The annual Tahoe: State of the Lake Report (Report)provides updates on the ecological health of the lake, discussing past and ongoing environmental challenges. UC Davis has conducted continuous monitoring of the lake since 1968. This accumulated data provides invaluable insights for this iconic, but vulnerable lake.
The latest 2024 Report indicates that Lake Tahoe is experiencing higher air temperatures, increased rainfall, and reduced snowfall compared to a century ago. The number of days with temperatures below freezing has decreased, and snow's contribution to annual precipitation has decreased from 50% in 1910 to 30–40% in 2024. Maximum temperatures have also noticeably increased, which has increased the rate of snowmelt.
Periphyton - or attached algae - is another data point that is monitored because it can create green, slimy shoreline rocks. While recent biomass measurements fell below average, monitoring individual sites remains challenging due to intense wave action. Therefore, a new remote sensing pilot program aims to enhance the accuracy of future periphyton monitoring.
Water clarity trends show complex patterns. Following major declines throughout the 1990s, annual average clarity now appears to have plateaued. Consequently, targeted research into clarity-reducing particles is crucial, as it seeks answers to inform restoration efforts.
These long-term trends underscore the importance of continuous monitoring and scientific research. Such efforts provide vital insights into the lake's changing environment. Ultimately, understanding these changes is essential for safeguarding the health and future of Lake Tahoe.
