Amends existing law to revise provisions regarding cloud seeding.

LEGISLATURE OF THE STATE OF IDAHO Sixty-eighth Legislature Second Regular Session - 2026 IN THE HOUSE OF REPRESENTATIVES HOUSE BILL NO. 977 BY HOSTETLER AN ACT1 RELATING TO CLOUD SEEDING; AMENDING SECTION 42-4301, IDAHO CODE, TO REVISE2 PROVISIONS REGARDING CLOUD SEEDING; AND DECLARING AN EMERGENCY AND PRO-3 VIDING AN EFFECTIVE DATE.4

Be It Enacted by the Legislature of the State of Idaho:5

SECTION 1. That Section 42-4301, Idaho Code, be, and the same is hereby6 amended to read as follows:7 42-4301. CLOUD SEEDING. (1) The legislature finds that:8 (a) Idaho's economy and the welfare of its citizens depend upon a re-9 liable and sustainable water supply. It is essential, therefore, that10 the state continues to identify, develop, and implement projects that11 augment and sustain the state's water resources are hereby declared to12 be a public use subject to the regulation and control of the state in the13 manner prescribed by law.14 (b) The cloud seeding program developed and implemented by the Idaho15 water resource board, in cooperation with interested stakeholders,16 presents a unique and innovative opportunity to augment and sustain the17 water resources of the state has insufficiently proven to be a sound18 investment of state resources.19 (c) Augmenting water supplies through cloud seeding is in the public20 interest. Public benefits of cloud seeding include drought mitigation,21 protection of water rights, protection of municipal and business ac-22 tivities dependent on water, water quality, recreation, and fish and23 wildlife. While augmenting water supplies is in the public interest,24 insufficient data exists to establish the effectiveness or safety of25 cloud seeding to augment water supplies.26 (d) Data accumulated and analysis undertaken since the initiation of27 the cloud seeding program demonstrates that cloud seeding has not reli-28 ably resulted in an annual increase in the water supplies in the basins29 in which cloud seeding has been performed. However, additional re-30 search and analysis is necessary to determine the precise nature and ex-31 tent of those increases. The legislature recommends that such research32 be continued as the cloud seeding program progresses and that annual re-33 ports on such research be provided to the legislature. According to the34 2024 government accountability office report on cloud seeding technol-35 ogy that assessed its effectiveness, "when uncertainty was considered36 in estimates of cloud seeding effectiveness, the estimated effect was37 not distinguishable from zero with a high degree of statistical confi-38 dence (e.g., with 95 percent confidence)."39 (e) The legislature shall reevaluate the cloud seeding program and may40 suspend or authorize future cloud seeding projects or programs after41 receiving an independent, third-party report, which includes an en-42

2 vironmental impact assessment, that indicates the project or program1 should not continue or be allowed to commence.2 (e) (f) The legislature recognizes that expansion of the cloud seeding3 program may benefit basins throughout the state that experience de-4 pleted or insufficient water supplies, and the legislature recommends5 requires that the water resource board complete an assessment of basins6 and work with affected stakeholders to implement the propose a cloud7 seeding program in basins that would benefit from the program, for ap-8 proval by the legislature.9 (2) As used in this chapter, "cloud seeding" means all acts undertaken10 to artificially distribute or create nuclei in cloud masses for the purposes11 of inducing precipitation, cloud forms, or other meteorological parameters.12 Cloud seeding for the suppression of fog and frost prevention measures for13 the protection of orchards and crops are excluded from the coverage of this14 chapter, including for suppression measures and frost prevention measures.15 (3) The water resource board shall authorize, and may sponsor or de-16 velop, local or statewide cloud seeding programs and A cloud seeding pro-17 gram or project shall not be implemented without first receiving legislative18 approval. The legislature may contract any individual or organization for19 consultation and assistance in developing cloud seeding programs or in fur-20 thering research related to cloud seeding experimentation.21 (4) State funds may shall not be used or expended on cloud seeding pro-22 grams only in basins where the water resource board finds that existing water23 supplies are not sufficient to support existing water rights, water quality,24 recreation, or fish and wildlife uses dependent on those water supplies.25 (5) Water generated through cloud seeding shall be distributed in ac-26 cordance with the prior appropriation doctrine.27 (5) (6) The act of cloud seeding pursuant to a project funded in whole or28 in part by the state of Idaho or authorized by the state water resource board29 shall not legislature may be the basis of any claim of liability, including30 but not limited to trespass or public or private nuisance, and shall not re-31 quire any state or local permits.32 (7) An individual who authorizes or engages in cloud seeding without33 legislative approval is guilty of a felony and shall be subject to imprison-34 ment for up to one (1) year or a fine of not more than fifty thousand dollars35 ($50,000), or both.36

SECTION 2. An emergency existing therefor, which emergency is hereby37 declared to exist, this act shall be in full force and effect on and after38 July 1, 2026.39