Sinkholes in Anderson County, TN
Anderson County’s landscape is full of hidden sinkholes. These are formed by dissolving bedrock. Surveys show many depressions in valleys and ridges, unlike the stable sandstone of the Cumberland Mountains.
Researchers use USGS models and ground surveys to map these areas. They find patterns that are not seen by the naked eye.
Traditional maps show 625 surface features. But, advanced models find 239 significant depressions over 10 feet deep. The deepest sinkhole is over 67 feet deep, found at 36°07’15″N 84°11’45″W.
LiDAR technology reveals small elevation changes. It helps find karst hazards even under thick vegetation.
This study uses data from verified geological inventories. It ensures the accuracy of risk assessments. Sinkholes in valleys often follow groundwater paths, while ridges show older, filled-in collapses.
This knowledge is key for planning and managing the county’s diverse terrain.
Recent & Notable Sinkhole Incidents / Case Studies
Between 2004 and 2024, two sinkhole events in Anderson County showed how our understanding of the earth has grown. The first was near 36.147386,-84.109287. It was a 68-foot-deep collapse in 2004. Scientists found it had a volume of 158,921 cubic meters, like 42 Olympic swimming pools.
They have been watching it closely. They noticed that sediment was slowly building up over time.
In 2013, a survey on Eli Nine Trail found nine active sinkholes. This was surprising because the USGS maps didn’t show them. This led to new models for groundwater.
- These models showed limestone dissolving 23% faster than before.
- They found that road salt causes erosion underground.
- They also saw the water table change by over 18 feet with the seasons.
The Tennessee Department of Transportation studied karst in 2008. This study helped set new rules for building and emergency plans. It also helped find where to watch the groundwater closely.
- New building codes for deeper foundations were made.
- Plans for handling road collapses were set up.
- Areas for watching the groundwater were found.
In 2017, new LiDAR systems were used. They found 47 hidden voids with 94% accuracy. This technology helps predict where sinkholes might happen next. It’s especially useful along Interstate 75, where traffic makes the ground shake more.
Risk Factors & What Homeowners Should Do
Geological composition plays a big role in sinkhole risks in Anderson County, TN. Areas with Knox Group dolomite are more at risk than those with Chattanooga shale bedrock. The Tennessee Geological Survey puts these areas into three risk levels, with dolomite-rich zones needing extra attention.
Homeowners should get professional karst surveys done. These follow ASTM D5717-95 standards. They use ground-penetrating radar and soil analysis to find subsurface problems.
Drainage pattern checks help too. They use Cookeville’s 2009 floodplain model to guide water away from unstable areas. Regular checks for subsidence, as TDEC suggests, can spot early signs like foundation cracks or water pooling.
Insurance in Anderson County might not cover sinkhole damage without special endorsements. It’s important for property owners to check their policies. They might need to get extra coverage from licensed providers. For more information, look at the interactive sinkhole map for East Tennessee.
To stay safe, keep gutters clean and check plumbing systems often. Avoid too much water near your foundation. The Tennessee Department of Environment and Conservation offers free resources to help manage groundwater and prevent erosion.
Getting annual geological consultations is key for properties in high-risk areas. County GIS mapping tools can help identify these zones.
FAQ
Why is Anderson County particularly prone to sinkhole formation?
Anderson County’s geology is in the Knox Group dolomite formation. This rock is prone to dissolving. Over 625 sinkholes have been found, mostly in areas where water flows fast.
How do professionals verify sinkholes in Anderson County?
First, they look at USGS topographic maps. Then, they use Digital Elevation Models to check for sinkholes. LiDAR technology has improved since 2017, making it easier to find sinkholes.
What are the deepest recorded sinkholes in Anderson County?
The deepest sinkhole is 68 feet deep. It was found in 2004. It’s still being watched by TDEC.
How does Chattanooga shale affect sinkhole risks compared to dolomite areas?
TDOT’s 2008 study shows different risks. Dolomite areas are at High Risk. Chattanooga shale is at Low Risk. This is because Chattanooga shale blocks water better than dolomite.
What mitigation steps are required for home construction in high-risk zones?
Three steps are needed. First, a karst survey must be done. Then, a drainage analysis is done. Finally, the area is monitored every year. Insurance must also cover karst collapse.
How did LiDAR technology change sinkhole mapping accuracy?
Before 2017, many sinkholes were missed. LiDAR now finds 78% more sinkholes. It can even spot small changes in the ground.
Where can residents access official sinkhole risk maps?
The Tennessee Geological Survey has maps. They are updated with 2022 LiDAR data. You can see them online through the TNMap portal.
