Randall Orndorff, Director of the Eastern Geology and Paleoclimate Science Center, discusses how Karst affects daily life. Beneath a quarter of the United States are rock types that can dissolve to form caves, sinkholes and other features. Nearly every state has rock layers of limestone, gypsum, and other soluble rocks we call ‘karst’.
I have (or think I have) a sinkhole on my property. What should I do?
While the USGS studies the types of rocks that can potentially form sinkholes, we don’t investigate individual sinkholes on private property.
First, rule out human causes for your feature. Some sinkholes are caused by leaky underground pipes (talk to your utility company) and some are old construction pits or other buried materials that have settled.
If you’re confident of a natural cause for your sinkhole, options include:
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Check your homeowner's insurance policy to see if you might be covered (depending on which state you live in, most insurance policies don't cover damage due to natural sinkholes).
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If you're concerned about damage to gas, electric, water, or sewer lines, contact the appropriate utility company.
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Contact your State Geological Survey. They are the experts on the geology of your area and they might be able to explain why a sinkhole is forming at your location. Some states have extensive online information about sinkholes, including a place to report them.
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You might need to hire a professional geologist or geotechnical engineer to help you determine exactly what’s happening and how it might be mitigated.
Learn more:
Related Content
How many sinkholes open up in a year?
There is no database of sinkhole collapses for the United States, so these data are unavailable. Some individual state geologic surveys track reported collapses within their state. Many sinkhole collapses are not reported to authorities or news organizations, and many occur in rural areas where they are unobserved. Learn more: USGS Water Science School - Sinkholes
How much does sinkhole damage cost each year in the United States?
Sinkhole damages over the last 15 years cost on average at least $300 million per year. Since there is no national tracking of sinkhole damage costs, this estimate is probably much lower than the actual cost. Learn more: USGS Water Science School - Sinkholes
What is a sinkhole?
A sinkhole is a depression in the ground that has no natural external surface drainage. Basically, this means that when it rains, all of the water stays inside the sinkhole and typically drains into the subsurface. Sinkholes are most common in what geologists call, “ karst terrain .” These are regions where the types of rock below the land surface can naturally be dissolved by groundwater...
What is the difference between a sinkhole and a pothole?
A sinkhole is a closed natural depression in the ground surface caused by removal of material below the ground and either collapse or gradual subsidence of the surface into the resulting void. A pothole is usually a fairly small feature caused by failure of paving materials, usually associated with roads, parking lots, and airports. In the colder parts of the country, potholes become more abundant...
What is the difference between a sinkhole and land subsidence?
Sinkholes are just one of many forms of ground collapse, or subsidence. Land subsidence is a gradual settling or sudden sinking of the Earth’s surface owing to subsurface movement of earth materials. The principal causes of land subsidence are aquifer-system compaction, drainage of organic soils, underground mining, hydrocompaction, natural compaction, sinkholes, and thawing permafrost. Land...
Can the USGS do a survey or study of my private property?
No. The USGS Organic Act (43 U.S. Code § 31) prohibits the USGS from making surveys or examinations for private parties or corporations. On rare occasion, however, the USGS might request access to private property as part of a larger study. If you need to engage a professional land surveyor, hydrologist, geologist, or geotechnical engineer, the following organizations should be able to identify...
Are there geologic maps or publications for where I live?
Detailed geologic mapping has not been completed for the entire United States, but maps are available for most locations. Geologic maps at many scales and from many sources are listed in the National Geologic Map Database . Some geologic maps can be purchased in hard copy through the USGS Store . Download digital geologic maps for entire states from the USGS Mineral Resources Online Geospatial...
An Unseen World Beneath Our Feet - Caves, Sinkholes and Springs
Randall Orndorff, Director of the Eastern Geology and Paleoclimate Science Center, discusses how Karst affects daily life. Beneath a quarter of the United States are rock types that can dissolve to form caves, sinkholes and other features. Nearly every state has rock layers of limestone, gypsum, and other soluble rocks we call ‘karst’.
Sinkholes in West-central Florida, Freeze Event of 2010
More than 110 sinkholes formed in the Dover area of Florida during a freeze event in January 2010. Ground water levels dropped to record-setting lows as farmers pumped water to irrigate their plants for protection from the cold temperatures. The sinkholes destroyed homes, roads and sections of cultivated areas.
More than 110 sinkholes formed in the Dover area of Florida during a freeze event in January 2010. Ground water levels dropped to record-setting lows as farmers pumped water to irrigate their plants for protection from the cold temperatures. The sinkholes destroyed homes, roads and sections of cultivated areas.
Sinkholes in West-central Florida, Freeze Event of 2010
More than 110 sinkholes formed in the Dover area of Florida during a freeze event in January 2010. Ground water levels dropped to record-setting lows as farmers pumped water to irrigate their plants for protection from the cold temperatures. The sinkholes destroyed homes, roads and sections of cultivated areas.
More than 110 sinkholes formed in the Dover area of Florida during a freeze event in January 2010. Ground water levels dropped to record-setting lows as farmers pumped water to irrigate their plants for protection from the cold temperatures. The sinkholes destroyed homes, roads and sections of cultivated areas.
What's Up With Sinkholes?
A huge sinkhole in Texas begs a few questions about this fascinating and sometimes hazardous phenomenon, so we sit down with USGS geologist Randy Orndorff to learn more.
A huge sinkhole in Texas begs a few questions about this fascinating and sometimes hazardous phenomenon, so we sit down with USGS geologist Randy Orndorff to learn more.
Sinkhole in Frederick, Maryland
Cover-collapse sinkhole in limestone near Frederick, Maryland (September 2003). Many sinkholes occur along highways where rainwater runoff is concentrated into storm drains and ditches increasing the rate of sinkhole development (note the sewer drain pipe beneath roadway).
Cover-collapse sinkhole in limestone near Frederick, Maryland (September 2003). Many sinkholes occur along highways where rainwater runoff is concentrated into storm drains and ditches increasing the rate of sinkhole development (note the sewer drain pipe beneath roadway).
Related Content
- FAQ
How many sinkholes open up in a year?
There is no database of sinkhole collapses for the United States, so these data are unavailable. Some individual state geologic surveys track reported collapses within their state. Many sinkhole collapses are not reported to authorities or news organizations, and many occur in rural areas where they are unobserved. Learn more: USGS Water Science School - Sinkholes
How much does sinkhole damage cost each year in the United States?
Sinkhole damages over the last 15 years cost on average at least $300 million per year. Since there is no national tracking of sinkhole damage costs, this estimate is probably much lower than the actual cost. Learn more: USGS Water Science School - Sinkholes
What is a sinkhole?
A sinkhole is a depression in the ground that has no natural external surface drainage. Basically, this means that when it rains, all of the water stays inside the sinkhole and typically drains into the subsurface. Sinkholes are most common in what geologists call, “ karst terrain .” These are regions where the types of rock below the land surface can naturally be dissolved by groundwater...
What is the difference between a sinkhole and a pothole?
A sinkhole is a closed natural depression in the ground surface caused by removal of material below the ground and either collapse or gradual subsidence of the surface into the resulting void. A pothole is usually a fairly small feature caused by failure of paving materials, usually associated with roads, parking lots, and airports. In the colder parts of the country, potholes become more abundant...
What is the difference between a sinkhole and land subsidence?
Sinkholes are just one of many forms of ground collapse, or subsidence. Land subsidence is a gradual settling or sudden sinking of the Earth’s surface owing to subsurface movement of earth materials. The principal causes of land subsidence are aquifer-system compaction, drainage of organic soils, underground mining, hydrocompaction, natural compaction, sinkholes, and thawing permafrost. Land...
Can the USGS do a survey or study of my private property?
No. The USGS Organic Act (43 U.S. Code § 31) prohibits the USGS from making surveys or examinations for private parties or corporations. On rare occasion, however, the USGS might request access to private property as part of a larger study. If you need to engage a professional land surveyor, hydrologist, geologist, or geotechnical engineer, the following organizations should be able to identify...
Are there geologic maps or publications for where I live?
Detailed geologic mapping has not been completed for the entire United States, but maps are available for most locations. Geologic maps at many scales and from many sources are listed in the National Geologic Map Database . Some geologic maps can be purchased in hard copy through the USGS Store . Download digital geologic maps for entire states from the USGS Mineral Resources Online Geospatial...
- Multimedia
An Unseen World Beneath Our Feet - Caves, Sinkholes and Springs
Randall Orndorff, Director of the Eastern Geology and Paleoclimate Science Center, discusses how Karst affects daily life. Beneath a quarter of the United States are rock types that can dissolve to form caves, sinkholes and other features. Nearly every state has rock layers of limestone, gypsum, and other soluble rocks we call ‘karst’.
Randall Orndorff, Director of the Eastern Geology and Paleoclimate Science Center, discusses how Karst affects daily life. Beneath a quarter of the United States are rock types that can dissolve to form caves, sinkholes and other features. Nearly every state has rock layers of limestone, gypsum, and other soluble rocks we call ‘karst’.
Sinkholes in West-central Florida, Freeze Event of 2010More than 110 sinkholes formed in the Dover area of Florida during a freeze event in January 2010. Ground water levels dropped to record-setting lows as farmers pumped water to irrigate their plants for protection from the cold temperatures. The sinkholes destroyed homes, roads and sections of cultivated areas.
More than 110 sinkholes formed in the Dover area of Florida during a freeze event in January 2010. Ground water levels dropped to record-setting lows as farmers pumped water to irrigate their plants for protection from the cold temperatures. The sinkholes destroyed homes, roads and sections of cultivated areas.
Sinkholes in West-central Florida, Freeze Event of 2010More than 110 sinkholes formed in the Dover area of Florida during a freeze event in January 2010. Ground water levels dropped to record-setting lows as farmers pumped water to irrigate their plants for protection from the cold temperatures. The sinkholes destroyed homes, roads and sections of cultivated areas.
More than 110 sinkholes formed in the Dover area of Florida during a freeze event in January 2010. Ground water levels dropped to record-setting lows as farmers pumped water to irrigate their plants for protection from the cold temperatures. The sinkholes destroyed homes, roads and sections of cultivated areas.
What's Up With Sinkholes?A huge sinkhole in Texas begs a few questions about this fascinating and sometimes hazardous phenomenon, so we sit down with USGS geologist Randy Orndorff to learn more.
A huge sinkhole in Texas begs a few questions about this fascinating and sometimes hazardous phenomenon, so we sit down with USGS geologist Randy Orndorff to learn more.
Sinkhole in Frederick, MarylandCover-collapse sinkhole in limestone near Frederick, Maryland (September 2003). Many sinkholes occur along highways where rainwater runoff is concentrated into storm drains and ditches increasing the rate of sinkhole development (note the sewer drain pipe beneath roadway).
Cover-collapse sinkhole in limestone near Frederick, Maryland (September 2003). Many sinkholes occur along highways where rainwater runoff is concentrated into storm drains and ditches increasing the rate of sinkhole development (note the sewer drain pipe beneath roadway).
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