How much does a French drain cost?

Exterior yard drain: DIY: $3-$10 per linear foot. Professional: $10-$30 per linear foot. Typical project: $500-$5,000. Exterior footing drain: $40-$80 per linear foot. Typical: $4,000-$12,000. Interior basement drain: $40-$80 per linear foot. Typical basement: $5,000-$12,000 (includes sump pump). National average: about $5,000 for a professional exterior French drain project. DIY can save 50-70%.

Can I install a French drain myself?

Yes, for exterior yard drains. A French drain is one of the most achievable DIY drainage projects. What you need: a shovel or trencher (rent a trencher for $200-$400/day for long runs), 4-inch perforated pipe, 3/4-inch washed gravel, landscape fabric, and a way to measure slope. Skills: basic digging, measuring, and pipe laying. Time: 1-2 days for a 50-100 foot run. The keys to success: maintain consistent slope (1 inch per 8 feet minimum). Use washed gravel (not dirt or sand). Wrap everything in filter fabric. Ensure a proper discharge point. What you should NOT DIY: interior basement drains (requires cutting concrete, sump pump, and waterproofing expertise). Exterior footing drains (deep excavation near the foundation). Any drain that connects to the municipal storm system (may require permits and professional installation).

How deep should a French drain be?

Yard French drain: 12-24 inches deep. The depth depends on what you are draining. For surface water runoff: 12 inches is sufficient. For subsurface water or a soggy yard: 18-24 inches. Behind a retaining wall: as deep as the wall footing. Footing drain (around foundation): down to the footing level (typically 3-6 feet). Interior basement drain: just below the slab level (6-12 inches below the floor). The pipe should always be above the water table (if possible) and below the level of the problem area.

French drain vs surface drain: which do I need?

French drain (subsurface): collects and redirects water that is IN the ground (groundwater and water seeping through soil). Best for: soggy yards, water against the foundation, behind retaining walls. Surface drain (catch basin with solid pipe): collects water sitting ON the surface (puddles and runoff). Best for: low spots where water pools, at the bottom of a driveway, next to a downspout. Many drainage systems use both: surface drains for visible water + French drain for subsurface water. If your yard is soggy even when it has not rained recently, you need a French drain (subsurface water). If water only pools during and after rain, a surface drain may be sufficient.

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Woodworking & Lumber

French Drain Guide: Cost, How It Works & Installation

Lumberama Editorial Team, Drainage & Foundation Specialists Nov 1, 2026 10 min read

What Is a French Drain?

A French drain is a trench filled with gravel containing a perforated pipe that redirects surface water and groundwater away from an area.

How it works: Water enters the gravel-filled trench. It flows through the gravel into the perforated pipe. The pipe carries the water downhill to a discharge point (storm drain, dry well, street, or lower part of the yard). Gravity does the work (no pump needed in most cases).

Common uses: Directing water away from the foundation (prevents basement flooding). Draining a soggy area of the yard. Behind a retaining wall (essential for wall longevity). Along a driveway or sidewalk. Interior basement waterproofing (interior perimeter drain).

Types

Exterior French drain (yard): Installed in the yard to redirect surface and subsurface water. Typical depth: 12-24 inches. Typical width: 12 inches. Pipe: 4-inch perforated pipe (rigid PVC or flexible corrugated). Cost: $10-$30 per linear foot (installed).

Exterior footing drain: Installed around the exterior foundation at the footing level. Deeper: 3-6 feet (down to the footing). Requires excavation around the foundation. Cost: $40-$80 per linear foot (installed). Very disruptive to landscaping. Best installed during construction.

Interior French drain (interior perimeter drain): Installed inside the basement along the perimeter. Concrete floor is cut, a trench is dug, pipe is installed, and concrete is re-poured. Water is collected and directed to a sump pump. The standard basement waterproofing method. Cost: $40-$80 per linear foot (installed). Typical basement: $5,000-$12,000.

Curtain drain: A shallow French drain placed uphill from the area to be protected. Intercepts water flowing down a slope before it reaches the problem area. Cost: $10-$25 per linear foot.

Cost

Exterior yard French drain: DIY: $3-$10 per linear foot (materials only). Professional: $10-$30 per linear foot. Typical project (50-100 linear feet): $500-$3,000 (DIY). $1,000-$5,000 (professional).

Exterior footing drain: Professional: $40-$80 per linear foot. Typical project (100-150 linear feet): $4,000-$12,000.

Interior basement French drain: Professional: $40-$80 per linear foot. Typical basement: $5,000-$12,000 (includes sump pump). Sump pump: $500-$1,500 (installed).

Materials (for DIY): Perforated pipe (4-inch): $0.50-$1.50 per foot. Gravel (3/4 inch washed): $25-$50 per cubic yard ($1-$3 per linear foot). Filter fabric (landscape fabric): $0.25-$0.50 per foot. Total materials: $3-$10 per linear foot.

DIY Installation

Steps for a basic yard French drain: 1. Plan the route: from the wet area to a discharge point. Ensure a slope of at least 1% (1 inch drop per 8 feet). 2. Dig the trench: 12-24 inches deep, 12 inches wide. Maintain consistent slope. 3. Line with filter fabric: lay landscape fabric in the trench with enough excess to fold over the top. 4. Add 2-3 inches of gravel to the bottom. 5. Lay the perforated pipe: holes facing down. Maintain slope. 6. Fill with gravel to within 2-4 inches of the surface. 7. Fold the fabric over the gravel (prevents soil from clogging the gravel). 8. Cover with soil and sod (or leave gravel exposed as a decorative feature).

Key tips: Use washed gravel (not crushed limestone, which can cement together). The pipe holes face DOWN (collects water from the bottom, not the top). Maintain slope (use a laser level or string line). The filter fabric is essential (keeps soil out of the gravel). Ensure a proper discharge point (not onto a neighbor's property).