American Rivers has published its 40th annual list of America’s Most Endangered Rivers®, highlighting ten waterways that face urgent threats from pollution, climate change, overdevelopment, and policy rollbacks. The 2025 report identifies rivers at a tipping point, where decisions made in the coming year could determine whether they are protected or permanently damaged.
The report is intended as a call to action for policymakers and the public. “Rivers and clean water are essential to our nation’s health, safety, and prosperity. But pollution and extreme weather are putting rivers, people, and wildlife at risk,” said Tom Kiernan, president and CEO of American Rivers. “For 40 years, America’s Most Endangered Rivers® has been a powerful call to action, advancing commonsense solutions and protecting the rivers we all depend on.”
1. Mississippi River: A Crisis of Floods, Pollution, and Policy
Leading the list is the Mississippi River, which stretches over 2,300 miles and supplies drinking water to nearly 20 million people. The river also supports a $400 billion shipping industry and a $25 billion recreation economy. Despite its significance, the Mississippi is increasingly vulnerable to record-breaking floods, habitat degradation, and aging infrastructure.
According to American Rivers, outdated flood management practices and the uncertain future of the Federal Emergency Management Agency (FEMA) put river communities at risk. The Trump administration’s proposed dismantling of FEMA and changes to the National Flood Insurance Program have raised alarms about the government’s ability to respond to natural disasters. “Communities along the river need significant support for disaster prevention and response, as well as river restoration,” the report states.
2. Tijuana River
In second place, the Tijuana River straddles the U.S.-Mexico border and has long been plagued by untreated sewage and industrial waste. Every day, tens of millions of gallons of polluted water flow into the river and into the Pacific Ocean, prompting extended beach closures in Southern California. According to American Rivers, "As of January 2025, San Diego County has closed the southernmost beach for over 1,200 days and counting.”
Health risks include respiratory issues and gastrointestinal illness, disproportionately impacting low-income and immigrant communities. Advocates are urging the federal government to declare a public health emergency and expedite funding to complete the Comprehensive Infrastructure Solution plan, which would modernize water infrastructure and reduce toxic flows.
3. Rivers of Southern Appalachia
The rivers of Southern Appalachia, such as the French Broad, Pigeon, and Catawba, sustained devastating damage in the wake of Hurricane Helene in September 2024. The storm killed 104 people, destroyed drinking water systems, and caused widespread ecological damage. Debris and damaged infrastructure continue to pose serious risks to water quality and public health.
More than 44 dams failed or were severely damaged, and thousands of properties were affected by erosion and sedimentation. While federal, state, and local aid have been allocated, American Rivers stresses that sustained funding and improved dam safety measures are necessary to prepare for future disasters.
4. Passaic River
In New Jersey and New York, the Passaic River, designated a Superfund site in 1984, continues to suffer from decades of industrial contamination. Pollutants include dioxins, PCBs, and heavy metals, stemming from past chemical manufacturing along the riverbanks. While a coalition of companies has agreed to partially fund the cleanup, many of the most polluted sites remain unaddressed.
American Rivers praises the work of local groups and calls on the Environmental Protection Agency (EPA) to ensure sustained momentum. “A cleaner Passaic River means a stronger economy and a healthier future for New Jersey’s communities,” the report notes.
5. Lower Rio Grande
Serving over six million people, the Rio Grande in South Texas is facing water scarcity from drought, overuse, and warming temperatures. The river often runs dry before reaching the Gulf of Mexico. A recent U.S.-Mexico agreement, Minute 331, has created a binational working group to coordinate conservation efforts—but advocates say it lacks the funding needed to achieve its goals.
Despite being the sole water source for many lower basin communities, the Rio Grande received little funding under the Inflation Reduction Act. “Without similar investment, restoration efforts will remain underfunded,” the report warns.
Other rivers on the list
The remaining rivers also face serious and varied threats:
Rappahannock River (VA) – Rising demand from expanding industries and dwindling groundwater levels are increasing pressure on this primary drinking water source. The report calls for a coordinated, basin-wide water management plan.
Clearwater River Basin (ID) – Logging and mining expansion in the Nez Perce-Clearwater National Forest threaten 700 miles of streams that were recently stripped of Wild and Scenic River protections.
Susitna River (AK) – A proposed 100-mile industrial access road could open the door to mining and gas development in one of the most intact ecosystems in the U.S., threatening salmon and other wildlife.
Calcasieu River (LA) – Home to the pink dolphin “Pinky,” this river has a history of industrial pollution. American Rivers is urging the EPA to update decades-old pollution standards for chemical and plastics manufacturers.
Gauley River (WV) – Coal mining near the river’s headwaters has resulted in repeated water pollution violations and legal challenges. The report calls on federal regulators to reject attempts by mining companies to bypass environmental laws.
Each river was selected based on three criteria: an imminent decision that can affect the river’s future, the river’s importance to people and ecosystems, and the severity of the threat it faces. American Rivers calls on the public to get involved and advocates for stronger federal leadership.
