I think I have a sinkhole in my yard. What should I do?
Small holes often require only filling with clean sand or soil. If the hole is under or very near a structure or swimming pool, your property owner’s insurance may cover assessment and repair. Mark the boundaries of the hole and keep children and pets away. If the hole is directly impacting a house, and sinking, sagging, or cracking walls are apparent, stay out of the dwelling. Call the property insurance adjuster and report it immediately. In some communities, local government agencies may assist in evacuating the home, assessing damage and reporting the sinkhole. In some counties, the local Emergency Management Offices (see contact list below) render assistance when a home is endangered. Personnel from your local water management district may also assist in sinkhole assessment, especially if the hole potentially impacts local groundwater. The incident should be reported on the appropriate Subsidence Incident Report Formand submitted to the Florida Geological Survey.
If you have a sinkhole on a large property and it is not actively developing or affecting some activity on the property, it can be left alone. If there is a danger of people or animals falling into the depression, it can be filled with clayey sand or fenced off. Do not fill it with organic material or something that could potentially decompose or release potential toxins into the underlying groundwater. Many people have sinkholes on their property that are just part of the natural landscape. If one suddenly appears, we suggest filling it with clayey sand as the clayey material will retard water movement. Water flowing into a sinkhole can cause it to expand and become more active. Never throw anything into a sinkhole that could possibly contaminate groundwater.
My yard is settling…do I have a sinkhole?
Perhaps, however, a number of other factors can cause holes, depressions or subsidence of the ground surface. Factors include expansive clay layers in the earth that shrink upon drying, buried organic material, poorly compacted soil after excavation work, buried trash or logs, and broken pipes. These settling events, when not verified as true sinkholes by professionals, are collectively called subsidence incidents. If the settling is affecting a dwelling, further testing by a licensed engineering firm with a professional geologist on staff or a professional geology firm may be in order. Property insurance may pay for testing, but in many cases insurance may not cover damage from settling due to causes other than sinkholes.
A sinkhole opened in my next door neighbor’s yard….should I be concerned?
Although sinkholes in Florida sometimes occur in sets, most are isolated events. The bedrock underlying the state is honeycombed with cavities of varying size, most of which will not collapse in our lifetimes. A quick inspection of your property for any sinking or soft areas might be prudent. Unless the neighbor's sinkhole is very large and extends to your property, there’s likely to be little reason for concern.
Is there any way to have my property evaluated as to the risk of a sinkhole forming?
Professional geologists and geotechnical engineering consultants with professional geologists on staff can perform a variety of tests to attempt to locate buried cavities that might form sinkholes. These tests include ground-penetrating radar surveys, electrical resistivity tests, and borings. However, test results may be affected by the local geology and elevation of the water table, and are not always conclusive. And in many cases, the cost of a detailed survey is beyond the typical homeowner’s budget.
Where can I find available subsidence incident information for a specific area?
You can find this information in the Subsidence Incident Reports data located on the Florida Department of Environmental Protection's Map Direct website. Additional information can also be found on our Sinkhole FAQ page.
September 13, 2019 - 4:18pm
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The Florida Department of Environmental Protection is the state’s lead agency for environmental management and stewardship – protecting our air, water and land. The vision of the Florida Department of Environmental Protection is to create strong community partnerships, safeguard Florida’s natural resources and enhance its ecosystems.