Reducing Sand Deposits in a Cobble-Lined Arroyo

A natural arroyo with a cobble-lined lower reach collects heavy silt at the transition from an unlined upper reach. The fix: elevate the cobbles on a screen to let silt pass through.

Screened Cobble Bed

1. Excavate the cobbled section.
2. Lay heavy-gauge welded wire mesh or geogrid on the subgrade.
3. Replace cobbles on top of the mesh.
4. Silt washes through openings; cobbles stay stable.
5. Periodically vacuum or flush accumulated silt from under the mesh.

This “dry stream” approach drastically reduces annual cleanout labor while maintaining flow capacity.