Groundwater Availability
 

Alluvium (Qa)
Topography
Alluvium forms terraces and floodplains along the Green River and tributaries.

Hydrology
Most wells in the alluvium furnish less than 100 gallons per day, inadequate for a domestic supply.

Ste. Genevieve Limestone (Mgl)
Topography
The Ste. Genevieve Limestone underlies rolling karst areas. It forms steep bluffs near the Green River.

Hydrology
This limestone yields more than 50 gallons per minute to wells from large solution openings in karst areas. Most wells penetrate solution openings, but in areas high above perennial streams, these solution openings are dry in late summer and fall, and many wells are inadequate. Wells that do not intersect karst conduits generally are inadequate for domestic use. Major caverns in the Ste. Genevieve in the Mammoth Cave area have large, connected subsurface streams. Springs having low flows ranging from less than 10 gallons per minute to more than 1,500 gallons per minute occur at or near stream level or near contact with the underlying St. Louis Limestone. Smaller springs discharge from perched water bodies in upland areas, but many go dry during late summer and fall.

St. Louis Limestone (Mgl)
Topography
The St. Louis Limestone underlies rolling karst areas. It commonly has less relief than karst in areas underlain by the Ste. Genevieve Limestone, but sinkholes in the St. Louis are steeper.

Hydrology
This limestone yields more than 50 gallons per minute to wells from large openings in karst areas. Most wells penetrate some solution openings, but in high areas above perennial streams yields are often inadequate for domestic supply. Yields of wells near major streams are large where solution openings are penetrated, but most wells near major streams are inadequate. Many springs in the major spring horizon have flows of several hundred to several thousand gallons a minute, and are used for public and industrial water supplies.

Salem, Warsaw, Harrodsburg Formations (Msh)
Topography
These formations underlie gently rolling uplands. They form steep bluffs where the limestone overlies rocks of Osagean age. In some areas numerous small sinkholes occur in the Warsaw.

Hydrology
These rocks yield enough water for a domestic supply where the formations are dominantly limestone and near perennial stream level. Yields are low where siltstone or argillaceous limestone is penetrated. A minor spring horizon occurs at the contact of the limestone with the underlying siltstone or argillaceous limestone. Another spring horizon occurs near the contact of the Warsaw and Fort Payne. Low flows generally are less than 5 gallons per minute.

Fort Payne Formation (Mbf), limestone bodies within Fort Payne (ls), Knifley Sandstone Member (Mfk)
Topography
These rock bodies underlie dissected rolling uplands. They form steep valley sides in maturely dissected topography. Small valleys are steep and V-shaped. Siltstone and chert form discontinuous ledges on hillsides.

Hydrology
Wells in lowland areas near streams produce enough water for a domestic supply and may produce more than 5 gallons per minute from solution openings. Most wells obtain water from perched or semiperched water bodies supported by discontinuous shale layers, and many are dry during late summer and fall. Minor spring horizons occur throughout the formation. Flows are as much as 30 gallons per minute, but most go dry in late summer or fall. Where shale layers are conspicuous or where the formation consists predominantly of siltstone, most wells are inadequate for domestic use (less than 100 gallons per day). Where chert layers are thick and extensive, yields of more than 5 gallons per minute may be obtained.

Borden Formation (Muldraugh (Mbf), Halls Gap, and Nancy Members (MDbb))
Topography
These rock formations underlie moderately to highly dissected rolling uplands. They form erosional remnants or knobs along the Cumberland Escarpment. Steep bluffs form along rivers.

Hydrology
Wells in lowland areas near streams produce enough water for a domestic supply. Most wells obtain water from perched or semiperched water bodies supported by discontinuous shale layers, and many are dry during late summer and fall. Minor spring horizons occur throughout the formations. Flows are as much as 30 gallons per minute, but most go dry in late summer and fall. Where the formation consists predominantly of siltstone, most wells are inadequate for domestic use.

Borden Formation (New Providence Shale Member) (MDbb)
Topography
The New Providence Shale forms moderate to steep slopes near the base of the Cumberland Escarpment and in areas of knobs (small, round hills).

Hydrology
This shale yields little or no water to wells.

Chattanooga Shale (MDnb)
Topography
The Chattanooga Shale forms steep slopes near the base of the Cumberland Escarpment and in areas of knobs. It underlies knobs near the base of the escarpment. The shale forms the lower part of steep valley sides and steep slopes of tributary streams. Resistant layers form small discontinuous ledges and minor waterfalls in streams.

Hydrology
This shale yields little or no water to wells. Seepage springs are present at numerous horizons, but most go dry during late summer and fall.

Boyle Dolomite (MDnb)
Topography
The Boyle Dolomite forms resistant ledges on valley sides between shale slopes above and below.

Hydrology
The dolomite yields water to many small perennial springs, but almost no water to drilled wells. Water is hard but otherwise of good quality.

Cumberland Formation, Leipers Limestone, Catheys Formation (Ocl)
Topography
These rock bodies form moderate to steep slopes and bluffs near the Cumberland River. Limestone layers, interbedded with shales, form discontinuous ledges along hillsides in some areas.

Hydrology
In lowland areas bordering large streams, yields are enough for a domestic supply (more than 500 gallons per day). Elsewhere these rocks yield little water to wells, but small quantities of water to springs. Deep wells generally yield sulfurous water or brines.

The U.S. Geological Survey's Hydrologic Atlas Series, published cooperatively with the Kentucky Geological Survey, provides hydrologic information for the entire state.

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