Water Resources Research Act Program

Details for Project ID 2019MT157B

Dynamics of changing water availability and water rights administration in the Upper Clark Fork River Basin, MT

Institute: Montana
Year Established: 2019 Start Date: 2019-03-01 End Date: 2020-02-28
Total Federal Funds: $2,000 Total Non-Federal Funds: $880

Principal Investigators: Holly Nesbitt

Abstract: Water is a critical component of social-ecological systems, specifically in terms of quantity, distribution, and timing. Although aridity is expected to increase globally under climate change projections (Flörke et al. 2018; Greve et al. 2018; IPCC, 2014), societal governance of water use and conservation can also be a significant driver of water scarcity at multiple scales around the globe (Grafton et al. 2013; OECD, 2011). A focus of water governance research and its application to date has been on adaptive governance at aggregate scales, such as the basin-level (Cosens & Gunderson, 2018; Chaffin et al. 2014; Moss & Newig, 2010; Pahl-Wostl, 2015); there remains a need to understand social-ecological dynamics at the level of individual decision-makers to clarify how systems currently function and are likely to respond to future social-ecological conditions. We plan to simulate interactions among individual water users and the environment with an agent-based model (ABM), enhanced with consumer data and coupled with an existing hydrologic model for Montana (MT). This coupled approach will allow us to predict flows and water use under different governance and climate scenarios to identify and understand areas of potential adaptive capacity to respond to increasing water scarcity. In western MT, water users face both climate change (Barnett et al. 2008) and imminent governance challenges due to the recent quantification of previously undetermined water rights held by the Confederated Salish and Kootenai Tribes (CSKT, 2015). In most western U.S. states, water rights are governed by prior appropriation, where older rights have higher priority than younger rights, and higher priority rights holders can call upon those with lower priority rights upstream to reduce water use. In the Upper Clark Fork watershed, a large tribal instream water right (non-consumptive) has been recently confirmed with a priority date older than many upstream irrigators’ water rights. This change means some irrigators in the basin, with rights previously uncontested since colonization, will have to reduce their water use during drought. The problem is that the impacts of this change are not known; this information will be necessary to mitigate unintended effects. Colleagues at the University of MT have developed a model that predicts flows and water use for MT (EPSCoR, 2018; Maneta et al. 2014); the existing model does not yet consider how relevant social dynamics, such as state-based administration of water rights and the potential for local conflict and economic impacts of reduced water rights, interact with the ecological system to determine outcomes. We propose to integrate governance within this model to address anticipated mechanisms in the emerging social-ecological system to incorporate feedbacks between water use decisions and water availability. In the Upper Clark Fork basin, the hydrology is well described, there is opportunity for a natural governance experiment, and the scope of this effort is tractable. We are immersed in a network of people, including researchers (EPSCoR; Maneta), planners (Shawn Johnson, UM Env. Policy Center), and community members (watershed groups), who will continue to help refine this approach and use the results.