How to Build a Dry Creek Bed for Drainage
Where a dry creek bed works, how to dig and line it, which rock to use, and how much river rock a typical bed needs.
A dry creek bed is a shallow, rock-lined channel that carries rainwater across the yard. Most of the year it’s a landscape feature; in a storm it guides runoff to where it can soak in or drain away, instead of cutting gullies through the lawn.
When it’s the right fix
A dry creek bed handles surface water: rain running off a roof, driveway or slope. If the soil itself stays soggy for days, a French drain is usually the better choice, because it collects water from below ground. The two are often combined.
The channel needs somewhere to send the water: a lower part of the yard, a rain garden, a dry well, or a street drain where that’s allowed. Don’t direct water toward your house or onto a neighbor’s property.
Planning the route
- Watch the yard in heavy rain and note where water collects and flows.
- Lay out the route with a hose or rope. Gentle curves look natural and slow the water down.
- Keep a fall from start to end. Natural slope often does this already; if not, the bottom of the channel needs to step down along its length.
- Size it. For most yards, 2–4 ft wide and about 12” deep in the middle works well. Make it wider where it bends or where a downspout empties into it.
Call 811 (in the US) before you dig.
Building it
- Dig the channel with sloped sides, like a shallow bowl, about twice as wide as it is deep. Use the soil elsewhere in the yard, or build up the banks.
- Compact the bottom and check the fall.
- Lay landscape fabric over the whole channel, overlapping seams by about a foot and tucking the edges under the banks. It keeps the rock from sinking and slows weeds.
- Place large stones and boulders along the edges and at the bends, setting them partly into the soil so they don’t roll.
- Fill with river rock, 1–3” in size, about 4–6” deep. Use a mix of sizes for a natural look.
- Armor the inlet. Where a downspout or pipe empties into the bed, use flat stones or larger rock so the water doesn’t wash the small stones away.
- Plant the edges with grasses or shrubs that tolerate both wet and dry spells.
How much river rock you need
River rock at 1.35 tons per cubic yard, over fabric:
| Creek bed | Tons at 4” deep | Tons at 6” deep | Fabric |
|---|---|---|---|
| 20 × 3 ft | 1 | 1.5 | 66 sq ft |
| 30 × 3 ft | 1.5 | 2.25 | 99 sq ft |
| 30 × 4 ft | 2 | 3 | 132 sq ft |
| 50 × 4 ft | 3.33 | 5 | 220 sq ft |
Measure the width across the curve of the channel rather than straight across the top, since the rock covers the sloped sides too. Boulders for the edges are bought separately, by the piece or by the ton.
Keeping it working
- Clear leaves and debris after the fall and after big storms.
- Rearrange any stones that wash out of place, and add larger rock where they keep moving.
- Pull weeds while they’re small.
Enter your creek bed’s length, width and depth in the Gravel & Stone Planner and choose river rock. For other stones, see Types of Gravel Explained.