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?

Dissolved oxygen

Microscopic bubbles of oxygen available for aquatic organisms

Total dissolved solids

The combined inorganic and organic content of the water

A measure of the water's acidity or alkalinity, which can show if the stream is a healthy habitat

Temperature

Of the air and the water at each sampling site

Water samples

To be tested in the lab for turbidity (cloudiness), nutrients and bacteria

Site-specific disturbances

Erosion or sources of pollution visible to the naked eye

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 Report, 2016 Annual Report, 2017 Annual Report, 2018 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 tahoetruckeesnapshotday.org where you can explore additional annual reports. You can also contact us at protect@keeptahoeblue.org for more information about Snapshot Day and to learn how you can get involved.