Interior of hydro genetration plant with turbines

Hydroelectric Operations

As the owner and operator of the nation’s largest investor-owned hydroelectric system, PG&E works diligently to be a responsible steward of our water resources, particularly as the drought in California continues. This approach holds true both for managing water supplies for fisheries and downstream users as well as at our hydroelectric facilities.

Our Approach

PG&E worker measuring snowpack.

For PG&E’s hydropower, every drop counts

The work of PG&E hydrographers is vital as they travel to designated courses in the high Sierra Nevada and Southern Cascades to measure water supply in snowpack. The greater the snowpack during winter months, the more clean and affordable energy PG&E can supply during summer.

PG&E’s hydroelectric system consists of 67 powerhouses, including a pumped storage facility, with a total generating capacity of nearly 4,000 MW that relies on nearly 100 reservoirs. We manage our hydroelectric system to ensure the safety of the public and our workforce, protect wildlife habitat and sensitive species and maintain popular recreation venues for the communities that we serve, including campgrounds, picnic areas, boat launches, trails, fishing streams and whitewater flows. As a consistent power source, hydropower also enables us to better integrate variable sources of power like wind and solar generation into the grid.

As California experiences one of the most severe droughts on record, PG&E is working closely with water districts, first responders and regulatory agencies to address the drought’s effects, including limited water deliveries, increased fire danger and environmental impacts.

Working Collaboratively

PG&E’s hydroelectric system consists of 26 federally licensed projects. During the license renewal process, we have made it a priority to work collaboratively with stakeholders, such as federal and state agencies, local community members, environmental organizations, Native American tribes, fishing interests and agricultural landholders. Together, we assess the impacts of these projects and work to reach agreement on appropriate resource management measures to include as conditions of the new licenses, such as fish and wildlife habitat protection and recreational opportunities.

Investing in Safety and Reliability

Many of PG&E’s dams and powerhouses have been in service for more than 75 years, and some of the water collection and transport systems date back to California’s gold mining years. We inspect and maintain our entire hydroelectric system according to strict safety guidelines, ensuring structural integrity under normal and extreme conditions. We continue to make significant investments to repair and upgrade these water conveyance systems to ensure their ongoing safety and reliability. In addition, we continue to engage customers in populated areas downstream from PG&E dams through safety outreach.

2015 Milestones


PG&E urges planning on National Dam Safety Awareness Day

In recognition of National Dam Safety Awareness Day, PG&E urged those living or working below dams to recognize the signs of a potential dam breach and to maintain a current evacuation plan. PG&E owns 170 dams in Northern and Central California as part of our hydropower system.

As the drought in California continues, PG&E’s focus remains on safely and reliably operating our hydroelectric system.

We are continually analyzing reservoir and stream conditions while collaborating with regulatory agencies and other stakeholders to conserve water whenever possible in individual regions. Together, we are working to assess the required water releases from our reservoirs to lessen the drought’s impact on the environment and prolong availability of water for downstream users’ needs.

Our commitment also includes working to manage our hydroelectric facilities in a manner that restores and enhances habitat for fish and other wildlife. Examples of our efforts include:

  • Shasta Crayfish Reintroduction. PG&E signed a Safe Harbor Agreement with the U.S. Fish and Wildlife Service (USFWS) and the California Department of Fish and Wildlife—paving the way to reintroduce highly endangered Shasta crayfish into a tributary of Hat Creek on PG&E land. Additionally, a short distance downstream on PG&E land, the federal and state agencies completed a meadow restoration project in mid-2016. The restored habitat has the potential to double the number of Shasta crayfish now in existence.
  • Wetland Habitat Improvement Project. We restored approximately 500 acres of wetland habitat on PG&E property located along the Pacific Flyway, a major path for migratory birds that extends from Alaska to Patagonia. The restored swamp has seen a 20-fold increase in migratory waterfowl, which are benefitting from the feeding and nesting habitat constructed by PG&E in collaboration with the California Waterfowl Association.
  • Battle Creek Salmon and Steelhead Restoration Project. In Tehama County near Mount Lassen, we continue to work with federal, state and regional agencies, conservation organizations and other groups to restore historic salmon runs along Battle Creek. This project is one of the country’s largest cold water fish restoration efforts. Between 2009 and 2019, we are removing five of the eight diversion dams in the area and retrofitting the remaining three with fish screens and ladders to allow spawning fish to travel upstream through 48 miles of streams and habitat.
  • Butte Creek. In Butte County, PG&E’s DeSabla-Centerville hydroelectric project provides a unique benefit to endangered Chinook salmon and steelhead. An 8-mile diversion canal brings colder water from the Feather River to Butte Creek, increasing spawning and holding habitat for these endangered fish. Additional efforts include work to improve water quality, install fish screens and remove barriers to fish migration.

Measuring Progress

We gauge our hydroelectric performance in a number of ways, primarily through our compliance with environmental requirements for our operating licenses. Our compliance rate in 2015 was 98.8 percent, nearly matching the prior year’s rate of 99.0.

PG&E also tracks key indicators of our performance related to maintaining and managing our hydroelectric system and the fish and wildlife habitats that it encompasses:

Environmental Stewardship in Our Hydroelectric Operations—2015
Miles of stream monitored for environmental condition Footnote 1 603
Acres of bird nesting territories monitored Footnote 2 8,125
Acres monitored and/or treated for noxious weed control 2,847
Acres monitored for use by special-status species Footnote 3 1,095
  • 1. Refers to miles of stream monitored for conditions such as water quality/flow, sediment management, habitat quality, fish populations and invasive species. Return to table
  • 2. Includes monitoring of bald eagle and other nesting territories at PG&E hydroelectric projects. Return to table
  • 3. Special status species include those that are listed under the federal or state Endangered Species Acts or are otherwise given a specific designation by California or a federal resource or land management agency. Monitoring studies are required under various hydroelectric licenses. Return to table

Looking Ahead

PG&E reminds customers to be safe

The reservoirs, dams, rivers and streams near PG&E’s hydroelectric facilities are available to the public for swimming, fishing and boating, as are campgrounds, picnic areas, boat launches and hiking trails. Before visiting any of these recreation sites, PG&E encourages our customers to learn about hydropower and how to be safe when recreating near a facility by visiting

As the drought in California persists, PG&E will continue to partner with policymakers, regulators, private industry and other stakeholders to manage the availability of water for hydroelectric power while minimizing fire danger and impacts to the environment and the communities we serve.

PG&E workers using a drone to inspect a facility.

PG&E tests drones, new safety tool for inspections of remote infrastructure

The Federal Aviation Administration granted PG&E permission to begin testing the use of small drone aircraft to inspect our facilities. The first test was completed in the Sierra Mountains high above Fresno at PG&E’s Balch 1 Powerhouse. The rough terrain makes it challenging for employees to conduct assessments. By using a drone, we are able to inspect the entire facility and determine areas that need to be addressed.

Photos by James Green





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