Susquehanna River, New York, Pennsylvania, and Maryland
This gallery is part of a special National Geographic News series on global water issues.
The Susquehanna River drains 27,500 square miles (71,224 square kilometers) of land in the eastern two-thirds of Pennsylvania, and parts of bordering states, flowing through the Marcellus Shale natural gas extraction area before emptying into the Chesapeake Bay.
It provides drinking water for more than six million people.
Now in its 26th year, the American Rivers Most Endangered Rivers List includes not necessarily the nation's most polluted rivers, but those "at a crossroads, whose fates will be determined in the coming year." The Susquehanna tops out the American Rivers list this year because it's in the Marcellus Shale region, which has become a target in the rush to develop natural gas reserves.
The process used to extract the natural gas, called hydraulic fracturing, or "fracking," starts with large quantities of water. The water is mixed with sand and chemicals and pumped underground to create extreme pressure, which cracks non-porous rock formations and allows the natural gas or oil trapped inside to rise to the surface.
Environmentalists worry because most of today's water-treatment facilities can’t adequately treat the toxic—and potentially carcinogenic—wastewater that is generated.
They are concerned that the current rules are inadequate to prevent the contamination of underground and surface drinking water supplies. Accidental spills have already threatened the Susquehanna and its tributaries.
Last year's top endangered river was the Upper Delaware, also threatened by natural gas extraction. Since last year's listing, the Delaware River Basin Commission has begun developing regulations that would be stronger than others in the region.
Bristol Bay, Alaska
The Nushagak and Kvichak rivers that flow into southern Alaska's Bristol Bay, along with their tributaries, are home to the last great wild salmon fishery in the world.
For more than 10,000 years, indigenous families have sustainably harvested salmon returning to the rivers during their annual migration. The same waters support a commercial fishery worth U.S. $350 million for its rainbow trout, char, dolly varden, and five salmon species.
But a proposed, 2-mile-deep (3.2-kilometer-deep) open pit mine at the headwaters of the Nushagak and Kvichak rivers has tribes and environmental groups worried. Opponents say the Pebble Mine, in its production of copper and gold, could consume 35 billion gallons of water each year that normally course through nearby streams.
In turn it could produce 10 billion tons of waste, including antimony, arsenic, copper, manganese, molybdenum, selenium, zinc, and sulfate. To contain the waste, the mining company would build an impoundment taller than Hoover Dam, which could further impede the fishery. The tribes and environmental groups are asking the Environmental Protection Agency to use the Clean Water Act to prevent Pebble Mine from going forward.
Roanoke River, Virginia and North Carolina
The Roanoke River flows from the Blue Ridge Mountains in Virginia to North Carolina's Outer Banks. Along the way, it provides drinking water to more than one million people in Virginia Beach, Norfolk, and other communities.
The Commonwealth of Virginia's legislature is considering lifting its own ban on uranium mining that’s been in place since 1982. The ruling would clear the way for a mining company interested in developing a deposit on a tributary of the Roanoke in Pittsylvania County, near Chatham just north of Virginia’s southern border.
American Rivers and other environmental groups say that giving the green light to uranium would threaten the Roanoke’s ecosystem as well as drinking water supplies in the region with radioactive pollution and toxic chemicals. Virginia's climate—which includes frequent, heavy downpours—would make it difficult to safely contain radioactive waste, they argue. Uranium mining in other locations, including the U.S. Southwest, has been linked with health impacts in nearby communities including cancer, birth defects, hormone disruption, and damage to vital organs.
Chicago River, Illinois
Six million residents of Chicago and the surrounding region depend on the human-made Chicago River, which flows through the heart of the city. Chicago and the Chicago Park District have invested tens of millions of dollars in river access and improvement over the past decade. Meanwhile, the Metropolitan Water Reclamation District (MWRD) dumps 1.2 billion gallons of sewage that hasn't been disinfected into the Chicago River system every day. The effluent comprises 70 percent of the water in the Chicago River system.
American Rivers, in naming the Chicago the nation's fourth most endangered river, is encouraging the Illinois Pollution Control Board to approve proposed water quality standards for the Chicago River that would require the MWRD to disinfect the effluent.
The District argues that studies have not been done to prove there would be any health benefits from disinfecting the effluent, but that disinfection would carry a high price tag for taxpayers. The tax-funded District is actively promoting the concept that the waterway was designed for shipping and sewage.
"Without the man-made waterway system, operated by the MWRD, the Chicago area would revert to being the pre-settlement swamp it was and every basement would become a floodwater reservoir," according to materials on its website that oppose the disinfection idea.
Yuba River, California
The Yuba River begins in California's Sierra Nevada Mountains and ends in the Sacramento Valley. In addition to supplying drinking water to 480,000 residents and irrigating thousands of acres of farmland, the Yuba provides critical habitat for wild Chinook salmon and steelhead.
But two Army Corps of Engineers dams—one built in 1946 and the other in 1906—cut salmon and steelhead off from more than 100 miles (160 kilometers) of historic spawning habitat upstream, required for salmon survival.
American Rivers and other environmental groups are asking the Army Corps of Engineers to consider all options, including dam removal, for moving fish around the 280-foot-high (85-meter-high) Englebright Dam and 25-foot-high (8-meter-high) Daguerre Point Dam. The National Marine Fisheries Service is under a court order to address the issue of fish passage at Englebright Dam.
Hoback River, Wyoming
Western Wyoming's Hoback River begins with springs, seeps, and wetlands in a roadless area of the Bridger-Teton National Forest and ends in an 8-mile (13-kilometer) stretch that was designated as a Wild and Scenic River in 2009 for its untrammeled character and its wildlife, including a thriving population of native cutthroat trout.
But American Rivers says a proposed industrial-scale natural gas drilling operation could inject toxic chemicals, including known carcinogens, into the ground that would threaten the ecosystem and local drinking water supplies.
Plains Exploration and Production (PXP), a Houston-based energy company, has plans to begin hydraulic fracturing near the Hoback's headwaters pending the go-ahead by the U.S. Forest Service. In its draft environmental impact study of the drilling proposal, the Bridger-Teton National Forest did not require a comprehensive baseline analysis of the area's groundwater before development, which the environmental group says precludes accountability by PXP for the pollution that's sure to result.
Green River, Washington
The Green River flows from Mount St. Helens National Volcanic Monument to the Toutle River, eventually converging with the Cowlitz River in southwestern Washington. Along its path, the river supplies drinking water to 50,000 residents in three communities.
A Canadian corporation recently started exploratory drilling for a copper mine near the headwaters of the Green River. Historically, prospectors have explored the area for copper, gold, silver, lead, and zinc, but only copper was mined with commercial success in the first half of the 20th century, according to the U.S. Geological Survey. Local environmental and recreation groups say further exploration isn't worth the river's health.
"I have been hunting and fishing in this area for 25 years and I hope future generations have the opportunity to do the same," said Craig Lynch, a conservation correspondent for Clark Skamania Flyfishers.
Black Warrior River, Alabama
The Black Warrior River and its tributaries are a major drinking water source for the communities of Birmingham, Jasper, Cullman, and Tuscaloosa in northern Alabama.
The river is renowned for its fishing, boating, recreation, and wildlife, and the U.S. National Park Service recognizes several of its tributaries as some of the country's top streams. The river also passes through the Warrior Coal Field, which contains most of Alabama's coal resources.
Despite coal regulations in other Appalachian states that have gotten tougher over the years, the Army Corps of Engineers has continued to regulate the Black Warrior River watershed’s 90-plus active coal mines under a general permit known as Nationwide Permit (NWP) 21. NWP 21 does not take local wetland and stream conditions into account, according to American Rivers.
The national nonprofit and regional environmental groups are asking the Corps to end the use of NWP 21, consider the cumulative impact of mines on the Black Warrior River, and allow locals to comment on the management of the mines.
Ozark National Scenic Riverways, Missouri
The famously beautiful Ozark National Scenic Riverways could crash under the weight of their own popularity, according to American Rivers' annual list.
Together, the riverways host more than 1.3 million visitors a year. In the past 30 years, 13 developed river access points and public campgrounds have expanded to more than 130, connected by mazes of unmanaged dirt roads that bleed suffocating sediment into the river, according to American Rivers.
The National Park Service expects to issue a draft management plan this year.
St. Croix River, Minnesota and Wisconsin
The St. Croix River begins in northwest Wisconsin and flows south, forming the border of Minnesota and Wisconsin and joining the Mississippi River near the Twin Cities.
The river—the only Wild and Scenic river in Minnesota, and one of only two Wild and Scenic rivers in Wisconsin—provides rare outdoor recreation opportunities in a growing metropolitan area.
But U.S. Representative Michele Bachmann, of Minnesota, has introduced a proposal to Congress to replace the Stillwater Bridge over the St. Croix with a four-lane freeway-style bridge that environmental groups say will would harm the river's scenic and recreational values, set a poor precedent for other Wild and Scenic Rivers, and cost taxpayers up to $690 million in tough economic times.
