Watershed Restoration Program
using Large Sediment Traps on Slope Failure
COFFEE CREEK PROJECT
Location: Nelson, British Columbia
Client: Meadow Creek Cedar Ltd.
Objective: To prevent sediment delivery to Coffee
Creek while establishing vegetation within riparian
Mitigation of Major Sediment Source
Coffee Creek is located in southeast British Columbia
near the town of Nelson. In November 1999, a major rain
on snow event occurred which caused a number of debris
slides and debris flows in the Coffee Creek watershed
and a debris flood in the Coffee Creek channel. Some
of the slides were related to logging and drainage diversion
on roads and some were natural.
As part of the Restoration Plan KL 18, prepared by
Meadow Creek Cedar Ltd., with funding from Forest Renewal
BC (Zimmer and Putt, 2001), a program for watershed
restoration was outlined. The program included mitigation
of major sediment sources in the Coffee Creek drainage.
The focus of the proposed rehabilitation work was to
help stabilize and re-vegetate the major point sediment
sources. The treatment was implemented in the fall of
2001. Local materials were used to build sediment traps,
and a grass/legume mix, together with alder (Alnus incana
ssp. tenuifolia) and black cottonwood (Populus balsamifera
ssp. trichocarpa) plugs, were planted to speed up re-vegetation
of the sites. Removal of trees from the slide headwall
was carried out to reduce the risk of further headwall
failure and for safety reasons. The sites were then
monitored in the summer of 2003 and functioning sediment
traps were observed.