Studying
Streambank
Stabilization
Research team studies
options, makes science-backed
recommendations
By Tawny Quast
W
hen it comes to stabilizing
a stream or river bank,
two basic schools of
thought exist: using a “hard”
engineered approach of rocks,
concrete blocks, and other man-
made materials to protect the bank;
or using the “soft” environmentally
sensitive approach of vegetation
and natural material. However,
the answer to what’s the best way
to protect a bank isn’t so basic,
with many opinions about what
techniques work best under what
circumstances. A combination
of these two approaches, often
called “biotechnical streambank
protection,” may in many cases offer
an optimal solution.
Essentially, keeping a highway
safe from an unstable bank is
a serious matter, with people’s
lives at risk if a structure such as
a bridge were to fail. And to an
engineer responsible for designing
streambank protection measures,
mere opinions of what works aren’t
good enough.
ABOUT THE TRANSPORTATION RESEARCH BOARD
The Transportation Research Board (TRB) is one of six major divisions
of the National Research Council. The mission of the TRB is to provide
leadership in transportation innovation and progress through research
and information exchange. The Board’s activities annually engage about
7,000 engineers, scientists, and other transportation researchers and
practitioners from the public and private sectors and academia. The
program is supported by state transportation departments and federal
agencies. For more information, see www.TRB.org.
Credit: www.national-academies.org
“You need to emphasize good
solid engineering when it comes to
streambank stabilization,” explained
Pete Lagasse, senior hydraulic
engineer at Ayres Associates. “The
problem with just using vegetation
(to protect a bank) has been
that there was little quantitative
information out there to give an
engineer the confidence to stand
behind that design.”
STUDY GOALS OUTLINED
Which is exactly why the
National Cooperative Highway
Research Program (NCHRP)
embarked on a study aimed at
backing the design and installation
of streambank protection measures
with solid, quantifiable research.
NCHRP is a forum for coordinated
and collaborative research
administered by the National
Academy of Science’s Transportation
Research Board in cooperation with
the American Association of State
Highway and Transportation Officials
(AASHTO) and the Federal Highway