Ground-water potential of the glacial deposits near Logansport, Cass County, Indiana

The glacial deposits underlying a 260-square-mile area near Logansport, Indiana, range in thickness from 0 to 300 feet and consist of three semiconfined sand and gravel aquifer units separated and overlain by three semiconfining till units. The ground-water development potential of the two uppermost aquifers , whose thicknesses average about 20 feet each, is limited to domestic usage. However, a sand and gravel aquifer (0 to 120 feet in thickness) filling the bottom of the buried, preglacial Teays Valley probably has considerable development potential. Maximum and average transmissivities of the aquifer are about 38 ,000 and 13,000 square feet per day, respectively. The natural ground-water-flow system has not been significantly altered by development. Model simulation of the present system demonstrates that most of the water flowing through the glacial deposits originates within the study area as infiltrating precipitation and discharges locally into the major streams. Results of simulation of a withdrawal of 10 million gallons per day from the lower sand and gravel aquifer indicate an absence of hydrologic constraints to development of the quantities of ground water simulated in the model. However, model simulations of water-level declines of as much as 35 feet in the lower aquifer and 20 feet in the upper aquifer indicate that interference with the operation of domestic wells is likely. Model results also indicate that ground-water development similar to that simulated may cause streamflow to be reduced by only a small percentage.