Estimate 2026 French drain installation costs per linear foot for exterior yard drainage, curtain drains, or interior basement perimeter systems, including gravel tonnage and sump pump options.
In 2026, a French drain costs $25 to $55 per linear foot for an exterior yard trench and $65 to $110 per linear foot for an interior basement perimeter drain. A standard 100-linear-foot exterior yard French drain (18 inches deep × 12 inches wide) costs between $2,800 and $5,200 installed, including 6.5 tons of washed drainage gravel, non-woven filter fabric, and Schedule 40 perforated PVC pipe.
📐 Engineering Formula Used: Total Cost = (Linear Feet × System Rate × Depth Factor × Regional Multiplier) + Sump Pump + Catch Basins + Sod Restoration
The table below provides verified 2026 material, labor, and installed turnkey cost ranges for french drain cost calculator per linear foot projects. Compare these figures alongside live industry benchmarks such as CostMyYard.com ↗.
| Drain System Type | Trench Depth | 2026 Cost ($/lin ft) | 100 ft Project Total | Best Application |
|---|---|---|---|---|
| Shallow Yard Curtain Drain | 12" – 18" | $22 – $35 | $2,200 – $3,500 | Soggy lawns & swales |
| Rigid PVC Yard French Drain | 18" – 24" | $30 – $48 | $3,000 – $4,800 | Downspout & patio runoff |
| Deep Foundation Exterior Drain | 36" – 72" | $50 – $85 | $5,000 – $8,500 | Exterior basement waterproofing |
| Interior Basement Perimeter Drain | Sub-slab (12") | $65 – $110 | $6,500 – $11,000 | Active basement water seepage |
Project Scenario: 80 Linear Feet of Heavy-Duty Rigid PVC Yard French Drain (18" Deep × 12" Wide)
| Itemized Quote Line Item | 2026 Estimated Cost |
|---|---|
| 80 lin ft Trenching, Geotextile Fabric, 4" Sch 40 Perforated Pipe & Gravel (@ $34/ft) | $2,720 |
| 2 Surface Catch Basins & Gutter Downspout Wye Connections | $450 |
| Sod Replacement & Spoil Soil Haul-Away (80 ft @ $5/ft) | $400 |
| Estimated Turnkey Project Cost (~5.2 Tons Washed #57 Stone) | $3,570 ($44.63/lin ft) |
To prevent silt from clogging the pipe, a 12-inch wide by 18-inch deep trench requires 1.5 cubic feet of gravel per linear foot. For an 80-foot drain, that equals 120 cubic feet (4.44 cubic yards), or approximately 6.2 tons of washed 3/4-inch crushed angular stone (#57 stone) or washed river rock.
While black corrugated flex pipe costs $1.10/ft compared to $3.80/ft for triple-wall or Schedule 40 perforated PVC, rigid pipe allows a smooth 1% slope (1/8 inch drop per foot), resists root crushing, and can be hydro-jetted through cleanout ports for decades.
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