The low level of Lake Tahoe makes it clear these are dry times, despite a wet summer and early snowstorms.
Evaporation caused Tahoe to drop below its natural level by several hundredths of a foot late last week. Once the lake goes below its rim, water no longer flows into the Truckee River.
The rim, at 6,223 feet, was a level selected when the dam was constructed at Tahoe City. It allows officials to legally store and release a little more 6 feet worth of water.
Enough water is now stored at places such as Donner Lake and Boca Reservoir to feed the Truckee River through about Dec. 3. If there is no precipitation before then, the river's flow will decrease dramatically.
"Pray for snow," advised federal Water Master Garry Stone. "Storms make all the difference in the world."
Farmers use the Truckee for irrigation, but the growing season is over. Low flow could negatively impact populations of fish, Stone said.
The Truckee River feeds Pyramid Lake, an important habitat for fish. Decreased flow to the lake will be supplemented by water released from Stampede Reservoir, Stone said.
The lake fell below the rim for a few hours last November, but snow arrived the same day and raised it back above the rim. The last time the lake dropped below the rim for more than a few hours was March 1995, according to Gary Barbato, hydrologist at the National Weather Service in Reno.
Tahoe reached its lowest recorded level - 6,220.26 feet - in November 1992. Its highest recorded level - 6,231.26 feet - occurred in July 1907.