LAKE TAHOE, Nev./Calif., June 16, 2025 — Today, the UC Davis Tahoe Environmental Research Center and Tahoe Regional Planning Agency released findings from the annual Lake Tahoe Clarity Report, which showed annual average clarity — or how deep a 10” white disk can be lowered into Lake Tahoe before it becomes invisible from the surface — measured 62.3 feet in 2024, as compared with 68.2 feet in 2023.

Since 2000, multi-year average clarity measurements, which are more telling of Lake health than annual averages, have remained relatively stable. The most recent annual average clarity readings show that the long-term plateau continues.

After decades of steady water clarity loss in the latter half of the 20th century, organized efforts by Keep Tahoe Blue and other partners in Tahoe’s Environmental Improvement Program helped stabilize Lake Tahoe’s world-famous water clarity. A key tool the partners used was the Lake Tahoe Total Maximum Daily Load (TMDL) which seeks to limit fine sediment particles from entering the Lake as runoff from roads, urban areas, and degraded marshes, creeks and meadows.

The latest report shows that the TMDL supports healthy water quality, but more understanding and action is needed to restore water clarity.

The following is a statement from Keep Tahoe Blue CEO Dr. Darcie Goodman Collins regarding the Lake Tahoe Clarity Report:

“For another year, Lake Tahoe’s multi-year averages for water clarity are stable, despite the continuing trend of declining summer clarity readings.  
 
Over the past two decades, investments in programs to limit the amount of fine sediment particles — from roads, urban areas, and degraded streams and wetlands — entering the Lake as stormwater have been successful. The report shows those dollars and efforts have been good for water clarity. Yet, we now know that stopping fine sediment pollution is not enough to bring back the water clarity lost last century. 
 
So, we need to dig deeper and learn more about the processes and interactions going on below and above the surface. What role do algae and phytoplankton play in clarity? What role does wildfire smoke and ash play? What about the effects of microplastic pollution and aquatic invasive species? 
 
These are questions that don’t have easy or fast answers. But anyone who has ever experienced Tahoe knows the effort is worth it, so we can give our kids and their kids the gift of a beautiful, blue, healthy Lake. The 68-year-and-counting movement to Keep Tahoe Blue is about future generations. So, let’s reinvest in scientific research, test innovative solutions, and then double-down on what works. 
 
In the meantime, there are things everyone should do to reduce their own impact on the Lake, like using alternative transportation, stopping the spread of invasive species by cleaning, draining, and drying your gear before putting it in the Lake, refusing to buy single-use plastics that often end up as trash in our environment, and volunteering at restoration events that repair Tahoe’s marshes, meadows, and creeks — the Lake’s natural pollution filters. 
 
Clarity matters because the water is our biggest clue about how the Lake is doing. If we lose the clear water of Tahoe, we lose everything we love about it. Let’s all do our part to Keep Tahoe Blue.”