Administration. The NCHRP provides
practical, ready-to-implement
solutions to pressing problems facing
the transportation industry.
In June 2013 NCHRP selected
a team led by Ayres Associates
to conduct an evaluation and
assessment of environmentally
sensitive streambank protection
measures. The objective of the
research project was to evaluate
and assess existing guidelines for
the design, installation, monitoring,
and maintenance of environmentally
sensitive bank stabilization and
protection. Another goal of the
project was to provide practical,
quantitative design guidelines that
engineers could use with confidence.
Lagasse served as principal
investigator, and Paul Clopper,
director of applied technology
at Ayres, served as a co-principal
investigator for the project, which
wrapped up in November 2015.
The NCHRP research report is in the
process of being published as NCHRP
Report 822.
Doug Shields, a hydraulic
engineering consultant at Shields
Engineering LLC and a member of
the Ayres NCHRP research team for
this project, agreed with Lagasse that
the lack of data behind vegetative
bank protection techniques was
problematic for engineers.
“Most people are willing to affirm
the environmental value of a river or
stream, but when you’re building a
highway, you need to make sure the
bank protection will hold up,” Shields
said. “The problem was that there
were no clear standards to do this.”
METHODS PUT IN PLACE
To start the project, the team
reviewed a 2005 NCHRP study
that focused primarily on using
vegetation techniques for streambank
stabilization. The study identified 44
different environmentally sensitive
bank protection measures but did
not test the techniques in real-world
scenarios. The Ayres NCHRP study
aimed to compare combinations
of engineered and vegetative bank
protection measures in a laboratory
set up to mimic real stream
conditions, Lagasse explained.
In essence, the Federal Highway
Administration recommends using
a combination of