Every year, American Rivers publishes a report about the country's most endangered rivers. In the past, issues identified by the non-profit have spurred environmental action. Either the organization prizes variety (which probably plays some role) or it's no coincidence that only one of the rivers named last year (the Colorado River) made it into this year's report.

Not only do rivers fuel natural ecosystems, they provide 65 percent of the nation's drinking water. Most of their problems relate to managing water flow or pollution runoff, putting the health of the water and the greater habitat at risk.

The top ten:

10. Clearwater and Lochsa Rivers (Idaho)

9. Haw River (North Carolina)

8. White River (Washington)

7. White River (Colorado)

6. South Fork Edisto River

5. San Fransisquito Creek (California)

4. Gila River (New Mexico)

3. Middle Mississippi River (Missouri, Illinois, Kentucky)

2. Upper Colorado River (Colorado)

1. San Joaquin River (California)

The San Joaquin vaulted into the number one spot because of the region's extreme drought this year. Already excessively dry in some areas before the drought, those areas have only worsened because of it.

Farming and industry has also affected river levels as water is diverted to irrigate crops and power machines. If the four million or so people who live along the San Joaquin watershed hope to continue to benefit from the river's natural powers, environmentalists must impose new regulations for more sustainable agriculture. American Rivers further recommends plans for fewer diversions to increase river flow.

On the east coast, North Carolina's Haw River suffers from a different problem: pollution from rainwater runoff. Old sewage systems (including outdated pipes and infrastructure) also contribute to the problem for the region's most popular whitewater rafting location.

"The river has been under the threat of storm water pollution and wastewater pollution for a while, and we've had an opportunity to deal with that," Peter Rabbe, the North Carolina Conservation Director for American Rivers, told wral.com, a local station. "Unfortunately, we've been delaying the cleanup plan for the Haw River mainly because I think folks think it's only about Jordan Lake. That's just not true, it's really an issue for the entire watershed."