EFFECT OF DEVELOPMENT ON COVE SEDIMENTATION IN LAKE WYLIE, NC

Increased sedimentation has become a major problem along coves in Lake Wylie, North Carolina. Some amount of cove sedimentation is natural, but upstream development increases the rate at which this occurs and ultimately shortens the reservoir lifespan and decreases lakefront property values. Development creates impervious surfaces that lead to increased erosion of the landscape and resultant downstream sedimentation rates. This study aims to better understand the relationship between upstream development and downstream cove sedimentation rates by comparing sedimentation in four different coves along Lake Wylie. We observed two undeveloped coves (<10% imperviousness) and two developed coves (>20% imperviousness) to better understand this relationship. The Livingstone coring system was implemented to obtain cores that we tested for sand content, organic content, and magnetic susceptibility. A galvanized probe was also used to measure total sediment and water depth. We found that greater development is associated with a higher sedimentation rate, a greater frequency of sand pulses, and a greater volume of sand on the delta. Specifically, the developed coves had higher sedimentation rates (1.8 - 2cm/year) and higher sediment volumes when normalized by basin area (6.1 - 6.9cm) when compared with undeveloped coves (1.2 - 1.5cm/year; 1.3 - 1.4cm). These results indicate that ongoing development will significantly impact the lifespan of the reservoir. As land use continues to change towards increased impervious surface coverage, it will be important for governmental organizations to consider the downstream effects of development and work to minimize soil erosion associated with development.