Drought Improves Tahoe's Clarity

The clarity of Lake Tahoe is 5-feet less than last year.

But researchers at UC Davis say such fluctuation is normal. In fact, clarity can vary 20 to 30 feet depending on where and when its measured. The long-term trend is that the lake’s clarity is remaining stabile. Geoffrey Schladow of the UC Davis Tahoe Environmental Research Center says one reason this year is the drought. Less rain means less runoff taking less pollution into the lake.

“And so I guess if we are looking for any bright sides to the drought, its the fact that it helps clarity.”

While the average year-round clarity is stabilizing, researchers say summer clarity continues to decline. A more in-depth assessment is expected in the State of the Lake Report due out in August. It will include data from a new storm water monitoring system installed last year to help researchers determine if restoration efforts are working.

Schladow says, rather than previous steep declines, the lake’s clarity continues to hover between 64 and 78 feet, as it has for the past 15 years.

“I think in large part that is a reflection of the activities and the investment and it has taken a lot of money to achieve this. It has taken a lot of money from the federal government, state government and even private funding.”

Conservation groups say continued funding to improve the lake’s clarity is dependent on congressional approval of the $415 million Lake Tahoe Restoration Act. It passed the Senate in early February, but it is not yet scheduled for a vote in the House.