11 May 2020
Waterford, New York: a large, damaging landslide
Posted by Dave Petley
Waterford, New York: a large, damaging landslide
An unexpected landslide at Waterford in New York state in the United States last week threatened a number of houses. There are many news reports about this event, which will have been devastating to those living in the vicinity. The best set of images that I have seen were collected by Jim Franco using a drone, and posted to Twitter:-
.
Unfortunately the rear scrap of the landslide continues to undergo retrogression, with up to 2 metres having been lost since the main failure, causing collapse of the decking. Local officials have noted, rightly, that stabilising the land is going to be a major challenge. The materials that form the landslide appear to me to be complex fluvioglacial deposits, which will be prone to erosion.
The image below provides a good sense of the whole of the failure:-
.
Note that whilst it might appear that the landslide is on the outside of the bend in the river, this is not the case. The water at the toe of the slope is a small lake. Given that the landslide was not triggered by rainfall, the cause of the failure is somewhat unclear.
The location of the landslide is 42.799, -73.680. The Google Earth image below was collected in June 2018. There is nothing that is immediately obvious here that appears to indicate that a failure was likely, although the dense vegetation makes interpretation very difficult:-
.
On reflection
Rainfall across Africa continues to cause high levels of loss from floods and landslides. In Rwanda, dozens of people have been killed, including eight members of a single family in a landslide at Gakenke. In Kenya, landslides have affected a number of areas, whilst three people have been killed by a landslide in Uganda. In Ethiopia, 12 people were killed in yet another landslide.
On one picture of Times Union it looks like that water coming from a broken pipe might have caused the slide. There is a bended pipe lying at the upper part of the slieding mass, as well there are two spots, where you see kind of mudflow – one just beneath the house and the other left beneath a tree (dark spot). Restoratin could be done by soil nailing and shotcrete or high quality mesh.
Es complejo, pero necesariamente hay que recorrer el sitio y caracterizar los suelos, conocer presión de poros (deformaciones) y niveles freaticos (oscilacion-piezometro), direcciones de flujo subterráneo. Aparentemente sigue activo.
[Google Translate: It is complex, but it is necessary to visit the site and characterize the soils, to know pore pressure (deformations) and phreatic levels (oscillation-piezometer), directions of underground flow. Apparently still active. D.]
Unbelievable. I have lived in Waterford NY most of my life. Walked Middletown Rd by this area many times as a teenager & never dreamed anything like this would happen. Just like a young lady never would have imagined such a horrendous situation could take place in Waterford.
Any word on how the people down below whose driveway was buried by the landslide are able to access their property?
They’re fine now thanks for asking 🙂
My name is Mary Murphy. My husband built this house. We got married in the yard (which was big BTW) . All these years later there has still been NO acceptable reason that this happened. I literally begged politicians and people who were supposedly experts in this field to help us and we got NOTHING. This has DEVASTATED our lives. But NO one cares. We have been treated like garbage from the get go. We lost everything