Hydrology of area 15, Eastern Coal province, Kentucky and Tennessee

Abstract

Area 15, in Eastern Kentucky and Tennessee consists of 3,095 square miles in the Cumberland, Rockcastle and Laurel River basins. The area is underlain by Permian, Pennsylvanian, Mississippian rocks. The Breathitt Formation of Pennsylvanian age crops out in about 75% of the area and contains most of the coal. About 22 million tons of coal were produced in the area in 1978, 52% from surface mines. The terrain is steep with acidic soils. Forestry and pastures are the principal land uses. Precipitation ranges from 47 to 54 inches per year, and the 24-hour 10-year frequency storm averages 4.5 inches. Flood prone areas along the rivers have been defined or can be determined from relations with drainage area and physiography. Low flows are poorly sustained, with most streams draining less than 100 square miles approaching a 7-day 10-year minimum flow of zero. Ground water is generally of good quality, although high iron concentrations are common. Sandstones are the principal aquifers. Water levels fluctuate seasonally, and yields of wells are usually less than 50 gallons per minute but range from about 1 to 250. Mine drainage affects the quality of streamflow at most sites in mined basins. Sulfate concentrations are as high as 1,000 milligrams per liter. Other constituents such as iron and manganese also occur in higher concentrations in waters of mined basins. Acid mine drainage generally is neutralized near its source. Most of the water in streams has pH values in the 7-8 range. (USGS)