Colorado Water June 2005 - Laserfiche WebLink

Home Browse Search

$1 Billion Annually on River Restoration in U.S.: What Role for Colorado Higher Education? The National River Restoration Science Synthesis (NRRSS) Project, in the April 29, 2005 issue of Sci- ence Magazine, estimates that $1 billion is being spent annually on stream restoration projects in the U.S. The finding portrays growing economic activity associated with `manipulating' river systems. The exact nature and purpose of the manipulation is not clear in 20% of the projects contained in the NRRSS database. For proj- ects with a stated purpose, the most common goals are: • Enhance water quality; • Manage riparian zones; • Improve in- stream habitat; • Fish passage; and, • Bank stabilization. Projects with the above goals are small, with median costs of less than $45,000. A large portion of the $1 bil- lion is spent on a few large projects reconnecting flood - plains, modifying flows, reconfiguring river and stream channels, and improving recreation and/or aesthetics. Two examples of large restoration efforts are the Kis- simmee River and Grand Canyon. The study notes the difficulty in gaining an accurate picture of river restoration in the U.S., due to lack of documentation, as well as the difficulty in agreeing on criteria for judging a successful river or stream restora- tion effort, particularly with respect to judging ecologi- cal success. Colorado's higher education system has a number of scientists developing the science and technology needed to restore rivers and streams. To provide insight into the nature of the efforts supporting restoration, several re- cent and current Colorado efforts to improve the science behind river and stream restoration, are summarized below. Ellen Wohl (Colorado State University, Department of Geosciences) and colleagues contend that while river restoration is at the forefront of applied hydrologic sci- ence, many river restoration projects are conducted with minimal scientific context. They suggest that projects aiming to restore natural biophysical processes are more likely to succeed than projects with a fixed endpoint in mind. Additionally, they propose that physical, chemi- cal, and biological processes are interconnected across watersheds and time scales, so restoration projects are more likely to be successful if planned in context of entire watersheds across time. In assessing the lack of success of river restoration projects, Wohl et al. cite these key limitations: • a lack of scientific knowledge of watershed -scale process dynamics • institutional structures that are poorly suited to large -scale adaptive management • and a lack of political support to reestablish delivery of the ecosystem amenities lost through river degra- dation. In an article to be published in Water Resources Re- search, Wohl and colleagues outline an approach for addressing these shortcomings. Planning river restoration projects based on observa- tions of the whole watershed over time is illustrated by a particular river study conducted by Wohl and others. The North Fork Gunnison River project utilized his- torical sources, aerial photographs, and comparison of bankfull discharge and gradient to compare the river's braided planform to standards published for braided and meandering rivers. They determined that land use in the past few hundred years was not the primary cause for the braiding as originally assumed, but that it decreased channel stability and that rehabilitation efforts should focus on reducing the effects of land use. John Pitlick (University of Colorado, Department of Geography) and his colleagues have examined flow - sediment -biota relations along different segments of the Colorado River in western Colorado and eastern Utah. According to their work, native fishes of the Colorado River, including the endangered Colorado pikemin- now, are generally more abundant in shallow channel reaches near Grand Junction than they are downstream; the biomass of native prey fishes, benthic invertebrates and algae is likewise much higher in upstream reaches. Additional work done to model relations between flow and sediment transport indicates that habitats used by the native fish community are formed and maintained by flows ranging from about half the bankfull discharge