Cloud Seeding as a Water Management Tool– The Idaho Approach�

Central Oregon Farm Fair | February 2, 2023

Kala Golden, IWRB Cloud Seeding Program Manager

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WATER IN IDAHO

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Idaho Department of Water Resources

Idaho Water Resource Board

MISSION �

To serve the citizens of Idaho by ensuring that water is conserved and available for the sustainability of Idaho’s economy, ecosystems, and resulting quality of life.

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VISION ��To achieve excellence in water management through innovation, efficiency, planning, and communication.

• Formulation and implementation of the State Water Plan�
• Implementation and financing of large water projects�
• Operation of programs that support sustainable management of Idaho’s water resources
• Water Supply Bank
• Managed Aquifer Recharge
• Cloud Seeding
• Water Transactions
• Financial Programs

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Idaho Department of Water Resources

Idaho Water Resource Board

Water Compliance Bureau

Geospatial

Technology Section

Hydrology Section

Purchasing

Financial

Human Resources

Water Allocations Bureau

Planning & Projects Bureau

Safety of Dams

Adjudication Section

Statewide Hearing Officer Coordinator

Director

Deputy Director

Water Rights Section

Western Region

Eastern Region

Southern Region

Northern Region

Stream Channel Protection

Legal Services

Ground Water Protection

Water Distribution Section

Floodplain Management

Water Supply Bank

Water Projects Section

Tech Services Bureau

Safety of Dams

WATER IN IDAHO

8-members, Governor appointed

Idaho Attorney General’s Office Natural Resources Division

OVERVIEW

• Cloud Seeding 101
• History of Cloud Seeding in Idaho
• Current Projects
• Program Development

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Image Courtesy of Idaho Power Company

CLOUD SEEDING 101

What is Cloud Seeding?�

Cloud seeding is a form of weather modification that increases the efficiency of a cloud by enhancing its natural ability to produce precipitation.

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Why do we seed clouds?�

• Augmentation of snowpack
• Rain Enhancement
• Fog suppression
• Hail Mitigation

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CLOUD SEEDING 101

How does a snowflake develop in nature?

Images Courtesy of Idaho Power Company

CLOUD SEEDING 101

How do we seed clouds?�

• A seeding agent is released into an existing cloud formation with “Supercooled Liquid Water” (SLW) �
• Seeding agent has structure like that of naturally occurring ice (hexagonal)�
• Cloud Seeding is a physically based process →

Provides surface for water molecules to bond to each other; does not bond to water molecules to form chemical reaction�

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Seeding Agent

CLOUD SEEDING 101

What is Supercooled Liquid Water (SLW)?�

• Water that is cold enough to freeze, but remains in the liquid state
• Water can freeze at 32°F
• Water requires a nucleation process to freeze
• Impurities in nature such as dust
• Water in the liquid state can be present in clouds much colder than 32°F

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Image Courtesy of Idaho Power Company

CLOUD SEEDING 101

Methods of seeding�

• Silver Iodide (AgI), most commonly used seeding agent
• Functions at warmer temperature, allowing ice formation to begin sooner
• Most effective at 17° F or colder
• Natural ice nuclei become effective below 5° F
• Ground Generators: AgI Solution is burned through propane flame
• Aircraft: AgI is incorporated into a flare (or solution is burned)

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CLOUD SEEDING 101

What is Silver Iodide (AgI)?�

• Inorganic compound
• Inert in the natural environment
• Insoluble in water 🡪 can’t become free silver available to aquatic organisms
• Solubility close to that of Quartz
• Similar hexagonal structure as naturally forming ice crystals

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Image Courtesy of WebElements.com

Water Molecules (H₂O)

AgI

CLOUD SEEDING 101

Types of Ground Generators

Images Courtesy of Idaho Power Company

Manually Operated Generator

• Inexpensive to operate
• Must be located where accessible for operation 🡪 mid to lower-level elevations
• Can be limited by inversions

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Remote Generator

• More flexibility in placement
• Can target higher elevation snowpack (last snow to melt → extended seasonal flows)
• More costly to operate

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The cost efficiency and effectiveness of using each type of generator is largely dependent upon the climatology and geography of the basin where they’re being used.

CLOUD SEEDING 101

Remote Ground Generators

Images Courtesy of Idaho Power Company

Base Platform ~9 feet from ground

CLOUD SEEDING 101

Aircraft Seeding

Images Courtesy of Idaho Power Company and Ice Crystal Engineering

Demonstration of flare ignition, actual dispersion occurs in cloud*

Wing mounted “Burn-in-Place” (BIP) flares

Belly Mounted Ejectable (EJ) flares

• Burn-in-Place (BIP) flares are released in cloud
• Plane flies through cloud when conditions are sustainable for the aircraft�
• Ejectable (EJ) flares are released above cloud
• Plane flies above cloud when conditions in cloud present hazardous to the aircraft and crew

CLOUD SEEDING 101

How much water are we talking?�

• Clouds form when invisible water vapor in the air condenses into visible water droplets or ice crystals�
• Nature will condense roughly 20% of the total available water vapor as moist air rises over a mountain barrier

Figure Courtesy of Idaho Power Company

20%

CLOUD SEEDING 101

How much water are we talking?�

Winter storms are typically about 30% efficient 🡪

“only 30% of that total 20% condensed water vapor will fall to the ground as precipitation, roughly equal to 6% of the total water content”

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Figure Courtesy of Idaho Power Company

20%

6%

CLOUD SEEDING 101

How much water are we talking?�

Cloud seeding enhances the storms efficiency 🡪 ��“with cloud seeding there could be ~10-15% more (on average) of that 20% condensed water vapor hitting the ground as precipitation; an increase of <1% from the total water content”

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Figure Courtesy of Idaho Power Company

20%

<1%

CLOUD SEEDING 101

Are we “Robbing Peter to Pay Paul,” or taking water from downwind users?

• Consider that an atmospheric river is very dynamic, and, like a surface flowing river, also has many gains and losses as it moves across the continent �
• Factoring the amount of overall water content “diverted” through seeding, and the rate of resaturation, it is unlikely to see negative impacts to downwind basins�
• It is more likely that there are benefits to downwind basins, as the nucleation process in a seeded cloud can continue for a given distance downwind of the target basin → aiding downwind precipitation as a result. �
• Further research is required to better address this question

Figure Courtesy of Idaho Power Company

20%

<1%

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2017 SNOWIE RESEARCH

How do we know it works?

National Science Foundation study | $2.1M

• Field campaign winter 2017 in the Payette River Basin of Idaho
• Over 75 research aircraft and ground-based instruments
• Objectives:
• Further understand winter precipitation processes
• Determine how cloud seeding effects winter precipitation�

“SNOWIE provided the ‘… first unambiguous observations of the physical chain of events following introduction of glaciogenic cloud seeding aerosol into supercooled liquid orographic clouds.”

Proceedings of the National Academy of Sciences

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Seeded and Natural Orographic Wintertime clouds: the Idaho Experiment

“SNOWIE”

Collaborating Organizations:

National Center for Atmospheric Research (NCAR)

University of Wyoming

University of Colorado, Boulder

University of Illinois

Idaho Power Company

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Additional Efforts

BSU – Silver sampling

WMI - Research seeding aircraft

WMI - Ice nuclei counter

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2017 SNOWIE RESEARCH

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2017 SNOWIE RESEARCH

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2017 SNOWIE RESEARCH

“SNOWIE has addressed many of the scientific questions, it is now transitioning to an engineering problem”

Flight Track

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Aircraft

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Burn-in-Place Flares

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Ejectable Flares- 30 sec intervals

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“SNOWIE provided the ‘… first unambiguous observations of the physical chain of events following introduction of glaciogenic cloud seeding aerosol into supercooled liquid orographic clouds.” – Proceedings of the National Academy of Sciences

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POCATELLO NWS RADAR

January 23, 2019

“Zig-zag” pattern from cloud seeding operations

CLOUD SEEDING �IN NORTH AMERICA

HISTORY OF CLOUD SEEDING IN IDAHO

COLLABORATIVE CLOUD SEEDING PROGRAM

What is Idaho’s Collaborative Cloud Seeding Program?

• Unique partnership between:
• Idaho Water Resource Board (IWRB)– State of Idaho
• Idaho Power Company (IPC)
• Local water users in basins of operation
• IPC operates the program, the State and local water users participate in program funding
• Includes the Boise, Wood, Upper Snake River Basins of Idaho
• IPC operates independent project in the Payette River Basin, in coordination with the collaborative program. �*IPC provides forecasting support to the Upper Snake’s High Country RCD program, however the HCRCD manual program is independently operated by Let it Snow�

2003

2005

2007

2009

2011

2013

2015

2017

Upper Snake Pilot Project

2008 - 2014

SNOWIE Field Campaign

Wood River Basin Project

Upper Snake River Basin Project

Boise River Basin Project

Payette River Basin

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COLLABORATIVE PROGRAM DEVELOPMENT

History of the Collaborative Program

• 1990’s, Idaho Power Company (IPC) began investigating cloud seeding to support hydropower
• 2003, first operational program in the Payette River Basin– IPC
• 2008, ESPA CAMP 🡪 implementation of 5-year pilot project in the Upper Snake Basin– IPC
• Water users in the Wood and Boise River Basins partnered with IPC to begin new projects
• 2014, the IWRB began participation in program funding with capital for new infrastructure
• 2016, the IWRB began contributing towards program operations and modeling
• 2019, program reached existing build-out (3 aircraft, 57 remote generators, network of weather instrumentation)

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IDAHO COLLABORATIVE CLOUD SEEDING PROGRAM

Average Additional Runoff (estimated): �1,240,000 AF annually

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- 57 Remote Ground Generators

- 3 Aircraft

- Network of Weather Instrumentation

- Sophisticated Modeling technologies

- Atmospheric Science Team

COLLABORATIVE CLOUD SEEDING PROGRAM

Program Operations

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• Guidelines for the operation of cloud seeding– American Society of Civil Engineers (ASCE)
• Operational Planning
• When, Where, How, Communications
• Suspension Criteria to mitigate risks for flooding/avalanche or other hazards
• Forecasting & Analysis
• Weather Instrumentation (precipitation gages, balloons, radiometers, etc.)
• High Resolution modeling, WRF Model
• Supported by team of atmospheric scientists, 24-7

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COLLABORATIVE CLOUD SEEDING PROGRAM

Estimated Average Additional Runoff (unregulated) &�Current Project Costs (Annually)�

Boise River Basin– 273 KAF | $910K

Wood River Basin – 112 KAF | $670K

Payette River Basin* – 223 KAF | $870K

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WCM Total: 608KAF |$2.45M

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*Independent project operated by Idaho Power Company in coordination with the Collaborative. 100% Funded by IPC.

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West Central Mountains Projects

COLLABORATIVE CLOUD SEEDING PROGRAM

Northern Upper Snake

168 KAF

Upper Snake Basin Projects

Southern Upper Snake

464 KAF

Upper Snake River Basin– 632 KAF | $1.54M

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COLLABORATIVE PROGRAM SUMMARY

Current Annual Operations Cost: $3,995,000

Average Annual Runoff Generated: 1,240,000 AF

Estimated Cost Per Acre Foot: $3.22/AF

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Current Goals:

• Determine equitable distribution of program funding
• Secure long term collaborative agreements
• Assess opportunities for program expansion or enhancement
• Ongoing monitoring and analysis

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TARGET/CONTROL ANALYSIS

How do we know the amount of precipitation that was increased?

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• Target/Control analysis compares historical data between 2 areas with similar climatology
• TARGET area: Seeded area; location where seeding impacts are intended to occur
• CONTROL area: non-seeded area; location just outside target area, with historically similar climatology
• A statistical relationship is developed between the 2 areas 🡪 used to compare % change in the target area

COLLABORATIVE CLOUD SEEDING PROGRAM

COLLABORATIVE CLOUD SEEDING PROGRAM

Target/Control Zones

COLLABORATIVE CLOUD SEEDING PROGRAM

Based on Target Control Analysis

Average % Increase in Snowpack

Idaho Cloud Seeding Program Costs

Today

2008

2010

2012

2014

2016

2018

2020

2022

2024

Upper Snake Pilot Project 5YR

Upper Snake Aircraft Pilot Project 1YR

Capital

Operations & Maintenance

WRF Model Development

Cloud Seeding Analysis

Statewide Assessment

Bear Pilot Aircraft Project 1YR

Bear Feasibility & Design

Lemhi Feasibility and Design

ESPA CAMP

SNOWIE Field Campaign

WRF-WxMod Kickoff

Wood River Basin Project

Upper Snake River Basin Project

Boise River Basin Project

HB266

Analysis Phase 1

Bear River Basin Project

IWRB Participation

Analysis Phase 2

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IWRB PROGRAM DEVELOPMENT

$490K

$8.3M

$2.7M

$350K

$30K

$390K

$340K

$120K

$310K

Total State Funding: ~ $14,050,000

Costs reflect State funding contributions only

MODELING

�Sophisticated modeling technologies are necessary for:

• Planning & Development of new projects
• Forecasting & Guiding Operations
• Analysis

Weather Research & Forecasting (WRF) Model

• Designed for atmospheric research and operational forecasting
• National WRF model struggles to resolve mountainous terrain, need for development of region-specific model
• ~40km grid size 🡪 1.8km
• IPC & IWRB partnered with NCAR to develop model for Idaho
• Continued model development using data from SNOWIE
• The IWRB and IPC share costs for model development�

MODELING

Water Supply Benefits

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Augmentation of winter snowpack results in the enhancement of runoff, increasing the availability of water for a variety of uses and providing a range of other resulting benefits�

• Reservoir storage
• Extended seasonal flows due to increase of high elevation snowpack*
• Fill of natural flow water rights
• Reduced dependence on storage water
• Increased reservoir carryover
• Flow Augmentation
• Recreation
• Water quality
• Aquatic habitat

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*When using remote ground generators and aircraft

CLOUD SEEDING 101

CLOUD SEEDING ANALYSIS

Objective: Determine the impact of cloud seeding operations in the Payette, Boise, Wood, Upper Snake River Basins�

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Phase 1 Preliminary Estimates

Total Project Cost: $350K

Phase 1 completed November 2020

• preliminary estimates
• several assumptions used

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Phase 2 estimated late 2023

• refine results using sophisticated modeling tools
• development of new tools

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• WRF-Hydro model (NCAR), How much water was generated?
• RiverWare planning model (IDWR), Where does the increase in supply go to?
• Route WRF-Hydro results through RiverWare model🡪 Determine impacts

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RECENT LEGISLATION

Idaho House Bill 266 (HB266, 2021)

Directed the IWRB to:

• Continue analysis of existing cloud seeding projects
• Complete an assessment of opportunities for cloud seeding in other basins
• Authorize cloud seeding programs in Idaho�

Provides the IWRB authority to:

• Sponsor or develop local or statewide cloud seeding programs

State funds may only be used in basins where the IWRB finds that existing water supplies are insufficient to support existing water rights, water quality, recreation, or fish and wildlife�

CLOUD SEEDING PROGRAM DEVELOPMENT

Statewide Assessment

• July 2021– Contracted with the National Center for Atmospheric Research (NCAR) to look at opportunities for cloud seeding across the State of Idaho
• Provides initial look, more detailed feasibility required for basins of interest
• Looks for ground and airborne seeding opportunities (AgI)
• Opportunities for seeding with propane�

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Total Project Cost: $30K

CLOUD SEEDING PROGRAM DEVELOPMENT

Statewide Assessment

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CLOUD SEEDING PROGRAM DEVELOPMENT

Statewide Assessment

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CLOUD SEEDING PROGRAM DEVELOPMENT

• Prioritizing new projects�
• Develop criteria for IWRB (State) participation�
• Funding requirements �
• Significant stakeholder interest in new projects�

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CLOUD SEEDING PROGRAM DEVELOPMENT

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Feasibility & Design Studies�

• Bear River Basin, Completed Dec 2022 | $390K
• Includes investigation of opportunities for shared infrastructure with the Upper Snake River Basin �
• Lemhi River Basin, est Sep 2023 | $340K

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CLOUD SEEDING PROGRAM DEVELOPMENT

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Feasibility & Design Studies�

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CLOUD SEEDING PROGRAM DEVELOPMENT

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Feasibility & Design Studies�

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CLOUD SEEDING PROGRAM DEVELOPMENT

Implementation

• Development of criteria for competitive bid
• Based on results of feasibility and design study
• Request for Proposal (RFP) for an operator
• Contract Development
• Build out of Infrastructure

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CLOUD SEEDING PROGRAM DEVELOPMENT

Implementation

• Development of criteria for competitive bid
• Based on results of feasibility and design study
• Request for Proposal (RFP) for an operator
• Contract Development
• Build out of Infrastructure
• Airborne
• Ground

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Considerations

• Availability of resources
• Generators
• Aircraft
• Weather instrumentation
• Siting Equipment
• Availability of suitable location
• Accessibility– land leases
• Installation & regular maintenance

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CLOUD SEEDING PROGRAM DEVELOPMENT

Operations & Maintenance

• Multi-year contracts
• Modeling
• Forecasting
• Analysis
• Reporting
• Equipment Maintenance

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Considerations

• WRF modeling
• Licensing
• Expansion of Domain
• Weather Instrumentation
• Coordination of multiple operations

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CLOUD SEEDING PROGRAM DEVELOPMENT

Monitoring & Analysis

• Ongoing for duration of operation
• Benefit Analysis
• Assessment of program design
• Ongoing communication/education

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Jul

Jan

Jul

Jan

Jul

Jan

Jul

Jan

Jul

2022

2023

2024

2025

2026

Feasibility & Design

Implementation

Gens 1-5

Gens 6-10

Gens 11-15

Operations & Maintenance

Feasibility and Design

Award Contract

Begin Operations

Average timeline for illustrative purposes only. Actual timeline for development will vary by project.

CLOUD SEEDING KEY TAKE-AWAYS

• Cloud seeding should be approached as a long-term investment
• Cloud seeding should be used as a water management tool used to support other water management strategies
• A well managed and scientifically based program can help mitigate water supply concerns
• Cloud seeding cannot cure or reverse drought
• Cloud Seeding does not work in all areas
• The specific climatology and geography of a basin determine whether it is “seedable”
• The scale of a program is dependent upon the “seedability” of the target basin and the program budget

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CLOUD SEEDING WRAP UP

Considerations for the Development of Programs�

• Educating stakeholders�
• Development of realistic expectations:
• Objectives: What problem are you trying to solve? What is the value of seeding?
• Budget: Capital, operations, monitoring, analysis, etc; who will fund?
• Timeline: Contracting, coordination of stakeholders, permitting & accessibility�
• Long term program commitments�
• Analysis and ongoing monitoring�
• Legislation: what, if any, statutory hurdles are in place? �(i.e. water user assessments, contracting, regulatory)

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For more information on Idaho’s Cloud Seeding Programs, please contact: �Kala Golden, IWRB Cloud Seeding Program Manager | Kala.Golden@idwr.idaho.gov (208) 287-4852

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Environmental Considerations of AgI

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• Weather Modification Association (WMA) statement on AgI:�“The published scientific literature clearly shows no environmentally harmful effects arising from cloud seeding with silver iodide aerosols have been observed; nor would they be expected to occur. Based on this work, the WMA finds that silver iodide is environmentally safe as it is currently being dispensed during cloud seeding programs.”�
• Australia’s Natural Resource Commission’s review of 5 year analysis on their seeded watersheds: �“ Our review of Snowy Hydro’s analysis of data from its environmental monitoring over the first phase of the trial (2004 to 2009) found that it provides no evidence that the trial has had adverse environmental impacts over this period. The analysis provides no evidence of accumulation of silver iodide or indium trioxide in sampled soils, sediment, potable water or moss in the areas being tested. It also provides no evidence of impacts on mountain riverine ecosystems or snow habitats. In addition, it detected no difference between the concentrations of ammonia and nitrogen oxides in seeded and unseeded snow.”�
• Idaho DEQ Review�- Reviewed cloud seeding with respect to water and air quality�- Water Quality: DEQ determined it is unlikely that cloud seeding will cause a detectable increase in silver concentrations in the target watershed or pose a chronic effect to sensitive aquatic organisms�- Air quality permit not needed based on screening thresholds

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Environmental Considerations of AgI

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More than 20 comprehensive studies and data reviews of the environmental effect of the use of silver iodide for cloud seeding all concur that there is no evidence for adverse effects to human health or the environment from the use of silver iodide for cloud seeding.

– PG&E EA – 1995, 2006

– Snowy Hydro – 2004-2014, ongoing

– Williams and Denholm – 2009

– USBR Project SkyWater – 1977, 2009, 2013

– Cardno/Entrix Geochemistry and Impacts of Silver Iodide Use in Cloud Seeding (for PG&E) – 2011

– Santa Barbara County CEQA – 2013

– BSU and Heritage Environmental: Literature Review – 2015

– Sacramento Municipal Utility District – 2017

– State of Wyoming Level III Feasibility Study Laramie Range Siting and Design Final Report – 2017

– Placer County Water Agency CEQA – 2018

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