Best Gravel for Drainage

Not all gravel drains equally. The wrong stone type — or the wrong size — can clog a French drain or flood a yard faster than no gravel at all. Here is a direct comparison of the best drainage gravels for every application.

Quick comparison

Gravel type	Drainage rate	Best for	Stays in place	Cost
#57 crushed stone	✅ Excellent	French drains, foundations	✅ Good	$35–$65/ton
#89 crushed stone	✅ Excellent	French drains, pipe bedding	✅ Good	$40–$70/ton
Pea gravel	✅ Good	Yard drainage, decorative	⚠️ Migrates	$35–$55/ton
River rock	✅ Good	Surface drainage	⚠️ Migrates	$45–$80/ton
Crusher run	❌ Poor	Driveways (not drainage)	✅ Excellent	$20–$40/ton
Decomposed granite	❌ Poor	Paths (not drainage)	✅ Good	$30–$50/ton

Best drainage gravels by application

French drains: #57 or #89 crushed stone

#57 crushed stone (3/4-inch angular washed stone) is the standard for French drain systems. Its angular shape locks stones together, resisting migration; the 3/4-inch size creates large void spaces for fast water flow; and “washed” means no fine particles to clog filter fabric over time.

#89 stone (3/8 inch) is used for smaller-diameter pipe bedding and tight trenches. Both work equally well — choose based on availability.

Do not use: Pea gravel in French drains. It is round, migrates through filter fabric tears, and packs down over time, reducing drainage over several years.

Foundation drainage: #57 stone + filter fabric

Around basement walls and footings, use #57 crushed stone wrapped in geotextile filter fabric. The fabric separates gravel from soil — without it, soil migrates into the gravel over 5–10 years and eliminates drainage capacity.

Depth: 12–18 inches of gravel along the foundation wall is standard. Slope the top of the gravel bed away from the foundation at 6 inches per 10 feet.

Yard drainage and low spots: pea gravel or #57

For surface yard drainage — filling low spots, drip lines under downspouts, or decorative dry creek beds — pea gravel and river rock both work well. They drain faster than compacted soil and redirect surface water.

For underground yard drains with a perforated pipe, use #57 stone: it is more stable and less likely to clog the pipe perforations.

Driveway drainage: crusher run base + #57 surface

If your driveway pools water, the issue is usually a compacted fine-stone surface. Crusher run (a mix of crushed stone and stone dust) compacts well for the base but does not drain quickly.

Fix: Add 2–3 inches of #57 or clean angular stone as a top layer. The open structure lets water drain to the sides while vehicles still have good traction.

Raised garden beds: pea gravel drainage layer

A 2-inch layer of pea gravel or small river rock at the bottom of a raised bed provides drainage. Do not use this in deep in-ground French drains — use it only for above-grade containment where containment prevents migration.

What to avoid for drainage

Crusher run / road base: Mixed with stone dust that fills voids — designed to compact and block water, not drain it.

Lava rock: Porous but lightweight; floats and migrates in heavy water flow.

Unwashed stone: Fine particles clog filter fabric within 2–3 years.

Pea gravel in French drains: Round shape migrates through any small gaps in liner or fabric.

How much gravel do you need?

For a French drain trench (12 in wide × 18 in deep × 50 ft long):

Volume = 1.0 × 1.5 × 50 ÷ 27 = 2.8 cubic yards
Weight (at 1.4 tons/cu yd) = 3.9 tons

Use the Gravel Calculator to get the exact amount for your project dimensions. The calculator handles rectangular trenches and drains directly.

Frequently Asked Questions

What is the best gravel for drainage?

#57 crushed stone (3/4-inch washed stone) is the best all-purpose drainage gravel. It drains quickly, resists clogging, and is available nationwide. For French drains, use washed river stone or #57 stone. For driveways with drainage issues, use #21A or crusher run with a #57 top layer.

How much gravel do I need for a French drain?

A standard 4-inch French drain trench (12 inches wide × 18 inches deep) needs about 0.67 cubic feet of gravel per linear foot of trench, or 0.025 cubic yards per linear foot. A 50-foot drain needs about 1.25 cubic yards.

What size gravel is best for drainage?

3/4 inch is the ideal size for most drainage applications — large enough to flow freely, small enough to compact around pipes. Larger stones (1.5 inch) work for heavy-flow areas. Pea gravel (3/8 inch) drains well but can migrate; use it only where contained.

Does gravel size matter for drainage?

Yes significantly. Larger void spaces between stones = faster drainage. Angular stone (crushed) stays in place better than round stone (river rock, pea gravel). For French drains, use washed angular stone — unwashed stone has fine particles that clog over time.