WMOD00285 ‎(2)‎

• Title: Feasibility Study of Wintertime Cloud Seeding to Augment Arizona Water Supplies
• Date: 1/1/1987
• State: AZ
• Weather Modification - Doc Type: Report

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
'I

study is confirmed by field observations, there is moderate potential for
precipitation augmentation on the Mogollon Rim.

A survey of previous modeling studies, two performed specifically for the
Mogollon Rim, and prior winter experiments of relevance to Arizona also
indicated moderate potential for precipitation and streamflow enhancement
by wintertime cloud seeding over the Mogollon Rim. When the hydrologic
model, CAPSIM (Central Arizona Project Simulation Model), was applied
employing a range of demands with three realistic enhancement scenarios,
the increases in yield to AMWUA (Arizona ~1unicip~1 W,at'er Users Association)
. "

varied from 11.1 to 23.6 percent. The three,enhancement scenarios con-
sisted of percentage increases obtained from a study. of Arizona conditions
by Beddome ~~. (1983), and 10 and 15 pl:rcent increases. Other results
from CAPSIM indicated that optimization of the SRP (Salt River Project)
demand, in conjunction with proper storag1e schemes, could additionally
enhance yields from cloud seeding. Analyses indicated that the CAP
(Central Arizona Project) canal has the capacity to transport additional
water to the Pinal and Tucson AMA1s (Active Management Area).
Consequently, exchange agreements could be executed that would enable those
areas to benefit from additional water supplies from cloud treatment.

A brief environmental study was performed to determine the broad environ-
mental resources and potential effects of cloud seeding in the Mogollon
Rim. In general, data collection and cloud seeding demonstration programs
were not identified as creating significant impacts on environmental
resources. Before seeding activities are begun, however, an EA
(environmental assessment) covering all environmental categories must be
prepared to address important environmental features. If no significant
effects are anticipated, a FONSI (Finding of No Significant Impact) will be
made. If it is determined that significant effects are possible, an EIS
(Environmental Impact Statement) will be required by the NEPA (National
Environmental Policy Act).

The EA should be prepared in consultation with appropriate Federal and
State agencies as well as the general public, the entire process taking
about 9 months for completion. The EIS, if necessary, will take 18 months

B