Snapshot Day is the oldest and largest single-day annual water quality monitoring event in California.

On the first Saturday in May each year hundreds of volunteers join the Coastal Watershed Council and Monterey Bay National Marine Sanctuary staff to take a “snapshot” of the health of rivers and streams flowing into the Sanctuary. This favorite event draws people of all ages from all over California’s Central Coast to collect scientifically valid water quality data and to learn more about their local watersheds. Data from field measurements and lab analysis are collected and analyzed to determine the biggest threats to water quality and best management practices to address them.

Saturday, May 4th, 2024

Training is required of all Snapshot Day volunteers to ensure that the data that you collect is scientifically valid and can be used effectively. Here are the training options for Santa Cruz County:

“When I first heard about Snapshot Day in early 2003 my son and I signed up to volunteer – he was interested in playing in creeks and I was looking to pass on my adoration of the outdoors to my family. Our baby Natalie soon joined the family and my wife and daughter both came along to the next Snapshot Day. Circumstances moved us away from Santa Cruz to the Chico area, but year after year we made the family trip down to Santa Cruz for Snapshot Day. Little did I realize how “our baby” Natalie would take to monitoring like she was born doing just that. In 2015, Natalie was even interviewed on the news at Snapshot Day! She will never forget that experience. I cannot tell you how proud I am of both of my children to be volunteers with CWC and how willing and caring they are to travel 250 miles each way in order to help others keep their water clean.”

— Gary Smith and his daughter Natalie

Dig in!

In two decades of water quality monitoring on California’s Central Coast, we’ve collected a lot of data. You can dig in to some of this data in the reports below.