The Community Collaborative Rain, Hail and Snow Network known as CoCoRaHS is a unique, non-profit, community-based network of volunteer citizen scientists of all ages and backgrounds working together to measure and map precipitation (rain, hail and snow). We use low-cost measurement tools, and enter our data into an interactive Web-site. Through education and training videos and help from other volunteers we aim to provide the highest quality data for natural resource, education and research applications.
The CoCoRaHS network just turned 18 years old and was started at the Colorado Climate Center at Colorado State University. CoCoRaHS was originally founded as the "Colorado Collaborative Rain and Hail Study" in response to the July 28, 1997 Fort Collins Flood. That flash flood producing storm dumped nearly a year's worth of rain (over 14" at the center) in a few hours, claimed 5 lives and did extensive damage to the Colorado State University campus and nearby communities.
In the early days of CoCoRaHS, the website was much more simplified. Many of the early volunteers called in their reports by phone as they did not yet have internet access. CoCoRaHS began studying local intense storms just in Colorado and didn't think volunteers would be interested in doing measurements of winter snow, too. Little did they know.
Today the National Oceanic and Atmospheric Administration (NOAA) and the National Science Foundation (NSF) are major sponsors of CoCoRaHS, but many of the volunteer station monitors also donate cash as well as time, and equipment. CoCoRaHS is now in all fifty states and Canada. Virginia was the seventh state to join the network. I got introduced to the program by a local farmer who volunteers with me as a director of the conservation district.
The data we collect is used by the National Weather Service, other meteorologists, hydrologists, emergency managers, city utilities (water supply, water conservation, storm water), insurance adjusters, USDA, engineers, mosquito control, ranchers and farmers, teachers, students, and neighbors in the community are just some examples of those who visit our Web site and use the data.
I got involved through my interest in groundwater and noticing that often it rained in parts of the county, but not others. Since I depend on a private well for water, keeping an eye on local rain and water conditions is important. Private wells draw their water from groundwater, and water recharge is very local in Prince William County. The rainfall in my yard is the best predictor of groundwater recharge and availability.
The image below is the month summary and annual rainfall of a nearby proxy well. I used a proxy because my data does not go that far back. I joined the CoCoRaHS network in October 2015.