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Intrastate Water Management & Development

Weather Modification Grants

The Weather Modification Program exists to issue and monitor cloud seeding and other weather modification activities in Colorado.  The program is statutorily authorized in Article 20, sections § 36-20-101 through 127.  House Bill 06-1313 expands the Weather Modification Program to provide state grants to water providers to assist in funding ground-based wintertime operational cloud seeding programs.  The bill also changed state authorities to accept contributions from other entities that benefit from cloud seeding.  Colorado water users developed many new cloud seeding programs in response to the drought that started in the early 2000s.  It is anticipated that interest in funding long-term wintertime cloud seeding programs will continue to grow as competition for water supplies increase.  The CWCB had grants of $20,000 in FY 04, $60,000 in FY 05, and has grants of $75,000 in FY 06 (starting July 1, 2006).  Currently there are active cloud seeding permits in the following watersheds: San Juan/Animas watershed (Southwestern Water Conservation District), Gunnison watershed (Gunnison County & many interests), Lower Colorado River Basin - Grand Mesa (Water Enhancement Authority), Upper Colorado River Basin (Denver Water), Upper Colorado River Basin (Colorado Springs Utilities), and the Upper San Miguel Basin (Telluride Ski & Golf and Southwestern Water Conservation District).

Who is Eligible for Grants?
The weather modification grants program provides grants to existing permitted cloud seeding programs.  The state funding is designed to model successes in Utah where state funding made available every year has helped local water user sponsored cloud seeding programs to span decades.  The state funding is only available to assist water user groups and city and county governments.  Ski areas and other interests are not currently eligible for cloud seeding grants even if they participate in an existing permitted cloud seeding program.  Currently all permitted projects in Colorado have local water users sponsoring all or part of the cloud seeding except for the Vail/Beaver Creek Ski area cloud seeding program.

What is a Permitted Program?
A cloud seeding contractor works with a local water user group to develop a plan and funding for a cloud seeding project.  The contractor applies for a permit to cloud seed from the State of Colorado on behalf of the project sponsors.  Public hearings, public notification, operational plans, proof of liability insurance, and demonstration that the project will provide local benefits are all needed before a permit will be issued.  A Record of Decision is developed from the public hearing to helps determine if a permit should be approved, denied, or approved with terms and conditions that address and/or resolve concerns.

How Can the Money be Used?
The money is to be used to help the local water users fund well-designed cloud seeding programs and help modernize programs to take advantage of new technologies.  Permits are issued for five months of winter (typically November 1 through March 31st). A few examples of how the funding is used follow: 

  1. Some water user groups cannot fund a full five months of cloud seeding, therefore the state funding helps them fully utilize all winter months in their weather modification permits. 
  2. There are uncertainties with cloud seeding, and additional funding helps with the evaluation of effectiveness that is in question year in and year out.  
  3. One existing program purchased their own propane tanks rather than renting them.  This allow them to purchase propane from the least cost provider and keep program costs down.  

How to Apply?
Grants are currently only available for permitted cloud seeding programs.  The CWCB staff works with contractors and project sponsors to determine programs in operation for the year, then develop recommendations.  However, the priorities and grant funding levels are set by the CWCB director with assistance from CWCB Board members.

What is the Application Process?
Water user groups interested in leveraging the Weather Modification Grants program will need to develop a plan and funding at a local level, and then apply for a weather modification permit.  The CWCB can provide contact information for representatives from cloud seeding contractors, existing permitted projects, researchers and evaluators.  For more information about cloud seeding or the Weather Modification Grants program, contact at 303 866.4807.

Did You Know?

The State and the cloud seeding contractors are required, by statute, to monitor snowpacks and are not allowed to cloud seed indiscriminately. Snowpack thresholds are called “suspension criteria” and are set at 175% of normal in November and 120% -140% of normal on April 1st, using the NRCS SNOTEL sites in and around the cloud seeding target areas.  The SNOTEL sites are checked and reported on regularly.  Therefore, cloud seeding boosts snowpacks a small amount, but it is within the natural variability of the local climate.  For the chart to the right, green is the suspension criteria, black is the 30-year average, and red is the current year’s data reported on every two weeks.


NOTE:  All monies granted must be contracted for and expended in the state fiscal year for which they were approved (July 1 through June 30). 



Department of
Natural Resources