Lake Tahoe waters plummet as drought, climate change plague resort

Lake Tahoe’s water level has dropped so low that water is no longer flowing into the Truckee River and salmon aren’t expected to spawn in a major tributary this year.

Some boat ramps and docks are hundreds of feet from the water line, and clumps of stringy algae have been washing up on beaches, said Geoffrey Schladow, director of the UC Davis Tahoe Environmental Research Center.

“It’s putting us on warning that things could get a lot worse,” he said.

The receding water level, which is driven by climate change and drought, comes as the latest insult to the treasured tourist destination nestled in the Sierra Nevada. Already its waters have been clouded by smoke and ash from multiple wildfires this summer.

Lake Tahoe’s water level is always fluctuating. It is typically lowest in December and January and then increases in the spring as melting snow from nearby mountains flows down, Schladow said.

“This year, we didn’t get that bump,” he said. “It was more or less dropping since the previous year.”

Multiple boat ramps were unable to open for the summer season.

And with no game-changing precipitation, conditions have continued to worsen. The water level is usually somewhere between the lake’s natural rim, which sits at 6,223 feet, and a dam at the top of the Truckee River that is six feet higher, Schladow said. But earlier this week, it dropped just below the rim. By Saturday afternoon, the water level was roughly half an inch below the rim — and falling, according to preliminary data from the U.S. Geological Survey.

That’s because the lake each year loses about six feet of water from evaporation — a rate of about a quarter-inch a day, which can increase with high winds, Schladow said.

“If this next year is just an average year, or worse, a dry year, it probably means that the water level this time next year will be maybe something like four feet below the rim,” he said. “And if the next year is dry, it sort of continues.”

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The water last dropped below Lake Tahoe’s rim toward the end of the 2012-17 drought, which was followed by the region’s wettest year on record, Schladow said. These swings from dry to wet are nothing new.

“What is changing is that these periods of extreme low and extreme high water seem to be happening more and more frequently,” he said.

That comes as climate change is causing droughts to become drier, hotter and longer, and bursts of precipitation to become shorter and more intense, he said.

“One of the manifestations of climate change that all the models seem to agree on is that there will be more extremes,” he said. “Hot and cold, wet and dry.”

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