Lake Tahoe clearing up?

Average annual clarity up from last year, still short of goal

The water of Lake Tahoe is the clearest it’s been in 10 years, analysis of 2012 recordings find.

Researchers from UC Davis tracked clarity in the lake with a white “Secchi disk” about the size of a dinner plate 22 times last year, finding the average depth at which the disk could be seen from the surface to be 75.3 feet, a 6.4-foot improvement over 2011, according to a UC Davis press release.

While runoff, pollution and sediment disturbance have diminished Lake Tahoe’s clarity in recent decades, the improvement is a step toward meeting the clarity-restoration target of 97.4 feet set by state and federal regulators.

Measurements have been taken since 1968, when the disk could be seen down to an average of 102.4 feet. In 1997 and 1998, average annual clarity in the lake reached an all-time low of 65.1 feet.