Snapshot Day

Connecting the Tahoe community to its watershed

Snapshot Day is a citizen science water quality monitoring event that takes place each May. Volunteers fan out across the Truckee River Watershed to take samples from creeks, streams and lakes – including Lake Tahoe – to capture a snapshot of Tahoe’s water quality at a moment in time.


What do volunteers monitor at Snapshot Day?

The information gathered by volunteers is compiled into long-term datasets on water quality conditions within the Truckee River watershed. Snapshot Day also provides baseline data that can be used in ongoing and future environmental projects.

A cumulative 14-Year Snapshot Day Report covering surveys completed from 2001 through 2014 is available for download here. You can also download the most recent annual reports: 2015 Annual Report2016 Annual Report2017 Annual Report2018 Annual Report, 2019 Annual Report.

Scroll down to view data from sites within South Tahoe from Snapshot Day events since 2001. The complete 20-year dataset is available to download here.

If you are interested in more detailed analyses of this data set, please visit where you can explore additional annual reports. You can also contact us at for more information about Snapshot Day and to learn how you can get involved.