Slow-motion disaster

By Brian Mann

 

O

n a rain-soaked May morning, Port Henry Mayor Ernest Guerin met with Governor Andrew Cuomo next to a washed-out road in his village. Guerin came to ask for state and federal help for local families whose homes were being washed away by spring floods.

“The land collapsed about five feet from their house,” he said, describing the plight of one family. “I’m talking a seventy-five foot drop to Lake Champlain. Without some help, these people are going to be destitute.”

Across the Adirondack Park, melting snow and record-setting rains that began in late April broke loose massive chunks of rock and gravel, destroying roads and creating mudslides. Part of historic Camp Dudley in Westport was compromised when a bluff above Lake Champlain gave way. New or enlarged bedrock slides were created on the upper slopes of Whiteface Mountain, the Brothers in Keene Valley, and other peaks. A stone wall in Hague collapsed under the weight of water and mud, sweeping away part of Route 9N and dumping silt into Lake George.

By far the biggest disaster occurred in May, when thousands of tons of rock and soil began oozing down the flank of Little Porter Mountain, damaging or destroying homes in the Keene Valley subdivision known as Adrian’s Acres—and rekindling a debate over the wisdom of building on steep slopes.

Andrew Kozlowski, a geologist with the New York State Museum, said the mudslide affects eighty-two acres, making it the biggest ever documented in the state. “That whole land mass on the side of the mountain is physically moving,” he said. “It’s well over a mile around. It’s a very big deal.”

The pace of the slow-motion disaster has varied, with the slide advancing only a few inches on some days. Charity Marlatt, who owns a home on Little Porter, first learned that her home was threatened when she returned from vacation to find her front yard had shifted. “My planting table [in the garden] was tilting, but at that point it was just a small crack in the lawn,” she said.

In the days that followed, the soil under Marlatt’s foundation sagged and then sheared away, leaving part of the house dangling in space. Engineers are trying to save the home, but a neighbor, Pamela Machold, has already seen her seasonal vacation home condemned.

“There’s nothing we can do,” Machold said, standing at the edge of one of the crevices that had fractured her driveway. She said the home, once valued at more than $600,000, is now worthless. “The house has got to be to be taken apart because it’ll collapse upon itself. The property is absolutely useless.”

Half a dozen other homes are threatened in Keene Valley alone, and at least one located at the bottom of the Little Porter slide has been evacuated. In an interview with the Plattsburgh Press-Republican, developer Martha-Lee Owen said the future of the Adrian’s Acres subdivision is uncertain.

The mudslide has added fuel to the simmering debate over upland development in the Park. Over the past decade, as shoreline properties became scarcer and pricier, developers have built vacation and retirement homes on ridges and mountainsides, capitalizing on the desire for prized vistas.

Environmental groups have lamented the trend. John Sheehan, a spokesman for the Adirondack Council, said development on steep slopes should be prohibited. He acknowledged, though, that such a measure would face “immense resistance from developers and their boosters.”

Critics contend that upland development is not only unsightly—spoiling views in Keene Valley, Lake George, and Saranac Lake, among other places—but also leads to soil erosion and the silting of streams.

Carol Treadwell, president of the Ausable River Association, once conducted a study of the storm-water runoff from the Adrian’s Acres development. “People don’t think that their house on top of a mountain affects the water quality in the river, but it does,” she said last year in an interview with the Explorer.

“Once you clear a site and increase impermeable areas, you increase storm-water runoff, and that is not reversible,” Treadwell added.

But the recent slides also raise questions about the safety and marketability of homes constructed on steep slopes.

Keene Supervisor Bill Ferebee expressed these concerns when he toured the Adrian’s Acres subdivision this spring. “See here how this house is lifting? This means the house is tipping forward,” he said during the visit. “It’s a dangerous situation.”

Ferebee said it may be time for his town to consider new regulations and guidelines that limit upland development. “Possibly some more stringent requirements for water runoff should be looked at,” he said. “The geologist today also recommended that we also put into place [the requirement] for core samples to establish the depth and quality of the rock.”

Kozlowski, the geologist, said that he doesn’t think construction of new homes over the last several decades triggered the massive slide. Rather, he blames the heavy rains. But he points out that many Adirondack slopes are covered by a thin layer of soil and rock deposited in the last ice age.  As a consequence, they are especially vulnerable to slides.

The geologist also noted that building lots with the most attractive views often sit at the edge of scarps or fault lines, where the risk of soil movement is greater. “This is a process that’s been going on in the Adirondacks for a very long time,” Kozlowski said. “This is a natural thing, but now the ball is rolling, so to speak, and that’s a major concern. Because of the glacial history [of the Adirondacks], all these sediments that are draped on hillsides are susceptible to failure.”

The Adirondack Park Agency often has little or no jurisdiction over upland development. That’s because much of the construction takes place either in hamlets where local governments have control over development or in subdivisions that were approved before APA’s zoning regulations were enacted in the early 1970s.  Adrian’s Acres was one of those subdivisions. If the APA had jurisdiction, the agency probably would not have allowed the development to have occurred as it did, according to APA spokesman Keith McKeever.

“Given the extensive areas of steep slopes, aesthetic issues, and soil types, it is unlikely that the existing build-out would have been approved by the APA,” he said.

But McKeever said the spring mudslides are not a reason for reforming the agency’s regulations. “The agency is confident in its regulatory oversight for construction proposed on ridgelines or areas with steep slopes,” he said.

But Sheehan of the Adirondack Council said widespread property damage from slides could become more frequent if upland development continues. “It’s already quite common for camps to be damaged or knocked off their piers on the slopes around Great Sacandaga Lake by rolling boulders and falling tree trunks,” he observed.

Some officials fear that global warming will cause heavy rains—and their attendant mudslides—to occur more frequently than in the past. “The snowfall and rainfall models we use are no longer correct,” said Warren County engineer Todd Beadnell in an interview with the Glens Falls Post-Star after a rainstorm triggered slides and washouts in the town of Thurman.  “The weather has changed.”

As to Little Porter Mountain, scientists say they don’t know when the earth will stop moving—or whether the slide will begin moving again next spring. Gathering good data has been difficult, in part because the slope remains unstable and treacherous.

“It definitely gets your attention when you hear the trunks cracking as a mass,” Kozlowski said. “You hear a thumping, tumbling sound, and you sort of look up and catch a glimpse of boulders falling.”

Meanwhile, the APA has given the Marlatts emergency approval to try to move their house back to a safer location, a project expected to cost at least $100,000.  For Charity Marlatt, the experience has been a “financially devastating” nightmare.

“If I weren’t so emotionally involved, if my heart weren’t so broken right now, this would be a fascinating situation,” she said.  “I’ve learned more about geology than I would probably care to.”