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 north Alabama, 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 details.
Data and Maps
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 mine subsidence.
Because the topographic maps were published
in the 1930s-1980s, 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.
KARST IN ALABAMA
Newsome Sinks area of Morgan County on the Newsome
Sinks 1:24,000 quadrangle map overlain with 2006 aerial imagery.
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
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
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.
The “Golly Hole” in Shelby County as shown on aerial imagery
(left), the 1:24,000 Alabaster topographic map (middle), and photo from the
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
ground 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.
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
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
Due to budgetary and staffing constraints, GSA does not perform site visits
to evaluate sinkholes. GSA also does not mitigate or repair sinkholes.
LEGAL ASPECTS OF SINKHOLES IN ALABAMA
Did you know that sinkholes are protected
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.
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 9-19-4. Click
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:
Code Chapter 420-3-1.