Risk Factors for a Sinkhole

 

The sinkhole may develop slowly or suddenly. If it develops suddenly it may be catastrophic depending on:

(1) its size

(2) its location relative to human habitation

(3) its contents (if filled with water then a person falling in could drown)

 

Types of underground holes:

(1) mine-related

(2) sewer or drainpipes

(3) limestone (calcium carbonate) cavern

(4) underground stream

 

Ground surface material may include:

(1) overburden (earth, sand, clay)

(2) street or parking lot

(3) buildings

Underground Hole	Risk for Sinkhole
mine	large, abandoned, underground fire
sewer	poor construction with leakage, heavy fluid flow, heavy overlying construction
limestone cavern	pumping out water, heavy rains, acid rain, heavy overlying construction
underground stream	increased flow, often after heavy rain