This study presents a state‐level systematic review of geospatial representation of Community Water Systems (CWSs) in the United States. We conducted online searches and contacted government, water industry, and academic representatives to obtain these data. CWS geospatial data were characterized by vector type, methodological approaches, data sources, availability to the public, entities involved in creation and maintenance of data, and CWS map requirements by primacy agency. We found that 24 states and the District of Columbia had geospatial representation of CWS estimated service area boundary (ESAB) (i.e., polygons), which were harmonized to construct a geospatial database representative of available CWS ESABs. Our findings aim to prompt discussion among myriad stakeholders on the need to create, standardize, and maintain CWS ESABs to ensure water justice for all communities.

Food, energy, and water (FEW) are primary resources required for human populations and ecosystems. Availability of the raw resources is essential, but equally important are the services that deliver resources to human populations, such as adequate access to safe drinking water, electricity, and sufficient food. Any failures in either resource availability or FEW resources‐related services will have an impact on human health. The ability of countries to intervene and overcome the challenges in the FEW domain depends on governance, education, and economic capacities. We distinguish between FEW resources, FEW services, and FEW health outcomes to develop an analysis framework for evaluating interrelationships among these critical resources. The framework is applied using a data‐driven approach for sub‐Saharan African countries, a region with notable FEW insecurity challenges. The data‐driven approach using a cross‐validated stepwise regression analysis indicates that limited governance and socioeconomic capacity in sub‐Saharan African countries, rather than lack of the primary resources, more significantly impact access to FEW services and associated health outcomes. The proposed framework helps develop a cohesive approach for evaluating FEW metrics and could be applied to other regions of the world to continue improving our understanding of the FEW nexus.

The growing impact of CO₂ and other greenhouse-gas (GHG) emissions on the socio-climate system in the Western Cape, South Africa, urgently calls for the need for better climate adaptation and emissions-reduction strategies. While the consensus has been that there is a strong correlation between CO₂ emissions and the global climate system, few studies on climate change in the Western Cape have quantified the impact of climate change on local climate metrics such as precipitation and evaporation under different future climate scenarios. The present study investigates three different CO₂ emissions scenarios: Representative Concentration Pathway (RCP) 2.6, RCP 4.5, and RCP 8.5, from moderate to severe, respectively. Specifically, we used climate metrics including precipitation, daily mean and maximum near-surface air temperature, and evaporation to evaluate the future climate in Western Cape under each different RCP climate scenario. The projected simulation results reveal that temperature-related metrics are more sensitive to CO₂ emissions than water-related metrics. Districts closer to the south coast are more resilient to severer GHG emissions scenarios compared to inland areas regarding temperature and rainfall; however, coastal regions are more likely to suffer from severe droughts such as the “Day-Zero” water crisis. As a result, a robust drying signal across the Western Cape region is likely to be seen in the second half of the 21st century, especially under the scenario of RCP 8.5 (business as usual) without efficient emissions reduction policies.

Deep connections between water resources and food and energy production—the food-energy-water (FEW) nexus—complicate the challenge of sustainably managing an uncertain water supply. We present an agent-based model as a testbed for studying different approaches to managing the FEW nexus and apply the model to the 2017–2018 water crisis in Cape Town, South Africa. We treat the FEW nexus connecting municipal water use by urban residents, agricultural water use by vineyards, and hydroelectric generation from reservoirs. We compare two scenarios for responding to drought: business-as-usual (BAU), and holistic-adaptive management (HAM), where BAU takes no action until the monthly supply is insufficient to meet demand, whereas HAM takes action by raising water tariffs when the reservoir storage level drops below its pre-drought monthly average. Simulation results suggest that holistic-adaptive management can alleviate the impact of drought on agricultural production, hydropower generation, and the availability of water for residential consumption.

Monitoring drinking water quality is essential to protect people’s health and wellbeing. In the United States, the Safe Drinking Water Information System (SDWIS) database records the occurrence of a drinking water violation regulation in public water systems. A notable shortcoming of SDWIS is the lack of the contaminant concentration level about the allowable maximum contaminant threshold. In this study, we take advantage of both the SDWIS violation database and the contaminants sampling database at the state level to examine the drinking water quality of all kinds of drinking water systems in detail. We obtained sampling data (i.e., the concentration level of contaminants) of public water systems (PWSs) in Tennessee and explored the statistical distribution of contaminant concentration data in relation to the enforceable maximum regulatory contaminant level). We use both SDWIS violation records and actual concentrations of contaminants from the sampling data to study the factors that influence the drinking water quality of PWSs. We find that different types of violations were more frequent in (1) specific geological regions, (2) counties with PWSs that serve a larger population (10,000 to 100,000 people), and (3) places with abundant surface water, such as near a lake or major river. Additionally, the distribution of measured concentrations for many contaminants was not smooth but was punctuated by discontinuities at selected levels, such as at 50% of the maximum contaminant level. Such anomalies in the sampling data do not indicate violations, but more investigation is needed to determine the reasons behind the punctuated changes.