This dissolved mineral concern has passed with the flushing that took place during the floods of 1991-1992. Historically, algae growth has been limited, and not much of a concern. This segment also has a possible concern for fecal coliform bacteria, and does not support the designated contact recreation use. This subwatershed lies within the Texas Hill Country characterized by steep hills with cedar-covered slopes. Sources of these salt constituents are unknown at this time.
Nutrients are also a possible concern for each segment.
In addition to these concerns, Sandy Creek has a possible concern for dissolved oxygen, the cause of which has not been determined at this time. The Llano Uplift, a unique geological formation, may contribute to the elevated metal measurements. The remaining segments within the watershed show a possible concern for all salt constituents. This subwatershed is impacted by highly saline overflows from Natural Dam Lake in 1987. Heavy rains and flooding that occurred in 1991-1992 throughout the basin flushed these saline waters from the watershed.