What Data-Driven Science Reveals About the Twisted Saga of Western Water Rights
Courtesy of Laura Taylor.
by Sabrina Pirzada
Courtesy of Laura Taylor.
In the American West, water is a sacred and scarce resource plagued by pollution, shortages, and contentious fights over legal rights, often between Indigenous peoples and business groups. At Caltech, Laura Taylor, a postdoctoral instructor in the Division of the Humanities and Social Sciences, conducts data-driven research that combines satellite imagery with historical and economic analysis to point to policy solutions for fairer resource allocation and cleaner water.
Through her work, Taylor has demonstrated that the processes tribes must go through to have their long-established legal rights to water quantified and enforced may actually be contributing to the degradation of this resource.
A Legacy of Water Injustice
Water shapes life, economy, and power, Taylor notes. But decades of overuse, drought, and inequitable allocation have made water a fiercely contested resource, particularly in the West.
Under the “first in time, first in right” doctrine, a principle of prior appropriation used in Western United States water law, the first person to divert water from a natural source and put it to “beneficial use” secures the legal right to that water. This principle was widely applied in the 19th and 20th centuries as settlers in arid western regions needed to allocate limited water resources. Historically, this system, while not explicitly codified to prioritize settlers and nontribal claimants, often did so due to a complex interplay of practical, financial, legal, and political factors.
The 1908 US Supreme Court decision in Winters v. United States created a unique category of water rights for Native American tribes that takes precedence over later nontribal appropriations under the “first in time, first in right” principle. Winters recognized that tribal water rights were implicitly reserved by treaties, even if these rights were not explicitly mentioned in the agreements. According to the court, when the US government established Native American reservations, it also implicitly reserved enough water for sustaining life there.
Despite rulings affirming tribal water rights, many tribes have found themselves caught in complex legal battles over access to their water, with cases often stretching on for decades. Part of this conflict is rooted in longstanding attitudes toward water in the western United States. “Water is a fundamentally different issue in the West,” Taylor explains. “Out here, not using water is seen as wasting it. That mentality has shaped decades of policy—and it’s a huge part of why water is so scarce today.”
A New Approach, Powered by Science
Taylor analyzed decades of data on water use and policy across the western United States, focusing her research on the impact of policy negotiations for Indigenous water rights on water quality. Her findings reveal a surprising and foreboding trend: Pollution increases during negotiations. Levels of dissolved oxygen—an essential indicator of water health—drop significantly near reservations as legal battles drag on. Pollution worsens upstream of Native American reservations, specifically, where industrial or agricultural runoff can have devastating effects on downstream water users.
Map of the watershed network within the Navajo and Hopi reservations region. Courtesy of Laura Taylor.
The outstanding question is: Why? Taylor’s findings suggest that during these negotiations, as stakeholders anticipate changes in control over water, they may be less incentivized to care for the resource due to this uncertainty. People may act carelessly not necessarily out of malice but out of self-interest, because they are uncertain about their future stake in the resource. With ownership in flux, there’s a psychological disconnect: Why invest in safeguarding a resource that may soon belong to someone else?
Furthermore, Taylor finds, these prolonged legal battles create a regulatory void in which no party feels fully accountable for the upkeep of the water, allowing pollutants to accumulate unchecked.
“To show that there is some connection between unresolved water rights and pollution is relatively easy. To show that ongoing litigation actually worsens environmental conditions is difficult,” says Jean-Laurent Rosenthal, Caltech’s Rea A. and Lela G. Axline Professor of Business Economics and director of the Ronald and Maxine Linde Institute of Economic and Management Sciences. “Taylor’s work provides critical insights into how unresolved litigation can perpetuate environmental harm.”
Taylor’s research also highlights the far-reaching consequences of this delayed action, emphasizing that ongoing water disputes put not only Indigenous communities at risk but also the broader populations who rely on these water resources. She hopes her findings will have extensive policy implications. “The federal government has taken a soft approach to these negotiations,” she says. “But we now have empirical evidence that this delay is actually harming the environment.”
In this way, Taylor hopes her research might pave the way for faster, more equitable water rights settlements that do not come at the cost of environmental degradation. As water scarcity continues to threaten the American West, Taylor’s findings could be essential to the development of policies that are not only fairer for Native American tribes but more sustainable across the board.
Taylor credits the ability to conduct this kind of wide-ranging research in part to Caltech’s spirit of interdisciplinary exploration, innovation, and fearlessness, in which economists, engineers, and scientists across disciplines come together to tackle complex challenges. This environment, Taylor says, has encouraged her to pursue questions about water rights and policy from fresh, multifaceted perspectives.
“I’m incredibly excited to be at Caltech,” Taylor adds. “The combination of hard science and social science is allowing me to ask and answer questions in ways we couldn’t before.”