According to a new report from the UC Davis Tahoe Environmental Research Center, the lake's average water clarity in 2025 measured just over 69 feet. That's roughly seven feet better than the previous year. However, scientists say statistical analysis indicates the difference falls within normal year-to-year variation.
"It was not statistically different than last year, so when you look at all of the variation in those measurements, it's just not enough to say that it was actually a meaningful difference," said Stephanie Hampton, director of the research center.
Researchers have monitored Lake Tahoe's clarity since the late 1960s. After decades of decline, visibility levels stabilized in the late 1990s and have remained near 70 feet in recent years.
Scientists say tiny particles in the water continue to reduce visibility. To better understand the factors limiting clarity, researchers are launching a major study this summer focused on the particles present in the lake.
"A big research project this summer is to look at all sizes of sediments and phytoplankton in the water and try to understand how these different types of particles are affecting the water clarity," Hampton said.
Scientists hope that a better understanding of the particles clouding the water will help guide future management strategies aimed at returning the lake to its renowned clarity of nearly 100 feet.
