Spatial and Temporal Variability of Near-Shore Clarity in an Alpine Lake

Spatial and temporal variability in localized near-shore locations of Lake Tahoe, CA/NV was investigated using turbidity and light attenuation measurements. Between 2001 and 2003, several areas were identified as turbidity hotspots and chosen for further study. The effects of storms, high winds, snowmelt runoff, and calm conditions on clarity were monitored at these areas. Data was continuously collected at a depth of one meter and displayed in real time. A comparison of the spatially plotted results shows an increase in turbidity after storms and during runoff events concentrated around the Upper Truckee River, Bijou Creek, and Edgewood Creek. Turbidity values ranged from 0.17 ntu in unaffected areas to up to 20 ntu in the most concentrated sections of the plume. In addition to the turbidity measurements, particle analysis was undertaken on water from three areas adjacent streams and from a distance of two kilometers off the mouth of the Upper Truckee River. Particles collected on a 0.1 micron filter