Pole Drain Systems
RIVER LIVE POLE DRAIN SYSTEM
West Kootenay Region, Akolkolex River main road at 21
Ministry of Environment, Lands, and Parks. Columbia
To provide drainage of subsurface seepage emerging below
a re-constructed road, re-vegetate and help stabilize
the slope using soil bioengineering structures.
Akolkolex road system was built approximately 25 years
ago using a three quarter to full bench cut method.
In the spring of 1997, a debris flow occurred at approximately
km 21 along the road; as a result the road suffered
a substantial failure (slump). The road was repaired
in 1998 using a concrete-block retaining wall system.
seepage water was found emerging from under the base
of the installed retaining wall after re-construction
of the road. The underground seepage water was saturating
the fill slope and flowing to the toe of the slope into
the river. This posed a hazard in terms of erosion and/or
further slumping of this slope.
short (15 m) live pole drain (LPD) system was installed
manually in the spring of 1999 to drain seepage water
from the base of the installed retaining wall to the
toe of the slope and into the existing riprap adjacent
to the river.
of locally collected Willow (Salix bebbiana/ scouleriana/exigua),
Black Cottonwood (Populus balsamifera ssp. trichocarpa),
and Red-Osier Dogwood (Cornus stolonifera)
were utilized to constructed the (LPD) system.
structure was monitored in 2000 and 2003; four years
after installation. At the time the system was found
to be working efficiently at draining seepage water
and stabilizing the slope.