SINKHOLES IN ALABAMA
the most common causes of land subsidence are the development of sinkholes
in areas underlain by soluble carbonate rocks or ground collapse above
abandoned mines. Many areas of the state, particularly
are underlain by carbonate rocks, such as limestone, that are susceptible
to dissolution and the formation of caves and sinkholes.
Click the above map to see
Sinkhole Data and
To explore sinkholes in your area, refer to the
interactive map below. The points on
this map represent topographic depression features on historical
1:24,000-scale topographic maps. While most of the topographic depressions are related to sinkholes, some may also be related to
Because the topographic maps were
published in the 1970s, more sinkholes may have developed since
then. Please note that this interactive map is for educational use only and
is not meant for use for site-specific
evaluations. Click here for sinkhole
GIS data and metadata associated with the interactive map below.
Not all web browsers or connection speeds support the below
interactive map. If you do not see the map below, click here.
EXAMPLES OF KARST IN ALABAMA
Sinks area of Morgan
County on the Newsome
Sinks 1:24,000 quadrangle map overlain with 2006
Largest Karst Topographic Area in Alabama
The topography of northern Alabama is dappled with sinkholes,
springs, and cave openings – all features of what is
referred to as karst topography. Of particular interest is the
Newsome Sinks area in Morgan
County. This topography is comprised of coalescing sinkholes and
represents the longest karst topographic feature in the state – a little
over 4 miles long! This area is underlain
by the Mississippian age Bangor Limestone.
Newsome Sinks area of Morgan County
on a 1:100,000 topographic map overlain with
geology. Blue areas are Bangor Limestone.
Newsome Sinks area and much of northeastern Alabama is part of the
Tennessee-Alabama-Georgia karst area that cavers call TAG. Click
here to see some amazing TAG photos and read a National Geographic
article featuring this karst area.
Largest Sinkhole in Alabama
The largest sinkhole in Alabama
developed near Calera in Shelby
County in December
1972 and has been called the “Golly Hole.” A local
resident heard what sounded like trees crashing during the night. The
following day, hunters in the area discovered a large sinkhole - about 325
feet long, 300 feet wide (roughly a football field length across!), and 120
feet deep. This sinkhole occurred during a drought when the water table was
much lower than normal.
This particular area of Shelby County
has had a history of sinkhole development and is
underlain by soft limestones. Previous research indicates hundreds of
historical collapse features within a 16- square-mile area (Warren and Wielchowsky, 1973). Most of these historical and recent
sinkholes are within the Dry
Valley which is underlain with deeply weathered Cambrian
dolomites of the Knox Group.
“Golly Hole” in Shelby County as shown on aerial imagery (left), the
1:24,000 Alabaster topographic map (middle), and photo from the ground (photo by Tom Stone).
To read more on the Golly Hole and its related
geology, see the below references:
LaMoreaux, P.E. and Warren, W.M.,
1973, Sinkhole: Geotimes. v. 18, no. 3, p. 15.
Warren, W.M. and Wielchowsky,
C.C., 1973, Aerial remote sensing of carbonate terranes
in Shelby County, Alabama: Groundwater, v. 11, no. 6, p. 14-26.
To download geology shapefiles for the Alabaster Quadrangle
geologic map, click here.
SINKHOLES NEAR YOU – WHAT YOU SHOULD DO
depression (like a sinkhole) can be caused by a variety of geologic and non-geologic issues including
drainage, abandoned water wells, buried construction material, septic tank collapse,
water or sewer line leaks, as well as other area-specific issues.
What to do or who to call may depend on the cause of the
depression. Below are some actions to consider
when dealing with a depression on your property:
1. Put up a barrier (caution
tape, rope, other) surrounding the hole for safety and liability purposes.
2. Contact your property or
homeowner's insurance company.
3. Consider contacting a
geologist, geotechnical or civil engineer, or foundation repair specialist
to assess the situation further.
4. If the sinkhole is affecting public safety or
public property (parks/sidewalks/etc.) or may be related
to city/county water/sewer drainage, consider contacting the city or county
engineer's office. Please note response capabilities vary from county to
5. If the sinkhole is affecting a public road, contact
the Department of Transportation.
Home affected by developing sinkhole in the Birmingham area.
* Due to budgetary
and staffing constraints, GSA does not perform site visits to evaluate
sinkholes. GSA also does not mitigate or repair sinkholes.
ASPECTS OF SINKHOLES IN ALABAMA
Did you know that sinkholes are
protected in Alabama?
Because sinkholes are a direct conduit to the groundwater, any contaminants
dumped into a sinkhole may end up in the groundwater. About 40% of public
water supplies in Alabama are from
ground-water sources and 27 south Alabama
counties receive all of their public water supplies from ground-water
sources. Since much of Alabama
gets their water from groundwater resources, it is important to protect the
groundwater quality, and therefore sinkholes too. The below information
lists some of the regulations related to karst, caves, and sinkholes in the
state of Alabama.
Specifically, the Alabama Cave Protection Law of
1988 states that “It shall be
unlawful and constitute a misdemeanor for any person, organization, firm,
corporation, including any officer, employee or agent of any town or
municipality to risk the pollution of the underground water resources of
the state by storing, dumping, disposing, or otherwise placing in caves,
sinkholes or natural wells: chemicals, refuse, dead animals, garbage or
other materials which are potentially injurious or hazardous to the
quality of the aquifer, water and/or water table.” Alabama Cave
Protection Law (1988), (Acts 1988, No. 88-582, p. 909, §4.), Section
here to go to the Alabama Legislative Information System Online to
read the full text.
regulations from the Alabama State Board of Health’s Division of
Community Environmental Protection relate to onsite sewage treatment and
disposal with respect to sinkholes and planning:
Administrative Code Chapter 420-3-1.