Identifying and Repairing Sinkholes Caused by Buried Construction Debris

Causes

Sinkholes often appear 5–10 years after construction when buried debris (tree branches, stumps, materials) decays, leaving a cavity that eventually collapses.

Inspection

Enlarge the opening, use a flashlight. If you see decayed wood or building materials, it's a construction sinkhole. Probe bottom and sides—if solid earth, it's man-made. If a large pipe is present, a leaking sewer may be the cause; contact municipal authorities.

Repair Steps

1. Call 811 for utility location.
2. Enlarge opening to access entire cavity.
3. Remove large undecayed debris.
4. Fill in 12-inch layers, packing firmly after each.
5. Establish grass; avoid planting trees for a couple of years.