River systems, including watersheds and surface and ground waters, are an integral part of the universal hydrologic cycle. Humans have become part of this cycle, both in our need for water and our effects on the quality and distribution of water. Increasingly, humans are influencing the global hydrological cycle. Human populations have grown exponentially from the beginning of time to reach a billion persons in 1800 A.D., and within the last 200 years increased to 6.5 billion, with projections to nearly 12 billion in the next 100 years. Clean water for drinking, agriculture, and industry is a critical resource that is increasingly endangered. Recent natural and human-created disasters, including tsunamis, earthquakes, hurricanes, industrial accidents, and aquifer depletion, demonstrate the vulnerability of water resources. Humans cannot continue to exist in our present state without becoming more in harmony with our environment-developing sustainable river systems is an integral and critical element of promoting a better future for people throughout the world.
 
Washington University in St. Louis, located within the Mississippi River water-shed, at the confluence of some of the world's largest rivers, has an opportunity to use its many talents to help develop a holistic interdisciplinary approach toward the development of sustainable river systems. Covering about 3.2 million km2 the Mississippi River watershed is the third largest in the world. Every human living within this basin, indeed everyone in the United States, is affected by the environmental, historical, economic, and political events that take place here. One only has to look at the financial, political, and human dimensions of the 1993 flood to see how broad the effects are. More recently, Hurricane Katrina and its aftermath amply demonstrate the consequences of environ-mental impacts on human and nonhuman populations alike. From economic losses associated with interrupted shipping to significant damage to fish stocks in the Mississippi River delta and estuary, environmental and ecological problems in the Mississippi and its tributaries affect our entire economy, society, and culture. Indeed, rivers are the lifeblood of most societies. Events in China, where 100 tons of benzene were released into a tributary of the Amur River, demonstrate the direct effects of environmental issues on humans living along rivers or in their watersheds. As demonstrated by this most recent environmental catastrophe, environ-mental effects on river systems do not respect national boundaries and the consequences affect people from headwaters to the mouth and in nearby bays, estuaries, and coasts.
 
With its research and educational leadership in medicine, engineering, and the arts and sciences, Washington University can provide campus-wide resources to integrate medicine, anthropology, earth sciences, engineering, business, economic, political science, and law to create a unique research and educational experience for its students and be an asset for the community. Focusing on environmental and ecological issues associated with promoting sustainable river systems is a logical opportunity for the University. Our location near the confluence of two of America's greatest rivers provides an ideal context for studying rivers as interrelated ecosystems and allows researchers from multiple fields and disciplines an opportunity to come together to share ideas and to create solutions for many of the problems that face the world's populations.
 
Many of the issues facing populations living within river watersheds will require interdisciplinary analysis if they are to be effectively studied. For example, while major progress has been made on many river systems in the United States, 33 years after the passage of the Clean Water Act, many rivers, including the Missouri and Mississippi, are still not fishable or safe for swimming. On a global basis, rivers and river systems are under increasing threat. Washington University scholars are already leading research in areas related to sustainable river systems. Work in the School of Engineering is exploring the effects of land-use changes on lakes as well as natural bio-geochemical processes within river systems. Recent research by J. Chase on disease vectors among birds identifies river system habitat issues as an important contributor to increased disease spread. Habitat loss or alteration within watersheds is specifically related to geological and geomorphic issues studied by Criss et al. in EPSc; their findings play a direct role in policy studies of how recent floodplain construction is negatively affecting down-stream habitats as well as threatening greater flooding in the future. These issues directly and indirectly play into the ongoing contentious disputes about the spring rise on the Missouri and how water rights are shared among the states along this river. The Interdisciplinary Environmental Clinic is part of a national collaborative of advocacy groups and legal and technical support organizations working collectively to improve water quality in the Mississippi River. Clearly, the issues are interrelated and require a holistic approach if they are to be understood beyond the confines of specific disciplines or even specific governmental agencies and advocacy groups.
 
Key issues:

• Water quality. This theme permeates virtually all other concerns and relates directly to the issue of developing sustainable river systems. Water quality encompasses problems such as health effects of water contamination, how water supplies are polluted (point vs. non-point sources), how we treat, distribute, use, and reuse water, how different organisms respond to water-quality issues, who is responsible for and who pays for potable water, and how we remediate affected river systems, to name only a few of the major problems.
• Floodplain development/habitat impact. At home and throughout the world, humans are increasingly populating and altering floodplains and floodplain habitats. What are the ecological and environmental effects and how can they be mitigated; what are the economic and political processes and consequences?
• Human alteration of rivers (e.g., levee construction, dams and locks, cutoffs, habitat loss, wetlands reclamation/restoration). What happens when you levee a river or alter its course? How does development affect river and watershed habitats? What are the best policies for encouraging habitat preservation? What are the real economic and political costs and benefits of engineered river facilities?
• Ecosystem biology. Rivers and watersheds are not well understood as a connected ecosystem. Basic research on ecosystem biology is required to better understand at micro- and macro-levels the effects of altering watersheds and rivers.
• Health and ecosystem effects of water contamination. Human-introduced fertilizers, herbicides, and insecticides (even caffeine and drug metabolites) are being transported within local watersheds and are entering the water supplies of downstream consumers. Urban runoff and sewer overflows are increasingly common problems within river systems. How can we control regulated and unregulated discharge of pollutants from point and non-point sources? What is the fate of emerging contaminants (e.g., pharmaceuticals) in natural systems and in water and wastewater treatment plants? What policies and regulations can be implemented to minimize system-wide impacts, and how can these policies be effectively and economically implemented?
• Effects of watershed clearing (e.g., sediment transport, pollution transport, mobilization of heavy metals, urban runoff, sewage discharge). What happens when watersheds are cleared of trees, intensively farmed, or covered with asphalt? How does this affect river water quality, groundwater recharge, and geological/geomorphic thresholds? What are the impacts on the overall nutrient cycle or on the movement of sediments or pollutants? How do these issues affect downstream populations?
• Industrial/residential pollution and their environmental impact (air, water, groundwater, health effects, law, policy). As populations grow, how do we under-stand and cope with increasing human waste, greater pollution, development, noise, health impacts, increased density, and delivery of social/governmental services?
• Drinking water issues, distribution networks, new treatment technologies, terrorism, and homeland security.
• Sustainable watershed development. Is it possible to attain a sustainable level of land/water use? What would be required and how could it be implemented? What are the economic and business costs and opportunities? What are social costs and benefits of alternative land-use initiatives (e.g., greenways, bike paths, less dense housing, brownfield reclamation)?

Interactions:
 
Because watershed/river issues are place-based, they touch on or can be incorporated into many other environmental research issues. There is obviously a great deal of overlap with health-related issues. Furthermore, watershed/river systems are potential contexts for exploring and studying ecology and biodiversity. Because of the human dimension of watershed/river systems, they are also obvious locations for some studies of energy development/sustainable use and aerosols. For example, there are important issues surrounding the use of river water for the production of energy. This concern is evident in the use of hydroelectric facilities, but it also encompasses problems such as water intake for cooling power plants and subsequent thermal pollution when warm water is discharged. Another example is river system contamination by mercury-the largest source of which is anthropogenic combustion of coal. An example of the coupling of air quality/aerosol issues and water quality is the gasoline additive MTBE. This product was added to gasoline to address an air-quality issue but ended up impacting groundwater quality across the country. Similarly, the contribution of NOx (e.g., from automobile exhaust, power plants) as a source of nutrients to surface waters in some parts of the United States is an area where there is overlap between those interested in air quality and river systems. Watersheds/rivers are also important contexts for understanding, developing, and implementing laws, regulations, and policies that integrate environmental issues with those related to economic, political, and social/cultural factors.
 
Scholarship at the center will also integrate with existing University entities, such as the program in nanotechnology, the McDonnell Scholars Academy, the program in Inter-national and Area Studies, the Center for Urban Research and Policy, the Center for Ethics and Human Values, The Center for Materials Innovation, the Gephardt Institute, and the Weidenbaum Center.
 
Washington University Strengths:

• Location at the confluence of Missouri and Mississippi. In addition, Tyson Research Center is situated near the Meramec River, one of the largest undammed rivers in the upper Mississippi River watershed. Our unique location provides faculty and students ready access to research and teaching opportunities.
• Existing campus facilities. The Medical School, Danforth Campus, and Tyson Research Center represent distinctive locations where faculty and students can conduct experiments in different physical settings.
• Existing/ongoing research and teaching in engineering, arts & sciences, architecture, and law
• Interaction with advocacy groups/governments/industry
• Solid research infrastructure and multiple opportunities for outreach and interaction with existing academic/research/governmental/policy entities.

Key Players:
 
EPSc (Amend, Criss, J. Smith); Anthropology (Kelly, Kidder, Stone); Architecture (Wolff, Hoal); History (Kastor); AmCS (Fields); Biology (Chase, Knight); Political Science (Lowry); Philosophy (Palmer, Evans); Law (Lipeles); Engineering (Buescher, Schwartz, Giammar, Angenent, Falke, Biswas, EPRI); Economics (Peterson, Pollard).
 
Areas that need further development:

• Cutting-edge teaching opportunities in areas related to sustainable river systems development. Initial focus would be on existing courses but should expand to include new courses, especially interdisciplinary, team-taught courses that incorporate scholarship from different schools and colleges.
• More ecosystem scientists/ecologists
• Resources for geospatial information systems (GIS) for research and teaching
• Integration of research among engineering and science disciplines; inclusion of economics and business
• Development/expansion of Tyson as a research facility

Summary:
 
The Center for Sustainable River Systems Research is distinctive because there is no such comprehensive entity in the United States or elsewhere. Many academic institutions have interests in water resources, but none are built around an interdisciplinary conceptualization of rivers as systems integrating atmospheric, surface, and ground water. The center will be positioned to undertake research in any location around the globe and to explore issues without regard to conventional disciplinary boundaries. By focusing on sustainable river systems research, center researchers can engage in scholarship at all levels, from the micro to the macro and from ground water to surface water. The topic can be engaged by researchers in engineering, sciences, humanities, and social sciences, and can encompass basic research as well as applied policy. By capitalizing on our location at the confluence of two of the world's great rivers and by leveraging our outstanding faculty and building on our existing strength, we have an opportunity to be a global leader in sustainable river research and the development and implementation of effective science and policies that will benefit the huge numbers of humans that are sustained by rivers and their water.
 
The center is also distinctive because it will provide a unique opportunity to integrate academic research with undergraduate and graduate education. By using our location as a classroom and by specifically developing our physical facilities as research and teaching locations for studies of sustainable river systems, we can position ourselves at the cutting edge of university teaching and research. Students at the University will be able to take their education out of the classroom and apply it in the field. By providing practical and exciting research opportunities, we will make our students better scholars, decision makers, and leaders.