Sinkholes in Florida

Sinkholes are common in Florida due to the state’s unique geological makeup. Florida has more sinkholes than any other state in the U.S. Sinkholes can cause a lot of problems in Florida, but overtime they can also become beautiful additions to the landscape. Many parks and springs sit on the site of sinkholes that have been around for hundreds of years.

What Causes Sinkholes?

Sinkholes occur when part of the underground aquifer erodes or contains voids. When these voids are filled with water, the ground above is usually supported. If the water table drops, these voids become weekend and can collapse, most commonly when the surface becomes saturated and too heavy to be supported by the void. The main causes include:

Natural Processes:

  • Rainwater, which is slightly acidic, erodes limestone over time.
  • Fluctuating water levels weaken underground support.

Human Activities:

  • Excessive groundwater pumping for drinking water and irrigation can drain underground support.
  • Construction and land development add weight and disturb natural drainage.
  • Leaky sewer lines and stormwater runoff accelerate erosion.

Types of Sinkholes

Cover-Collapse Sinkholes (Most dramatic)

  • Form suddenly when the surface layer caves in.
  • Can cause property damage and road collapses.

Cover-Subsidence Sinkholes

  • Form gradually as the ground slowly sinks over time.
  • Often go unnoticed until structures develop cracks.

Dissolution Sinkholes

  • Occur when water dissolves limestone at the surface.
  • Often found in lakes and wetland areas.

Where Do Sinkholes Happen in Florida?

Florida has more sinkholes than any other state. Sinkholes are most common in Central Florida, especially in the region known as “Sinkhole Alley”, which includes:

  • Hillsborough County (Tampa area)

  • Pasco County

  • Hernando County

  • Marion County (Ocala area)

  • Polk County (Lakeland area)

Other high-risk areas include Gainesville, Orlando, and Tallahassee. In 1981, a sinkhole in Winter Park (Orlando area) 10 stories deep swallowed a house, cars and businesses. Most sinkholes are not that big. The Florida Department of Environmental Protection has created a map for residents that shows the of areas in Florida most prone to sinkholes or where sinkholes actually exist.

Signs of a Developing Sinkhole

  • Cracks in walls, floors, or foundations

  • Doors and windows that won’t close properly

  • Depressions or soft spots in the yard

  • Sudden appearance of ponds or standing water

  • Tilting fences, trees, or poles

How Dangerous Are Sinkholes?

  • Some sinkholes are small and harmless, while others can swallow entire buildings and roads.

  • The 2013 Seffner Sinkhole near Tampa tragically killed a man when his home collapsed.

  • Many sinkholes appear in open land and cause minimal damage.

Can Sinkholes Be Prevented?

  • Regular property inspections (especially in high-risk areas)

  • Reducing water use to prevent underground erosion

  • Proper drainage systems to prevent excessive water from weakening the ground

  • Grouting (injecting concrete-like material into underground voids) to stabilize weak ground