The Flood of 1993 and What It Taught Des Moines Homeowners About Basements

In July 1993 the Raccoon River crested at 26.8 feet on the morning of July 11 and flooded the Des Moines Water Works treatment plant, leaving about 250,000 people without running water (Des Moines Public Library, Project Des Moines). Statewide, January through September 1993 was the wettest such period in more than a century of records.

River flooding vs. a wet basement. Homes near the rivers took in floodwater, which is covered by flood insurance and not by a standard homeowner's policy. Many more basements across the city leaked because months of rain had saturated the soil: groundwater pushing in at the floor joint and through cracks. That kind of water is what drain tile and sump pumps handle.

The normal year. Even without a flood, May and June bring about 5.2 inches of rain each at the Des Moines airport (NOAA 1991-2020), so late spring is when weak spots show. A pump that runs constantly in June is a sign to check capacity and add a backup.

Sewer backups. Heavy rain can also push water up floor drains when sewers are overloaded. A backwater valve and a sewer backup endorsement on the insurance policy address that risk, which drain tile does not.

Practical steps. Know which kind of water reached your basement in the past, keep photos and dates, and match the fix to the cause. See the Des Moines page for local facts and sources.