In the News

Lake Tahoe is Losing Water Clarity
date posted: December 12 2001

Lake Tahoe waters have been losing transparency at an average of about one foot each year since the late 1960s.

Lake Tahoe’s exceptional clarity is a result of the absence of suspended sediment and free-floating, single-celled algae in the water. Given undisturbed conditions, the lake’s water quality would change so slowly the changes would be undetectable over a human lifetime. Human settlements and logging activities that began in the late 1880s have contributed to the rapidly declining clarity. Lake Tahoe’s clarity has decreased by more than 33 percent since the 1960s and is steadily declining at the rate of one foot a year. Scientists say that the rate of water quality deterioration at Lake Tahoe has been steady for so long it may become irreversible in 10 years.

Lake Tahoe’s water quality problems are not caused by industry or by wastewater treatment plants. The causes of water pollution are the daily activities of the thousands of residents and visitors in the Lake Tahoe watershed. We all need to learn to reduce our impact on the environment—impacts like erosion, over-fertilization, spills, leaks, and disturbances of soils and stream environment zones.