Opinion Pieces

League to Save Lake Tahoe statement on 2019 Lake Tahoe Clarity Report

June 10, 2020

Today, the UC Davis Tahoe Environmental Research Center released findings from its annual Lake Tahoe Clarity Report, which showed average Lake clarity for 2019 was 62.7 feet, the second-lowest annual average depth recorded since systematic annual measurements began in 1968.

This drop in clarity from 70.9 feet in 2018 marks a significant downturn and a warning that large annual swings in variability should be expected as the impacts of climate change on the Tahoe-Truckee watershed become more extreme.

The following is a statement regarding the 2019 Clarity Report from League to Save Lake Tahoe CEO Darcie Goodman Collins, PhD:

“On its face, this data is startling, but not unexpected. After an encouraging 10-foot gain in clarity from 2017 to 2018, the losses from 2018 to 2019 reveal how strongly Tahoe’s blue is tied to the effects of the climate crisis and influenced by the Lake ‘turning over’ or mixing all the way to the bottom. It also spotlights the need for everyone of us – public agencies, environmental organizations, local businesses, visitors and residents – to do all we can to Keep Tahoe Blue.

This year’s results send a clear message that large swings in Lake clarity year-over-year are the new norm as climate change exerts its influence here in the Basin. More intense and sporadic weather events, prolonged dry periods, a shift in precipitation to more rain than snow and warming surface temperatures all impact how deeply we can see into Tahoe’s waters.

What’s more troubling is that climate change intensifies all the other threats facing Tahoe, such as the spread of aquatic invasive species, hazardous algal blooms, the risk of wildfire and stormwater pollution.

While Mother Nature got a well-deserved break when shelter-in-place orders were in effect, climate change won’t go away that easily. The quick recovery we witnessed in air quality and wildlife activity over the last few months should give us hope that by reducing global emissions, the ecosystem will bounce back and Tahoe’s clarity will improve. On a local level, it’s crucial that we are aware of the forces damaging Lake clarity and are actively working to minimize their impacts here in the Basin.

The League’s singular goal and focus has always been to Keep Tahoe Blue. Since our founding in 1957, we’ve harnessed the latest scientific findings to guide our action, and we’ll use this latest data to continue working from science to solutions.

By restoring Tahoe’s marshes, meadows, streams and forests, we have the ability to build the ecosystem’s resilience to climate change, so it can ride out wild swings in weather and human impacts. Healthy and functioning wetlands, in particular, filter pollutants and fine sediments before they can enter and cloud the Lake, which is why they’re the top target for restoration projects.

Advancing restoration in the Basin is a key focus of the League’s innovative, advocacy and engagement work. We’re playing a leading role in advancing the pace and scale of restoration projects through the Cutting the Green Tape Initiative in coordination with California Secretary for Natural Resources Wade Crowfoot.

It’s also important that we get our hands dirty and tackle the threats to clarity right where they pop up. Our volunteer citizen science programs and community cleanup events target the drivers of degraded Lake health, such as litter, stormwater pollution and invasive species on our beaches, in our forests and across our community.

Residents and visitors who want to be part of the solution are encouraged to visit keeptahoeblue.org and get involved.”


The League to Save Lake Tahoe, also known by the slogan “Keep Tahoe Blue,” is Tahoe’s oldest and largest nonprofit environmental advocacy organization. The League is dedicated to community engagement and education, and collaborating to find solutions to Tahoe’s environmental challenges. Through the League’s main campaigns, its expert staff and dedicated volunteers A.C.T. to Keep Tahoe Blue: we Advance restoration, Combat pollution and Tackle invasive species. Learn more at keeptahoeblue.org.

More related articles