Why Quad Cities basements take on water

The ground holds water

Much of the soil in the Quad Cities area is clay or loam. Clay swells when it is wet and shrinks when it dries, and it drains slowly. After a long rain or a spring thaw, water collects in the soil around the foundation and presses on the basement walls and the joint where the wall meets the floor. That water has nowhere to go, so it finds the weak spots.

Many homes are older than people think

Census estimates put the median home in Scott County, Iowa, at about 1972, with roughly 23% built before 1950. In Rock Island County, Illinois, the median is around 1970 and about 31% were built before 1950. Houses from the early and mid 1900s often have stone, brick or block foundations and original clay tile drains. Those drains were built to last decades, not a century, and many have clogged or collapsed.

Homes built since then are not immune. See what we see in newer homes.

The rivers raise the water table

The Mississippi and the Rock River run through the middle of the area. Near the rivers, the water table sits high, and when river levels rise, groundwater under nearby homes can rise with them. This is a different problem from river flooding. A sump pump handles groundwater. It cannot stop a river from overtopping a levee.

Freeze, thaw and heavy rain

Frozen ground cannot absorb snowmelt, so spring thaw runs toward your house and sits there. Many parts of the Midwest have also seen heavier downpours in recent decades, and a pump or a drain that handled ordinary rain can fall behind in a big one.

The part you can control

• Point downspouts so they empty several feet from the house.
• Make sure the soil near the foundation slopes away from the house.
• Test your sump pump once a year. Here is how.
• Do not ignore a musty smell or a white powder on the walls. They are early signs of moisture.

If you want to know how your own basement stacks up, take the basement check. If you are seeing water, book a free visit.

Housing figures are Census and American Community Survey estimates for the counties named.