Kinney pool: Defining the western boundary of the Edwards (Balcones Fault Zone) Aquifer, Texas

Abstract

The western boundary of the San Antonio segment of the Edwards (Balcones Fault Zone) Aquifer has been historically mapped to extend to a groundwater divide thought to be near Brackettville in Kinney County, Texas. A revised conceptualization is developed here that contends the Edwards Aquifer forms a separate pool in Kinney County, referred to as the Kinney Pool, which extends from a groundwater divide located between Mud Spring and Pinto Spring on the west to an effective structural, hydraulic barrier near the Kinney-Uvalde County line. The barrier is a result of dewatering of the permeable portion of the Edwards Aquifer in eastern Kinney County. No groundwater flow in the Edwards Aquifer from Kinney County to Uvalde County is expected during periods of low to average groundwater elevation, but limited flow from west to east could be possible during periods when groundwater elevations are high. Natural discharge from the Kinney Pool occurs as spring discharge and underflow through floodplains at the southern (downdip) boundary of the segment.