Basement Leaks When It Rains? Fix Grading & Downspouts First
If your basement leaks during rain, check outside first. Downspouts that empty next to the foundation and soil that slopes toward the house send water straight to the basement walls. Downspout extensions are cheap; regrading around a house typically costs $1,000–$3,000.
Last reviewed September 2026
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Does rain collect against the foundation?
Walk around the house in rain. Water pooling near the walls or downspouts emptying beside the house confirms it.
Signs it's this problem
- Leaks on the same side of the house as a downspout
- Water pooling against the foundation during rain
- Soil, mulch beds or patios that slope toward the house
- Gutters overflowing in heavy rain
Why it happens
A single roof can shed thousands of gallons of water in a storm. If gutters overflow or downspouts drop that water at the wall, the soil beside the foundation saturates and water pushes through cracks and joints.
Not sure? Run the basement leak finderHow to fix it, step by step
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Safety: Call 811 before digging to locate buried utilities, and keep soil at least 6 inches below siding to avoid rot and pests.
Basement Leaks When It Rains? Fix Grading & Downspouts First cost
| Job | Typical cost |
|---|---|
| Regrade one side of the house | $500–$1,000 |
| Regrade around the whole house | $1,000–$3,000 |
| Buried downspout or drain line, per linear foot | $20–$60/ft |
Got a quote? Check if it's fair
Typical professional price for this job: $500–$3,000
Common questions
How far should downspouts extend from the house?
At least 6 feet, and ideally 10 feet or into a buried line, so water soaks in well away from the foundation.
What slope should the ground have around my house?
A common guideline is at least 6 inches of fall over the first 10 feet away from the foundation.