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Cody, Kelsey C ¹ ; Andersson, Krister ²

¹ Environmental Studies Program, ²ÊÃñ±¦µä
² Department of Political Science, ²ÊÃñ±¦µä

In the coming century another three billion people will need to be fed. Irrigation of crops is responsible for 40 percent of the globe's food supply, and climate change threatens water supply to irrigation systems. This challenge cannot be met by central governments alone: worldwide, in 1992 approximately 85 percent of irrigated cropland relied on small-scale, self-governed irrigation systems. Today, irrigators reliant on snowmelt are especially vulnerable to the effects of climate change. Irrigation is a necessity in the western United States, where approximately four fifths of irrigation organizations and a third of cropland are user-governed. In Colorado, where four fifths of stream flow originates as snow, about 75 percent of acres harvested are irrigated and about 70 percent of irrigated acres are managed by user-governed irrigation canal systems.

These self-governed systems are challenged to adapt their institutions to their changing environments, resulting in varying irrigation performance and levels of collective action. However, attributing outcomes to particular institutional characteristics of user-governed irrigation systems is difficult in practice due to the numerous data needs and the complicated interactions between these systems. And while we have good evidence and theoretical reasons to expect that certain attributes make groups more likely to sustain resources over time, how user-chosen institutions work to produce outcomes is still not well understood, especially in a highly developed, globalized economy undergoing climate change. Self-governing irrigation systems have different geographic, hydrologic, technological, social, economic, and cultural attributes to consider among their chosen institutions. Thankfully, data on these variables are available in a state with robust record keeping such as Colorado.

How do the institutions of user-governed irrigation systems interact with climate variability and change to influence irrigation performance and collective action? To answer this question, this research uses the IAD framework, CPR theory, and a natural experiment in the San Luis Valley (SLV) of Colorado to analyze the influence of particular user-group institutions on collective action and irrigation performance. Analysis of remotely sensed biomass, agricultural surveys, and water diversions reveal that physical variables influence irrigation performance greatly, but that water rights are more important. Further, collective action and irrigation performance are significantly influenced by sharing water in times of shortage. And culture influences the effect of institutions, making institutions more or less influential for performance and collective action depending on their congruence with cultural norms.

Supported by NSF Grant BCS-1115009.

Cody, K., Smith, S., Cox, M., Andersson, K. 2015. Emergence of Collective Action in a Groundwater Commons: Irrigators in the San Luis Valley of Colorado. Society and Natural Resoruces. Published Online 2/11/2015.

Poteete, A. R., M. A. Janssen, and E. Ostrom. 2010. Working together: Collective action, the commons, and multiple methods in practice. Princeton, NJ: Princeton University Press.

Sax, J., Thompson, Jr., B., , Leshy, J., Abrams, R. (2006) Sax, Thompson, Leshy and Abrams' Legal Control of Water Resources, 4th Edition. St. Paul, MN: West Publishing Co.