Endangered rivers are threatened by climate change and human development. Waterways experiencing the worst dangers are chronicled in a new report, highlighting the dangers to rivers around the United States.

American Rivers, a non-profit environmental group, lately released their newest annual study, the Most Endangered Rivers report. The United States has more than 250,000 rivers, and many of these are threatened in one way or another, based on the new study.

Around 65 percent of all drinking water used in the United States comes from rivers, so protecting those resources is a vital issue for public health. Rivers also provide irrigation for crops and supply water to plants and animals in areas where they run.

The San Joaquin River was named the most endangered river in the country, followed by the Upper Colorado River. The Middle Mississippi River rounds out the top three and the group warns that a proposed new levee there could cut off the river from vital floodplains.

The Gila River, where a new pipeline could harm wildlife including fish, is number four on the most endangered rivers list. Local businesses dependent on tourism could be affected by the changes to the river, said the organization.

San Francisco Creek and environmental damage caused by the Searsville Dam rounds out the top five.

America's Most Endangered Rivers report is one of the most respected reports on the subject among many environmental activists. The studies have been released every year since 1984.

Nominations for most endangered rivers are sent to the group by local environmental groups. From there, dangers to the waterways are based on three criteria. First, the public must be able to influence a decision on the waterways within the next twelve months. Second, candidate rivers were judged on how great of a danger changes to the waterway could pose to local human communities and ecosystems. The third criteria to make the list was the possible future impact of changes with increased climate change.

"The report is not a list of the nation's 'worst' or most polluted rivers, but rather it highlights rivers confronted by critical decisions that will determine their future. The report presents alternatives to proposals that would damage rivers, identifies those who make the crucial decisions, and points out opportunities for the public to take action on behalf of each listed river," the group wrote in the report.

South Fork Edisto River, the White River in Colorado, White River in Washington, the Haw River and the Clearwater/Lochsa Rivers finish the top ten list.

An interactive map based on the annual report is available on the American Rivers website.

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