By: Larry Flynn
The Ohio DOT (ODOT) showed concern for both the environment and community
during a recent road widening project in Logan County when state engineers
preserved the natural beauty of the Ohio farming area by rerouting a creek
to make room for the lane expansion.
Part of an 18-month-long project, State Route 33 between Logan County and
Columbus is being widened to four lanes. Otter Creek, a meandering stream
that runs along S.R. 33 for about 5 miles in Logan County, is an important
feature of the west-central Ohio landscape and state officials did not want
it ravaged by heavy construction during the project.
Engineers needed an adaptable material to provide erosion control on the
side slopes of the reconstructed creek bed. To accomplish this task, engineers
selected a three-dimensional Geosynthetic nylon matting, called Enkamat,
manufactured by Akzo Nobel Geosynthetics Co., Asheville, N.C.
"A lot of care was taken to relocate Otter Creek and restore it to
as much of a natural stream as possible," said Steve Kremer, ODOT project
engineer. "Enkamat was used to keep the least amount of erosion possible
from occurring in the creek."
Kremer said the company tailored the product to conform to the varying widths
of the creek bed's side slopes. "The mat was custom-made for the job,"
he said. "The pieces were specially put together for it."
The product, which was manufactured in rolls that tapered from 34 ft to
8 ft in width, was laid along the stream and fastened with pins. According
to Kremer, approximately 36,000 sq yd of matting was applied to the side
slopes over the summer and the stream relocation was completed last fall.
The product's three-dimensional geomatrix of heavy nylon monofilaments is
90% open space, which facilitates root growth and helps prevent compaction,
according to the maker. Its nylon matting is designed to provide a tough,
natural root reinforcing system that revives and protects turf. The product's
resilient matting remains open, allowing oxygen and moisture to reach plant
roots.
Department engineer Nicole Feser said the stream relocation was completed
in early October. The matting has been filled with soil and grass is being
planted along the side slopes, she said.
The product was specified for the S.R. 33 project by the consulting engineer,
who prepared the project plans with the approval of the DOT's Hydraulic
section. John Hurd, assistant hydraulic engineer, said the department has
had positive results with the matting on other projects similar to the Logan
County job.
"We've been specifying the product for a while and haven't heard any
complaints," said Hurd. "We like to use it to protect large channels
on flatter grades. We had a lot of large relocated channel [in Logan County].
That's the main reason we used the product."
Kremer said about half of the paving has been completed. The department
has set a completion date for road expansion of Sept. 1.
