Serving Ann Arbor
Groundwater & Basement Water Intrusion in Ann Arbor, MI
Basement seepage, failed sumps, and hydrostatic pressure against the foundation are extracted and dried, and the path from the ground is identified so the loss does not repeat. Groundwater and basement seepage are extracted and dried only after the path from the soil is identified — a wall, a slab, a drain, or a failed sump. Drying the interior without stopping that path returns the same water to the same floor.
Frequently asked questions
There is a creek under the downtown.
There is, culverted generations ago as the city grew over it. A buried channel has a fixed capacity and no ability to spread when that is exceeded, so the surplus surfaces wherever it can, sometimes well away from the original streambed. The historic drainage mapping is the only reliable guide to where those runs go.
Thirty-six inches a year is moderate.
The total is moderate and the ground is not accommodating. Clay till across much of the city takes water very slowly, so a larger share of each storm becomes runoff than the rainfall figure suggests. What matters is the fraction that runs off rather than the amount that falls.
Some neighborhoods sit on terraces above the river.
The city is built across a series of river terraces and slopes, and the level a property sits on is more informative than its distance from the water. A terrace well above the river has no realistic exposure to it and may still have significant slope drainage arriving from above. The two questions are separate.
Read it with the local conditions on the Ann Arbor page.