Should I be concerned that water is pooling when ground is dug near the foundation?

Question

My house is approximately 7~8 years old, and we bought it newly built. The foundation is mainly clay, and I live in a relatively dry environment (Calgary, Alberta, Canada). It is a walkout house, so there is a slight grade away from my house.

Recently, I dug some post holes for a deck near the house, and 3 or 4 feet down, water began pooling (approximately 20~30cm deep). This was following an infrequent, but repetitive rain lasting about a day at one time.

The question is, is it natural for that much water to form that shallow and close to the house foundation? I was not conscious of the issue until lately, and understood the importance of lowering downspouts during the rainy season.

Is this a concern, and if so, what can be done to remedy the issue?

Answer 1

Water isn't "forming" -- the hole is either catching rain, or the water table really is that high in that area. Dry surface doesn't necessarily mean dry underground, if there's a layer of stone or clay that's keeping it from easily soaking deeper, or if you happen to be in the path of drainage from farther up a hill.

For new construction I would hope that the builders were aware of local conditions and did something appropriate with the foundation. I presume that your builders are subject to the same kinds of inspections those in the US are, and here I don't think they're allowed to fill in the ground around the foundation until it has been approved.

I think your choices are either to trust that, or to hire someone to carefully excavate alongside the foundation, look at what was done, and tell you whether it's properly designed or not.

Personally, unless you have reason to worry, I wouldn't.

Answer 2

We have a high water table where we live, and I have a pump installed in a hole underneath the foundation in my basement, as well as a pump in the lawn outside. In springtime they are both running quite a bit, pumping the water into a ditch behind the home, and this has prevented any flooding issues. I've been told I don't need the one in the lawn if I have the one in the basement, but it was the only one there when we moved in. Getting a local plumber to cut out the hole and install the one in the basement ran us ~$800, which is definitely cheaper than routine cleaning and flooring replacement.