Approved by the Energy, Environment, and Water Policy Committee on February 24, 2021
Approved by the Public Policy and Practice Committee on May 4, 2021
Adopted by the Board of Direction on July 16, 2021


The American Society of Civil Engineers (ASCE) supports:

  • The careful and well-designed management of atmospheric water (also known as “weather modification” or “cloud seeding”) to enhance water supply for agriculture, municipal, hydroelectric generation, winter and summer recreation and tourism or to reduce agricultural and structural hail damage, or to disperse certain types of fog. 
  • Sustained funding and infrastructure for atmospheric water data collection, research and operational programs, and the scientific evaluations of such efforts, including the assessment of extra-area and long-term environmental effects, resulting in further adjustments and designs.
  • Dissemination of the results and findings of all atmospheric water management programs and projects to the professional community, water managers, and the public via publication of study results in peer-reviewed scientific journals.


Atmospheric water management capabilities are built on over seven decades of science and engineering practices. They are still being developed and represent evolving science and technology. Programs designed to enhance winter and summer precipitation are the only current means to potentially augment precipitation over natural precipitation amounts. Some studies suggest that hailstone sizes can be reduced through cloud seeding leading to less damage to crops or property. Longer-term commitments to atmospheric water management research and development leads to better operational programs. Continual improvement is necessary to realize the full potential of this combined science and technology approach to operational program design.


Water resources worldwide are being stressed by competing demands generated by population growth and environmental concerns. Changing climate is accompanied by world-wide alterations in precipitation patterns. As a result, regions have become more sensitive to year-to-year variations in natural precipitation. Well-designed management of atmospheric water offers the potential to significantly enhance naturally occurring water resources essential to agricultural and water supply needs, while minimizing capital expenditures or construction of new facilities. Other programs have been designed and operated to reduce the impacts of hail on property and agriculture and the dispersal of certain types of fog. ASCE, in conjunction with weather modification organizations, has developed materials providing guidelines and standards in the use of atmospheric water-management technology for dissemination to local communities and all levels of government worldwide. These publications can be found at

This policy has worldwide application
ASCE Policy Statement 275
First Approved in 1980