More than two million years ago, the land that is now Pittsburgh was at the heart of a prehistoric delta of rivers and streams. The land was relatively flat; the rivers flowed north and west to the Great Lakes from the mountains and hills to the east. Their waters carried mud and sand and clay-rich rock across present-day Allegheny County, depositing layers of sediment that would become our modern geology. 

When the ice age began, glacial flows blocked the water’s path, damming and re-routing the ancestral Ohio River toward the Gulf of Mexico. The shift caused the rivers to erode steep gullies and slopes into the layers of coal, sandstone, shale and clay and carved Pittsburgh’s tilted topography. 

As a result, the Pittsburgh area is the most landslide-prone region in the state. The soft “Pittsburgh red beds” are notoriously unstable when wet, and the name Monongahela is believed to be derived from a Native American word meaning “river with the sliding banks.” In the industrialized age, populations grew and houses and infrastructure were constructed increasingly on a precarious quagmire of steep slopes and soft earth.

As climate change looms, more extreme rainfall threatens to intensify that instability. The city has budgeted more than $5 million for landslide remediation in 2023, and Mayor Ed Gainey has announced a new team within the Department of Mobility and Infrastructure [DOMI] assigned to landslides. 

University of Pittsburgh researchers are developing a new tool, Cyberwater, to better model climate-related disasters such as landslides, which could help local governments to be better prepared. State lawmakers from this area, meanwhile, have proposed legislation to create a new insurance program for landslide victims, who to this point have had no recourse.

Those measures reflect the serious threat climate change poses to an area and people that are unusually vulnerable.

“We have both rock and soil that are susceptible to landslides in the Greater Pittsburgh area,” explained Helen Delano, a senior geologic scientist at the Pennsylvania Department of Conservation and Natural Resources [DCNR] who has worked on landslides since 1980. “And we built a city on it, and the city’s been around for a couple of hundred years.” 

A hillside no more

In January 2019, the better portion of Mary Kaye Kienke’s backyard slid 70 feet to the bottom of a gully. It looked as if a knife had cut a line across her lawn, she said, cleanly separating the earth just a few feet from her Bon Air home.

Mary Kaye Kienke stands at the edge of the 2019 landslide in her backyard in Bon Air. (Photo by Quinn Glabicki/PublicSource)

“Never in a million years would I’ve thought that we’re going to sustain a landslide back here,” said Kienke. “I would have never thought that that would have been an issue. Ever.” She pointed down the hillside to where the sugar maple that used to shade her backyard now rests on a mound of earth.

After nearly four years, the remnants of her yard are still at the bottom of the hillside, and she has found no source of aid. To the contrary, she has been repeatedly cited by the city for code violations as a result of the slide, most recently on May 9. A city condemnation sign is pasted to her garage. She’s concerned that her house, which her parents built in 1954, will be condemned if she can’t stabilize the slide, a fix that one estimate placed at $200,000. 

“I’m retired,” said Kienke. “I don’t have that kind of money to do this.” 

Kienke hired an independent engineer who determined that the slide was caused by “excessive stormwater flow” at a stream running at the base of the hill.

Her landslide isn’t an exception. It happened on the heels of Pennsylvania’s wettest year on record, when heavy and sustained rainfall inundated Western Pennsylvania’s soils and caused landslides to run rampant across the county.

“We had rain beginning in February [2018], which is usually the driest month in Pittsburgh,” recalled Delano of DCNR. “The ground was not frozen as it normally would have been. We ended the year setting the total record rainfall for the year, and we had over 200 landslides” in Pittsburgh and surrounding counties. “We got a state disaster declaration, although not a federal one. So we had a lot of landslides.”

Climate projections caution that rainfall like that of 2018 could occur more often as the Earth continues to warm.

Public costs

While there’s little public money available for those who experience landslides on their property, the City of Pittsburgh spends millions in taxpayer dollars annually to deal with landslides that happen on public property and affect public infrastructure.

The mayor’s 2023 capital budget calls for more than $5 million to address “slope failure remediation,” a budget line that includes retaining walls for McArdle Roadway and $2.3 million in construction on Polish Hill’s Ruthven Street.

A steep hillside rests along Ruthven Street in Polish Hill, where the city has allocated $2.3 million for slope failure remediation in the 2023 capital budget. (Photo by Quinn Glabicki/PublicSource)

Those funds come after a $14 million investment from the city last year, which consisted largely of an $8.6 million Federal Emergency Management Agency grant for hillside remediation on Mount Washington. 

The mayor has also laid plans to build staff capacity to deal with landslides, adding numerous roles at DOMI, which will organize a unit to focus on the issue. But the city is struggling to hire across the board, and during a budget hearing in December, officials said low salary offerings and residency requirements make it difficult to attract and retain engineers. 

Rebecca Kiernan, assistant director of sustainability and resilience at Pittsburgh’s Department of City Planning, said the threat posed by landslides has grown significantly since she joined the city seven years ago, with big cleanup projects eating into resources that could otherwise go toward mitigation and prevention. She said the turning point was 2018, when the city spent $12 million on cleanup.

A map shows landslide incidence and susceptibility across Pennsylvania, with Pittsburgh and Allegheny County prone to the greatest risk in the state. (Screenshot/PA Emergency Management Agency)

“All of a sudden in 2018, that climate change was here, and we’re seeing it,” Kiernan said. “That puts us in a position where we want to get ahead of the problem, but the problem is already here.”

The city budget’s long-term forecast includes less funding, though: After $4.4 million for remediation in 2024, the budget passed by City Council last month allots less than $1 million in 2025 and less than $3 million in each of 2026, 2027 and 2028. 

Kiernan said she expects the city’s expenses associated with landslides to grow in the coming years, and while the city budget may not yet reflect it, increased federal funding could come in handy. 

Climate connection

As climate change accelerates and global temperatures continue to rise, so, too, will the frequency and intensity of heavy rainfall — a primary trigger for landslides.

Locally, the intensity of rainfall will “dramatically increase,” said Xu Liang, professor of civil and environmental engineering at Pitt and an expert in hydrology. “We will have drier periods of time, but then when it is wet, it is really wet, and we will just have downpours.”

A 2021 climate impacts assessment by the state Department of Environmental Protection [DEP] likewise projects extreme rainfall to increase in magnitude, frequency and intensity. 

With rising temperatures, projections suggest more winter rain rather than snow, and faster snow melts, making soil wetter, heavier and less structurally sound. The winter and spring are already the most prone times of year for landslides, and climate change-related increases in precipitation in Pennsylvania are projected during that same time of year.

Earth, rock and asphalt rest beneath the site of a 2019 landslide near Mary Kaye Kienke’s home in Bon Air. (Photo by Quinn Glabicki/PublicSource)

Ecological collapse, too, has driven landslide risk in recent years, said Kiernan, who pointed to the city’s portfolio of vacant and overgrown greenways as high-risk areas. Invasive vine overgrowth, deer overpopulation and invasive “crazy worms”, she said, are degrading slope stability. The city has embarked on a pilot program to address greenway issues by partnering with local organizations to clear debris, develop trails, plant slope-stabilizing trees and use goats to clear invasive species.

“We really just need to manage the spaces that have been unmanaged for decades,” she said, “and make sure their ecosystems are functioning as they should be.”

Kiernan added that the City Planning Department will be working this year to update maps to more accurately portray landslide-prone areas and potentially add new zoning changes to restrict development in places with high landslide risk.

Liang and fellow Pitt engineering professor Jeen-Shang Lin are working on Cyberwater, a digital infrastructure effort that could, among other uses, model the impact of climate change locally and help decision-makers to better understand at-risk areas and predict climate change’s impact. 

“How, specifically and locally, would climate change actually affect landslides, water resources, floods and so on?” said Liang. “We want to develop modeling tools to help the research and science communities to study this.”

The first phase of Cyberwater will conclude this winter, and the second phase is set to begin in the coming months with $1.8 million in funding from the National Science Foundation. Liang and Lin will collaborate with researchers from institutions across the country to create a software infrastructure that could be used across scientific disciplines to more accurately model landslide risk in the event of heavy rainfall, for example.

The project, said Liang, could help to localize predictive climate modeling that has to this point been available only to well-resourced and often global institutions, which could ultimately save lives.

Help on the way?

After the landslide took out her backyard in 2019, Kienke reached out to the city, her local state representative, her councilperson and even the federal government. Nobody could point her to any kind of aid for landslide victims, and her homeowners insurance didn’t cover them, either.

“There is nothing that they can do to help,” she said. “There’s nothing out there for anyone.”

Mary Kaye Kienke’s home sits high above a gully where more than half of her backyard slipped away in 2019. (Photo by Quinn Glabicki/PublicSource)

That’s not a unique problem, said Delano, who said that for 40 years she’s watched people lose their homes because of landslides that were not of their own making. Fixing a single landslide, she added, can easily run up to $1 million.

“Homeowners insurance almost always specifically excludes land motion,” she said. “Lots of people get rude awakenings when they have a landslide and call their insurance agent and learn that they’re not insured.” 

For years, there have been pushes to create a landslide insurance program, both nationally and statewide, but efforts to pass legislation have met little success. 

Recently, however, a bipartisan bill introduced in the state House of Representatives would create a landslide insurance program out of an existing state program, which its sponsors hope will lower the hurdle to passage. 

The bill, introduced by Rep. Emily Kinkead, D-Brighton Heights, and co-sponsored by Rep. Valerie Gaydos, R-Sewickley, would add coverage of landslides, slope movement and sinkholes to an existing program at the DEP intended to cover mine subsidence.

“Landslides financially devastate families because there is no insurance that currently exists to address it,” said Kinkead. “This is a way for our government to actually help people who are being impacted by climate change.”

The proposed program, said Kinkead, wouldn’t be a cost to taxpayers, with the funds instead coming from insurance premiums. Kinkead and Gaydos plan to reintroduce the bill in the new legislative session.

In Bon Air, Kienke sat in her living room poring over stability reports and citations from the city. She said she’s been hospitalized twice since the landslide for anxiety she attributes to the stress from the muddy situation in her backyard.

“They need to do something to help us residents,” she said. “I’m praying this legislation goes through.”

Quinn Glabicki is the environment and climate reporter at PublicSource and a Report for America corps member. He can be reached at quinn@publicsource.org and on Twitter and Instagram @quinnglabicki.

Charlie Wolfson is PublicSource’s local government reporter and a Report for America corps member. He can be reached at charlie@publicsource.org or on Twitter @chwolfson.

This story was fact-checked by Abigail Nemec-Merwede.

Do you feel more informed?

Help us inform people in the Pittsburgh region with more stories like this — support our nonprofit newsroom with a donation.

Quinn Glabicki

Quinn Glabicki is a writer and photographer covering climate and environment for PublicSource. He is also a Report for America corps member. Quinn uses visual and written mediums to tell stories about...

Charlie Wolfson is an enterprise reporter for PublicSource, focusing on local government accountability in Pittsburgh and Allegheny County. He is also a Report for America corps member. Charlie aims to...