Building drought early warning systems for fisheries and water management across the U.S.
As droughts become more frequent and severe, freshwater ecosystems and the valuable fisheries they support face increasing challenges. These impacts can lead to declines in fish populations, threatening biodiversity, recreational fishing, and economies. To address these threats, scientists at the USGS Northern Rocky Mountain Science Center and Montana State University are developing Drought Early Warning Systems (DEWS) to help resource managers better understand and manage drought effects on valuable cold-water fisheries. As part of DEWS, a new interactive web-based tool, TroutCast, was launched in June 2026 to help forecast drought impacts on trout populations and support stakeholders across the western U.S. prepare for and respond to drought, strengthening resilience in freshwater ecosystems and economies.
Drought Early Warning Systems for Freshwater Ecosystems and Fisheries
Extreme droughts are becoming more frequent and severe, threatening freshwater ecosystems and the critical services they provide. Drought reduces streamflows, increases water temperatures, and stresses freshwater fish populations, particularly cold-water fishes like trout. These impacts can lead to population declines, with important ecological and economic implications for communities that rely on recreational fishing, outfitting, and tourism.
To address these challenges, scientists at the USGS Northern Rocky Mountain Science Center (NOROCK) and Montana State University are developing Drought Early Warning Systems (DEWS) to help state, federal, and Tribal resource managers better understand, prepare for, and pro-actively manage drought risks to cold-water fisheries. By combining biological, hydrological, and weather data, these systems offer a comprehensive view of how drought impacts freshwater ecosystems, particularly trout habitats
How DEWS Help Manage Drought Risks
DEWS are designed to predict drought impacts on fish populations, allowing resource managers to make proactive decisions to protect freshwater ecosystems and by extension the local economies that rely on them. These early warning systems provide:
- Seasonal Outlooks (1-3 months): Short-term forecasts of drought risk on streamflow and fish populations to help prepare for immediate drought impacts on freshwater fisheries.
- Long-Lead Forecasts (1-3 years): Long-lead forecasts of fish abundance to guide planning and adaptive management.
- Streamflow Effects on Fish Production: Long-term insights into how changes in streamflow affect the production of fisheries.
With these tools, managers can better anticipate drought impacts, improve resilience, and protect ecological health, angling opportunities, and local economies.
Key Objectives of the Drought Early Warning Systems
The DEWS initiative aims to achieve the following:
- Quantify Drought Impacts on Trout Populations: Analyze long-term fisheries and climate data to understand how drought affects trout recruitment, survival, and production.
- Create Real-Time Forecasting Tools: Develop models that predict fish population vulnerability and management targets based on streamflow and climate forecasts, water quality, and fish abundance.
- Build Streamflow-Fish Production Rule Curves: Build river-specific relationships of the value of streamflow to production of valuable fisheries. These empirical relationships will help managers with long-term planning and decision-making around streamflow management and fish production.
- Develop Decision-Support Tools: Develop user-friendly tools and data visualizations to help managers and the public understand, assess, and mitigate drought risks, ensuring sustainable fisheries
Empowering Stakeholders with Data and Decision Tools
This project is creating the first regional DEWS for cold-water fisheries across the western U.S. Initially focused on Montana’s famous “blue-ribbon” trout rivers, the project is expanding to the upper Snake River system in Wyoming and Idaho, in collaboration with a broad range of partners. This initiative will help resource managers, stakeholders, and communities adaptively manage the impacts of drought and water uses on diverse freshwater ecosystems.
A key component of DEWS is TroutCast, an integrated web tool designed for data sharing and communication among state, federal, Tribal, and nonprofit partners. Released in June 2026, TroutCast provides a centralized platform for real-time drought-related data and forecasts to enhance public awareness and decision-making during drought events.
TroutCast is a decision support tool that supports the aims of the DEWS initiative by performing the following:
- Generating seasonal (1-3 month) and long-term (1-3 year) trout population trend and drought risk forecasts by Integrating long-term trout population monitoring data from state management agencies, USGS streamflow and temperature records, and weather information.
Estimating the likelihood of fisheries management actions triggered by drought-related low streamflows or elevated water temperatures
Supporting Sustainable Freshwater Ecosystems and Recreational Opportunities
This project aligns with the Department of the Interior's goal to enhance recreational fishing opportunities—a \$1.4 billion industry in Montana alone (BBER 2025)—by providing coordinated hydrological and biological data, forecasts, and decision-support tools to resource managers and the public. DEWS aims to improve drought planning, communication, and resilience for freshwater ecosystems across the U.S.
The strength of this work lies in its integrated approach and proactive decision-making tools for water and fisheries management. By improving the science foundation for drought planning and water management, TroutCast helps communities make informed decisions that safeguard fisheries, sustain fishing opportunities, guide water use (agriculture, hydropower, municipal supply), and protect freshwater ecosystem health
Through this collaborative effort, DEWS will help protect freshwater ecosystems, support local economies, and provide science-based tools for adaptive management in the face of increasing drought risks.
This project has been funded by the National Oceanic and Atmospheric Administration's National Integrated Drought Information System (NIDIS) and the USGS Ecosystems Mission Area.
As droughts become more frequent and severe, freshwater ecosystems and the valuable fisheries they support face increasing challenges. These impacts can lead to declines in fish populations, threatening biodiversity, recreational fishing, and economies. To address these threats, scientists at the USGS Northern Rocky Mountain Science Center and Montana State University are developing Drought Early Warning Systems (DEWS) to help resource managers better understand and manage drought effects on valuable cold-water fisheries. As part of DEWS, a new interactive web-based tool, TroutCast, was launched in June 2026 to help forecast drought impacts on trout populations and support stakeholders across the western U.S. prepare for and respond to drought, strengthening resilience in freshwater ecosystems and economies.
Drought Early Warning Systems for Freshwater Ecosystems and Fisheries
Extreme droughts are becoming more frequent and severe, threatening freshwater ecosystems and the critical services they provide. Drought reduces streamflows, increases water temperatures, and stresses freshwater fish populations, particularly cold-water fishes like trout. These impacts can lead to population declines, with important ecological and economic implications for communities that rely on recreational fishing, outfitting, and tourism.
To address these challenges, scientists at the USGS Northern Rocky Mountain Science Center (NOROCK) and Montana State University are developing Drought Early Warning Systems (DEWS) to help state, federal, and Tribal resource managers better understand, prepare for, and pro-actively manage drought risks to cold-water fisheries. By combining biological, hydrological, and weather data, these systems offer a comprehensive view of how drought impacts freshwater ecosystems, particularly trout habitats
How DEWS Help Manage Drought Risks
DEWS are designed to predict drought impacts on fish populations, allowing resource managers to make proactive decisions to protect freshwater ecosystems and by extension the local economies that rely on them. These early warning systems provide:
- Seasonal Outlooks (1-3 months): Short-term forecasts of drought risk on streamflow and fish populations to help prepare for immediate drought impacts on freshwater fisheries.
- Long-Lead Forecasts (1-3 years): Long-lead forecasts of fish abundance to guide planning and adaptive management.
- Streamflow Effects on Fish Production: Long-term insights into how changes in streamflow affect the production of fisheries.
With these tools, managers can better anticipate drought impacts, improve resilience, and protect ecological health, angling opportunities, and local economies.
Key Objectives of the Drought Early Warning Systems
The DEWS initiative aims to achieve the following:
- Quantify Drought Impacts on Trout Populations: Analyze long-term fisheries and climate data to understand how drought affects trout recruitment, survival, and production.
- Create Real-Time Forecasting Tools: Develop models that predict fish population vulnerability and management targets based on streamflow and climate forecasts, water quality, and fish abundance.
- Build Streamflow-Fish Production Rule Curves: Build river-specific relationships of the value of streamflow to production of valuable fisheries. These empirical relationships will help managers with long-term planning and decision-making around streamflow management and fish production.
- Develop Decision-Support Tools: Develop user-friendly tools and data visualizations to help managers and the public understand, assess, and mitigate drought risks, ensuring sustainable fisheries
Empowering Stakeholders with Data and Decision Tools
This project is creating the first regional DEWS for cold-water fisheries across the western U.S. Initially focused on Montana’s famous “blue-ribbon” trout rivers, the project is expanding to the upper Snake River system in Wyoming and Idaho, in collaboration with a broad range of partners. This initiative will help resource managers, stakeholders, and communities adaptively manage the impacts of drought and water uses on diverse freshwater ecosystems.
A key component of DEWS is TroutCast, an integrated web tool designed for data sharing and communication among state, federal, Tribal, and nonprofit partners. Released in June 2026, TroutCast provides a centralized platform for real-time drought-related data and forecasts to enhance public awareness and decision-making during drought events.
TroutCast is a decision support tool that supports the aims of the DEWS initiative by performing the following:
- Generating seasonal (1-3 month) and long-term (1-3 year) trout population trend and drought risk forecasts by Integrating long-term trout population monitoring data from state management agencies, USGS streamflow and temperature records, and weather information.
Estimating the likelihood of fisheries management actions triggered by drought-related low streamflows or elevated water temperatures
Supporting Sustainable Freshwater Ecosystems and Recreational Opportunities
This project aligns with the Department of the Interior's goal to enhance recreational fishing opportunities—a \$1.4 billion industry in Montana alone (BBER 2025)—by providing coordinated hydrological and biological data, forecasts, and decision-support tools to resource managers and the public. DEWS aims to improve drought planning, communication, and resilience for freshwater ecosystems across the U.S.
The strength of this work lies in its integrated approach and proactive decision-making tools for water and fisheries management. By improving the science foundation for drought planning and water management, TroutCast helps communities make informed decisions that safeguard fisheries, sustain fishing opportunities, guide water use (agriculture, hydropower, municipal supply), and protect freshwater ecosystem health
Through this collaborative effort, DEWS will help protect freshwater ecosystems, support local economies, and provide science-based tools for adaptive management in the face of increasing drought risks.
This project has been funded by the National Oceanic and Atmospheric Administration's National Integrated Drought Information System (NIDIS) and the USGS Ecosystems Mission Area.