Adaptable and comprehensive vulnerability assessments for water resources systems in a rapidly changing world.

Comprehensive and adaptive approaches to vulnerability assessment are crucial for guiding effective adaptation in global water resources systems. A common approach to quantify vulnerability is through indicators, which capture the 'spirit of vulnerability' while retaining practical ease-of-use benefits. However, a comprehensive meta-analysis of reveals two specific limitations of global indicator-based vulnerability assessments for water resources systems: 1) vulnerability is influenced by complex interactions among multi-domain factors, for which indicator quality and data vary; and 2) vulnerability is dynamic and evolves over time, an aspect overlooked in most approaches. In response to these identified challenges, we propose a new dynamic "build-your-own" approach to vulnerability assessment. Our approach focuses on correcting for the identified gaps and biases in indicators and data to improve assessment comprehensiveness. This approach also incorporates guidance around adapting assessments over time to better reflect vulnerability under changing conditions. The open-source nature of our approach and underlying data can facilitate the development and customization of indicator-based vulnerability assessments for diverse applications, supporting practical and relevant planning for more resilient water resources systems.

Building water resilience in the face of cascading wildfire risks.

Severe wildfire is altering the natural and the built environment and posing risks to environmental and societal health and well-being, including cascading impacts to water systems and built water infrastructure. Research on wildfire-resilient water systems is growing but not keeping pace with the scale and severity of wildfire impacts, despite their intensifying threat. In this study, we evaluate the state of knowledge regarding wildfire-related hazards to water systems. We propose a holistic framework to assess interactions and feedback loops between water quality, quantity, and infrastructure hazards as determinants of post-fire water availability and access. Efforts to address the evolving threat of wildfires to water systems will require more interdisciplinary research on the complex relationships shaping wildfire's threat to water availability and access. To support this, we need reliable long-term data availability, consistent metrics, greater research in shared contexts, more extensive research beyond the burn area, and multistakeholder collaboration on wildfire risks to water systems.

A case-study based framework for assessing the multi-sector performance of green infrastructure.

Green infrastructure is emerging as a holistic stormwater management strategy that can also provide multi-sector benefits. Robust demonstration of project success can help leverage the appeal of green infrastructure to different sectors and open the door to a variety of funding opportunities. Yet comprehensively assessing the performance of these natural systems can be challenging, especially when communicating the benefits to a wide variety of stakeholders. A cohesive, well-described assessment structure may promote a higher degree of investor confidence by more comprehensively monitoring and measuring green infrastructure success. This paper develops a conceptual framework that incorporates a robust assessment component for communicating with potential investors through the inclusion of multiple evaluation methods, performance metrics, and risk categories. The applied performance of this framework is then validated using fourteen U.S. and international case studies. We found that our framework fit a wide range of projects while maintaining a degree of flexibility that did not sacrifice specificity when applied to individual case studies. This suggests that: 1) some GI projects already incorporate one or more evaluation methods; 2) a number of highly specific metrics-particularly social and economic performance metrics-exist that are capable of capturing a wide-range of benefits that can be easily integrated into a framework; 3) the incorporation of risk and risk management technique identification could be emphasized to increase investor confidence; 4) at least some degree of standardization across projects exists already which can help future project implementers design GI strategies that best fit their needs.

Evaluating Environmental Governance along Cross-Border Electricity Supply Chains with Policy-Informed Life Cycle Assessment: The California-Mexico Energy Exchange.

This paper presents a "policy-informed" life cycle assessment of a cross-border electricity supply chain that links the impact of each unit process to its governing policy framework. An assessment method is developed and applied to the California-Mexico energy exchange as a unique case study. CO2-equivalent emissions impacts, water withdrawals, and air quality impacts associated with California's imports of electricity from Mexican combined-cycle facilities fueled by natural gas from the U.S. Southwest are estimated, and U.S. and Mexican state and federal environmental regulations are examined to assess well-to-wire consistency of energy policies. Results indicate most of the water withdrawn per kWh exported to California occurs in Baja California, most of the air quality impacts accrue in the U.S. Southwest, and emissions of CO2-equivalents are more evenly divided between the two regions. California energy policy design addresses generation-phase CO2 emissions, but not upstream CO2-eq emissions of methane during the fuel cycle. Water and air quality impacts are not regulated consistently due to varying U.S. state policies and a lack of stringent federal regulation of unconventional gas development. Considering local impacts and the regulatory context where they occur provides essential qualitative information for functional-unit-based measures of life cycle impact and is necessary for a more complete environmental impact assessment.

Changes in water consumption linked to heavy news media coverage of extreme climatic events.

Public awareness of water- and drought-related issues is an important yet relatively unexplored component of water use behavior. To examine this relationship, we first quantified news media coverage of drought in California from 2005 to 2015, a period with two distinct droughts; the later drought received unprecedentedly high media coverage, whereas the earlier drought did not, as the United States was experiencing an economic downturn coinciding with a historic presidential election. Comparing this coverage to Google search frequency confirmed that public attention followed news media trends. We then modeled single-family residential water consumption in 20 service areas in the San Francisco Bay Area during the same period using geospatially explicit data and including news media coverage as a covariate. Model outputs revealed the factors affecting water use for populations of varying demographics. Importantly, the models estimated that an increase of 100 drought-related articles in a bimonthly period was associated with an 11 to 18% reduction in water use. Then, we evaluated high-resolution water consumption data from smart meters, known as advanced metering infrastructure, in one of the previously modeled service areas to evaluate breakpoints in water use trends. Results demonstrated that whereas nonresidential commercial irrigation customers responded to changes in climate, single-family residential customers decreased water use at the fastest rate following heavy drought-related news media coverage. These results highlight the need for water resource planners and decision makers to further consider the importance of effective, internally and externally driven, public awareness and education in water demand behavior and management.

Accelerating the Integration of Distributed Water Solutions: A Conceptual Financing Model from the Electricity Sector.

Modern challenges require new approaches to urban water management. One solution in the portfolio of potential strategies is the integration of distributed water infrastructure, practices, and technologies into existing systems. However, many practical barriers have prevented the widespread adoption of these systems in the US. The objective of this paper is to address these challenges by developing a conceptual model encompassing regulatory, financial, and governance components that can be used to incorporate new distributed water solutions into our current network. To construct the model, case studies of successfully implemented distributed electricity systems, specifically energy efficiency and renewable energy technologies, were examined to determine how these solutions have become prominent in recent years and what lessons can be applied to the water sector in a similar pursuit. The proposed model includes four action-oriented elements: catalyzing change, establishing funding sources, using resource pathways, and creating innovative governance structures. As illustrated in the model, the water sector should use suite of coordinated policies to promote change, engage end users through fiscal incentives, and encourage research, development and dissemination of new technologies over time.