Eagle River Watershed Council: How cloud seeding helps our rivers
Resiliency planning takes a look at future risks related to climate change and creates systems, strategies and programs to help address them before effects are felt in the community. Here in Colorado, state planning includes ways to increase snowpack that ultimately fuels our flowing rivers. One tool widely used throughout the state, but that is a mystery to many, is known as “cloud seeding.”
Statewide, there are nine active permits regulated by the Colorado Department of Natural Resources. Western Weather Consultants, a cloud seeding operator, holds the permit for the Central Colorado Mountain River Basin Program. Within the Central Colorado Mountain River Basin, the Colorado River District manages 29 cloud seeding generators. The technology is in use, but the question still lingers: what is cloud seeding and what are the potential impacts on snowpack and stream health?
Cloud seeding is a type of weather modification used primarily in the State of Colorado. The technology dates back to 1946, when General Electric scientists Vincent Schaefer, Irving Langmuir and Kurt Vonnegut’s brother, Bernard, discovered an innovative way to create more snow. Their idea involved dispersing dry ice over super-cooled clouds, a theory they tested in a GE laboratory freezer and later by dropping dry ice in a cloud from a small plane. Nearly 70 years later, this weather augmentation tool is used with a slightly different approach.
Today, the process begins with the spraying of silver iodide across a propane flame. This sends tiny particles into the clouds above, allowing the silver iodide to act as the “seed.” Ice crystals are formed, and precipitation in the form of snow is created. Data from the River District and the North American Weather Modification Council show that this process can increase snowstorm totals from 5 to 15 percent above non-seeded storms, when conditions are favorable.
There is some uncertainty of the overall downstream effectiveness and skepticism among some citizens; however, views within the scientific community generally support cloud seeding as an effective tool. Many agencies argue that although it only slightly increases snow totals, additional snow is still beneficial for the arid soils. Organizations like the American Meteorological Society and the World Health Organization support the effectiveness of winter cloud seeding projects. They view it as a low-risk, high-benefit scenario for the Colorado River Basin.
A large concern is not how much snow the process actually creates, but how silver iodide affects the health of the river and surrounding environment. The Weather Modification Council states that silver iodide has been extensively reviewed, and the research shows no environmentally harmful effects.
Cloud seeding may be able to help relieve tensions a little, but this is just one part of the solution to our changing climate. Other innovative solutions to reduce water use and increase water supply, such as demand management and water conservation efforts, have been incorporated into drought contingency planning and are being implemented in the Upper and Lower Colorado River basins. These efforts, including cloud seeding, are all essential components to ensure the longevity of our western waterways.
Want to learn more about the people, policy and process behind cloud seeding? Join Eagle River Watershed Council and the Colorado River District for a cloud seeding presentation on November 20 at Loaded Joe’s in Avon. More information is available at erwc.org/events.
Sarah Vergara is the Community Outreach AmeriCorps Vista Intern for Eagle River Watershed Council. The Watershed Council has a mission to advocate for the health and conservation of the Upper Colorado and Eagle River basins through research, education, and projects. Contact the Watershed Council at (970) 827-5406 or visit erwc.org.