Snapshot Day

Tahoe Forest Stewardship Days

Snapshot Day is a citizen science water quality monitoring event that takes place every May with the goal of connecting the community with its watershed. Volunteers fan out across the Truckee River Watershed to take water samples from creeks, streams and smaller lakes, as well as Lake Tahoe itself, to get a snapshot of one moment in time of the water quality of the Tahoe-Truckee watershed.

What do volunteers monitor for at Snapshot Day?

Volunteers field test streams for dissolved oxygen, total dissolved solids, pH and temperature; and collect water samples for laboratory analysis of turbidity, nutrients and bacteria. Teams also conduct thorough visual assessments of each monitoring site, watching for sources of pollution or disturbance. The information gathered by volunteers is compiled into long-term datasets on water quality conditions within the 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 Report, 2016 Annual Report, 2017 Annual Report, 2018 Annual Report, 2019 Annual Report.

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.

Below are 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 to read annual reports from each year. Contact us at

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