Download Mankota Low Level Crossing Project Profile

EROSION &
SEDIMENT CONTROL
PROJECT PROFILE
Mankota
Low Level
Crossing
EnviroGrid eliminates the need for
annual road and culvert washout
repairs and traffic interruptions.
LOCATION:
Mankota, Saskatchewan
PRODUCTS:
EnviroGrid cellular confinement system
Woven geotextile
PROJECT PARTNERS:
Owner and Contractor
Regional Municipality of Mankota
Completion Date:
October 2015
Managing the impacts of spring runoff in
Saskatchewan is tough. It can make an
infrastructure manager feel like Bill Murray in
Groundhog Day; the same problems over and
over again. Like Bill, the RM of Mankota decided
it was time for a change, and approached Nilex
to explore their options.
Challenge
When spring runoff comes, it comes with a
vengance. Dry streambeds fill rapidly and flows
can quickly overwhelm even well-set culverts.
Once a culvert reaches capacity, the water only
has one place to go: Across the road above. This
heavy flow, across a surface built on a round
culvert, evenutally causes the road material and
culvert to shift, or “wash-out.” Spring also brings
heavy rains which create the same problems as
the flows from snow thaw. For years, repair from
washouts was a standard budget item for the
municipality, much as it was an accepted reality
for drivers who worked their way around repairs.
As frustrating as these annual rituals were, the
concept of a culvert-free “low level crossing”
design was something new to the municipality
and its constituents.
Solution
EnviroGrid cellular confinement is central to low
level crossing design. It’s manufactured from
rugged High Density Polyethylene which is UVresistant and designed to confine a variety of
fill materials. Instead of water running under the
road via culverts, low level crossing design uses
the increased strength of the confined aggregate
in the cell network to allow the water to pass
over the road during high flows without damage
to the surface. The material’s tensile strength,
pinned to the subgrade, holds the road in place.
Mankota Low Level Crossing
Lake Wabamun Shoreline Protection
In extreme high flows, some aggregate may
still be washed aside, but that represents a
much easier and cheaper repair than culvert
replacement. The work also helped shrink the
RM’s environmental impact by reducing repair
equipment carbon emissions and reducing the
amount of native gravel and aggregate material
excavated to accomodate annual repairs.
The Nilex Advantage
Installation
The EnviroGrid arrives on site in a compact
flattened state that makes it easy to carry and
place. Once the damaged culvert was removed
and the ground leveled, geotextile was laid
to cover the project area. The EnviroGrid was
staked to the subgrade and stretched to expand
the cells to their designed size. Tendons in
the material contribute to system strength by
creating solid fastening locations that conform
to ground contours, offering higher levels of
protection against flows. Aggregate was then
poured by a bucket loader to fill all the cells,
and overtopped to create a level surface. Once
complete, the RM returned the area to its
desired elevation using the existing fill material
available on site.
Nilex is committed to unearthing better
results. Whether it’s for a civil, resource or
environmental project, we offer the latest
engineered and technically-superior materials
and techniques to save our customers time
and money, minimize the need to move or
remove earth, and reduce the need for granular
materials.
With over 38 years of experience, a longstanding commitment to the environment and
highly qualified staff, Nilex delivers the products
and technologies that give clients an economic
advantage with environmental benefit.
Results
EnviroGrid gave the RM of Mankota a solution
that was economical and eliminated the need for
costly and repetitive gravel hauls and repairs.
nilex.com
Rev. 05/2016