California & Nevada Lake Tahoe Total Maximum Daily Load Program 10-year Performance Report Released

The California Environmental Protection Agency reported that pollution and restoration reduction efforts at Lake Tahoe’s remain on track, according to a bi-state report released by the Nevada Division of Environmental Protection (NDEP) and the Lahontan Regional Water Quality Control Board.

Results from the bi-state report show that local government and California and Nevada transportation agencies have achieved the 10-year goals set to reduce urban stormwater pollution and improve lake water quality.

According to the bi-state Lake Tahoe Total Maximum Daily Load (TMDL) Program’s 10-year Performance Report shows, pollution from fine sediment was reduced by nearly 600,000 pounds in 2021. Last year saw a reduction of 523,000 pounds.

Additionally, nitrogen and phosphorus have also been reduced by thousands of pounds per year through the program, reported the California EPA.

Key Findings from the 2022 Performance Report include:

• Annual clarity measured 61 feet;

• Over the last 20 years lake clarity has remained relatively stable and is no longer declining;

• Researchers found that fine particles and algal chlorophyll are the primary variables affecting Lake Tahoe’s clarity;

• Evolving and new threats to Lake Tahoe as climate change occurs includes: increasing temperatures, floods, drought, and wildfires;

• Wildfire continues to be a primary threat to restoring water clarity; And

• Analyses show that efforts to reduce pollutants entering the lake through forestland runoff, erosion of stream beds and banks, and air deposition are on track to achieve 10-year goals.

The Lake Clarity Tracker can be viewed here.

“Our program’s efforts have become even more critical as Lake Tahoe faces other water clarity challenges from wildfire, smoke, and climate change,” said Mike Plaziak, Lahontan Water Board’s Executive Officer, reported the California EPA. “Going forward, restoring lake clarity will require us to continue our close coordination and implementation of best practices at every level, from how we maintain roads to how we gather data and adapt our strategies to manage climate impacts.”

“I’m proud of the progress made over the past decade to restore and enhance Lake Tahoe’s iconic water clarity,” said NDEP Administrator, Greg Lovato, reported the California EPA. “Looking ahead, we will continue to collaborate with the Lahontan Water Board, Tahoe Regional Planning Agency, and Lake Tahoe science and implementation partners to advance science-driven strategies and solutions that create a more vibrant, sustainable, climate-resilient Lake Tahoe.”

The Lake Tahoe TMDL Program was launched in 2011 to restore and enhance Lake Tahoe’s water clarity and aims to help Lake Tahoe meet the Clarity Challenge goal of water clarity down to at least 78 feet by the end of 2031.