WMOD00011

• Applicant: Don Griffith North American Weather Consultants, Inc.
• Sponsor Name: City and County of Gunnison
• Project Name: Cloud Seeding Evaluation
• Title: The Development, Conduct and Evaluation of a Cloud Seeding Program for the Gunnison River Basin, Colorado During the 2003-2004 Season
• Prepared For: City and County of Gunnison
• Prepared By: North American Weather Consultants
• Date: 8/1/2004
• County: Gunnison
• Weather Modification - Doc Type: Report

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TIlE DEVELOP~IENT, CONDUCT AND EVALUATION
Of A CLOUD SEEDING PROGRA~I
fOR GUNNISOi'o' COUNTY, COLORADO
2003-2004 WINTER SEASON

1.0 INTRODUCTION

North American Weather Consultants (NA We) conducted a five month winter cloud
seeding program for the upper Gunnison River watersheds above Blue Mesa Reservoir from
November 15. 2003 through April 15. 2004, \vhich is the second winter season of project
operations. NA we had been contacted in the fall of 2002 regarding the design and conduct of a
program within Gunnison County. A program \vas designed. including the preparation of a
feasibility study, and a permit obtained for the program from the Colorado Water Conservation
Board. That initial program was operated from February I through April 15, 2003 (Griffith, et
ai, 2003). The program sponsors requested that the intended target area be expanded from only
those drainages above 9000' in Gunnison County to include '....atersheds that had their headwaters
in adjoining counties to the south. Figure I. I provides the location of this expanded area.
NA we submitted an application for a new five year permit to include these areas of interest in
the program. The Colorado Water Conservation Board (CWCB) held a public hearing in
Gunnison on this application on October 9, 2003. The ewes granted a five year permit to
NA WC for the new addition to the earlier target area on November 20, 2004. CWeB personnel
gave NA WC verbal approval to begin seeding on November 15th.
NA we installed an additional nine cloud seeding generator sites for the 2003.2004
'....inter season to cover the expanded larget area, bringing the (Otal number of generators to
twcnty.seven. Twenty different storm periods were seeded during the five months of the seeding
operations. The following sections describe this season's operations and evaluation of
effectiveness in more detail.