Hydraulics of sheetlike solution cavities

The sheetlike solution cavities that supply water to most wells in central Tennessee are 100 to 2,500 feet wide and less than 0.2 inch high. These dimensions have a scale similar to those in Hele-Shaw models. Both logical and mathematical evidence indicate laminar ground-water flow, except close to pumping wells. The Theis nonequilibrium formula may be used to analyze aquifer-test data and to calculate significant values for transmissivity and storage. The Navier-Stokes equation and the Darcy equation for steady-state conditions may be used to estimate cavity dimensions.