Success of stream restoration
projects go largely unknown
Aug
03, 2006
by John
Mueller, Bigfork Eagle
Dollars spent on restoring America's
rivers are increasing exponentially, but
does anyone know how effective river
restoration projects really are?
Finding the answer to
that question prompted Duke University
Assistant Professor Emily Bernhardt to
participate in a survey study. The results
of that study were presented July 27 in a
lecture titled "Measuring, managing and
restoring freshwater ecosystem services" as
part of the University of Montana Biological
Station Summer Seminar series Thursday
evenings at Yellow Bay.
Despite the fact that river systems
represent just one percent of all freshwater
on earth, Bernhardt said 90 percent of U.S.
rivers have been strongly impacted by
channel manipulation and fragmentation,
dams, reservoirs, diversions or irrigation.
In addition, 20 percent of freshwater fishes
are threatened or extinct and freshwater
species represent 47 percent of all
endangered species in the U.S.
Changes to river systems occur in large part
due to an increase in the number of people
in an area, Bernhardt said. Agriculture,
high density housing and impervious surfaces
such as road, parking lots and rooftops
increases the amount of nutrients,
particularly nitrates, phosphates and
petroleum products entering rivers. Where
water once percolated slowly into soil,
impervious surfaces send it rushing off a
landscape into stream channels and eroding
them. Macro-invertebrates and other aquatic
species in those streams are reduced. Slow
moving streams with a diversity of substrate
habitats, such as deep pools, slow moving
water and riffles become uniform. Streamside
riparian vegetation and wetlands are
affected when channel modifications
disconnect streams from their floodplains
and wetland habitats.
Bernhardt said a
number of stream restoration practices are
common throughout the country. They include
bank stabilization by planting trees,
reconnecting channelized streams to adjacent
wetlands, creating stormwater retention
ponds to capture stormwater runoff coming
off developments with impervious surfaces,
channel reconfiguration, dam removal and
using hard materials such as rock to armor
stream banks.
As part of the ongoing, 40-year-old National
River Restoration Science Synthesis project,
Bernhardt's study was a collaborative effort
conducted in North Carolina between
ecologists, morphologists and hydrologists
focused on determining whether stream
restoration projects were effective and
successful. Finding that answer meant
determining whether individuals actively
monitored projects after completion.
Bernhardt's findings suggested that most did
not monitor projects, thus the project was
largely unable to determine individual
project successes.
Despite more than 37,000 restoration
projects in just seven regions across the
U.S., each costing an average of $380,000,
Bernhardt said there is no federal program
requiring record keeping of restoration
projects. Preliminary assessment of the
37,000 projects determined that fewer than
10 percent contained records indicating
intentional monitoring of project
effectiveness. Bernhardt said most projects
were funded by a combination of state,
federal, nonprofit organization and private
landowner money.
Bernhardt and her associates created a
sub-sample from the large number of
restoration projects in order to survey
project managers to assess project
successes. The team conducted telephone
interviews with 317 project managers. It
found less than half of the projects had a
stated goal, as most projects were funded by
funds allotted for streambank stabilization.
Bernhardt said improving water quality and
wildlife habitat were the most common stated
goals, but said they were often a guise. Of
the 317 projects, only 33 percent evaluated
project success using monitoring data, and
32 percent conducted before and after
restoration work monitoring. Less than 30
percent had information on how big the
project was in terms of feet or stream
miles.
Of the 317 project managers interviewed,
Bernhardt said 63 percent said their project
was completely successful, 30 percent said
the project was partially successful, five
percent said it was hard to tell and two
percent said the project was not at all
successful. However, because 65 percent of
"successful" reports were based on
photographs that were easy to manipulate,
such as taking pictures at different seasons
in the year, the team determined the rate of
success likely is not as high as reported.
The study concluded successful projects had
a few things in common. The projects
differed little in cost, size or number of
funders, and each displayed a higher level
of public involvement and were more likely
to have an advisory committee overseeing
them. Therefore, the more accountability the
project faced the more likely it was to be
successful.
In conclusion, Bernhardt said she would like
to see a portion of a project's funds
allocated for assessment and long-term
monitoring. Statistical data of water
quality and subsequent invertebrate and
aquatic species populations, stream
substrate and instream habitat types,
nutrients and other factors determining
stream health is necessary to determine
project success and to justify expenditures.
In addition, using a successful project as a
guide; having a goal of ecologically
improving the stream; using natural,
self-sustaining channel improvements rather
than hard armoring with concrete or rip-rap;
and ensuring more good than harm is done to
the stream area additional criteria
Bernhardt said should be considered in any
stream restoration project.
For more information on river restoration
across the U.S. and the National River
Restoration Science Synthesis project, visit
www.nrrss.umd.edu.
The final FLBS Summer Series lecture is
Thursday, Aug. 3 in the biological station's
Elrod Lecture Hall. That lecture is titled
"Interpretations of climate change for the
northern Rocky Mountains."
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