Community Perspectives and Environmental Justice in California's San Joaquin Valley

University of California, Merced | December 1st, 2022

Compilation of 2018 Delta Levee Five-Year Plan Data

California Department of Water Resources (DWR) | December 14th, 2024

Information provided in the Plans of the participating 74 Levee Maintaining Agencies (LMAs) include the level of protection of the LMAS' levee system at the time of the c

Information provided in the Plans of the participating 74 Levee Maintaining Agencies (LMAs) include the level of protection of the LMAS' levee system at the time of the creation of the Plans, the proposed work within the next five years to bring the LMAS' levee system to their desired level of protection, and a summary of the cost related to the proposed work. Proposed work includes multi-benefit projects, levee projects to meet a desired level of protection, studies, emergency planning, habitat enhancement projects, and additional protection. Also in this report is a summary of the LMAs’ 2009 five-Year plans, which were submitted to DWR in accordance with the Delta Levees Special Flood Control Projects Program 2009 Five-Year Plan Solicitation.

Concepts and evolution of urban hydrology

Nature Portfolio (Springer Nature) | October 24th, 2024

Connecting the dots between water, energy, food, and ecosystems issues for Integrated Water Management in a changing climate

California Department of Water Resources (DWR) | March 7th, 2017

Global climate change creates critical challenges through increasing temperature, reducing snowpack, and changing precipitation for water, energy, and food, as well as fo

Global climate change creates critical challenges through increasing temperature, reducing snowpack, and changing precipitation for water, energy, and food, as well as for ecosystem processes at a regional scale. The water, energy, and food (WEF) nexus and related ecosystems have complex linkages with climate change implications. The overall objectives of this white paper are to provide background on this important subject, and help local water managers and the public better understand: *The ecosystem services for water, energy, and food in a changing climate. *The water-energy nexus and related climate change mitigation actions in California. *The energy used in California’s water sector and estimates of the energy intensity of regional water supplies. Particularly, this paper largely consolidates the water-energy content originally published in California Water Plan Update 2013 (Volumes I, II, and III), which included: *A framework for the energy intensity of California water systems. *An estimate of the regional energy intensity of water supplies. *Water-energy related climate change mitigation policies and actions. *Climate change mitigation benefits and tradeoffs associated with each of the 30 Resource Management Strategies found in Volume III. Furthermore, this paper will explore how water, energy, food, and climate change are interconnected with ecosystems, and why we need to understand these connections and identify the information gaps and related challenges and opportunities for ecosystem services in multiple sectors. Ecosystem services provide life support, goods, and natural resources in water, energy, and food, as well as environments. These are knowledge gaps for lack of conceptual framework and practices to interlink major climate change drivers of water resources with water-energy-food nexus and related ecosystem processes. This white paper provides information review and a conceptual framework to bridge these knowledge gaps. The case studies summarized in this paper indicate there is a large variation in energy intensities for groundwater and federal, state, and local water supplies, both within each hydrological region and among the 10 hydrological regions in California. Regional decisions were critically important in addressing water-energy conflicts and meeting local climate change challenges. These examples can be applicable for the United States and other countries with similar climate change challenges that use diversity of regional water resources for energy and food production. Future interdisciplinary research and support could bridge information and data gaps that are important for using best management practices to obtain efficiency of water, energy, and food systems related to climate change. The increased regional temperature, changes in snowpack and precipitation, and increased water stresses from drought can reduce ecosystem services and affect the water and energy nexus, agricultural food production, and fish and wildlife habitats in California. Regional decisions and practices in integrated management of water, energy, food, and related ecosystem processes are essential to adapting to and mitigating global climate change effects. Science and policy support for interdisciplinary research are critical in developing databases and tools for comprehensive analysis to fill knowledge gaps and address ecosystem service complexity, related natural resource investment, and integrated planning needs. There are significant challenges and opportunities in California to use integrated water management for water, energy, food, and the environment related to climate change. The California Water Action Plan and California Water Plan Update provide a road map and resource management strategies to use integrated water resource management for the multiple benefits of these sectors. The examples and case studies in this white paper have been used to identify information gaps and address related complexity and challenges. Questions posed in this paper regarding water and energy related to the food production cycle need further research and discussion. Overall, we should identify opportunities for innovation and technologies with multiple benefits, evaluate tradeoffs, and address integrated challenges in water, energy, food, and the environment to adapt and mitigate climate change.

Conserving California’s Coastal Habitats: A Legacy and a Future with Sea Level Rise

Nature Conservancy | May 15th, 2018

The California coast that we know today will not be the coast of the future. Sea level rise and other climate change impacts will have profound effects on o

The California coast that we know today will not be the coast of the future. Sea level rise and other climate change impacts will have profound effects on our coastline and its natural resources. California harbors high numbers of native, rare, and imperiled species in an array of unique coastal habitats. A majority of California’s coastline exists as natural habitat, over one-third of which has been preserved by a legacy of conservation efforts. Yet, this conservation legacy is at risk and we must act now to conserve the unique values of California’s coast—for both people and nature—into the future. To inform current and future adaptation decisions and conservation actions we conducted the first statewide, comprehensive assessment of the vulnerability of California’s coastal habitats, imperiled species, and conservation lands to sea level rise. Coastal habitats exist in narrow bands at the land-sea interface and are therefore extremely susceptible to inundation by sea level rise. However, some habitats may be able to adapt vertically and possibly move inland, assuming local topography and the built environment do not constrain this movement. We assessed the vulnerability of 40 habitats to sea level rise by quantifying the sensitivity and spatial extent of projected exposure of each habitat patch to intertidal and subtidal waters, relative to its ability to move inland in response to rising sea levels.

Considerations for Selecting Climate Projections for Water Resources, Planning, and Environmental Analyses

U.S. Bureau of Reclamation (USBR) | March 2nd, 2016

For over a century, Reclamation’s mission has focused on managing water resources in the Western United States. Water resources, planning, and environmental studies car

For over a century, Reclamation’s mission has focused on managing water resources in the Western United States. Water resources, planning, and environmental studies carried out to support Reclamation’s mission have routinely considered hydrologic variability, including variability of water supplies and demands from season to season and year to year. Because weather and climate are two of the primary drivers of water supply and demand, Reclamation studies have also routinely considered weather and climate variability. The SECURE Water Act directs Reclamation to evaluate the risks and impacts of climate change in long-range planning and decision making (see Section 1.1. of the main report), including: •Water resources and environmental analyses •Planning studies •Design and analysis of current and proposed infrastructure and operating plans Considering climate change involves analyzing projected changes in weather and climate conditions as well as the effects of these changes on water supplies, demands, and management.  This document provides an overview of the primary considerations relevant to selecting climate projection information for use in a given water resources, planning, or environmental analysis. Audience For technical specialists involved in selecting and using climate projections for a given study—e.g., climatologist, hydrologists, and water resources engineers— this document provides a brief overview of the models and methods used to develop climate projections (Section 2.) and relevant considerations for selecting an appropriate climate projection dataset and set of climate projections to meet their specific study objectives (Section 3.). This document also provides a detailed summary of available climate projection datasets (Section 4.) and established methods for selecting climate projections for use in a detailed analysis (Section 5.). For other study team members involved in interpreting and documenting the use of climate change information in a given study—e.g., planners, environmental specialists, and resource managers—this document provides an overview of how climate projections are developed (Section 2.) and the choices and considerations involved in selecting climate projections for analysis in the study (Section 3.).

Consumption Change Detection for Urban Planning: Monitoring and Segmenting Water Customers During Drought

American Geophysical Union (AGU) | March 11th, 2020

Demand management is a powerful way for water utilities to address the challenges of population growth and climate change. Although active conservation efforts have been

Demand management is a powerful way for water utilities to address the challenges of population growth and climate change. Although active conservation efforts have been studied extensively, recent evidence suggests households respond to many external events beyond a utility's control, including political responses to extreme climatic episodes and corresponding mass media coverage. Despite their importance, these external factors are difficult to analyze in a controlled setting, and few tools exist to evaluate their influence on customers. Here, we present a consumption change detection (CCD) method that offers new insights into how climate‐related mass media and policy events affect conservation by pinpointing the timing and magnitude of customer‐level water use shifts. We use CCD to monitor and segment the responses of residential water customers to policy and media events in Costa Mesa, California, during the severe 2012–2016 drought. Our results show consumption reductions among 75% of customers. Of these, 80% reduced water use before mandatory restrictions were imposed, coincident with intensifying state policy responses and spikes in media coverage that affected all customer types during 2014. Analysis of standardized drought consumption trajectories indicates that 16% of conserving customers increased consumption in 2015–2016. Conservation and rebound were both more likely among affluent and educated customers, suggesting that CCD can identify engaged and informed water savers who make suitable targets for water‐efficient retrofit incentive schemes. This study demonstrates CCD's potential as a novel demand analysis tool in an interconnected world where external social, political, and climatic stressors can exert an important influence on customer behavior.

Contraction of the World's Storm-Cloud Zones the Primary Contributor to the 21st Century Increase in the Earth's Sunlight Absorption

American Geophysical Union (AGU) | June 8th, 2025

Recent Earth energy budget observations show an increase in the sunlight absorbed by the Earth of 0.45 W/m2 per decade, caused primarily by a decrease in cloud reflectio

Recent Earth energy budget observations show an increase in the sunlight absorbed by the Earth of 0.45 W/m2 per decade, caused primarily by a decrease in cloud reflection. Here we decompose the solar radiative budget trends into general circulation and cloud controlling process components. Regimes representing the midlatitude and tropical storm zones are defined, and the trends in the areal coverage of those regimes which are potentially induced by circulation changes are separated from trends in the cloud radiative effect within each regime which are potentially induced by changes in local cloud controlling processes. The regime area change component, which manifests itself as a contraction of the midlatitude and tropical storm regimes, constitutes the largest contribution to the solar absorption trend, causing decreased sunlight reflection of 0.37 W/m2 per decade. This result provides a crucial missing piece in the puzzle of the 21st century increase of the Earth's solar absorption.

Contraction of the World's Storm‐Cloud Zones the Primary Contributor to the 21st Century Increase in the Earth's Sunlight Absorption

American Geophysical Union (AGU) | June 8th, 2025

Recent Earth energy budget observations show an increase in the sunlight absorbed by the Earth of 0.45 W/m2 per decade, caused primarily by a decrease in cloud reflectio

Recent Earth energy budget observations show an increase in the sunlight absorbed by the Earth of 0.45 W/m2 per decade, caused primarily by a decrease in cloud reflection. Here we decompose the solar radiative budget trends into general circulation and cloud controlling process components. Regimes representing the midlatitude and tropical storm zones are defined, and the trends in the areal coverage of those regimes which are potentially induced by circulation changes are separated from trends in the cloud radiative effect within each regime which are potentially induced by changes in local cloud controlling processes. The regime area change component, which manifests itself as a contraction of the midlatitude and tropical storm regimes, constitutes the largest contribution to the solar absorption trend, causing decreased sunlight reflection of 0.37 W/m2 per decade. This result provides a crucial missing piece in the puzzle of the 21st century increase of the Earth's solar absorption.

Contribution of Changes in Atmospheric Circulation Patterns to Extreme Temperature Trends

Nature Portfolio (Springer Nature) | July 24th, 2015

Surface weather conditions are closely governed by the large-scale circulation of the Earth’s atmosphere. Recent increases in the occurrence of some extreme wea

Surface weather conditions are closely governed by the large-scale circulation of the Earth’s atmosphere. Recent increases in the occurrence of some extreme weather phenomena have led to multiple mechanistic hypotheses linking changes in atmospheric circulation to increasing probability of extreme events. However, observed evidence of long-term change in atmospheric circulation remains inconclusive. Here we identify statistically significant trends in the occurrence of atmospheric circulation patterns, which partially explain observed trends in surface temperature extremes over seven mid-latitude regions of the Northern Hemisphere. Using self-organizing map cluster analysis, we detect robust circulation pattern trends in a subset of these regions during both the satellite observation era (1979–2013) and the recent period of rapid Arctic sea-ice decline (1990–2013). Particularly substantial influences include the contribution of increasing trends in anticyclonic circulations to summer and autumn hot extremes over portions of Eurasia and North America, and the contribution of increasing trends in northerly flow to winter cold extremes over central Asia. Our results indicate that although a substantial portion of the observed change in extreme temperature occurrence has resulted from regional- and global-scale thermodynamic changes, the risk of extreme temperatures over some regions has also been altered by recent changes in the frequency, persistence and maximum duration of regional circulation patterns.