Foundation drains

When the code requires one

The 2024 International Residential Code requires drains around concrete or masonry foundations that retain earth and enclose habitable or usable space below grade (IRC R405.1). The drain can be drainage tile, a gravel or crushed-stone drain or perforated pipe, set at or below the top of the footing or below the bottom of the slab, and it has to discharge by gravity or by a pump into an approved drainage system (IRC R405.1). No drain is required on well-drained ground or sand-gravel soils, the code's Group I (IRC R405.1, exception).

How a footing drain works

Water that reaches the footing flows into the pipe's perforations and is carried away instead of pooling against the wall; filter fabric around the pipe and its stone bed keeps silt out (DOE Building America). The drain empties to daylight or to a sump pit that a pump empties, which keeps groundwater below the basement floor (DOE Building America). The sump's outflow should go to a storm sewer, where the city allows it, or to a dry well away from the foundation (DOE Building America).

Fix the surface water first

University of Minnesota Extension says a great number of basement water problems can be solved with gutters, downspouts with extenders and a grade that slopes away from the house, and that this should come before any below-grade drainage system (UMN Extension). The Maryland Geological Survey says most wet basements are likely caused by how the foundation, landscaping or grading was handled, not by rising groundwater, though a shallow water table can cause seepage, worst after heavy rain and in spring and early summer (Maryland Geological Survey). Illinois Extension adds that in heavy rain, saturated soil can push water through small cracks by hydrostatic pressure, and advises clear downspouts that drain away from the home and a 5 to 10% slope away from the foundation (Illinois Extension, 2026).

Why drains fail

Drain tile can stop working for reasons such as a collapsed pipe, a pipe clogged with silt or tree roots, or a broken connection to the sump, and the sump pump itself can fail (UMN Extension). Because the water table can rise with floods and seasons, Minnesota Extension recommends drain tile around basement walls even in sandy or gravel soils (UMN Extension).

Where the water table is high and basements are common

Saginaw County, MI ranks first: a shallow water table limits basements on 95% of its mapped land, and 64% of its flood-loss buildings with a recorded foundation type had basements. The list covers counties with 50,000 or more homes where at least 30% of the buildings in FEMA's flood records since 2016 (NFIP v3, refreshed September 9, 2026; with a recorded foundation type) had basements, ranked by that water-table share. For your own county, use the soil by ZIP code lookup.

What drains cost

Published US prices for a French drain run from $400 (HomeAdvisor) to $27,000 (HomeAdvisor) a job, and HomeGuide puts an interior basement drain at $4,000 to $17,000. Most rows below are French drain prices; HomeGuide's yard and curtain drain rows are not foundation drains. Basement waterproofing costs covers interior and exterior systems, and sump pump cost lists every published pump price.