This reservoir is the second-largest in the state. The dam serves three very important purposes. It provides water for cities and farms. It also creates electricity for people to use. Finally, it helps control floods to keep people safe.

This dam works by managing the flow of water. It stores water in the lake behind the dam. When people need water, it is sent through paths called aqueducts. These paths carry water to the San Joaquin Valley for farms. They also send water to Southern California for homes and industry. To make electricity, the dam uses the Edward Hyatt Power Plant. This is a large underground station. The water moves through the plant to create power. The dam also has spillways. A spillway is a path used to let extra water out safely.

Building this giant dam was a long and difficult job. Work began in 1961. It was led by an engineer named Donald Thayer. Workers had to move a huge amount of earth and rock. They used a special rail line to do this. About 120 train cars ran along the line every hour. They moved material from big piles left over from the Gold Rush. The dam was finally topped out in 1967. It was ready to use in 1968. Many famous people attended the dedication ceremony in May 1968.

Construction faced many hard moments and accidents. In 1964, a huge Christmas flood nearly went over the dam. The dam helped by reducing the water flow by 40 percent. Sadly, 34 men died during the construction period. In 1965, two work trains crashed into each other. This accident caused a forest fire and delayed the work. In 2017, the dam had a major problem during a very wet winter. The main spillway began to erode and break. This was dangerous, so 188,000 people had to leave their homes.

Engineers worked hard to fix the dam and keep it safe. They rebuilt the main spillway by November 1, 2018. They tested it with lots of water in April 2019. The dam is also very smart. It has hundreds of instruments to measure water pressure. Because it sends back data, people call it "the dam that talks back." The dam also affects the river animals. It can stop fish from swimming up the river. To help, people built a fish hatchery nearby to support them.

The Oroville Dam is a massive earthfill embankment dam located on the Feather River in California.

Situated in the Sierra Nevada foothills, it stands 770 feet tall. This height makes it the tallest dam in the United States. The dam serves three primary functions: water supply, hydroelectricity generation, and flood control. It creates Lake Oroville, which is the second-largest reservoir in California. The dam is a central part of the California State Water Project (SWP). This project helps manage water across the entire state.

To manage water, the dam controls the flow of the Feather River. Water is stored in Lake Oroville and then sent through the California Aqueduct. This system provides water for irrigation in the San Joaquin Valley. It also supplies municipal and industrial water to coastal Southern California. To generate power, the dam uses the Edward Hyatt Power Plant. This facility was once the largest underground power station in the country.

The dam also uses spillways to release extra water during heavy rains.

Construction of the dam began in 1961 under engineer Donald Thayer.

Workers used two large concrete-lined diversion tunnels to move the river around the site. One tunnel handled normal flows, while the second was for floods. To build the embankment, a specialized rail line moved earth and rock. About 120 train cars ran on this line every hour. Much of the material came from old hydraulic mining debris from the Gold Rush. The dam was topped out in 1967 and officially dedicated in May 1968.

Building the dam was a dangerous and difficult process. In 1964, a massive Christmas flood nearly overtopped the incomplete structure. However, the dam reduced the peak water flow by nearly 40 percent. This helped prevent massive damage to the surrounding area. Construction also saw tragic accidents, including a head-on train collision in 1965. In total, 34 men died during the construction period. The dam was designed to withstand strong earthquakes. It contains hundreds of instruments to measure water pressure and earth movement. Because it sends data back to engineers, it is nicknamed "the dam that talks back."

The dam has also had significant environmental and safety challenges. It blocks fish migration up the Feather River, which affects the local habitat. To help, a salmon and steelhead fish hatchery was built nearby. In 2009, a dangerous accident occurred in a river valve chamber. Suction from a flowing valve created a vacuum that injured a worker. More recently, the dam faced a major crisis in 2017.

During the wettest winter in over 100 years, the main spillway began to fail. Erosion damaged the concrete and the foundation under the spillway.

This 2017 spillway failure was a serious event for the region. The damage was so large that engineers had to use the emergency spillway.

This caused the evacuation of 188,000 people living near the dam. High water levels and debris also affected the Feather River Fish Hatchery. Engineers worked to stabilize the site and lower the reservoir levels. The main spillway was eventually reconstructed by November 1, 2018. In April 2019, officials successfully tested the repairs with large water releases.

The history of the Oroville Dam shows how California's needs changed over time. In 1935, the federal government focused on the Central Valley Project for agriculture. After World War II, California experienced an economic boom. The state needed water for growing cities and industries, not just farms. This led to the proposal of the Feather River Project by A. D. Edmonston in 1951. Although there was political opposition, major flooding in the 1950s helped secure funding. Today, the dam remains a vital part of the state's massive water infrastructure.