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Tahoe Nugget #22:

Shoreline erosion

Many people consider Lake Tahoe to be one of the most beautiful bodies of water in the world. However, its famous water clarity is at risk. Development and the commensurate erosion associated with it are threatening the remarkable clearness of Tahoe's water. Soil, sand, silt and clay from the watershed cloud the water and shoreline erosion can release nutrients such as phosphorus and nitrogen that are causing an increase in algae growth.

Another problem is the sand and salt mixture the highway department spreads on the main roads during winter storms for traction. Automobile tires crush it into a fine powder which eventually find its way into the lake where the suspended particulates cause additional loss of clarity.

These and other problems have reduced the lake's clarity from 102 feet in 1968 to about 74 feet today. California, Nevada, and the federal government have promised to spend a total of nearly $1 billion to mitigate these issues. We now have a fleet of new street sweepers that constantly gather up the road sand. This and other Better Management Practices may have contributed to last year's marked improvement in the lake's clarity. There is also talk of lowering the maximum elevation of Lake Tahoe to reduce some of the erosion that you see in this photograph. The actual scale of this eroded escarpment is about 12 to 14 inches in height.