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Multiobjective River Corridor Management: An Introduction to Issues: Recommendations for Implementing Programs Jon Kusler Association of Wetland Managers INTRODUCTION This paper describes a relatively new approach to rivers and streams and adjacent lands in the United States -- multiobjective river corridor management -- including the relationship of such management to protection and restoration of riverine wetlands. A multiobjective approach to river and stream corridor management has gained increasing support and momentum in the U.S. over the last two decades at all levels of government, particularly at local and state levels. Multiobjective management of rivers alone is not new concept. But, a multiobjective management approach for rivers and their adjacent corridors including floodplains and wetlands with a balanced consideration of natural values is quite new. It reflects a shift in emphasis and implementation techniques in river and stream management. This shift has been driven by cost-consciousness, the need to simultaneously meet a larger number of goals, and a broadened interest in environmental values. The goals for multiobjective river corridor management efforts vary. But an attempt to simultaneously achieve all or many of the following goals is common: - reduce present and potential future flood and stormwater losses, - reduce present and potential future erosion losses (streambank erosion, meander) and sedimentation problems, - protect and, in some instances, enhance water quality from both point and nonpoint sources of pollution by reducing point and nonpoint sources and increasing the capacity of the river or adjacent wetlands to absorb pollution, - protect and, in some instances, improve river water quality for water supply purposes, protect and, in some instances, enhance aesthetic values as viewed from the river and adjacent lands for boaters, hikers, joggers, residential users, etc., and promote waterfront renewal and economic revitalization for the adjacent floodplain. A multiobjective approach attempts to simultaneously achieve as many goals as possible, recognizing the interdependencies of rivers and streams and adjacent floodplain and wetland areas and of upstream and downstream areas (See Figure 1). The approach emphasizes long term as well as short term hydrologic and geomorphological processes and the protection of natural functions and values. The approach does not reject traditional river engineering but rather broadens river management goals and techniques. It gives equal weight to alternative approaches which may be less costly and environmentally damaging. It emphasizes balanced consideration of structural and nonstructural adjustments of man's activities to natural hazards and natural values including various "soft engineering" techniques such as "bioengineering" for stream bank erosion control rather than use of rip rap or concrete channels (Sotir, this volume). The movement in the United States toward multiobjective river corridor management may be traced to the pioneering work of Dr. Gilbert White in the 1940s (White 1945) and to a 1966 federal task force on flood control on which Dr. White served. Discouraged with the expenditure of hugh sums of federal monies and continued large flood losses, the Federal Flood Control Task Force made sweeping recommendations for changes in federal policy. These recommendations, incorporated in House Document 465 (Task Force on Federal Flood Control Policy 1966) have formed the cornerstone of federal floodplain management policy since the late 1960's. The document recommended a changed philosophy for floodplain occupancy which considers net benefits of activities at floodplain locations and at non-floodplain locations: - protect and, in some instances, enhance fish, waterfowl, and other wildlife by protecting and enhancing habitat (including instream, wetland, and slope or bank habitat), food chain support, water quality, etc., - protect and enhance the recreational opportu- nities for both the river (canoeing, boating, swimming, fishing, hunting) and adjacent cor- ridor lands (hiking, bird watching, jogging, scenic driving, viewing from residences or commercial establishments, etc.), "Floodplain occupation in which benefits do not exceed the estimated total costs, or which yields lower returns than other uses such as recreation and wildlife conservation is undesirable, because it causes an eventual net loss to society. Any public policy which encourages submarginal develop- ment adds to these losses." This paper first examines differences between traditional river engineering approaches and multiobjective approaches. It then provides Z