Cloud seeding permits in Washington State come in two parts: you need a license from the Department of Ecology showing meteorological competence, and then a separate permit for each individual operation. The program sits in Chapter 70A.10 RCW, and running an operation without both authorizations exposes you to license revocation and penalties. Federal law adds its own layer, requiring NOAA notification at least ten days before any weather modification activity begins.1Washington State Legislature. Washington Code 70A.10 – Weather Modification
License First, Then a Permit for Every Operation
The license is about the person. The Department of Ecology evaluates whether the applicant has the meteorological competence to conduct weather modification. When an organization applies, the individual actually running operations has to personally meet that standard. Licenses cost $100 and expire at the end of the calendar year they’re issued in, so renewal is annual.1Washington State Legislature. Washington Code 70A.10 – Weather Modification
The permit is about the project. Chapter 70A.10 defines an “operation” as weather modification activities aimed at producing a specific effect within one geographic area over a continuous period of no more than one year. Two regions, two contracts, two projects running in parallel: two permits.2Washington State Legislature. Washington Code 70A.10.100 – Separate Permit for Each Operation, Filing and Publishing Notice of Intention, Activities Restricted by Permit and Notice
One citation note worth flagging: older references you’ll find online point to Chapter 43.37 RCW. That chapter was recodified as Chapter 70A.10 in 2020. Any RCW 43.37 citation you see for weather modification is outdated.3Washington State Legislature. Washington Code 43.37 Dispositions – Weather Modification
Public Notice and the Olympia Hearing
Before starting an operation, the licensee files a notice of intention with the Department and publishes that same notice publicly. The notice has to list the licensee’s name and address, the nature and purpose of the operation, who it’s being done for, the geographic area of operation and the area intended to be affected, the approximate timeline, and the materials and methods to be used.4Washington State Legislature. Washington Code 70A.10.110 – Notice of Intention, Contents
Publication runs at least once a week for three consecutive weeks in a legal newspaper of general circulation in each county where the operation will take place or where the affected area is located. If no legal newspaper is published within a relevant county, the applicant publishes in one that circulates generally within it.5Washington State Legislature. Washington Code 70A.10.120 – Notice of Intention, Publication
The Department also holds an open public hearing in Olympia before issuing any permit. This isn’t triggered only when someone objects. It’s a standing condition for issuance.6Washington State Legislature. Washington Code 70A.10.090 – Permits, Requirements, Hearing as to Issuance
Once the permit is granted, activities have to stay within the time and area described in the notice of intention unless the Department approves a modification. Any conditions attached to the permit are binding.2Washington State Legislature. Washington Code 70A.10.100 – Separate Permit for Each Operation, Filing and Publishing Notice of Intention, Activities Restricted by Permit and Notice
Proving Financial Responsibility
Before issuing a permit, the Department requires the applicant to demonstrate the ability to cover damages that could reasonably result from the operation. The statute doesn’t set a dollar figure and doesn’t require a specific instrument such as a surety bond. The applicant has to satisfy the Department that adequate resources exist.7Washington State Legislature. Washington Code 70A.10.130 – Financial Responsibility
The Federal NOAA Report
State approval doesn’t cover the federal obligation. The Weather Modification Reporting Act of 1972 requires anyone conducting weather modification in the United States to notify the Administrator of NOAA at least ten days before the activity starts, with a final report after it ends. Fines for failure to report run up to $10,000.8NOAA Library. Weather Modification Project Reports
Reports go in by email using a specific file-naming convention that includes year, state, and project name. NOAA publishes two standard forms: the Initial Report (Form 17-4), filed before the project begins, and the Interim/Final Report (Form 17-4A), filed during and after. Covered activities go beyond cloud seeding to include using heat sources to influence convection, dispersing materials to modify solar radiation, and applying electromagnetic radiation or shock waves to the atmosphere.8NOAA Library. Weather Modification Project Reports
Narrow exceptions exist. Purely local activities not expected to affect weather beyond the immediate area, such as small heat sources or fans used to prevent frost damage to crops, are not covered. Religious ceremonies or rituals intended to modify weather are also exempt.
Records the Operator Must Keep
Every licensee keeps detailed records of each operation: method used, type of equipment, materials and quantities dispersed, times and locations equipment was operated, and the name and address of every individual who participated. The Department sets the reporting deadlines and formats. These records are open to public examination.9Washington State Legislature. Washington Code 70A.10.150 – Records and Reports, Open to Public Examination
Organizations exempt from license and permit requirements under RCW 70A.10.070 still file written reports with the Department. Exemption from permitting isn’t exemption from oversight.
The Drought Emergency Shortcut
Washington has a faster track for drought conditions. When the governor declares a state of emergency related to a lack of precipitation or a water supply shortage under RCW 43.06.210, the Department must waive certain requirements for already-licensed operators. The emergency provisions exempt licensees from the public hearing and the three-week newspaper publication, so operations can start much sooner.10Washington State Legislature. Washington Code 70A.10.210 – Exemption of Licensee From Certain Requirements
The exemption applies only to operators who already hold a valid license. It doesn’t waive the licensing requirement itself, the financial responsibility requirement, or the record-keeping and reporting obligations. Private legal rights and operator liability also stay fully in place.
What Happens if You Seed Without Authorization
The Department of Ecology can suspend or revoke any license or permit when the licensee no longer meets the qualifications for a new license or has violated any provision of the weather modification chapter. Suspension or revocation requires notice and a reasonable opportunity to be heard. The Department can also refuse to renew a license or issue another permit to someone who has failed to comply.11Washington State Legislature. Washington Code 70A.10.160 – Revocation, Suspension, Modification of License or Permit
If problems come up after issuance, the Department can modify the permit’s terms, but only after notice and a reasonable opportunity for a hearing, and only on grounds related to protecting health or property.11Washington State Legislature. Washington Code 70A.10.160 – Revocation, Suspension, Modification of License or Permit
Beyond permit actions, the Department has general enforcement authority under RCW 43.27A.190, which historically has authorized regulatory orders, including cease-and-desist orders, when a person violates or is about to violate the weather modification chapter. Chapter 70A.10 also includes a criminal penalty provision at RCW 70A.10.180 for violations of the chapter.
If Someone Else’s Seeding Damages Your Property
Washington’s statute takes a clear position on government liability: the state, the Department of Ecology, and state employees have none. RCW 70A.10.170 says nothing in the chapter creates or accepts state liability for the cloud seeding activities of private operators.12Washington State Legislature. Washington Code 70A.10.170 – Liability of State Denied, Legal Rights of Private Persons Not Affected
Legal rights between private parties are preserved in full. If a cloud seeding operation causes flooding, erosion, crop damage, or other harm to your property, your right to bring a tort claim, a breach of contract action, or any other legal action against the operator remains intact. The financial responsibility requirement exists so operators can actually pay when they cause damage. Standard theories such as negligence, nuisance, and trespass are all available, and courts can award damages for reduced crop yields, property damage, or compromised water supplies.12Washington State Legislature. Washington Code 70A.10.170 – Liability of State Denied, Legal Rights of Private Persons Not Affected
The practical difficulty is causation. Weather varies naturally, and linking a specific storm, hailstorm, or flood to a particular seeding operation rather than natural conditions calls for expert meteorological and hydrological testimony. That evidentiary burden is the real obstacle for landowners, not any statutory shield around the operator.
Concerned neighbors have a cheaper option than litigation, which is to participate in the permit process. The three-week newspaper notice and the mandatory Olympia hearing both open a door before the Department decides. Significant concerns raised there can lead to conditions on the permit or a denial.