Choose between a French drain and grading only after observing the water source, available slope, outlet, utilities, and maintenance path.
Homeowner resource
The symptom does not choose the method
Start with where water appears, when it appears, and where it needs to go. Grading and swales manage surface flow with elevation; a French drain collects water in a buried trench. A downspout extension, catch basin, channel drain, or foundation waterproofing scope may fit a different source.
The system must have a legal and maintainable discharge. A trench without an outlet, or grading that sends water to a neighbor, may move the problem rather than solve it.
The symptom does not choose the method comparison
Option
Best for
Watch for
Grading or swale
Surface runoff with room to shape a stable positive slope.
Available fall, erosion, property lines, neighboring flow, and mowing.
French drain
A defined collection path with a pipe, aggregate, cleanouts, and a verified outlet.
Utilities, excavation safety, soil, roots, restoration, and maintenance.
Questions before excavation
Measure the proposed length and depth, record soil and access, identify utilities, and photograph the surface flow during or after rain. Include pipe, aggregate, fabric, basins, discharge, backfill, grading, and restoration in the scope.
Is the source roof runoff, surface flow, groundwater, plumbing, or unknown?
Where can water discharge without harming the property or others?
Will the route cross paving, roots, retaining work, utilities, or structures?
Who will maintain cleanouts, grates, outlets, and planted or graded areas?
Safety and locality disclaimer
Drainage, grading, stormwater, right-of-way, erosion, and discharge requirements vary by locality. Verify them before construction. Call for utility locating before digging and do not enter an unsafe excavation. Structural cracking, foundation movement, recurring flooding, mold, sewage, electrical exposure, or an unknown source requires appropriate evaluation.
No Ads Ever. No sponsored recommendations. Any supplier or material discussion here is an estimating input, not paid placement.
Planning ranges are not bids. Final pricing depends on field conditions, selections, permits, local requirements, and contractor scope. Confirm the work and current local costs before committing.
Worked planning examples
What is the French drain cost for 100 feet?
$2,996–$4,406 planning range using the existing drainage model at its baseline regional factor.
Baseline assumptions
100 linear feet of French drain with the baseline trench depth, loam soil, pipe, aggregate, fabric, access, and restoration assumptions.
The outlet, utility conditions, landscape restoration, and water source require property-specific review.
This is drainage planning, not a diagnosis of a foundation or plumbing problem.
Drainage is a planning estimate, not a diagnosis; only dimensions for selected drainage methods are billed.
Source notes
Planning assumptions only; prices are not supplier-verified quotes, retailer prices, or a bid.
Broad residential cost-guide evidence was fetched 2026-09-15 for reasonableness checks, not imported as precise component rates; confirm current local labor, material, disposal, permit, tax, and site costs.
Regional adjustment is applied once to normalized line-item base costs; the caller supplies the existing ZIP/regional factor.