About the Black Hills Aquifer Maps Project
Four different types of maps are being developed for this project. These four maps are developed for each aquifer unit that occurs in the quadrangle.
Depth to Aquifer Map
A Depth to Formation map shows the depth of the top of the aquifer below the earth's surface. It gives the estimated depth that one would need to drill to hit the aquifer. These depths are approximate only, with uncertainties of 50-100 feet or higher. (
Structure Contour Map
A Structure Contour map shows the elevation of the surface of the aquifer relative to sea level. It is like a topo map of the top of the aquifer, and allows you to see geologic structures such as folds or faults.
An Aquifer Susceptibility map reflects the innate ability of an aquifer to transmit water and contaminants from the surface into the aquifer, based on the rock type and other properties such as fracturing and porosity. (
An Aquifer Vulnerability map highlights sensitive regions where aquifers are at especial risk due to their susceptability and the potential for manmade hazards such as faulty septic systems or contaminent spills. (