PHILADELPHIA — A group of the nation’s leading river scientists, including Dr. David Hart and Jamie Carr of The Academy of Natural Science’s Patrick Center for Environmental Research, has taken an important step to propel the country’s $1 billion-per-year river-restoration movement from an art to a science.
A policy paper, appearing in the April 29 edition of the journal Science, details key results from the first comprehensive effort to evaluate the science and practice of river restoration throughout the nation.
The group of 25 scientists has developed a database of 37,099 restoration projects, and have used it to draw conclusions about regional and national trends in the numbers and types of projects being performed, along with their costs and environmental benefits. Although restoration is clearly beneficial to the health of streams and rivers, one key finding is that much more work needs to be done to evaluate the environmental benefits of different restoration practices.
“River restoration” applies to activities such as reforesting riverbanks to curb erosion, recreating the natural river channel to reduce downstream flooding, restoring wetlands to filter pollution, and removing dams to allow fish to migrate freely up and downstream. Restoring the natural form and function of rivers and streams helps reverse a decline in water quality.
Pennsylvania is a leader in removing old and obsolete dams from rivers to improve their health. One restoration “success story” occurred in Pottstown, Pa., in 2000, when a small dam was removed from Manatawny Creek. Monitoring by The Academy of Natural Sciences and its partners has yielded one of the first comprehensive assessments of the large-scale physical, chemical and biological changes in a river system following dam removal.
Some 30 more are scheduled for removal in the next two years. “Dam removal can be a very effective method of improving river health, but additional studies are needed to predict how different rivers will respond to this novel restoration practice,” Hart said.
According to the authors of the Science paper, at least $14 billion has been invested in river restoration since 1990. The average cost per project is just $45,000. California, the Chesapeake Bay watershed, and the Pacific Northwest are hotspots of restoration work.
“River restoration is evolving from an art into a science. A critical first step in this evolution has been to document what is being done in the name of river restoration,” said Dr. Emily Bernhardt, lead author of the paper.
It’s no mystery why river restoration is booming,” said Andrew Fahlund, Vice President for Protection and Restoration at American Rivers. “Rivers in good condition more readily meet the needs of the surrounding community than polluted and degraded rivers.”
Source: The Academy of Natural Sciences. April 2005