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Cody, Kelsey ¹

¹ Â鶹Ãâ·Ñ°æÏÂÔØBoulder

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 (Gleick, 2003). This challenge cannot be met by central governments alone: worldwide, approximately three quarters of irrigated cropland relied on small-scale, self-governed irrigation systems (Mabry, 1996), and 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 (Sax et al., 2006).

These self-governed systems are challenged to adapt their institutions to their changing environments , resulting in varying irrigation performance. 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 (Poteete et al., 2010). 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 rules 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 Institutional Analysis and Design framework, Common Pool Resource theory, and a natural experiment in the San Luis Valley of Colorado to analyze the influence of particular rules on irrigation performance. Analysis of remotely sensed biomass, agricultural surveys, and water diversions reveal that physical variables influence irrigation performance greatly, but that water rights can be more important. Further, irrigation performance is significantly improved by sharing water in times of shortage. Finally, cultural norms alter the selection and effects of rules, making rules more or less influential for performance and collective action depending on their congruence with cultural norms.

Gleick, P. 2003. Global freshwater resources: Soft-path solutions for the 21st century. Science, 302(5650): 1524–1528.

Mabry, J. 1996. Canals and Communities. Tucson, AZ: The University of Arizona Press.

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.