A new renewable energy resource assessment released last week estimates 6 gigawatts of potential new hydropower development across Washington State’s rivers and streams.

Nationally, the report estimates there are more than 65 gigawatts of potential new hydropower development, nearly equivalent to the current U.S. hydropower capacity.

The U.S. Department of Energy and its Oak Ridge National Laboratory issued the release, which said the findings build on the “Obama Administration’s commitment to an all-of-the-above energy strategy.” The findings, it said, demonstrate one of the ways the nation can further diversify its energy portfolio with sustainable and clean domestic power generation.

“The United States has tremendous untapped clean energy resources and responsible development will help pave the way to a cleaner, more sustainable and diverse energy portfolio,” says Energy Secretary Ernest Moniz in a press release about the report.

“As the Energy Department works with industry, universities and state and local governments to advance innovative hydropower technologies, the resource assessment released today (April 29) provides unparalleled insight into new hydropower opportunities throughout the country,” Moniz says.

Hydropower makes up 7 percent of total U.S. electricity generation and continues to be the country’s largest source of renewable electricity, avoiding more than 200 million metric tons of carbon emissions each year. Hydropower also provides reliable base-load power day and night—providing greater flexibility and diversity to the electric grid and allowing utilities to integrate other renewable sources such as wind and solar power, the federal agency says.

The report capitalizes on recent advancements in geospatial datasets and represents the most detailed evaluation of U.S. hydropower potential at undeveloped streams and rivers to date, it says. The greatest hydropower potential was found in western U.S. states, including Alaska, California, Colorado, Idaho, Montana, Oregon, and Washington. Kansas, Missouri, Pennsylvania, and Wyoming led the rest of the country in new stream-reach hydropower potential.

The hydropower resource assessment also analyzed technical, socioeconomic, and environmental characteristics that will help energy developers, policymakers, and local communities identify the most promising locations for sustainable hydropower facilities, the Energy Department says. The assessment includes stream- and river-specific information on local wildlife habitats, protected lands, water use and quality, and fishing access areas.

Titled “New Stream-reach Development Assessment,” the report builds on a 2012 Energy Department assessment that found over 12 gigawatts of hydropower potential at the nation’s existing 80,000 nonpowered dams.

The results of the resource assessment show that there are still many opportunities to develop new hydropower projects around the country, most of which likely would be smaller, run-of-river facilities that could utilize new low-impact designs and technologies, the agency says.