Upper Delaware River most endangered in U.S.
Floodwaters converging from the Delaware River and the Delaware and Raritan Canal surge through the yard of an evacuated home in Yardley, Pennsylvania, June 29, 2006.
Credit: Reuters/Jeff Zelevansky
The Upper Delaware topped the list because of the threat of contamination from chemicals used in gas drilling in New York and on the Pennsylvania side of the watershed.
Gas drilling was also the reason why the Monongahela River in western Pennsylvania was rated ninth on the list.
Others endangered rivers include the Gauley River in West Virginia, which came in third and is threatened by mountain-top mining, and the Upper Colorado River, which is sixth and has been diminished by water diversions. The report said it could become "a shadow of its former self" if two new diversion projects proceed.
The Sacramento-San Joaquin River Delta in California was second on the list, and Little River in North Carolina and Cedar River in Iowa rounded out the top five.
The Little River is under threat because of a proposed new dam. But American Rivers said the project could be avoided by improved water-efficiency methods and the expansion of existing reservoirs.
In the Upper Delaware campaigners are trying to prevent gas drilling in the Marcellus Shale, a major source of natural gas that lies beneath the river's watershed.
"This clean water source is threatened by natural gas extraction activities in the Marcellus Shale, where chemicals injected into the ground create untreatable toxic waste water," American Rivers said.
The group urged the Delaware River Basin Commission, an interstate regulator, to deny drilling permits to energy companies until it fully investigates whether a drilling technique called "fracking" poses a threat to the river's water.
American Rivers also wants Congress to pass legislation that would give the federal government oversight of the drilling industry, and require companies to meet requirements on disclosure of chemicals.
Other endangered rivers include the Upper Colorado River at No. 6, the Chetco River in southern Oregon, the Teton River in Idaho and the Coosa River in Alabama.
The Chetco, classified as a wild and scenic river, could be damaged by a strip mining plan that would use a damaging method of dredging, the report said. It called on federal regulators to ban mining in or near the river and allow Congress time to pass laws that would protect it.
The 10 rivers are selected according to the significance of the threat to human and natural communities, the degree to which the proposed action would exacerbate the effect of climate change, and if they are the focus of a major decision in the coming year that could determine their health.