The Columbus study area is in part of a glacial outwash sand and gravel aquifer that was deposited in a preglacial bedrock valley. The study area extends from the north line of Bartholomew County to the south county line and includes a small part of Jackson County south of Sand Creek and east of the East Fork White River. This report area includes about 100 square miles of the aquifer.
In the Columbus area, ground water in the outwash aquifer is unconfined. Results of pumping tests and estimates derived from specific-capacity data indicate that the average horizontal permeability for this aquifer is about 3,500 gallons per day per square foot. An average coefficient of storage of about 0.2 was determined from pumping tests. Transmissibilities range from near zero in some places along the boundary to about 500,000 gallons per day per foot in the thicker parts of the aquifer. About 800,000 acre-feet of water is in storage in the aquifer. This storage is equivalent to an average yield of 34 million gallons per day for about 21 years without recharge.
An electrical-analog model was built to analyze the aquifer system and determine the effects of development. Analysis of the model indicates that there is more than enough water to meet the estimated needs of the city of Columbus without seriously depleting the aquifer. Additional withdrawals will affect the flow in the Flatrock River, but if the withdrawals are made south of the city, they will not affect the river any more than present pumping. Future pumping should be confined to the deepest part of the outwash aquifer and (or) to the area adjacent to the streams.
On the basis of an hypothesized amount and distribution of pumping, the decline in water levels in the Columbus area as predicted by the model for the period 1970-2015 ranged from about 20 feet in the center of the areas of pumping to 3 feet or less in the areas upstream and downstream from these areas of pumping.
Additional Publication Details
USGS Numbered Series
Electrical-analog-model study of water resources of the Columbus area, Bartholomew County, Indiana