From a recent Forbes article: http://www.forbes.com/sites/trevornace/2017/02/07/lake-tahoe-gained-8-7-billion-gallons-water-2-days/#6ce4630036c6
Lake Tahoe has had a great past few months, receiving 8.7 billion gallons of water in just two days. It hasn’t stopped there; the lake has been receiving tremendous amounts of water lately to fill the lake above its natural rim level.
The sudden rise in lake level is a result of several winter storms that hit the lake in late 2016 and early 2017. The National Weather Service calculated that since Jan. 1 of 2017 the lake has gained over 40 billion gallons of water. The stormy weather and heavy rains don’t appear to be slowing down with sequential blizzards hitting the region in almost weekly intervals.
NOAA calculated that in the two-day span from Dec. 9 through 11 Lake Tahoe gained 8,690,131,707 gallons of fresh water. The natural rim of Lake Tahoe is 6,223 feet and on Dec. 11 the height got up to 6,222.97 feet.
That’s the equivalent of filling 13,158 Olympic size swimming pools. It is early in the winter season for Lake Tahoe to gain so much water and a good sign for drought conditions in Nevada and Southern California this year.