HR: 09:45h
AN: NB21G-06 INVITED     [Abstracts]
TI: A General Approach for Establishing National Priorities for River Restoration
AU: * Schmidt, J C
EM: jack.schmidt@usu.edu
AF: Aquatic, Watershed, and Earth Resources, Utah State University, Logan, UT 84322-5210 United States
AB: The effort to restore the nation's rivers necessarily involves the interplay among physical and biological science, engineering design and implementation, and policy science. Policy science helps decision-makers prioritize where to undertake restoration and what the goal or objective of remediation should be. Some commentators have advocated that restoration be pursued on streams that constitute the "low hanging fruit," that is the streams where the greatest gain can be obtained for the least investment. There is a general need for a unifying concept with which to evaluate these policy tradeoffs. The restoration response function defines the relationship between the costs of flow and sediment alteration and the results of those actions in reversing undesired channel change. Development of these functional relations should be an essential element in stream restoration, especially where there are many environmental management programs in a basin and they all affect regional water delivery and hydroelectric power production. The nation's regulated streams - those that are extensively dammed or diverted - are typically proposed for restoration. These streams can be distinguished into three categories: (1) physically transformed, (2) essentially wild and in sediment deficit, and (3) essentially wild and in sediment surplus. Physically transformed streams are those that have been channelized or leveed. Streams in sediment deficit are those whose sediment delivery has been decreased much more than has the ability to transport the available supply. Those in surplus are those whose sediment delivery now exceeds the ability to transport the available supply. Major efforts at riverine ecosystem rehabilitation are underway in all types of streams. The Lower Colorado River Multi-Species Conservation Program and efforts on the lower Missouri River and the Columbia Rivers are focused on transformed rivers. The Grand Canyon Adaptive Management Program is focused on a river in sediment deficit. The Upper Colorado River Endangered Fish Recovery Program and the Trinity River Restoration Program are focused on streams in sediment surplus. Restoration response functions differ significantly in transformed segments and in conditions of sediment deficit and conditions of sediment surplus. In conditions of severe sediment deficit, large costs are sustained without significant results, but larger benefits are potentially possible for smaller costs in conditions of sediment surplus. Policy makers would be well served if restoration response functions were generally available and regional priorities were made based on an assessment of the comparative costs and benefits of altering flow regimes in different parts of the basin.
DE: 1803 Anthropogenic effects
DE: 1824 Geomorphology (1625)
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly