The Susquehanna River winding through Pennsylvania's Bradford County. (Wikimedia Photo)

The Susquehanna River winding through Pennsylvania’s Bradford County. (Wikimedia Photo)

A national conservation group recently listed three Northeast rivers among a list of the 10 most endangered rivers in the United States.

The group American Rivers, which works to protect and restore the nation’s rivers, creates the list annually to spotlight rivers facing urgent threats across the country. This year’s list includes the Merrimack River in Massachusetts and New Hampshire, Pennsylvania’s Susquehanna River and New York’s St. Lawrence River.

The Susquehanna was listed at Number 3 on the list. American Rivers officials said the Susquehanna is threatened by pollution and by the Conowingo Hydroelectric Dam, which alters river flow, blocks fish and impacts water quality.

The Merrimack River. (Wikimedia Photo)

The Merrimack River. (Wikimedia Photo)

The Merrimack River was Number 8 on the list and was described as one of New England’s treasures. Officials said the river is a source of drinking water for over a half million people, and it is home to Eastern brook trout and other fish and wildlife. However, its forests are disappearing, cut down to make way for developments, roads and parking lots. They said unless steps are taken to protect sensitive lands in the area, the river will be increasingly harmed by runoff.

In an article on, local environmental advocates said the Merrimack is also threatened by dams along the river. There are reportedly 847 dams harnessing the river and its tributaries. River advocates say the dams slow down the river, warming its water temperatures and making it difficult for some native fish species to survive.

New York’s St. Lawrence River came in at Number 9 on the list. Officials described the river’s dam management as being stuck in the 1950s with little consideration given to environmental values. They said unless U.S. Secretary of State John Kerry and Canadian Foreign Affairs Minister Stéphane Dion approve a proposed plan for improved dam operations, the river and its fish and wildlife will suffer irreversible damage.

Read the full list of America’s most endangered rivers from American Rivers.