Ecosystems & Fish

Hydropower Protects Ecosystems and Fish

The hydropower industry, which generates approximately 7 percent of the nation’s electricity, invests considerable time, effort and financial resources to better understand its environmental impacts and mitigate them to the fullest extent possible. Through voluntary efforts and through the licensing process, the hydropower industry is undertaking thoughtful and well-planned measures to protect the environment in which it operates.


Employing fish passage and ladder devices, dam operators help migrating species (such as salmon, steelhead and shad) move through river systems, while a number of best practices and technologies help preserve the aquatic environment for in-river fish species (such as bull trout and rainbow trout) The hydropower industry has for many years pursued a variety of measures to improve fish populations and new technologies are being developed and deployed successfully by hydropower operators to further reduce hydropower’s impacts.

Techniques to lessen dam impacts on animals, plants and surrounding lands include:

  • Reservoir sediment and river erosion management
  • Constructing fish passage facilities
  • Modifying dam operations to restore river flows
  • Building fish hatcheries
  • Controlling the temperature and oxygen levels of water released from dams
  • Conserving and remediating land surrounding reservoirs, rivers and dams

Puget Sound Energy efforts result in record sockeye salmon returns to Baker River in 2010 and 2011

For decades now, America’s hydropower industry has undertaken major efforts to improve aquatic habitat, replenish fisheries and protect endangered species.  Accomplished mostly through investing in environmentally-friendly technologies and vigilant monitoring upriver and downriver from facilities, hydropower producers have seen efforts pay off in dramatic ways. One of the most recent – and ecologically significant – successes can be found on Washington State’s Baker River where Puget Sound Energy (PSE) has worked with community stakeholders to bring about record returns for adult sockeye salmon.

Things weren’t always so great on this tributary of the Skagit River. Before PSE turned things around, the sockeye’s survival there was in serious jeopardy. An average of approximately 3,000 adults returned to the river between 1926 and 1959, with the situation growing dire in the 1980s. In 1985, a historic low of 99 fish returned to the Baker River.  And in 1987, only 75 juveniles migrated out of the watershed.

All of that changed when PSE, federal and state fisheries agencies, tribal biologists and the U.S. Forest Service came together to save the sockeye. The solution for downstream migration of juvenile salmon has been an innovative floating surface collector (FSC). Paired with shore-to-shore, surface to lake-bottom guide nets, the 1,000-ton facility contains massive, variable-speed water pumps that simulate river current to lure young salmon into the FSC’s holding pens. From there, the fish are trucked downstream by “fish taxi” around PSE’s two Baker River dams.  For getting adult sockeye back upstream (traditionally the more difficult task), PSE completed construction in 2010 of a new, highly-automated fish trap below Lower Baker Dam. As with juvenile salmon, the captured adult sockeye receive “fish taxi” transport around both Baker River dams.

The results have been dramatic.  In 2010, 22,500 adult sockeye returned to the Baker River and 436,000 migrated from the watershed – stunning turnarounds from the mid-1980s. And 2011 has already blown past those numbers.  At the end of September, more than 36,600 sockeye had returned to the river, approximately 62% higher than the prior year’s record run.

Puget Sound Energy and its Baker River watershed partners demonstrate that it’s possible to have clean, sustainable hydropower and greater numbers of fish.  It’s the primary reason the company won NHA’s Outstanding Stewards of America’s Waters award for Recreational, Environmental or Historical Enhancement last year. NHA continues to work with the environmental and scientific communities to find solutions that meet our energy needs in the most sustainable way possible.

Fish Lifts

Fish lifts are one of several technologies used by the hydropower industry to help local wildlife move through and around dam structures.

The Safe Harbor Fish Lift System

The 417 MW Safe Harbor Dam in Pennsylvania sits on the Susquehanna River. Since the early 1950s, a partnership of electric utilities, government agencies and environmental and sporting groups have worked together to restore American shad to the Susquehanna River. Safe Harbor has been called a success story, and the facility owner a “good corporate citizen,” by American Rivers.

By installing fish lifts, Safe Harbor and three other hydropower projects on the Susquehanna (Conowingo, York Haven and Holtwood) have reopened 435 miles of the river to natural migrations and restored annual spawning populations, spending over $75 million to help these migratory fish, which are a vital part of Pennsylvania’s natural, cultural and economic heritage.

The fish lift at Safe Harbor was completed in 1997 at a cost of $17 million. During the first year of operation, the Safe Harbor fish lift’s performance beat all expectations. The facility lifted over 200,000 fish past the dam, including nearly 21,000 American shad.

Fish Ladders

Fish ladders are another way that hydropower facilities mitigate dam impacts and help local wildlife to flourish. Structures like the one pictured above allow migrating fish to bypass the dam by swimming up a series of shallow steps and into the waters on the other side of the structure.

Working with local communities, environmental groups and regulators, dam operators around the country have taken steps to enhance the local ecosystem surrounding their facilities.

The Chelan County Public Utility District, which recently relicensed its Lake Chelan Hydro Project, is developing a $16 million project to restore the natural function of the Chelan River among other benefits to the local environment.

Learn more about the project, which won an NHA Outstanding Stewards of America’s Waters Award in 2010.

Habitat Restoration

Working with local communities, environmental groups and regulators, dam operators around the country have taken steps to enhance the local ecosystem surrounding their facilities.

Southern Company, the nation’s largest electricity generator, is a prime example of stewardship within the hydropower industry. Southern Company operates 34 hydropower facilities in Alabama and Georgia totaling 2,730MW. Generating up to 5pc of the company’s electricity output, hydropower is a valuable energy resource keeping the light on for millions of the utility’s customers in the Southeast.

With waterways providing power, flood and drought control, and recreational benefits to communities throughout the South, taking care of these valuable resources is a high priority. Southern Company’s nationally-recognized initiative, Renew Our Rivers, has removed more than 10 million pounds of trash since the program began in 2000. The program began with one volunteer from Southern subsidiary Alabama Power cleaning up the banks of the Coosa River, and has grown to encompass yearly activities on the Chattahoochee, Coosa, Tallapoosa, Mobile, Alabama and Black Warrior Rivers. Alabama Power’s 14 hydroelectric plants provide more than 150,000 acres of water and 4,000 miles of shoreline for the public’s enjoyment, and the company has taken a lead role in maintaining the many additional benefits that hydropower can provide and ensuring that there is a healthy ecosystem for fish and wildlife.

The Renew Our Rivers program won an Outstanding Stewards of America’s Waters award from the National Hydropower Association.