The last 30 years of urbanization around Lake Tahoe has caused as high a sedimentation rate as the clear-cut logging of the late 1800, which removed timber from more than 60 % of the basin, according to a report by graduate student Alan Heyvaert and his colleagues in the UC Davis Lake Tahoe Research Group.

Over the last three decades, population of the lake basin has increased tenfold, while the water clarity has been declining about 1.5 feet per year.

The study also revealed a period of recovery by the lake and basin in the early 1900s, as well as evidence that the famous Sierra Nevada lake was able to respond to the forest restoration in the basin after logging was complete. These early results of sediment core studies from the bottom of the lake suggest that plans to control erosion are on the right track, says co-author John Reuter, a UC Davis researcher and director of the Lake Tahoe Interagency Monitoring Program. The sediment cores, analogous to tree rings, also provide a way of measuring the effectiveness of such efforts.