In 1969, Nevada and California established the Tahoe Regional Planning Agency (TRPA) to manage development and protect Lake Tahoe. The agency unified environmental standards in the Tahoe Basin, safeguarded sensitive wetland areas, and implemented a growth management system to cap development. In 1997, TRPA initiated the Lake Tahoe Environmental Improvement Program (EIP) to accelerate environmental restoration projects. Under EIP, TRPA collaborates with states and over 80 public and private organizations to restore lake clarity to its historic 97 feet. These efforts include meeting pollutant load reduction targets set by the Clarity Challenge plan, capturing more than 500,000 pounds of fine sediment particles annually through stormwater treatment and wetland restoration projects.
“Science-driven policies have underpinned Lake Tahoe’s protection for decades, and seeing lake clarity stabilize is an indicator that we are making progress,” said Julie Regan, executive director of the Tahoe Regional Planning Agency.
In 2024, summer and winter clarity at Lake Tahoe showed patterns similar to recent years. Winter clarity averaged 69 feet in 2024 after an historic average of 92 feet the previous winter. Summer averages were lower, with a clarity of just 53 feet in 2024. Researchers are questioning what drives these trends as factors like warmer temperatures, wildfires, smoke, and aquatic invasive species impact the lake's ecology. The report suggests future research should utilize new data and technologies to understand better how biological elements like algae and physical processes affect water clarity.
Executive Director Regan noted that while stabilizing lake clarity is positive, other concerning trends exist alongside insufficient data. TRPA is working with the Tahoe Science Advisory Council to determine the best path forward.