Basement Waterproofing in Des Moines, Where Groundwater Runs High

Fixr's 2026 basement waterproofing guide places most projects at $3,000–$10,000, about $5,000 on average. Interior drain tile runs $40–$120 per linear foot, a sump pump $600–$2,500, and injecting a leaking crack $250–$1,000. Regrading the yard, at $500–$3,000, can make a smaller system enough.

Where is the water coming in?

• A wet line where the floor meets the wall after storms or a thaw: groundwater pressing at the joint, the most common leak in any basement.
• One crack that weeps: a poured-wall crack that can often be injected on its own.
• Water near the top of the wall or under a window: surface water, usually from grading, gutters or a window well that does not drain.
• Water rising through floor cracks: a high water table under the slab.
• Damp walls with no drips, mostly in summer: humidity condensing on cool concrete, which a dehumidifier handles.

Why Des Moines basements take on water

In Polk County's soil survey, a saturated zone close to the surface is the most common reason soils are rated limited for houses with basements, and close to half of the county's major soil acreage is classed as poorly or somewhat poorly drained (USDA NRCS). The Iowa Geological Survey notes that the glacial plain north of the city never developed complete surface drainage. Add 36.5 inches of average snowfall and about 14.5 inches of precipitation from April through June (NOAA 1991–2020 normals), and spring is the season to watch for seepage. Polk County's latest federal declaration, DR-4942, covered severe storms and flooding from July 1 to 4, 2026 (FEMA).

What does basement waterproofing include?

Interior drain tile is the usual answer for groundwater: a channel is cut along the floor edge, perforated pipe laid in gravel beside the footing, and the water led to a sump pit, where a pump lifts it out. Crack injection handles a single leaking crack. Outside excavation exposes the wall for a membrane and footing drain; it costs more and tears up the yard, but stops water on the soil side. Coatings, $1–$8 per square foot in Fixr's guide, slow dampness through a wall face and do little against water under pressure. A wall that has moved needs structural wall repair before any of this goes on.

Where the sump water should go

Ask where the discharge line will end: well clear of the foundation, on ground that falls away, and protected from freezing, since the low hits 32°F or colder on about 128 nights a year (NOAA). The City of Des Moines wants sump water kept out of the sanitary sewer. Its Private Property Protection Program reimburses up to $1,500 to redirect a sump to a storm sewer, rain garden or the ground, provided a licensed plumber pulls a permit and the city's pre-approval letter comes first. Compare system prices in the Des Moines foundation and waterproofing cost table.