“GROUNDBREAKING INKARSTABLE” INTERACTIONS: A CASE STUDY OF BERRY COLLEGE GROUNDWATER HYDROLOGY, SEASONALITY, AND SINKHOLE FORMATION

An important aspect of sinkhole formation, is the geologic substrate material and groundwater flow patterns that can influence sinkhole activity through the process of suffosion. Sections of limestone, rocks of carbonate composition, or material susceptible to dissolving as the groundwater circulates around these geological units, are indicators of a karst environment. By studying the local groundwater fluctuations and evaluating collected data with seasonality patterns, these hydrologic interactions can be correlated with sinkhole formation events. Situated in Rome, GA. 66.2 miles from Atlanta is Berry College (34.2904° N, 85.1892° W), the world’s largest college campus (27,000 acres). The northwest Georgia region in which Berry College is located, is prone to significant sinkhole activity due to the karst topography. The purpose of this study is to visualize groundwater data from the Berry College campus, to highlight significant seasonal patterns that correlate with sinkhole events, and to provide a baseline for future monitoring activities. In this project, we evaluate 9 representative monitoring well sites. Over 5-years (September 2014 through November 2017) the groundwater levels have been monitored weekly. Within an area of 3 km² all 9 well sites responded to changes in seasonal precipitation with water level data mimicking influxes of precipitation. In this study, we identified three high precipitation (> 120 mm) periods of rainfall (January 2-23, 2015, February 13-March 13, 2015, and February 16-April 6, 2017). Site comparison mapping of sinkhole formations show that areas of campus nearest to sites PZ 1, PZ 3, PZ 13, PZ 14A, and PZ 18 were the most affected post rainfall events. Identifying large fluctuations in groundwater levels (> 7 m) due to periods of rainfall episodes lasting (> 2 weeks) and inputs of precipitation (> 120 mm) maybe linked to sinkhole dissolution. Continual monitoring of the seasonal changes of groundwater levels is important to predicting campus safety hazards and sink hole collapse.