WMOD00213

• Applicant: North American Weather Consultants
• Sponsor Name: Upper Colorado River Commission
• Project Name: The Potential Use of Winter Cloud Seeding Programs to Augment the Flow of the Colorado River
• Title: The Potential Use of Winter Cloud Seeding Programs to Augment the Flow of the Colorado River
• Prepared For: Upper Colorado River Commission
• Prepared By: Don Griffith, NAWC
• Date: 3/1/2006
• Weather Modification - Doc Type: Report

result using diOcrent assumptions. The associated estimated cost of producing the additional
runofTwas $7.91 pcr acre foot.

9.0 Summary of Capahilit). Statemenls

Thc principal societies or associations conccrned with weathcr mouilication capabilitics
in all or part include the following.

. The Weather t-.1odilication Association (WMA)
. The Amcriean Mcteorological Socicty (A~tS)
. The World Metcorological Organization (Wt\tO)
. The American Society of Civil Enginecrs (ASCE)

Each group maintains and publishes a policy or capability statement regarding weather
modification in its primary categories. Excerpted from their ovcrall statements. the statements of
each organization pertaining to winter prccipitation augmentation are provided in Appendix A.

From the organizational statemcnts contained in Appendix A. thc follo\ving key points
regarding the currcnt status of winter orographic seeding for snowpack augmentation emergc.

. Of the primary categorics of cloud seeding for precipitation increase. seeding of winter
orographic stoml systems seems to ofTcr the best prospects for increasing precipitation
in an economically-viable manner.
. Strong (albcitlargely non-randomized) statistical evidence exists for (\vinter) seasonal
increascs of the order of 5% to 15%.
. Many ofthc microphysical links in the \vinrcr precipitation augmcntation chain of
cvents have been doeumentcd via various physical experimcnts and observations.

10.0 Areas within the Colorado Ri\'(~r Basin without Cloud Seeding Pro~rams
Currcntl~. but with Good Seedin~ Potential

Scction ..J of this paper bricfly deseribcs on-going operational winter cloud seeding
programs in the wcst. Some of these programs arc already opcrating in drainage areas that are
tributary to the Colorado River. There are additional arcas \vithin the four statcs of Arizona.
Colorado. Utah and \Vyoming that may be considered for the establishment ofncw winter cloud
secding programs. Some earlicr studics pcrfonned for Reclamation documcntcd arcas within
thesc states that werc considered as potential operating areas. Tvo'o of these studics \vere I) "The
Impacts of Snow Enhancement" complicd by Leo \Veisbecker ofthc Stanford Research Institute.
)Q7..J. and 2) "Twelve Basin Investigation" by North American Wcather Consultants. I Q73.

Figure 3. L1.ken from a recent report prepared by Reclamation (Iluntcr ct al. 2005). shows
current and potential cloud sceding areas \I,:ithin the four states. Table I (also from that report)
providcs names of thc areas of the existing programs according to the numbering scheme used in
Figure 3. Thc basis for selection of potential areas was based primarily on sdeetion criteria
contained in a Reclamation proposal (Super ct al. 1993) for a rescarch oricntcd cloud secding