Framingham is Creepy!

Do you see anything odd about this picture?



The trees on the side of the hill are tilted. This is an example of a process known as "Downhill Creep" or just "Creep."



SOIL CREEP

"Soil Creep is just a slow adjustment of soil and rocks that is so hard to notice unless you can see the effects of the movement. These effects would be things like fenceposts shifted out of alignment, or telephone poles tipping downslope.
Another effect is the way a grass covered slope seems to ooze downhill forming little bulges in the soil. This heaving of the soil occurs in regions subjected to freeze-thaw conditions. The freeze lifts particles of soil and rocks and when there is a thaw, the particles are set back down, but not in the same place as before.

Gravity always causes the rocks and soil to settle just a little farther downslope than where they started from. This is the slow movement that defines creep. Creep can also be seen in areas that experience a constant alternation of wetting and drying periods which work in the same way as the freeze/thaw. Monitoring is essentially done through observation of the effects of creep. Since the process is so slow, it can only be monitored in terms of flow over long periods of time."

http://earthsci.org/processes/geopro/massmov/massmov.html



This hill is a lot bigger and a lot steeper than it looks! The slope is well in excess of 15% in both direction, so it qualifies as a steep hill. According the the Framingham Conservation Committee Master Plan Draft, "The development costs associated with construction on steep slopes are extremely high. Necessary expenses in order to develop these sloped include grading, retaining wall and vegetation in order to reduce run-off, erosion, lateral creep, or frost heaving. Consequently, these areas would be best left as undeveloped open space or conservation land."

Framingham Conservation Committee Master Plan Draft

The side of the hill that faces east has a 15% to 20% slope.


The south face of the hill leads directly to the house, and has a slope that exceeds 25%.

Creep is a normal process that affects every sloped surface. The amount of creep is affected by other factors besides the pitch of the grade. Excessive water, especially if the soil contains a large amount of clay, makes the slippery and more inclined to creep.

EXPANSIVE CLAY SOILS

In some parts of the country they have something called "expansive clay soils". The clay expands when wet and contracts when dry. The expansion/contraction action exacerbates the creep process just as the freeze/thaw cycle described above. Despite the fact that Massachusetts is not affected by expansive clay soil according to the above map, the soil sample I dug up a few weeks ago definitely contracted when it dried.

Vegetation helps to stabilize the soils if present. The roots of plants, shrubs, and trees not only hold the soil in place, they also absorb excess moisture. In general, a slope without vegetation tends to move more than a slope with vegetation. There are exceptions to this rule, however. The weight of trees, plants, and bushes can also make soil heavier and more susceptible to gravity. This is especially true for slippery soils on bedrock.

A Little Knowledge Really is Dangerous!

We did our homework before deciding on a house, but evidently not well enough. What was our first mistake? Maybe believing the realtor when she said the house never had any water problems? Probably. But there many more mistakes along the way.

By then, we knew that in northwest Framingham, "the lack of till and vegetation on the hills creates extreme runoff situations during heavy rains. A lot of these nice houses have multiple sump pumps, perimeter drains (whatever they are!), and specially graded lawns in order to keep their basement dry – and many still end up damp and clammy downstairs."

We weren't at all intimidated by the geography/geology of the area, though, because we were buying a slab home. We thought only basements were affected by water problems, but guess what? Nothing could be farther from the truth! Guess what else? Heavy rains aren't the only cause of "extreme runoff situations." Melting snow also creates rushing rivers where there were no rivers before, and snow melts all winter long.

So, we don't have a wet basement; we have wet bedrooms, instead! The floors are damp all the time, and sometimes the floors are SOAKING WET! (If you leave a plastic box on the floor for a few days, and then sit on the floor where the box was, you'll get wet to the skin - even wearing three layers of clothing!)

Why is this happening? Because the foundation is wet. Why is the foundation wet? We think it's a combination of things (all of which cost money to fix). Why are we getting wet? Because like most foundations, ours is made of concrete. Concrete is a porous material, and it actually acts something like a sponge. The small air pockets in concrete gives it a property known as capillary action.

image by Pearson Scott Foresman, donated to the Wikimedia Foundation

Water is attracted to the concrete surface, and will pull itself through small openings, even against the force of gravity. Since our foundation is wet, the water moves up through the concrete and into the house.

The trick is to keep the foundation dry, whether you have a basement or not. You can usually control moisture by having the land sloped away from the house itself,

Installing gutters and drain spouts appropriately, and keeping them clean, and

Keeping flower beds and bushes away from the house.

At our house, the yard is sloping down to the house. The gutters were installed wrong, and they don't work AT ALL. Water pours through them and gushes down every corner, too. And there are very wet flower beds right smack against the foundation all around the house.

Add in the steeply sloped hill in the backyard, the lack of till and consequently sparse vegetation, the unusually high water table, and the soil that is 100% clay, and it is a recipe for disaster.

The location is ideal and the yard is my idea of paradise - but what a helluva mess we're in now!

Framingham Topography and Glaciers

Hydrology isn't the only factor that determines whether your house and basement is dry. How much SOIL(and the kind of soil)under and around your hose is important. The TOPOGRAPHY of the area (or how many hills are around you and how steep the hills are) is very important, too. Soil and Slope determine whether you are affected by runoff of water; either seasonally or after heavy precipitation.

In Massachusetts, the soil is usually made up of glacial and post glacial deposits over bedrock.

Framingham soil is typically made up of sand and gravel deposits left behind from retreating glaciers.

The glacial history of Framingham is easy to see because of the glacial landforms present in the town. Framingham had a lot of DRUMLINS, for instance.

Drumlins are oval or elongated hills composed of dense till believed to have been formed by the streamlined movement of glacial ice. The most famous drumlins in Massachusetts are Bunker Hill and Beacon Hill. The Harbor Islands in Boston Harbor are drumlins, as well. When I personally imagine a drumlin, I always picture World's End in Hingham, a Trustees of Reservations property where I spend a lot of time as a child. It turns out that World's End is one of the 30 islands of the Boston Harbor Islands National Recreational Area.

Framingham also has Kettle Holes, or Kettle Lakes, which are formed by chunks of ice left behind by glaciers that melt into lakes.

Lake Cochituate is also a kettle lake, as is Walden Pond in Concord, MA.

There are areas in Framingham that are not buildable because they are designated wetlands, or because they are under water, or because the slope of the hills is too steep (>15 degrees.) You also can't build on sites where there isn't enough soil over the bedrock to excavate for sewage systems or septic systems.