Threats to Tahoe's clarity and ecosystem

Urban Stormwater: The Lake's Largest Pollution Source


Urban stormwater is the largest source of pollution clouding Lake Tahoe's clear water. When it rains, or as snow melts, water flows down streets and across parking lots, picking up dirt, road sand, fine particles and oil, all of which flow directly into storm drains that lead to Lake Tahoe.

Read more about Urban Stormwater.

Invasive Species


One of the biggest threats to Lake Tahoe is the introduction and spread of invasive species. Weeds and non-native clams are changing the lake’s ecosystem, concentrating nutrients, causing algae blooms and creating habitat for more invasives like large goldfish and bass. Eurasian watermilfoil, a common aquarium plant, is now established in dozens of locations across the lake’s shoreline. Our volunteer program Eyes on the Lake aims to keep water weeds in check along Tahoe's shore.

Read more about Invasive Species.

Trash and Graffiti


The League conducts extensive outreach and education on the environmental challenges facing Lake Tahoe.

Trash and debris that litter the beaches of Lake Tahoe can be harmful and even fatal to wildlife, damage the local economy, pose a human health hazard, as well as contribute to Lake Tahoe’s clarity loss. Graffiti permanently scars granite and has been an issue particularly on the East Shore. The League partners with local land agencies to implement beach cleanups in areas of high recreation use, and assists local groups with graffiti cleanups.

Read more about Trash and Graffiti.

Climate Change


Climate change is one of the biggest threats facing Lake Tahoe. It is causing more precipitaton to fall as rain rather than snow. More rain means more more floods and stormwater runoff that carries sediment into Lake Tahoe. Climate change is also increasing the lake’s water temperature and affecting regional weather patterns in ways that could change the lake’s ecosystem and cause more of a decline in the lake’s clarity.

Read more about Climate Change.




Photo: Ward Creek pours sediment into Lake Tahoe during the 1997 flood. Source: Tahoe Environmental Research Center

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