Des Moines Egress Windows Window well fills with water: what is wrong and what the fix costs in Des Moines
A window well that fills with water has a drainage problem, not a window problem. Water reaching the bottom of the well is normal; water sitting there is not. In Des Moines that failure has one dominant cause: the gravel bed under the well has silted shut with the fine clay that our glacial till sheds, so there is nowhere for meltwater to go. The repair is $300–$1,000 for a drainage rebuild on a sound well, or $1,000–$3,000 if the well has to come out with it.
Check this first (ten minutes, no tools)
- When does it fill? Note whether it happens during rain, during the spring thaw, or both. Rain-only points at the cover and the grade above. Thaw-driven flooding points at the gravel column, because frozen ground forces melt to travel sideways until it finds the loose backfill around your foundation, which is exactly where the well sits.
- Look at the grade. Stand back and look at the six feet of ground uphill of the well. It should fall away from the house roughly an inch per foot. Flat or reverse-pitched soil, mulch beds, or a sidewalk pitched the wrong way delivers the whole roof-and-yard catchment straight into the well.
- Find your downspout. A downspout discharging within eight feet of a well is the single most common preventable cause in this city. Follow it. Extensions are cheap.
- Dig a hand’s depth in the bottom of the well. Loose rock that keeps going means the bed is probably intact and the water is arriving faster than it can drain. Clay or silt an inch under the surface rock means the bed is gone.
If the bottom is packed silt, no cover and no amount of caulk will help. That is a drainage rebuild.
What is usually wrong
| What you see | Likely cause | Fix and cost |
|---|---|---|
| Fills during heavy rain only, drains in a day | Cover missing or grading tips toward house | Fitted cover $150–$600, regrade often included with other work |
| Fills every March and April, stays for weeks | Gravel bed silted, no outlet | Drainage rebuild $300–$1,000 |
| Fills and the steel is rusted at the soil line | Well is at end of life, drainage gone with it | Well replacement with new bed $1,000–$3,000 |
| Water stains inside on the window frame | Standing water has been sitting against the seal | Drainage first, then basement window replacement $400–$1,100 |
| Never flooded before, started after a new patio or landscaping | Grade changed, or drain tile crushed | Site look, usually $300–$1,000 |
| Flat lot on the Des Moines Lobe, nowhere lower to drain to | No usable outfall | Tie-in to the footing drain and sump, or a pumped line |
Every number here matches the pricing page.
Why Des Moines wells flood
Three local facts drive nearly all of it.
Soils. Central Iowa sits on the Des Moines Lobe, the youngest glacial landscape in the state, and it is exactly what that sounds like: flat, poorly drained till with a heavy clay fraction. It percolates slowly and it silts a gravel bed from the inside as fines migrate down. The same geology is the reason this region has so much tile drainage in its farmland.
Frost. Local code works to roughly a 42-inch frost depth. Frozen ground through February and March means spring melt cannot soak in vertically, so it runs along the top of the frost line until it reaches the loose backfill chimney around your foundation, and your window well is the low point in that chimney.
Nowhere lower to go. On a flat Des Moines Lobe lot, a gravel column has no outfall. Water put into it stays there. That is why a rebuilt bed here so often has to be tied into the footing drain and the sump rather than relying on infiltration, and why the sump discharge location matters: a sump dumping at grade near the house on clay is recirculating.
None of this is a defect in your house. It is what a 1990s corrugated well set on native clay does after twenty-five winters.
When the well has to come out
If the corrugated steel is rusted through at the soil line, if the anchors have pulled and the well has walked away from the wall, or if soil has sloughed in behind it, a drainage rebuild is throwing good money after bad, because we have to pull the well to fix the bed anyway. That is a window well replacement at $1,000–$3,000, which buys a code-sized well, anchored ladder where the depth requires one, and a new gravel column underneath. If you like the existing well body and just want the rust handled, a well liner at $400–$900 is the smaller honest fix.
Do not wait for it to reach the drywall
A well holding a foot of water puts constant pressure on the window frame and on the joint where the well meets the foundation. Seals are not designed to be underwater. The progression is predictable: seeping at the corners, a musty smell, then staining on the sill, then a ruined finished basement and a radon conversation, and Iowa has the highest average indoor radon levels in the country, because water paths and soil gas paths are the same paths.
What to expect on the call
Take one photo looking straight down into the well and one from six feet back showing the grade and any downspout. Say whether it fills in rain, in thaw, or both, and roughly how old the house is. That is usually enough to tell you on the phone whether you are looking at a cover, a rebuild, or a replacement. The measure is free and the quote is flat. We run this work across Des Moines, Ankeny, West Des Moines, Urbandale, and Waukee.
Frequently Asked Questions
Why does my window well fill with water every spring?
The gravel bed under the well has silted shut, so meltwater has nowhere to go and the well becomes a bucket. On Des Moines' glacial till and clay soils that takes about 15 to 25 years from install. The window is rarely the problem; the drainage under it almost always is.
What does it cost to fix a flooding window well?
A drainage rebuild, meaning excavating the well, laying a new gravel column, and tying into the footing drain where one exists, runs $300–$1,000. If the well itself is rusted or undersized, replacement with proper drainage runs $1,000–$3,000. A cover to keep rain and snow out is $150–$600.
Can I just add a cover and be done?
Sometimes. If the well only floods during rain and stays dry through the spring melt, a fitted polycarbonate cover solves it for $150–$600. If it fills when snow melts or after the ground thaws, water is coming up and sideways through the soil and a cover will not touch it.
Will water in the well leak into my basement?
Eventually, yes. A well holding standing water puts hydrostatic pressure directly against the window frame and the foundation joint, which is how a dry basement becomes a wet one. A leaking basement window often starts as a flooding well someone lived with for a few seasons.