River flows and water wars: emerging science for environmental decision making

www.frontiersinecology.org © The Ecological Society of America C based on the perceived needs of ecosystems versus humans for fresh water are increasingly seen in the news. In the US, a fiery debate has erupted in the Klamath basin of Oregon and California, where farmers have protested the loss of irrigation water to protect endangered fish, and where over 30 000 chinook salmon and other fish recently died, perhaps due to insufficient water quantity and/or quality (Levy 2003; Figure 1). The states of Georgia, Alabama, and Florida have been engaged for over a decade in contentious negotiations over water allocation in the Apalachicola-Chattahoochee-Flint River basin, with demands coming from the growth of metropolitan Atlanta, agricultural irrigation, and the Apalachicola Bay oyster fishery (Richter et al. 2003b). In New Zealand, a debate rages over how to allocate enough water to maintain the ecological needs of the Rangitata River while addressing the water demands of the dairy industry (Robson 2002). Similar conflicts between water requirements for irrigation and environment along the Lower Balonne River system in Australia have prompted an independent review of the science underlying river condition assessments and environmental flow recommendations (Cullen et al. 2003). As human population growth and climate change impose new constraints on the spatial and temporal distribution of water (Postel et al. 1996; Vörösmarty et al. 2000), we may expect more such water conflicts, and even environmental water “wars”, such as in the Klamath basin. Increased human demand will compete with the real needs of freshwater ecosystems (Baron et al. 2002; Poff et al. 2002; Arthington and Pusey in press). The challenge now facing river scientists is to define ecosystem needs clearly enough to guide policy formulation and management actions that strive to balance competing demands and visions. Is the current science up to this challenge? Recent events in the Klamath basin suggest a number of problems. An interim National Research Council (NRC) report evaluating the science underlying the federal management of water to protect endangered fishes in the Klamath highlighted the uncertainty of available science to support decision making (NRC 2002c). The Klamath conflict, and many others around the world, REVIEWS REVIEWS REVIEWS