Adapting Restoration for a Changing Climate Symposium

Delta Stewardship Council (Delta Council) | November 5th, 2021

Adapting to Climate Change and Drought in Selected California Groundwater Basins: Local Achievements and Challenges

California Natural Resources Agency (CNRA) | August 27th, 2018

Climate change projections are for higher temperatures and extreme droughts by the end of the 21st century. This will alter the natural recharge of groundwater, including

Climate change projections are for higher temperatures and extreme droughts by the end of the 21st century. This will alter the natural recharge of groundwater, including decreased inflow from runoff, increased evaporative losses, and warmer and shorter winter seasons, impacts that are likely to exacerbate already existing groundwater overdraft in many basins. Additionally, the imported surface water that can be delivered from the Central Valley Project (CVP) and State Water Project (SWP) to areas reliant on this water for groundwater recharge and consumptive use is projected to be less reliable and more expensive. Yet groundwater is a critical water supply source during drought when it compensates for reduced surface water supplies. The need for proactive adaptation strategies to address the extreme droughts projected under climate change are frequently discussed, yet there are limited examples of such groundwater management strategies. This paper therefore explores:  1) How groundwater management agencies are planning for drought  2) What new approaches are currently being used that show promise for addressing the more extreme droughts projected under climate change? 

Adapting to Climate Change: Catching and Moving Water from Big Storms

California Department of Water Resources (DWR) | February 15th, 2024

Addressing Institutional Vulnerabilities in California’s Drought Water Allocation, Part 1: Water Rights Administration and Oversight During Major Statewide Droughts, 1976–2016

California Natural Resources Agency (CNRA) | August 30th, 2018

Climate change has already begun to affect California’s hydrology and water resources, and droughts are likely to become more frequent, longer, and more intense

Climate change has already begun to affect California’s hydrology and water resources, and droughts are likely to become more frequent, longer, and more intense in the future (see Section 2.2.4). This project is designed to help state water governance and decision-making structures adapt to this changing climatic reality. We focus on how one of California’s primary water management institutions, the State Water Resources Control Board (Board), has responded in the past, and could better respond in the future, to droughts and their attendant challenges, including water shortage, uncertainty, and conflict. Click here for Part 2.

Addressing Institutional Vulnerabilities in California’s Drought Water Allocation, Part 2: Improving Water Rights Administration and Oversight for Future Droughts

California Natural Resources Agency (CNRA) | August 30th, 2018

 In California, droughts are likely to become more frequent, longer, and more intense in the future, posing increasing challenges for water management, and raising the s

 In California, droughts are likely to become more frequent, longer, and more intense in the future, posing increasing challenges for water management, and raising the stakes for effective drought response. This project aims to help state water governance and decision-making structures adapt to the changing climatic reality. In a companion report in this volume, we analyzed the strategies the State Water Resources Control Board (Board) used for water rights administration and oversight during the last four major statewide droughts. Our findings suggest that more proactive planning and preparation, enabling reduced reliance on in-drought improvisation, would improve the Board’s future drought responses. This report builds on that retrospective analysis with specific recommendations.  Click here for Part 1.

Advanced Quantitative Precipitation Information: Improving Monitoring and Forecasts of Precipitation, Streamflow, and Coastal Flooding in the San Francisco Bay Area

American Meteorological Society (AMS) | October 26th, 2022

Advanced Quantitative Precipitation Information (AQPI) is a synergistic project that combines observations and models to improve monitoring and forecasts of precipitation

Advanced Quantitative Precipitation Information (AQPI) is a synergistic project that combines observations and models to improve monitoring and forecasts of precipitation, streamflow, and coastal flooding in the San Francisco Bay area. As an experimental system, AQPI leverages more than a decade of research, innovation, and implementation of a statewide, state-of-the-art network of observations, and development of the next generation of weather and coastal forecast models. AQPI was developed as a prototype in response to requests from the water management community for improved information on precipitation, riverine, and coastal conditions to inform their decision making processes. Observation of precipitation in the complex Bay Area landscape of California’s coastal mountain ranges is known to be a challenging problem. But, with new advanced radar network techniques, AQPI is helping fill an important observational gap for this highly populated and vulnerable metropolitan area. The prototype AQPI system consists of improved weather radar data for precipitation estimation; additional surface measurements of precipitation, streamflow and soil moisture; and a suite of integrated forecast modeling systems to improve situational awareness about current and future water conditions from sky to sea. Together these tools will help improve emergency preparedness and public response to prevent loss of life and destruction of property during extreme storms accompanied by heavy precipitation and high coastal water levels - especially high-moisture laden atmospheric rivers. The Bay Area AQPI system could potentially be replicated in other urban regions in California, the United States, and world-wide.

Advancing Hydro-Economic Optimization to Identify Vulnerabilities and Adaptation Opportunities in California’s Water System

California Natural Resources Agency (CNRA) | August 27th, 2018

Long-term shifts in the timing and magnitude of reservoir inflows will affect water supply reliability in California. Hydro-economic models can help explore climate chang

Long-term shifts in the timing and magnitude of reservoir inflows will affect water supply reliability in California. Hydro-economic models can help explore climate change concerns by identifying system vulnerabilities and adaptation strategies for statewide water operations. This work contributes a new open-source limited foresight implementation of the CALVIN model, a hydro-economic model including roughly 90% of California’s urban and agricultural water demands. The model includes the ability to determine water allocations on an annual basis without knowledge of future availability, and to efficiently evaluate ensembles of streamflow projections representing a range of possible future climates. We then assess the vulnerability of the statewide system to changes in total annual runoff and the fraction of runoff occurring during winter, which primarily depends on temperature. Results are analyzed with a focus on adaptation strategies, aided by the economic representation of water demand in the model. These strategies include changes to reservoir operating policies, and conveyance and storage expansion. As water availability decreases, model results show quadratic increases in shortage cost, and corresponding increases in the marginal costs of adaptation strategies and environmental flow constraints. Reservoirs adapt to warmer climates by increasing average storage levels in winter and routing excess runoff to downstream reservoirs with available capacity. Both small and large changes to reservoir operations were observed compared to historical hydrology, showing that no single operating strategy achieves optimality for all reservoirs. Increasing the fraction of winter flow causes small increases in total shortage cost, indicating the ability to manage a changing hydrologic regime with adaptive reservoir operations. The results of this project improve estimates of the cost of climate change to California’s water system under a range of future conditions and highlight adaptation strategies that minimize costs of increased hydrologic variability. 

Agricultural risks from changing snowmelt

Nature Portfolio (Springer Nature) | April 20th, 2020

Snowpack stores cold-season precipitation to meet warm-season water demand. Climate change threatens to disturb this balance by altering the fraction of precipita

Snowpack stores cold-season precipitation to meet warm-season water demand. Climate change threatens to disturb this balance by altering the fraction of precipitation falling as snow and the timing of snowmelt, which may have profound effects on food production in basins where irrigated agriculture relies heavily on snowmelt runoff. Here, we analyse global patterns of snowmelt and agricultural water uses to identify regions and crops that are most dependent on snowmelt water resources. We find hotspots primarily in high-mountain Asia (the Tibetan Plateau), Central Asia, western Russia, western US and the southern Andes. Using projections of sub-annual runoff under warming scenarios, we identify the basins most at risk from changing snowmelt patterns, where up to 40% of irrigation demand must be met by new alternative water supplies under a 4 °C warming scenario. Our results highlight basins and crops where adaptation of water management and agricultural systems may be especially critical in a changing climate.

Alternative management paradigms for the future of the Colorado and Green Rivers

U.S. Department of Agriculture (USDA) | January 28th, 2021

The Colorado River is among the most extensively managed river systems in the world. The river’s headwaters are within the Rocky Mountains in the United States. From t

The Colorado River is among the most extensively managed river systems in the world. The river’s headwaters are within the Rocky Mountains in the United States. From there, it flows through the arid lands of the Colorado Plateau and the Basin-and-Range to its delta in northwestern Mexico. Here, the river is the only significant water supply in an otherwise starkly arid landscape and has long been called “America’s Nile.” It provides a critical water supply for nearly four million acres of irrigated land, municipal supplies for 30 million people located within and outside the basin, and more than 4,200 MW of hydropower generation capacity. The Colorado River and some of its tributaries also provide an existing or potential water supply for at least 15 Native American tribes. The river flows through seven National Wildlife Refuges, four National Recreation Areas, and five National Parks. Today, the annual consumptive uses and losses of streamflow in the basin typically exceed the amount of water available, and the river rarely flows into the Gulf of California. The impacts of climate change are likely to decrease future runoff and intensify droughts, thereby threatening current and future uses in the basin. Clearly, new ways of thinking about and managing the river need to be sought and implemented.

Amphibian responses in the aftermath of extreme climate events

Nature Portfolio (Springer Nature) | February 25th, 2020

Climate change-induced extinctions are estimated to eliminate one in six known species by the end of the century. One major factor that will contribute to thes

Climate change-induced extinctions are estimated to eliminate one in six known species by the end of the century. One major factor that will contribute to these extinctions is extreme climatic events. Here, we show the ecological impacts of recent record warm air temperatures and simultaneous peak drought conditions in California. From 2008–2016, the southern populations of a wide-ranging endemic amphibian (the California newt, Taricha torosa) showed a 20% reduction to mean body condition and significant losses to variation in body condition linked with extreme climate deviations. However, body condition in northern populations remained relatively unaffected during this period. Range-wide population estimates of change to body condition under future climate change scenarios within the next 50 years suggest that northern populations will mirror the loss of body condition recently observed in southern populations. This change is predicated on latter 21st century climate deviations that resemble recent conditions in Southern California. Thus, the ecological consequences of climate change have already occurred across the warmer, drier regions of Southern California, and our results suggest that predicted climate vulnerable regions in the more mesic northern range likely will not provide climate refuge for numerous amphibian communities.