In ecosystems characterized by flowing water, such as rivers and streams, the dynamics of how the water moves - how deep it is, how fast it flows, how often it floods - have direct effects on the health, diversity, and sustainability of underlying communities. Yet increasingly, climate extremes like droughts and floods are disrupting fragile stream ecosystems by specifically changing their internal aquatic flows. Human infrastructure, such as irrigation and dams, further disrupt these dynamics. These changes in climate and land use are leading to teh fragmentation of aquatic habtiat, degraded water quality, altered sediment transport processes, variation in the timing and duration of floodplain inundation, shifts in stream and lake temperatures, and the conversion of flowing streams to lakes and wetlands. This project, termed the “Future of Aquatic Flows,” has three primary components: 1) Regional projects focused on key research questions related to the future of aquatic flows in a changing climate at each CASC region around the country;  2) A national synthesis component which will synthesize the state of the science on how aquatic changes will be impacted by climate change, and implications for ecosystems and human communities; 3) A training component for the post-doctoral researchers who participate in this cohort of the CAP Fellows program "Future of Aquatic Flows: Towards a National Synthesis" is the umbrella project for the 2022-2024 Climate Adaptation Postdoctoral (CAP) Fellows cohort. Fellows situated at each of the nine regional CASCs will work with USGS, university, and regional partners to conduct research directly applicable to regional management priorities relating to aquatic flows, and will also work with each other on a national synthesis project on the topic. More information about the Future of Aquatic Flows CAP Fellowship can be found here: https://www.usgs.gov/programs/climate-adaptation-science-centers/science/2022-24-future-aquatic-flows 

Project Overview The Fort Berthold Indian Reservation faces challenges in maintaining stream health due to recent extreme weather events, oil and gas development, and row crop expansion. Researchers supported by this North Central CASC project will assess how these changes affect stream health while providing career development for undergraduate researchers from Nueta Hidatsa Sahnish College (NHSC) and United Tribes Technical College. The project will inform climate adaptation strategies and support sustainable resource management for the Mandan Arikara Nation. Project Summary The Fort Berthold Indian Reservation has faced many environmental challenges since 2001, including extreme drought and precipitation events, oil and gas development, and row crop expansion. These changes have likely impacted the health of prairie streams, which are important for reducing flood risk, drought risk, and erosion, and for supporting diverse plant and animal communities, cycling nutrients, and providing cultural and recreational value (e.g., angling, nature watching). Clean streams also offer valuable water for human consumption, and provide water, forage, and shelter to wildlife and livestock. This project aims to assess how climate and land-use changes affect the ecological integrity of prairie streams located within the Fort Berthold Indian Reservation. The project will build on a 2001 assessment of stream health conducted in the region, updating the assessment to consider recent extreme climate events and development. Additionally, the project will provide hands-on training and leadership experiences for undergraduate researchers from Nueta Hidatsa Sahnish College (NHSC) and United Tribes Technical College. The project is a collaborative effort with NHSC to develop the workforce and empower young researchers to pursue careers in science. The outcomes of this project will provide information on how regional factors of climate change, oil and gas development, and land-use change have impacted the health of small prairie streams within the Fort Berthold Indian Reservation. This information will be invaluable for the Mandan Arikara Nation in identifying areas for climate adaptation and management, as well as supporting community decision-making and sustainable surface water resource management.

Project Overview Climate change and human activities are threatening many sensitive aquatic species in prairie streams across the Great Plains region. Researchers supported by this North Central CASC project will combine and analyze data collected independently by Great Plains states to identify thresholds of environmental change that may lead to species loss and changes in aquatic communities. This information can guide managers in deciding whether to resist, accept, or direct change in these ecosystems to protect organisms and ecosystem services. Project Summary Prairie streams provide economic, recreational, and municipal services for human society and critical habitat for aquatic organisms including fish, crayfish, and mussels. However, environmental conditions in and around these streams have been significantly altered by landcover conversion, road and dam construction, and climate change. Many organisms in streams are sensitive to these environmental changes, which often dictate where and when they can successfully survive. Yet, across the Great Plains, there is limited knowledge about thresholds in environmental conditions that cause some organisms to disappear from local habitat. This research team will work with managers and conservation practitioners across Great Plains states to predict the level of environmental change that leads to changes in species composition across the region. Independent data collection efforts (stream monitoring data and data of aquatic species’ assemblages) across states in the Great Plains will be combined, analyzed, and summarized to identify these thresholds of environmental change and estimate the overall health of streams in prairie ecosystems. Not all prairie stream organisms will be able to track their ideal environmental conditions, so on-the-ground management actions will be needed to promote the persistence of some species. Results from this project will provide essential data to guide management and decision-making on where and when to implement actions to deal with climate and human-induced shifts in the presence and composition of aquatic organisms.

Project Overview: Native Yellowstone cutthroat trout and mountain whitefish in the Greater Yellowstone Ecosystem (GYA) are ecologically and socio-economically important species, but are threatened by drought, rising water temperatures, habitat loss, and non-native species. Researchers supported by this North Central CASC project will use climate data and extensive population records to assess the various threats to the species and to create a data visualization tool to help managers prioritize conservation actions for these vulnerable and valuable fish populations. Project Summary: In the Greater Yellowstone Area (GYA), drought, rising water temperatures, habitat loss, and non-native species are threatening the persistence of native fishes, including trout and whitefish. These fishes have enormous ecological and socioeconomic value. Recreationally, for example, hundreds of millions of dollars are spent by tourists each year to fish for these species. Understanding the vulnerability of these populations to interacting climate-related threats is critical for informing management decisions. Researchers supported by this project will use extensive records (from over 10,000 sites) collected by multiple management agencies and project partners, and climate data across the GYA to: (1) determine the effect of multiple threats on populations of native Yellowstone cutthroat trout and mountain whitefish; (2) identify the vulnerability of populations to climate change; and (3) use this information to help resource managers identify and prioritize actions that will benefit native fishes, and to identify locations where taking action would be most beneficial. Results from this project will be incorporated into the RAD (Resist-Accept-Direct) decision framework and distributed to managers through a series of workshops. The workshops will also allow the managers to help the project team build a public data visualization tool that best suits their needs. The tool will compile data and modeling results from the project and display current and future vulnerabilities of fish populations to threats at local and regional spatial scales. These products will help managers make informed decisions about how to best allocate limited time and money towards conservation of Yellowstone cutthroat trout and mountain whitefish.

Human fossil fuel use and agricultural practices have increased atmospheric nitrogen deposits (e.g., through snow and rain) to mountain ecosystems. This, along with increasing measurable climate warming is affecting soil and water acidity and altering nutrient balances. In this project, North Central CASC-supported researchers will analyze decades of unexplored data, including surface water chemistry from the Loch Vale watershed in Rocky Mountain National Park and other long-term data from Colorado and Wyoming, to understand climate change and atmospheric nitrogen deposition impacts on high-elevation ecosystems. Synthesis workshops with resource management partners will be held to apply the data products and new knowledge to frame future conditions and management options for these mountain ecosystems. Climate change and atmospheric nitrogen deposition are rapidly altering the ecology and biogeochemistry of mountain ecosystems worldwide. In the US, nearly all high elevation ecosystems are on public lands that are managed federally (e.g., National Park Service, USDA Forest Service, and Bureau of Land Management) or by states and tribes. Changes to ecological processes and species’ assemblages that began in the mid-20th century are continuing at accelerated rates, especially in high-elevation lakes, forests, and the alpine. This work will augment and extend research supported by the USGS Climate Research & Development program for the project “Interpreting the impact of global change on alpine and subalpine ecosystems – synthesizing legacy data to provide scientific and management insight for Rocky Mountain National Park and beyond.” Long-term research by this project team in Loch Vale watershed in Rocky Mountain National Park has been foundational for guiding public policy in Colorado and informing resource management in the park. While many products (a book, more than 120 papers and 22 graduate projects) have shared knowledge and insight on ecosystem processes related to climate and nutrient impacts in the area, a vast amount of data are still unpublished and unexplored. This project will evaluate past patterns of surface water chemistry and ecosystem processes using a legacy of long-term data in Loch Value watershed (from 1983) and Green Lakes Valley (from 1968). The project team will also initiate discussions and host a synthesis workshop with the North Central CASC and natural resource management partners to apply the knowledge gained from the legacy data to help frame potential future conditions and management options for alpine and subalpine ecosystems. 

Project Overview Climate change has reduced the amount of water stored in snowpacks and altered avalanche risks in mountainous areas of western North America. Researchers supported by this North Central-CASC project will develop tools for predicting and managing future water resources and future avalanche patterns, particularly in areas of major transportation corridors and important habitats. Results from this project will help federal, tribal, and state agencies manage snow water resources and mitigate avalanche hazards across temporal and spatial scales. Project Summary Climate change is profoundly affecting seasonal snowpack, with implications for water resources and water-related hazards like avalanches. Since 1950, the amount of water stored in snowpacks in western North America has decreased substantially because of declining winter precipitation and earlier snowmelt. These climatic changes also affect the frequency and magnitude of snow avalanches, which are dangerous to people, infrastructure, and mountain ecosystems. However, predicting future water resources and avalanche frequency is a challenge, as previous research from this project team demonstrates that avalanches are driven by complex interactions between weather, climate, and snowpack structure. This project has two distinct components related to snow as a water resource and a hazard. The first component addresses tribal partner needs for better tools for predicting and managing water resources and encompasses high-resolution snowpack data at a drainage scale. The second component focuses on snow as a hazard, addressing how changes to snowpack properties will impact future avalanche frequency and magnitude across the western United States. These research goals will help project team develop better tools for partners and stakeholders to address climate change impacts on snow and build more resilient communities. Understanding future changes in snowpack properties and avalanche behavior, including a shift in avalanche regime from cold and dry to warm and wet, can help managers predict and adapt to new water storage and avalanche patterns. Results from this project will provide valuable data for federal, tribal, and state management of snow water resources and avalanche mitigation.

Land and water managers often rely on hydrological models to make informed management decisions. Understanding water availability in streams, rivers, and reservoirs during high demand periods that coincide with seasonal low flows can affect how water managers plan for its distribution for human consumption while sustaining aquatic ecosystems. Substantial advancement in hydrological modeling has occurred in the last several decades resulting in models that range widely in complexity and outputs. However, managers can still struggle to make informed decisions with these models for a variety of reasons, including misalignments between model outputs and the specific decision they are intended to inform, limitations in the technical capabilities of managers that may not have the experience or resources to use complex or expensive models, or the limitations of the models themselves. This project will provide a state of the science on low flow hydrological modeling that can be used to address management decisions specific to low flow hydrology, drought, and impacts from climate change. Specifically, through a worshop series, this project will 1) detail the decisions that managers must make related to low flow hydrology, drought, and climate change, 2) provide an inventory of appropriate hydrological models and model output that align to case-by-case decision making, and 3) identify areas for model improvements to address gaps, limitations, and uncertainties. A synthesis that summarizes and aligns hydrological models to the appropriate management decisions is expected to support more informed decision making and better outcomes as a result of more efficient and effective model application.

Surface-water availability has been identified as one of the biggest issues facing society in the 21st century. Where and when water is on the landscape can have profound impacts on the economy, wildlife behavior, recreational use, industrial practices, energy development, and many other aspects of life, society, and the environment. Projections indicate that surface-water availability will be generally reduced in the future because of multiple factors including climate change, increased drought frequency and severity, and altered water and land use. Thus, it is important resource managers understand which areas are most vulnerable to reduced water availability impacts, and to what extent current conditions may change.   This project aims to create an index, the Surface-Water Index of Permanence (SWIPe), to determine when and where surface water will remain permanent on the landscape. It will build on previous work looking at streamflow permanence (using the USGS PROSPER model), surface-water inundation extent (using the USGS DSWE model), and wetland extents and permanence (using remotely sensed vegetation characteristics). Outcomes of this work will deliver crucial information on where surface water is most likely to be reduced under drought conditions.   The research team will also work with partners to develop index outputs that are useful for exploring current and potential future surface-water availability characteristics and how they might affect bison behavior. This information linking surface-water permanence with wildlife behavior will be critical to improving the ability to mitigate the potential effects of reduced surface-water availability for wildlife and humans. 

Understanding the paths by which water flows through the landscape is critical for providing fresh water for human use, maintaining ecosystem function, and better predicting how disturbances such as fire or drought may impact water quantity and water quality. Yet projected changes in climate, disturbances, and land use , are likely to alter hydrologic flow paths, and .natural resource managers increasingly require information about projected changes in water flow paths to plan for the future.  To meet this need, researchers will conduct a synthesis of changing hydrologic processes in the North Central region, and communicate the identified management options and opportunities to natural resource managers in federal and state agencies. Through this project, a postdoctoral fellow will evaluate:   1) how water flow paths and water quality vary with land-use and disturbance regimes;   2)how shifts in the timing and magnitude of snow and rain inputs alter low flows and stream permanence; and  3) how forest management techniques, such as forest thinning, can mitigate the sensitivity of forests and streamflow to droughts   The results of this project can help natural resource managers better understand the future of aquatic flows in the North Central region and will also contribute to a national-scale synthesis on the future of aquatic flows across the United States.  

Atmospheric warming is driving a shift in precipitation from snow to rain, changing precipitation intensity and seasonality, and increasing atmospheric demand for moisture in mountain river watersheds across the western United States. These changes will likely alter the timing and quantity of streamflow in rivers draining from the mountains. The Tongue River flows from the Bighorn mountains in north-central Wyoming into Montana through alpine meadows to sagebrush steppe, prior to its confluence with the Yellowstone River at Miles City, MT. The Tongue River is a little-studied river with hydrologic conditions (e.g. water flow, temperature, quantity) relevant to Tribal water rights and management, fisheries, interstate water rights, irrigation, and reservoir operations. A better understanding of the current and future hydrology of the Tongue River watershed will help Tribal water management professionals make data-driven decisions about how to manage, lease, and utilize their water rights. This project will use future hydrology estimates (2070-2099) from a previously published database containing two future climate scenarios and 32 different climate models. These data will be used in conjunction with a river system model and input from the Northern Cheyenne Tribe, a project partner, and other area stakeholders to produce estimates and analyses of future streamflow throughout the Tongue River watershed. The river system model will account for irrigation withdrawals and reservoir operations, allowing for future streamflow estimates that include these processes. Project researchers will work with Northern Cheyenne Tribal members and resource managers to ensure that the project analyses are useful for their management objectives.