UC Davis

There is a strong scientific consensus that river corridors are badly damaged by societal impacts, costing the United States alone more than $76 billion yr-1 and harming many species beyond assignment of any dollar value. In response to this problem, society has called upon governments, scientists, and private consultants to rehabilitate rivers. A scientific consensus has emerged that process-based rehabilitation within a watershed-scale context is highly important for a successful outcome. Unfortunately, the science underlying linked abiotic-biotic processes in rivers is still rudimentary, relative to the complexity of the ecosystem to design and build process-based solutions with the same success evident in the practice of medicine or the manufacture of buildings and other civil structures. Many existing practices have been vetted and found by scientific experts to be largely ineffective. Multiple paradigms for rehabilitation based on different combinations of scientific complexity, universality, and comprehensivity are diverging and splintering the technical community. Lacking a consensus among academic scientists and private practitioners, it is too soon to establish professional standards or regulatory requirements. Within this context, geomorphologists have a key role in getting involved in all phases of river rehabilitation and bringing their perspective and capabilities to bear on the grand challenge of preventing environmental collapse. © 2013 Elsevier Inc. All rights reserved.