Peripheral Canal facts for kids

The Peripheral Canal was a big idea that started in the 1940s in California. It was a plan to move water from the Sacramento River to places farther south in the state. The idea was to build a canal that would go around the edge of the Delta.

The main goal of the canal was to fix a problem with the water quality. Big pumps that move water south can pull so strongly that salty ocean water mixes with fresh river water. This harms the environment in the Delta. These pumps send a huge amount of water, about 5 to 7 million acre-feet (which is like 6 to 8.6 cubic kilometers), every year to the Central Valley and Southern California. However, the Peripheral Canal itself would have reduced the fresh water flowing into the Delta. This would have pushed the salty water even further inland, causing problems for farms and nature in the Delta.

Why California Needs Water

Before big water projects were built, all the fresh water from the Sierra Nevada mountains flowed into the Sacramento–San Joaquin River Delta. From there, it went into the San Francisco Bay. But after the Central Valley Project and the California State Water Project started working, things changed.

Now, fresh water is pulled from the Delta through many channels and small rivers. It then goes to a place called the Clifton Court Forebay near Tracy. From there, powerful pumps send the water into the California Aqueduct and the Delta-Mendota Canal. These aqueducts carry water to farms and cities far away.

How Water Projects Affect Fish

A big problem with these pumps is that they can harm fish. Many fish, like the Delta smelt (which is an endangered species), get killed by the pumping plants. These plants provide water for millions of people, but they also impact the environment. Fresh water flowing into the Delta helps push back the salt water coming from the San Francisco Bay. When less fresh water flows in, more salt water can enter the Delta.

Who Supported and Opposed the Canal?

Some important leaders supported the Peripheral Canal idea. These included Senator Dianne Feinstein and former California Governors Arnold Schwarzenegger and Jerry Brown.

However, many people criticized the plan. They worried it would reduce the amount of fresh water flowing through the Delta even more. Farmers in the Delta were especially against the project. They feared it would mean less water for their crops. In 2014, the United States Environmental Protection Agency even said the plan might break the Clean Water Act and harm endangered fish.

What's the Latest Idea?

By 2016, a new plan came up that aimed to do something similar to the Peripheral Canal. This new idea involved building two very large tunnels. These tunnels would be part of a huge project called the California Water Fix and Eco Restore. This project was expected to cost about $25 billion.

Governor Jerry Brown strongly supported this tunnel project. But it also faced many challenges. People worried about how to pay for it and what its environmental impact would be.

Past Water Plans

For a long time, water was taken from the southern part of the Delta. But starting in the 1940s, different groups pushed for the Peripheral Canal. They wanted to take water directly from the Sacramento and San Joaquin rivers, bypassing the Delta.

Sometimes, during droughts or when river flow is low, salty ocean water can reach the pumping stations in the southern Delta. This can contaminate water meant for drinking and farming. To fix this, state and federal agencies proposed a canal in 1965. This canal would have moved fresh water from the Sacramento River around the Delta, instead of through it.

In 1982, voters in California had a chance to approve building a similar canal. But they voted against it, and the plan was defeated.