Experts believe the city of Schenectady could be entering a period of increased slope instability, thanks to climate change.
Bill Kappel, hydrologist with the United States Geological Survey, said there has been more variability in precipitation and temperature patterns over the past four decades, and extreme temperature shifts, along with more intense rain storms, could destabilize vulnerable slopes.
“It goes into the equation of why land slips,” Kappel said.
This comes after a Jan. 28 landslide sent debris crashing into an apartment at 223 Nott Terrace. The incident sent three residents to the hospital, with one of them being trapped by debris for about an hour before rescue crews were able to free him.
It is still unclear why the slope above Nott Terrace failed. The city said in a press release on Friday it was extending its State of Emergency to other properties on Barney Street, Daggett Terrace and Barney Street so it could perform soil boring tests to evaluate sub-surface conditions along the ridge.
The ridge has seen landslides before, including one along Broadway in 2004, and a slide in 1996 that killed one person. The city received $1.5 million through a federal Hazard Mitigation Grant in 2008 to stabilize the slope along Broadway, after the county published the Schenectady County Hazard Mitigation Plan in 2007.
That study contained a map that showed that the ridge,which runs along Barney Street, is also susceptible to landslides.
This was evident not only from the map, but also the makeup of the trees on the ridge, Kappel said. After examining photos of trees on the hill that failed on Jan. 28, he determined they were “J’d,” meaning their trunks were curved, even as the trees tried to straighten themselves out.
“So, that means the slope was moving, indicating it was not stable,” Kappel said.
Union College Professor of Geology John Garver said the ridge’s geological composition contributed to the landslide. He said the hill is made up of both clay and sand layers. While water can pass through the sand, it stops when it hits clay.
All that is needed to cause a slide on such a slope is excess water, both Garver and Kappel said.
“Everything was ready to go,” Garver said of the hill above Nott Terrace. “And too much water will initiate failure.”
The excess water can come from a large amount of rain, which Garver said we have seen and could see in the future, or it could be caused by a pipe bursting underground.
What is known about Sunday’s incident is that city officials on Friday discovered a water leak at 11 Barney St. Inside the home, city crews found a flooded basement, and water was shut off to the building.
On Monday, demolition crews hired by the city razed buildings at 11 and 13 Barney St. after they were deemed unstable following the mudslide.
Water was also found in the basement of 223 Nott Terrace, which was hit by landslide debris. It was unclear how water got into the downslope building.
It was also unclear whether the city plans to change any policies with regard to neighborhoods situated along potentially vulnerable slopes. Mayor Gary McCarthy did not return requests for comment, and Fire Chief Ray Senecal, who was named incident commander for the landslide, refused to comment for this story.
Experts believe there are some steps that can be taken to prevent landslides. These can include making sure pipes aren’t leaking and trying to stabilize slopes as much as possible, according to Kappel.
Independent City Councilman Vince Riggi said he would like to see better monitoring of slopes in the city, though he said he was unsure how the City Council could address those issues. He said it is the mayor’s responsibility to present those options.
“I think [unstable hills] need to be monitored more closely,” Riggi said. “If we have to hire an outside firm, maybe we have to do that.”
However, he did praise the city for extending the state of emergency, because he said that meant the city was taking the time to look into the cause of the slide.
“Extending the state of emergency is a good thing,” Riggi said. “I’m sure there is a concern about liability.”
Councilwoman Leesa Perazzo said she isn’t sure what else could be done. She did, however, compliment the city and its emergency crews for their response to the landslide.
“I can’t give enough credit to our first responders,” Perazzo said. “They really are amazing.”
Riggi and Perazzo said council members have not been briefed on the landslide or what is being done to address it.
City Council President Ed Kosiur did not return a request for comment.
Kappel said remediation efforts can’t be done everywhere in the city, though. He said a lack of available funds prevents most municipalities from being able to mitigate those risks.
Kappel likened landslides to floods, because neither are easy to prevent.
“You can’t prevent a flood, and you can’t prevent a landslide all of the time unless you invest a lot of money,” Kappel said. “It all falls back on availability of funding to address each and every problem.”
Kristin Devoe, director of public information for the state Division of Homeland Security and Emergency Services, said that agency helps residents prepare for emergency situations by offering classes on hazard awareness.
Some of the precautions include talking to a local emergency manager about the hazards that exist in their neighborhoods and making sure they have an evacuation plan or are prepared if they need to shelter in place.
“It’s all about having a discussion with your family and having a plan,” Devoe said. “You have to get out of the mindset this is never going to happen.”