Posted on August 11, 2021
As the climate crisis hastens, many experts believe Pittsburgh — at the center of the Rust Belt — will be a part of something new: the “waterbelt.”
In Washington, D.C., this week, lawmakers are set to pass a $1 trillion infrastructure deal that includes billions to prepare for the effects of climate change, such as flood control, river dredging, highway relocation and more. It would be the largest investment in climate resilience in the nation’s history. And it would be timely, as the United Nations on Monday released its own report calling climate change a “code red for humanity.”
At the top of many experts’ lists on how climate change affects Pittsburgh is flooding. They echoed that more precipitation because of climate change leads to more extreme floods — a challenge for the region’s aging stormwater management system.
David Dzombak, a professor and the head of civil and environmental engineering at Carnegie Mellon University, studies the effects of regional climate change. In 2019, he published climate histories for more than 100 U.S. cities in the Journal of Climate that showed that climate change’s global trends are well defined — higher temperatures, rising sea levels and more extreme weather events — but its impact on individual cities is more nuanced.
“In general, dry places are getting drier and hotter, and wetter places are getting wetter,” Mr. Dzombak said. “In Pittsburgh, we get pretty uniform precipitation over the course of the year. But the amount of precipitation has been going up here a bit, and what is also changing is the extremes. There have always been occasional extreme storms here with very intense rain or very intense winds, but it’s the frequency with which those occur. That’s changing.”
The intensity of recent summer storms in the city isn’t a coincidence, Mr. Dzombak said, citing an example. At his Oakland office in mid-July, he witnessed a heavy storm that lasted 10 to 15 minutes and dropped around an inch of rain.
“The system was overwhelmed and the effect occurs on a broad basis,” he said. “You can get really widespread flooding as we’ve seen.”
In 2018, Pittsburgh experienced its wettest year on record with 57.83 inches of precipitation. As of June, 2021 has seen slightly more than 19 inches of precipitation, according to the National Weather Service. The weather trend is why some scientists are referring to the mid-Atlantic and upper Midwest regions of the U.S. as the “waterbelt,” Mr. Dzombak said.
The problem, experts say, is that Pittsburgh’s current stormwater infrastructure — grates, gutters and pipes — isn’t equipped to handle the heightened level of precipitation. Pittsburgh has a combined sewer system, meaning wastewater and stormwater is sent through one pipe to the Allegheny County Sanitary Authority.
The system was revolutionary when it was built in the 19th century, but today the Pittsburgh Water and Sewer Authority acknowledges on its website that putting wastewater and stormwater through one pipe is “no longer acceptable,” because sewage overflows into rivers, streets and basements. This leads to property damage as well as severe health risks, which disproportionately affect Pittsburgh’s low-income and predominantly Black neighborhoods.
“What’s happening with climate change is … more rainfall means more combined sewer overflow. What also happens is those bigger storms are more likely to produce these big overflows,” said Jordan Fischbach, the director of planning and policy research at the Water Institute of the Gulf, who has extensively studied Pittsburgh’s stormwater system.
Pittsburgh and PWSA are working to address this problem. The city announced in late July that the state awarded PWSA an almost $24 million loan for wastewater infrastructure repairs, although that’s considered a fraction of what’s needed at Alcosan. But Mr. Fischbach said overhauling the system is complex, costly, and, because of climate change, changing over time.
Heavy rainfall also leaves the Pittsburgh region at a higher risk of landslides, he noted. He said landslides can “block roads, damage infrastructure, cause outages for periods of time, and lead to increased expenses for road maintenance.”
But while the risk of flooding is high, the scientists also stressed that water will make Pittsburgh a more sustainable place to live as the effects of climate change, particularly droughts and wildfires, become more prevalent nationwide.
The electric grid, roads and more
Pittsburgh might be as hot as Alabama in the next one or two centuries, according to Michael Blackhurst, the co-director of the urban and regional analysis program at the University of Pittsburgh’s Center for Social and Urban Research.
Pennsylvania has already warmed about 1.8 degrees Fahrenheit in the past century, and is expected to warm another 5.9 degrees by 2050, according to Pennsylvania’s Department of Environmental Protection. The state also will see “many more days” above 90 degrees per year by mid-century.
“I think we’re going to see more stress on our power grid,” Mr. Blackhurst said. “I think it can handle a lot because it was designed for heavy industrial loads, but I think we’re going to see increased adaptation of air conditioning for buildings, and that’s going to mean ensuring that we have adequate energy supplies for those buildings.”
Kent Harries, a civil and environmental engineering professor at Pitt, added that extended energy use can leave the region at risk for more power outages and blackouts.
If the region continues to have continued 100-degree temperature days, he said, more roads will buckle. Heat has already caused roads to buckle across the state because concrete expands and pops the pavement upward. A similar phenomenon can impact rail lines and bridges as well, he added.
“This stuff is showing up on our radar, but it’s showing up very slowly,” he said. “We design buildings with 75-year life. We design bridges with 100, hopefully a little more, life in mind. We never really considered a change in the environment because that was beyond our comprehension realistically up until the last couple of decades.”
Possible solutions
The experts reiterated that no single solution protects Pittsburgh’s infrastructure from the effects of climate change. But some things can help.
At the top of many experts’ and government officials’ minds for the past 10 years is green stormwater infrastructure. GSI uses natural elements, such as vegetation and soil, to reduce sewer overflow, lower the stress on the current storm water collection system, and provide shade — an important asset as temperatures rise.
A current GSI projects is located at Wightman Park in Squirrel Hill.
“Under normal sunny day conditions, it’s a park. and it provides this amazing resource to residents. And then during the rainstorm, it serves as stormwater detention, and it helps prevent flooding, and it helps to reduce the amount of sewer overflow,” Mr. Fischbach, the water institute director, said. “That is the idea with green infrastructure, that it can provide significant amenities to residents.”
But he said green infrastructure can’t be the only solution. He said there’s too much water and green infrastructure is too expensive, overall. He said there needs to be an investment in traditional systems that take into account the already changing climate.
Mr. Harries, the Pitt professor, agrees. He said the effects of deferred maintenance on the nation’s infrastructure is already a challenge, and there is “no well-consolidated effort” to address climate change.
“I mean look at what’s happening with the infrastructure bill on a federal level,” he said. “It’s a wonderful start, but it’s painfully short of what’s actually needed.”
In Pittsburgh, scientists are proposing other tactics to help the city’s infrastructure adapt. For example, Melissa Bilec, the deputy director of Pitt’s Mascaro Center for Sustainable Innovation, and her team just released a map of the city’s commercial energy use. She said she hopes this will encourage local companies to track their energy output and complete a greenhouse gas inventory.
But Pitt’s Mr. Blackhurst, who also specializes in green infrastructure, emphasized that the conversation shouldn’t only be about adapting. Rather, he said, the region needs to take steps to prevent climate change altogether.
“I recognize that Pittsburgh is a relatively small greenhouse gas contributor,” he said. “But, personally, I think as a region with a legacy in fossil fuels, we sort of owe a little bit to the world from an ethics standpoint to be making this shift away from fossil fuels and promoting mitigation alongside adaptation.”
