Today, I published an article that surprised me as I was reporting it out. We often hear about the sorry state of U.S. waterways. But thanks to the removal of dams, more sections of rivers across the U.S. were reconnected last year than at any other point in history, according to the nonprofit group American Rivers. Nearly 4,900 miles of waterways were reconnected because of the removal of around 100 dams.
The biggest reason cited for the removals? The ecological benefits, followed by concerns about dam dilapidation and failure, with safety issues coming in third.
Last year, Pennsylvania led the way, with 14 dams removed; followed by Massachusetts, with 11; and Vermont, with 9. This tracks with where dams were built in the U.S. in the first place.
“Dams were part of our early history and the Industrial Revolution,” said Serena McClain, who oversees dam removal for American Rivers. “If you look at all the dams in the Northeast, they powered grist mills to grind flour, and textile mills to make fabric. And all of these early industries certainly put in dams for irrigation so that farmers and others could withdraw water from the stream.”
America’s aging, ‘deadbeat’ dams
Of course, the Industrial Revolution happened a long time ago, and many of the dams built then, and since, have become not just obsolete, but also harmful. The average dam in the U.S. was built around 60 years ago. Along with creating stagnant water and preventing fish and other aquatic species from reaching healthy habitats, many of America’s dams are in danger of failing, and can pose a safety risk.
A vast majority of the country’s dams are what Desiree Tullos, a professor in biological and ecological engineering at Oregon State University, described as “dinky” and “deadbeat.” Oftentimes, they were built decades ago to create swimming holes and for fishing. While the National Inventory of Dams tracks 92,000 dams, including those deemed high-risk, there are hundreds of thousands of such smaller dams in place all over the country.
Over the years, an increasing number of dams have been taken out. Between 1912 and 2025, some 2,350 dams have been removed, according to American Rivers.
Two big reasons that states such as Pennsylvania and Massachusetts lead the way in removals are the state measures put in place to deal with aging infrastructure and the initiatives that promote resilience in the face of extreme weather. For example, Massachusetts has a bond act that funds dam repair and removal, McClain said. And Pennsylvania has a dam safety law that dates back more than 100 years, and also allows dams to be removed for ecological reasons.
‘A dam removal matriarch’
Pennsylvania also has a secret weapon: Lisa Hollingsworth-Segedy, a representative with American Rivers who helps municipalities navigate the dam removal process. She has personally overseen the removal of about 110 dams and counting, including two dams removed last summer from the river in Bedford, Pa., which I wrote about in today’s article.
Indeed, Hollingsworth-Segedy’s colleagues consider her a “dam removal matriarch.”
She has shepherded the removal of hydropower dams that no longer serve a purpose and centuries-old dams that powered long-gone mills on family farms and had become too expensive for the property owners to take out.
“When it comes to fish and problems with the environment, it’s not the size of the dam that matters,” Hollingsworth-Segedy told me, “it’s the fact that the dam is there and it’s changing the river.”
She said dams have often become so much a part of the landscape that locals can’t imagine waterways without them, regardless of how obsolete or harmful the dam might be. At public meetings, she told me, she has heard people say that if a dam were to be removed, the river would go away, or the fish would never come back, or the waterway would turn into a permanent ugly mudhole.
But after pretty much every dam removal, she told me, when water again flows freely, and fish and other wildlife and plants return, the people who initially opposed it do an about-face. They’ll tell her, “‘I can’t believe I was ever against it,’” she said.
Climate science
A new study examines the link between deforestation and a tipping point in the Amazon
If deforestation and global warming continue unchecked, the Amazon rainforest could begin a gradual transition to a degraded, grassland-like ecosystem in just a few decades, according to new research published on Wednesday. The study provides new insight into when the forest might start to slip over an incremental but irreversible ecological tipping point.
Deforestation can create a feedback loop that reduces rainfall and causes even more trees to die, and can raise wildfire risk. As one researcher put it: “If you lose forests, then you lose rainfall.”
Among the study’s other findings: In a theoretical world without deforestation in the Amazon, the rainforest would be able to withstand up to 3.7 degrees Celsius, or about 6.7 degrees Fahrenheit, of global warming over preindustrial temperatures, the researchers found.
But in a scenario where 22 percent or more of the Amazon rainforest is deforested, a majority of the ecosystem becomes vulnerable to collapse at temperatures over 1.5 degrees Celsius of warming.
In today’s world, the planet has already warmed an estimated 1.4 degrees Celsius and at least 17 percent of the Amazon rainforest has already been cut down, burned or otherwise lost.— Sachi Kitajima Mulkey
Read more.
Number of the day
Battery storage costs are down 93 percent since 2010
The global oil crisis may be helping one industry: renewable energy. “At a time when oil and gas supply is faltering, the cost of wind and solar energy keeps declining,” Chico Harlan reports. And when the sun doesn’t shine or the wind doesn’t blow, there are increasingly affordable battery storage options available, he writes.
A new report by the International Renewable Energy Agency, an intergovernmental organization based in Abu Dhabi, said that battery storage costs have fallen precipitously over the last 15 years. “In this case, storage will make renewables become dominant in the energy system,” one expert told Harlan. “There is no doubt.”
The Trump administration
Trump panel recommends FEMA respond to fewer disasters
An expert panel appointed by President Trump recommended today that the Federal Emergency Management Agency make changes that could speed the flow of disaster aid to communities but also force states to cover more of the costs of more disasters without federal help.
Members of the panel described a disaster agency that they said has become too involved in long-term recovery efforts and has become political, specifically criticizing its actions to help states during the coronavirus pandemic. The changes they recommended — which they acknowledged would require action by Congress — included significant overhaul of the way FEMA helps state and local governments pay for recovery and provides housing to disaster survivors. — Scott Dance
Read more.
Climate science
The National Weather Service is understaffed as storm season approaches
The National Weather Service is struggling to recover from last year’s deep staff cuts, raising doubts among some meteorologists about whether the agency is ready for severe storms or hurricane season, which starts next month.
The agency’s roster of more than 2,500 scientists shrank by about 15 percent last year through firings and early retirements. The government has been trying to hire people back to reverse the damage. In the last six months, officials have hired more than 200 meteorologists and hydrologists. — Scott Dance, Judson Jones and Amy Graff
Read more.
Quote of the day
“If it gets any hotter, I don’t think it would be easy to conduct business.”
That’s from Terry Ridon, a member of the Philippine House of Representatives, where industrial fans now line the lobby and hallways where air-conditioning units once ran, and where some lawmakers are donning T-shirts in the heat.
The Times reports that what air-conditioning is available in parts of South and Southeast Asia has become too expensive to run since the war in Iran began, thanks to higher oil and gas prices. (About 80 percent of the oil that normally passes through the Strait of Hormuz goes to Asia.)
That has meant an intense heat wave is colliding with high electricity and fuel prices, making life hard to bear in some countries in the region. Governments in Indonesia, Pakistan and Sri Lanka have declared four-day workweeks for the public sector. In Sri Lanka and Bangladesh, some universities have partly closed. Rural areas in Bangladesh have been hit by unannounced blackouts for more than 10 hours a day.
Read more.
More climate news from around the web:
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Bloomberg reports that Microsoft may shelve one of the corporate world’s most ambitious clean energy targets.
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Trees are countering about half of the heat from pavement and buildings in urban environments, according a new study highlighted by The Associated Press. “About 185 million people living in 31 of the larger cities already feel an average cooling from tree cover of at least half a degree Fahrenheit,” the A.P. writes.
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U.S. electricity prices in April were 6.7 percent higher, on average, than the same month last year, according to data from Heatmap and M.I.T.’s Electricity Price Hub. Some areas saw much bigger increases: In New Jersey and Washington, D.C., prices were up 21 percent and 25 percent between May 2025 and April 2026.
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