Sinkhole Risk in Fort Lauderdale, Florida

No official sinkhole risk map covers Fort Lauderdale, because the Florida Geological Survey says there is no ready reference on sinkhole prediction or risk assessment (FGS Sinkhole FAQ).

The survey explains why: underground cavities are largely undetectable without expensive geophysical surveys or test drilling, so little progress has been made on predicting where a sinkhole will open. At least one geotechnical company has built a fee-based risk assessment registry from a private database of known sinkholes and local geologic conditions, and some Florida insurers use it to help determine sinkhole risk in specific areas, so an insurer's sinkhole-area label on a Fort Lauderdale street can come from a private registry rather than a state map (Florida Geological Survey).

That is not the same as zero risk. The FGS says the entire state is underlain by carbonate rock, so sinkholes could in theory form anywhere, while sinkhole activity is higher where limestone is close to the surface or where deeper limestone has a conducive configuration of water table elevation, stratigraphy and aquifer characteristics (FGS Sinkhole FAQ). The Broward County record count in the state database follows in the next section.

The state subsidence database lists 10 reports in Broward County out of 4,457 statewide on October 18, 2026, and two of them list Ft. Lauderdale in the Owner's City field (FGS subsidence layer, Broward records).

The statewide total comes from the same Florida Geological Survey layer, published on the Florida DEP open data server (FGS layer, statewide count). The layer defines the Verified Sinkhole field (TRUE_SINK) with the codes Y for Yes, N for No and U for Unknown, and gives width and depth in feet (FGS subsidence layer fields). Only one Broward record carries Y: a query for Broward events on August 15, 1988 returns that single record, with Ft. Lauderdale as the owner's city, 22.0 feet wide and 3.5 feet deep (FGS layer, August 15, 1988 query). The other record listing Ft. Lauderdale as owner's city, dated June 24, 2016, was 2.0 feet wide and 1.0 foot deep and carries U (FGS layer).

Broward's count is small next to the counties with the most records. Hillsborough County alone has 618 records, Marion 489 and Citrus 450, while Palm Beach has 12, Broward 10, Dade 4 and Monroe 1 (FGS layer, count by county). The FGS notes that reported incidents cluster in populated areas where they are readily seen and often affect roads and homes, and that the database presents only those incidents reported by observers, so the Broward count reflects what people reported, not a survey of the ground (FGS Sinkhole FAQ).

At Fort Lauderdale the U.S. Geological Survey says the Anastasia Formation makes up much of the Biscayne aquifer and the Pamlico Sand is the surficial unit (USGS Ground Water Atlas HA 730-G).

The USGS atlas says the Biscayne aquifer is the principal water source for Dade and Broward Counties, that the Anastasia Formation makes up much of the aquifer at Fort Lauderdale and northward, and that the whole aquifer is sandier in its northern and eastern parts, with more limestone and calcareous sandstone to the south and west. The same atlas notes that at Fort Lauderdale the Tamiami Formation is a productive aquifer where it consists of calcareous sandstone, with most of the water obtained from solution cavities in the sandstone (USGS).

The Florida Geological Survey ties sinkhole type to that kind of cover. Solution sinkholes form where little or no sediment covers the limestone; cover-subsidence sinkholes form where thick permeable sediments cover the limestone, and the ground surface often shows a gentle circular dip; where a relatively thick layer of impermeable sediments covers the limestone, a subsurface collapse may have no surface expression; and cover-collapse sinkholes open when sediments over a void suddenly collapse (FGS Sinkhole FAQ). Neither agency ranks Fort Lauderdale by type, and the state records above are the only Broward-specific count.

A sunken spot in a Fort Lauderdale yard or street is not a proven sinkhole until it is verified, because the Florida Geological Survey calls a sunken spot not verified as a true sinkhole a subsidence incident (FGS Sinkholes).

The survey lists the usual impostors: subsurface expansive clay or organic layers that compress as water is removed, collapsed or broken sewer and drain pipes, broken septic tanks, improperly compacted soil after excavation work, and buried trash, logs and other debris (Florida Geological Survey). Any of those can open a sunken spot in a Fort Lauderdale lawn or roadway that looks like a sinkhole until a licensed professional geologist or engineer verifies it.

The Broward records reflect that uncertainty: nine of the ten carry an unknown flag. The FGS says most of its database has not been field-checked, that a majority of records come from the State Watch Office, the clearinghouse for emergency response calls, and that there was never a legal requirement to report sinkholes or sinkhole insurance claims to it (FGS Subsidence Incident Reports). A Fort Lauderdale hole that was repaired and never reported will not appear in the count at all.

A non-emergency hole in a Fort Lauderdale city street is reported to FixIt FTL at 954-828-8000, through the free FixIt FTL app or on the city map form (City of Fort Lauderdale FixIt FTL).

FixIt FTL is the city system for non-emergency issues such as potholes and flooding. Where there is a risk of physical harm, Florida DEP says to call the local law enforcement agency (Florida DEP), and a sinkhole on private property is the responsibility of the property owner, according to the FGS (FGS Sinkhole FAQ).

For a street hole, the Florida Geological Survey says it should be cordoned off and marked to protect traffic, local law enforcement should be told, and the city or county road department called to start repairs; a private road is usually the landowner's or association's job (FGS Sinkhole FAQ). FixIt FTL requests are reviewed by the appropriate city department, and the work is assigned and scheduled, and status updates go to anyone who leaves an email address (FixIt FTL).

No agency inspects private sinkholes in Florida. The Department of Environmental Protection says it does not inspect possible sinkholes, and the FGS runs a Sinkhole Helpline at 850-245-2118 that provides verbal guidance relating to a sinkhole situation (Florida DEP). The FGS FAQ adds that home inspectors and insurance adjusters are not trained to decide whether sinkhole activity is present; licensed professional geologists or engineers are (FGS). A Fort Lauderdale owner can also file an FGS subsidence incident report so the event enters the state record.

Every insurer authorized to transact property insurance in Florida, Fort Lauderdale homes included, must cover a catastrophic ground cover collapse, while sinkhole loss coverage must be made available for an appropriate additional premium under section 627.706 of the Florida Statutes (Florida Statutes 627.706).

The statute sets a narrow test for the mandatory coverage. A catastrophic ground cover collapse needs all four of these: an abrupt collapse of the ground cover, a sunken area in the ground cover clearly visible to the naked eye, structural damage to the covered building including its foundation, and the insured structure being condemned and ordered to be vacated by the governmental agency authorized by law to issue such an order (Florida Statutes). The statute adds that damage consisting merely of the settling or cracking of a foundation, structure or building does not constitute a loss resulting from a catastrophic ground cover collapse.

A residential policy on a Fort Lauderdale home may include a sinkhole loss deductible of 1, 2, 5 or 10 percent of the policy dwelling limits, with appropriate premium discounts offered with each, the insurer may require an inspection before issuing sinkhole loss coverage, and it may restrict both coverages to the principal building (section 627.706). For insurance questions involving sinkhole claims, the FGS points to the Florida Department of Financial Services Division of Consumer Services (FGS Sinkholes).

Last verified: October 18, 2026, by re-running the Broward County and statewide queries on the FGS subsidence layer and re-reading the FGS, USGS, Florida Statutes and City of Fort Lauderdale pages cited here.