The pristine blue waters of Lake Tahoe were murkier last year and researchers say a lack of mountain snow was likely to blame.
UC Davis researchers announced Tuesday that Tahoe’s clarity declined in both summer and winter last year, hitting an average annual clarity level of around 73 feet. Researchers test Tahoe’s clarity by lowering a 10-inch white disk into the water to test how far it’s visible from the surface. In 2014, the disk was visible about 5 feet farther down, researchers at the UC Davis Tahoe Environmental Research Center reported.
The researchers say the worse 2015 readings were due in part to warmer waters flowing into the lake, likely caused by substantially more rain than snow falling last year.
Still, the numbers aren’t an immediate cause for concern; researchers say the worst year for water clarity was in 1997, when Tahoe’s water clarity averaged 64 feet.
For the past 15 years, the lake has had an average clarity of around 71 feet.