The range
$1,500 to $6,000 for typical residential work.
$1.5K
Downspout extensions and minor regrade on one side of the house
$3.5K
Full perimeter regrade with minor French drain run
$6K+
Major grade change, multiple French drain runs, hardscape work involved
Exterior drainage work is the most variable in cost of any waterproofing scope because it touches the yard, landscape, hardscape, and grade in ways no other scope does. A simple downspout extension is a couple hundred dollars. A regrade that requires removing trees, lifting concrete, or coordinating with a fence is several thousand.
When this fits
When exterior drainage is the right fix.
Key takeaway
Surface water management addresses the source of the problem, where the water is coming from on the outside. Interior drain tile addresses where the water ends up, inside, after it has already gotten to the foundation. The right answer depends on which one is the actual problem.
Cases where exterior drainage is the right call:
- Negative grade. Soil slopes toward the foundation instead of away. Common after 20+ years of settling, mulch top-dressing, or landscape changes.
- Downspout dump. Roof water concentrated at the foundation perimeter with no extension or splash block. Easy fix.
- Surface water from neighbor or upgrade. Water from an uphill lot pooling against your house. Sometimes solved with a French drain along the property line.
- Soft spot in lawn near foundation. Localized saturation often caused by a downspout, AC condensate line, or sprinkler head pointed at the wall.
Cases where exterior drainage will not solve the problem:
- High groundwater table. If the water is coming up from below the slab during spring thaw, regrading does not help. Interior drain tile does.
- Cracked footing. Structural water intrusion. Different scope entirely.
- Hydrostatic pressure on the foundation wall. The water table is above the slab. Interior is the fix.
For the full diagnostic, see our interior vs exterior drainage article.
Price drivers
What moves the number.
- Linear footage of regrade or French drain. Same as drain tile, linear input drives the cost. A 20-foot regrade is a half-day. A 120-foot regrade with a French drain run is a multi-day job.
- Grade change depth. A 6 inch grade correction is mostly fill and finish. A 24 inch correction starts to involve significant earthwork and disposal.
- Landscape disruption. Bare lawn is easy. Mature landscaping, retaining walls, hardscape, irrigation systems, fencing, and tree roots all add cost and time.
- Downspout work. Simple PVC extensions are inexpensive. Buried downspout drains run to a pop-up emitter at the lot edge cost more.
- Disposal. Excess soil, sod, and debris have to go somewhere. Disposal fees are part of the line item.
- Restoration. We grade, compact, and seed. We do not install sod, replace mature plantings, or restore hardscape, those are owner-elected scope additions.
What is included
What a real regrading quote covers.
What we do
- •Site walk and grade survey. Where water is going now, where it should go.
- •Sod removal in the regrade area.
- •Earthwork. Cut and fill to achieve positive grade away from foundation, code-standard 6 inches in first 10 feet.
- •French drain if part of scope. Perforated PVC, gravel envelope, geotextile, daylight exit.
- •Downspout extensions or buried discharge lines to pop-up emitters.
- •Soil compaction to prevent post-install settling.
- •Topsoil and seed finish in disturbed areas.
- •Cleanup of work areas, disposal of excess material.
What we don't
- •Sod installation (we seed; sod is owner-elected).
- •Hardscape restoration (pavers, walls, fences).
- •Tree work or arborist coordination.
- •Sprinkler system repair if disturbed (owner coordinates with irrigation contractor).
- •Interior basement work (separate scope, see drain tile pricing).
Warnings
When the wrong fix gets quoted.
Regrading is sometimes the wrong answer to a problem that needs interior drain tile, and vice versa. A contractor who quotes you both before diagnosing is selling, not diagnosing.
Common ways exterior drainage gets misapplied:
- Recommended when the actual problem is groundwater. Regrading does nothing for hydrostatic pressure rising from below.
- Used as a cheap substitute for needed interior work. If the customer cannot afford interior drain tile, a contractor sometimes pitches regrading as the “starter” fix. It will not stop the seepage if interior is what was needed.
- Quoted without a site walk. Exterior drainage scope cannot be estimated from a photo. Anyone quoting without walking the property is guessing.
Other quote watch-outs
- No grade survey or measurements in the quote
- French drain priced under $20/linear foot (skipping gravel or geotextile)
- Buried downspout drain without specified exit point
- Disposal not included or listed as “TBD”
- Restoration scope vague or excluded entirely