Managing Irrigation for Better River Ecosystems—A Case Study of the Middle Rio Grande

The technology of irrigated agriculture has often been controversial. The development agencies would praise its productivity, as only 18% of the world’s cultivated land is irrigated but produces roughly 33% of the world’s human food supply. Environmental and ecological concerns cite the degradation of natural landscapes, elimination of floodplains and wetlands, and profound impacts on wildlife habitats. Dr. Mark Fiege (University of Washington Press, Seattle, 1999) in his book entitled Irrigated Eden: The Making of an Agricultural Landscape in the American West proposes a possible reconciling view—that irrigation should be viewed as a manmade ecological system, in which land and water are modified to increase agricultural production. The reported research has used this ecological approach to study the Middle Rio Grande irrigated landscape, for the purpose of identifying options for water and ecosystem conservation. This article presents research findings related to opportunities in the agricultural sector to reduce water diversions from the river, primarily by changing the practice of continuous canal water delivery to rotational water delivery. Following the research recommendations since 2002, irrigation water users in the Middle Rio Grande Valley have reduced their diversions by more than 30%, which means more water is now available in the river for better ecology in general and for better fish and wildlife habitat in particular.