Wednesday, February 13, 2019

Columbia County's Sleeping Dragon: Part X

We've gotten to the penultimate article in Margaret Schram's series about Lake Albany clay. It seems particularly relevant in light of the report today that the developers of the proposed Hudson Housing Authority project are undertaking soil studies that "could alter the design or scope of the project." The following article appeared in The Independent on September 8, 1988.

Where the Dragon Sleeps Today 
Because there have been no major landslides since 1924, readers may think that our county's dragon no longer exists, but the highway departments of the state, county, and affected towns would be the first to disagree. Slippage along ridge roads built on Lake Albany clay are an ongoing problem according to these agencies. The major difficulties at present occur in the towns of Stockport and Stuyvesant and will be described in the next article. Mt. Merino Road in the Town of Greenport and Oak Hill Road in Livingston have continuing problems. As indicated on the accompanying map [shown below], Wire Road in the Town of Livingston, located between the Roeliff Jansen and Klein kills, should be endangered, but Supervisor Donald Kline reports no difficulties.

Activating Landslides
Roads left in their original, narrow, lightly surfaced condition would not be apt to slide. When more homes are built in an area, residents usually demand a wider, heavily paved road, which brings into play the factors that lead to landslides--weight and a change in drainage. Widening a road by adding fill to the edge of the hillside is one sure way of activating a slide. Since I started this series, I have been told of many sinking and shifting foundations in the City of Hudson, particularly in the northern and southern streets.
Prime Landslide Area 
A prime example of landslide potential is at the edge of the parking lot of the county building--constructed in 1924--now housing the sheriff's office and the health department on North Third Street. The area below the parking lot was the site of brickyards for over 100 years. Because of slippage, the guide rails have had to be moved more than a car length closer to the building.
A large crack in the pavement and the sinking of the surface near the hillside is typical of a lake clay bank just waiting to move. (The county health department was moved to this location after the building they were in on Allen Street had shifted to such a degree that it was eventually torn down.)
On a side street off Harry Howard Avenue, a group of fairly new homes have been built on a bank overlooking the same brickyard site. At least one house has some foundation problems.
Construction Problems 
The shaded, or dotted, areas on the map [above] indicate the large sections that contain beds of Lake Albany clay. A lack of slopes (sheer factor) precludes the danger of landslides, but if the deposits are deep, and they usually are, a myriad of problems exist related to construction. 
One concern is the inability of the clay soil to "perc" or absorb water. The traditional septic system, with tile drain field, cannot be placed in lake clay soils. In an area with sewer connections, builders do not have the problem, and alternative septic systems are available, but there are other difficulties with the Lake Albany clay.
Tremendous Pressure
Within the deposits are several layers, or strata, of different clays and silts. While the clays remain sticky, plastic and impermeable, water is flowing constantly through the non-clay strata. Obstruct these natural underground drainage flows by a large, deep "dam"--such as a below-ground foundation--and the water will create a tremendous pressure against the substructure.
Lake Albany clays hold water and have a tendency to shrink and swell. The high moisture content makes the soil very susceptible to severe frost action. None of these factors are conducive to maintaining a stable, in-ground foundation. In-ground pools within the deep clay soils are notorious for shifting and cracking. Some developments built in the lake clay are beginning to experience cracked foundations.
Of the buildings mentioned in "Prime Landslide Area," the section of this article that has to do specifically with Hudson, the first, of course, is the former Charles Williams School, now the location of the Second Ward Foundation. 

The house on Allen Street that Schram reported had to be demolished because its foundation had shifted is the house shown below, in photographs taken by Walker Evans in the early 1930s. It stood just west of the courthouse, at the end of West Court Street, where today there is a parking lot.

The house on the side street off Harry Howard Avenue with foundation problems is 6 Lucille Drive, about which Gossips has reported recently.


No comments:

Post a Comment