The Metro-North Railroad’s Hudson Line is one of the MTA’s most picturesque railroads. But the line’s proximity to the Hudson River on one side and steep hillsides on the other makes it particularly vulnerable to climate change.
That vulnerability was made clear on Oct. 21 after a series of retaining walls along a property in Briarcliff Manor overlooking the railroad collapsed after a rainstorm. The ensuing mudslide buried three of the train line’s four tracks in dirt, concrete and trees. No one was injured.
The walls failed after weeks of heavy rain, including torrential downpours from Tropical Storm Ophelia.
Workers were still fixing the damage during a visit to the site on Nov. 6 – more than two weeks after the incident. One of the tracks was still buried. The mudslide was so powerful that 80 feet of rail had been ripped out of the ground in one section.
Up the hill, a jagged chunk of manicured lawn on the private property where the retaining walls failed hung over a newly formed cliff. A below-ground swimming pool was now strikingly close to the edge.
Because the Hudson Line has four tracks, the MTA was able to restore service within a week for its 37,000 daily riders.
But the incident highlights the mounting risk of extreme weather along the Hudson Line. The tracks run along the east side of the river, meaning it faces the risk of flooding on one side and mudslides on the other.
Average rainfall intensity in the Northeast has increased 13% since 1970, according to research by Climate Central. The state’s research and development authority wrote in 2011 that some particularly vulnerable areas along the Hudson Line are in flood zones where the chances of a 100-year flood will increase three to 10 times by the end of the century.
“I think that when you see something like this, it really brings home how vulnerable our infrastructure is and how important the investments are to be made,” Metro-North President Cathy Rinaldi said as she surveyed the wreckage.
Rinaldi said the MTA is monitoring 700 retaining walls near Metro-North tracks — more than 50 of them on private property like the one at Briarcliff Manor — that could spark another mudslide that disrupts train service.
And in the MTA’s 20-year needs assessment released last month, the agency said 50% of the 74-mile Hudson Line risks flooding from coastal storm surge.
“It’s a complicated issue that has multiple solutions, but that’s why it’s such a centerpiece of the 20-year needs document, because we’re going to need to secure funding to be able to address this issue comprehensively,” Rinaldi said.
While the agency may be aware of the problem, the retaining wall failure at Briarcliff Manor also illustrates the whack-a-mole nature of climate change.
The debris and mud didn’t just rip train tracks out of the ground; the mudslide also tore out about 200 feet of newly installed elevated power cables. Those cables were put in as part of a Hurricane Sandy resiliency project meant to protect them from storm surges. But the work didn’t protect the cables from the mudslide.
Mike Loney, the Metro-North’s vice president of engineering, said the cable relocation project was nearly complete, but the mudslide set the work back by months.
“Like a secondary impact to this event is not getting other things done that may have been programmed for this time period,” Loney said. “It’s a great system, but it is prone, it’s vulnerable in certain areas. The Hudson Line is one of those vulnerabilities.”