If your yard floods or pools after rain, rock-based drainage gives the water somewhere to go. French drains, gravel swales, dry creek beds, dry wells, and permeable gravel areas all move standing water away from the spots where it collects. The right fix depends on where the water sits and where you can send it. Most of these builds run on two materials: washed drainage gravel for the trenches and pits, and river rock for anything you can see.
Why yards flood and how rock helps
Standing water comes from a few common causes: a low spot with nowhere to drain, compacted or clay soil that sheds water instead of absorbing it, or downspouts dumping roof runoff faster than the ground can take it. Rock does not absorb the water itself. It creates open, fast paths and reservoirs that carry or hold water while it drains, so the surface clears instead of staying a puddle. Gravel and river rock give water room to move through the voids between stones, which is exactly what saturated soil cannot do.
Rock drainage solutions compared
Each solution handles a different flooding pattern. Some move water across the yard, some collect and infiltrate it in place.
| Solution | How it works | Best rock |
|---|---|---|
| French drain | Perforated pipe in a gravel trench carries subsurface water to an outlet | Gravel around the pipe |
| Gravel swale | Shallow channel guides surface runoff to a lower point | Pea gravel or river rock |
| Dry creek bed | Rock-lined channel routes and slows runoff while looking like a streambed | River rock with boulder accents |
| Dry well | Buried gravel-filled pit holds water and lets it soak in slowly | Gravel fill |
| Permeable gravel area | Replaces a puddling surface with rock that water passes through | Pea gravel |
| Regrading to a low line | Reshapes the surface so water flows to a drain or swale | Gravel or river rock cover |
Sizing the rock
Drainage rock works because of the gaps between stones, so cleaner, more uniform rock drains faster. For a French drain or dry well, use washed gravel in the 3/4 inch range so the voids stay open and do not clog with fines. For a visible swale or creek bed, mix river rock sizes so the channel reads natural and the larger stones stay put under flow. For a permeable surface area, pea gravel gives a walkable top that still passes water. Wrap French drains and dry wells in fabric so soil does not migrate in and choke the voids.
The buried layer: drainage gravel
This is the material that does the actual work, and it is the one people most often get wrong by buying something with too many fines in it.
Shop drainage gravel
Class II road base is the opposite of drain rock. It is engineered to compact tight, which is exactly what you want under a paver patio and exactly what you do not want inside a French drain. Use drain rock in the trench.
The visible layer: river rock and pebbles
Anything you can see wants rounded stone. It reads like a natural streambed and is kinder underfoot than angular gravel.
Shop river rock for creek beds and swales
Arizona River Rock
San Gabriel River Rock
Salt River Rock
Lodi Gold River Rock
Mission River Rock Cobbles
Sespe Wild River Cobble
Noiyo River Rock
Montecito Rustic Cobble
Mix two or three sizes in a creek bed so the channel does not read as a stripe of uniform stone. Larger cobble holds position under flow; smaller pebble fills between.
Permeable surfaces: pea gravel
Where a surface puddles and you want to walk on it, pea gravel passes water while staying comfortable underfoot.
Shop pea gravel
Where water leaves fast: rip rap
Where water exits the property at speed, or where a bank is actively washing out, gravel is not enough on its own. Rip rap is large angular stone sized to the flow so the water cannot move it. Our rip rap guide to erosion control covers how to size it.
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Apache Brown Rip Rap
Apache Red Rip Rap
Apache Sunset Rip Rap
Arizona Blonde Rip Rap
Desert Tan Rip Rap
Grey Granite Rip Rap
Palomino Gold Rip Rap
Saddleback Brown Rip Rap
Desert Vista Rip Rap
Rebel Red Rip Rap
What to buy for each build
Drainage projects usually take two or three materials rather than one. Here is what each build actually needs.
| Build | Buried or structural | Visible surface |
|---|---|---|
| French drain | Drain rock plus non-woven filter fabric | Pea gravel or sod over the trench |
| Dry well | Drain rock fill plus filter fabric | River rock cap |
| Dry creek bed | Streambed gravel base | River rock with boulder accents and beach pebbles in the channel |
| Gravel swale | Gravel shaped to the fall line | Pea gravel or river rock |
| Slope or outfall erosion | Bedding sand where specified | Rip rap sized to the flow |
Pick the fix for your flooding pattern
Match the solution to where the water is. A soggy lawn over clay points to a French drain that pulls subsurface water out. A puddle that forms in one low spot every storm is a candidate for a dry well or regrading. Runoff that sheets across the yard wants a swale or dry creek bed to catch and route it. Downspouts that flood a corner need a creek bed or swale leading away from the house. Many yards use two of these together. If the water is coming down a hill rather than sitting in a flat spot, rock solutions for sloped yards is the better starting point.
How much rock the project will take
Drainage builds are trenches and channels rather than open beds, so size them by volume, not by square footage. Work out the length, width, and depth of the trench or channel in feet, multiply the three together for cubic feet, then divide by 27 for cubic yards. A 40 foot French drain trench at 12 inches wide and 18 inches deep is 60 cubic feet, or about 2.2 cubic yards of gravel, which is roughly 3 tons.
The coverage calculator handles the conversion, and cubic yards vs tons explains which unit each material is sold in. For the visible surface layer, size it like any other rock cover using how much river rock do I need or how much landscape rock do I need.
Frequently asked questions
What is the best rock for a French drain?
Use clean, washed gravel around 3/4 inch. It has consistent voids that move water fast and resist clogging. Avoid material with a lot of fines or dust, which packs down and blocks flow. Wrap the trench in non-woven fabric to keep soil out.
How do I stop water pooling in one low spot?
A dry well works well for an isolated low spot: dig a pit, line it with fabric, and fill it with gravel so collected water soaks in slowly. If the spot is large or close to the house, regrading the surface to send water toward a swale or drain is the more permanent fix.
Does a dry creek bed actually drain water?
Yes, when it is graded to fall toward an outlet. A dry creek bed is a rock-lined channel that catches runoff and routes it away, slowing the flow so it does not erode. It handles surface water and storm runoff, and it looks like a natural streambed when dry.
Do I need a pipe, or is gravel enough?
It depends on the job. Surface fixes like swales, dry creek beds, and permeable gravel areas move water with rock alone. Subsurface fixes like French drains use a perforated pipe inside the gravel to carry water faster and farther than gravel voids could on their own.
What size gravel is best for drainage?
Washed 3/4 inch gravel is the standard for French drains and dry wells because the voids between stones stay open. Avoid crushed material with a lot of fines, which packs tight and blocks flow. Pea gravel works for permeable surfaces where you also want a walkable finish.
How deep should a French drain trench be?
Most residential French drains run 12 to 18 inches deep and about 12 inches wide, with the pipe bedded in gravel and gravel filled over the top. The trench has to fall consistently toward the outlet, generally about 1 inch of drop every 8 feet, or the water will sit in the pipe.
Do I need landscape fabric around drainage rock?
Around buried gravel, yes. Non-woven filter fabric lets water through while keeping soil out of the voids, which is what makes a French drain or dry well fail over time. Surface rock on a swale or creek bed does not need it for drainage, though fabric under a decorative layer still helps with weeds.
Drain the standing water for good
Stop the puddles with the right rock and a path for the water. Browse our river rock and pea gravel, then plan the channel with our guides to building a dry creek bed, river rock vs pea gravel for drainage, and landscape rock for drainage and erosion control. We deliver nationwide from our California yards.