Violence associated with freshwater resources has occurred throughout recorded history, with water triggering violence and armed conflict, water or water systems being used as weapons, and water or water systems becoming casualties during conflicts. Understanding the causes of water-related violence and regional and temporal trends is critical for identifying priority areas for conflict resolution and strategies to reduce the risk of future conflicts. The purpose of this paper is to introduce the structure, content, and design of The Water Conflict Chronology, an open-source online database, which tracks water-related conflicts from around the globe. Some analysis is provided with caveats about the limitations of the data, but further analysis will be forthcoming. The database is updated approximately annually using information from other conflict-related databases, news reports, eyewitness accounts, and a review of historical documents. As of October 2022, the Chronology had 1298 entries, from the earliest events around 2400 BCE through early 2022. Initial analysis of data shows trends in the nature, location, and social and political characteristics of water-related violence, including a sharp increase in water-related violence in recent years, especially where water has been a trigger or casualty of violence, a concentration of events in the Middle East, southern Asia, and the Sahel, and the increased targeting of civilian water systems during civil and regional armed conflicts.

Urban stormwater is increasingly being considered a viable alternative water supply in California and throughout the southwestern U.S. However, current economic analyses of stormwater capture do not adequately examine differences in stormwater project types and do not evaluate co-benefits provided by the projects. As a result, urban stormwater capture is undervalued as a water supply option. To advance economic analyses of stormwater capture, we determined the levelized cost of water in U.S. dollar per acre-foot of water supply (AF; 1 AF = 1233.5 m 3) for 50 proposed stormwater capture projects in California, characterizing the projects by water source, process, and water supply yield. In addition, we incorporated reported co-benefits of projects into the analysis to determine the net benefit of proposed projects. Proposed urban stormwater capture projects were more expensive than non-urban stormwater capture projects on a per-volume basis ($1,180 per AF and $531 per AF, respectively); however, this was primarily driven by the relatively large size of the nonurban stormwater capture projects examined. When incorporating the limited number of reported co-benefits of the projects, the expected levelized cost of water from urban stormwater capture projects decreased dramatically. For projects that reported even a limited number of additional benefits, the net levelized cost decreased from $1,030 per AF to $150 per AF, with some of the projects demonstrating a net benefit. Thus, scaling urban stormwater capture projects to capitalize on economies of scale and incorporating co-benefits of projects can dramatically improve the economic feasibility of these projects. This work demonstrates that stormwater capture can present a cost-effective water supply option in California, and that beyond California, fairer comparisons among projects and inclusion of cobenefits can provide decision makers with adequate information to maximize investments in water management.

Residential sprinkler audit programs are commonly used as a tool for municipalities to achieve their water conservation goals, but little evaluative work has been done to measure the water savings from these efforts. Results include a statistical analysis of the impact of 2,000 residential sprinkler audits in Colorado and guidance for future conservation program design. Analysis of water billing records from at least two years pre‐ and two years post‐irrigation audit from five seasons (2007–2012) were used to answer key questions about irrigation audit impact on water use as well as to understand factors that contribute to water savings from irrigation programs. While the average water savings one year post‐audit were 5,000 gal/participant and median savings were 2,000 gal/participant, high variability among savings beyond one year suggests that audits may not produce as robust long‐term benefits.