Shasta Dam

Shasta Dam, also known before its construction as Kennett Dam, is a large concrete arch-gravity dam across the Sacramento River in Northern California. It stands 602 feet high and is the eighth-tallest dam in the United States. The dam creates Shasta Lake, the largest reservoir in California, which can store about 4,500,000 acre-feet of water. Shasta Lake helps store water for the future, control floods, make electricity, and keep salty water from moving into the river.

People first thought about building Shasta Dam in 1919 to help manage water for California’s main farming area, the Central Valley. The project was approved in the 1930s but had delays because of the Great Depression. It became a federal project led by the Bureau of Reclamation. Construction began in 1937 under Chief Engineer Frank Crowe and gave jobs to many people. The dam was finished in 1945, 26 months earlier than planned. When it was done, it was the second-tallest dam in the United States after Hoover and was seen as a great achievement in engineering.

Even before it was officially opened, Shasta Dam helped provide electricity to factories in California during World War II. Today, it is still important for managing water in the state. However, the dam has changed the environment of the Sacramento River and covered lands that were sacred to Native American tribes. Recently, people have talked about raising the dam to store more water and make more electricity. This could help reduce carbon emissions, but it is opposed by tribes and groups that protect fish because it could harm river flows and endangered species.

History

In the late 1800s, many people moved to California’s Central Valley to farm because the land was rich and the weather was nice. The Sacramento River flows through this area and brings lots of water, but most of it comes in the winter, leaving very little in the summer. This caused problems for farms, especially when salty water from the Pacific Ocean would mix into the river.

To fix this, people suggested building a big dam on the Sacramento River near a place called Kennett. The dam would store water for use in dry months, help control floods, and give more water to farms. In 1931, a plan called the State Water Plan was made, which included this dam and canals to bring water to other dry areas.

Because of the Great Depression, California needed help paying for the project. In 1935, President Franklin Delano Roosevelt approved the Central Valley Project as part of programs to create jobs. The dam was built by experts who had worked on the famous Hoover Dam.

Construction

The Shasta Dam was named on September 12, 1937, in a town called Kennett. Congress gave $12 million for the project. The dam was built in a deep canyon near Kennett. The winning bid came from Pacific Constructors Inc.

Construction began by digging out bedrock for the dam’s foundations. Roads and railroads were moved to make way for the rising waters of Shasta Lake. A new town called Toyon was built to house workers and officials.

Construction started on a channel to move water aside so the dam’s foundations could be built. A very long conveyor belt was used to bring sand and gravel from Redding to the dam site.

Once the foundations were ready, workers began pouring concrete for the main dam. A special system of towers and cables moved concrete buckets quickly to the workers.

Building the main dam began in July 1940. Thousands of workers poured concrete into large blocks to form the dam. In December 1941, Japan attacked Pearl Harbor, and the United States entered World War II. This caused a shortage of workers, so many women and high school students helped build the dam. The dam provided important electricity for factories during the war.

When the tunnel was ready, the river was moved through it, allowing work on the middle part of the dam. The spillways were finished in the summer of 1943.

Water began to fill behind the dam in February 1944. The last bucket of concrete was poured on January 2, 1945. When finished, Shasta Dam was the second tallest dam in the world and the highest structure in California.

Design and operations

Shasta Dam helps control flooding and store water for dry times. This is important for farming in the Sacramento Valley and for boats on the Sacramento River. It also keeps fresh water in the Sacramento-San Joaquin Delta for other areas. The dam makes electricity too. It can make 676 megawatts of power using five big machines called turbines.

The dam is very tall, standing 602 feet above its base. It is also very long, stretching 3,460 feet. It has special valves that let out extra water during floods, and a big concrete area called a spillway that helps manage the water flow. The dam creates a large lake called Shasta Lake, which is the biggest man-made lake in California. This lake stores a lot of water and is fed by several rivers and streams.

Future expansion

In the 1990s, California had trouble getting enough water. People thought about making Shasta Dam taller. There were three ways to do this: a small raise, a medium raise, or a big raise. The small raise would just add a wall on top. The bigger raises would need new buildings and might cover bridges and towns. The biggest raise would hold three times as much water as before.

Some people do not want the dam made taller. They worry it would cover places important for fish and Native American traditions. They also think it might not save much water and could cost too much money. Studies have started to see how the raise would affect the environment, and some land has been bought to make it possible. In 2020, plans were shared to greatly increase how much water Shasta Lake could hold.

Potential geologic hazards

Plans for changing Shasta Dam remember that some natural dangers could happen nearby. These include earthquakes from fault zones, volcanic eruptions from mountains like Mount Shasta and Mount Lassen, mudflows, snow avalanches, land sliding, and a wave effect in lakes called seiches. The closest fault zone is about 27 miles south of the dam and could cause a big earthquake.

Criticism

Ecological effects

The Shasta Dam has changed the Sacramento River, making it hard for Pacific salmon to reach their homes to have babies. This has hurt the salmon population. The dam also changed the river's water temperature, which is bad for fish like steelhead and trout.

To help the salmon, a fish hatchery was built in 1942. In 1991, a device was added to the dam to control the water temperature, which has helped the fish.

Wintu lands

The land now covered by Shasta Lake used to belong to the Winnemem Wintu people. When the dam was built, most of their land became flooded, leaving only a small part along the McCloud River. Many important places for their culture and traditions are now underwater. The Winnemem Wintu are not officially recognized by the U.S. government, and they work to protect what is left of their land and traditions.

Tours and recreation

The Shasta Dam offers guided tours all year. These tours last two to three hours. Visitors take a long elevator ride down to the base of the dam. They also visit inner areas and the power station. Shasta Lake, created by the dam, covers a large area. It is surrounded by the Shasta-Trinity National Forest. The lake is a popular spot for boating, fishing, swimming, and water sports. Visitors can also enjoy hiking, picnics, biking, and camping near the lake. There are many places to stay and play around the area.

Shasta Dam on January 6, 2006