Banff National Park of Canada
Park Management
Trans-Canada Highway Twinning Project: Phase IIIB
Environmental Screening Report - Report Summary
Environmental Screening Results
Table A provides a summary of the issues, impact characteristics and examples
of key mitigations that have been incorporated into the project design, or
are being recommended.
Wildlife
The wildlife species selected as VECs for the assessment were elk, deer,
moose, grizzly bear, black bear, wolf, lynx, wolverine, harlequin duck and
boreal toad. In addition, two general classes of wildlife were also considered:
small to medium-sized mammals, and passerines (i.e., songbirds).
The wildlife assessment considered three types of impacts:
- habitat loss;
- habitat connectivity; and
- wildlife mortality.
Habitat loss for most species is expected to be of low magnitude, be limited
to the local study area (LSA), and last for the duration of highway operations.
As a result, the habitat loss consequence was rated as -1 for most species.
Some species which benefit from edge habitat might benefit and so have a habitat
loss consequence of O. Because three or four of the top 10 harlequin duck
feeding and loafing concentration areas along the Bow River between Castle
Junction and Lake Louise will be affected during construction, the predicted
habitat loss consequence for harlequin ducks is -2 as a result of sensory
disturbance along the Bow River during construction. (See footnotes to Table
A for explanation of consequence ratings.)
Although numerous wildlife crossing structures will be built, it is
predicted that Phase IIIB will adversely affect wildlife's ability to
move across the landscape. Some species, such as harlequin ducks,
passerines, elk and deer will be minimally affected (connectivity
consequence score of -1). Small to medium-sized mammals are
predicted to retain demographic connectivity (e.g., animals of both
sexes and all age groups continue to move across the landscape), but
other processes may be substantially impaired (connectivity
consequence score of -2). For boreal toads, lynx, wolves, black
bears, grizzly bears, and moose, there is evidence of genetic
connectivity, but movement of females, and adult and subadult
dispersers is limited, which results in a connectivity consequence
score of -3. Habitat connectivity for wolverine was rated as most
affected, -4, because monitoring to-date has not demonstrated that
wolverine use wildlife crossing structures.
The Project's effects on wildlife's ability to move across the landscape
are off-set by the reduced mortality which will result by limiting wildlife
access to the TCH where vehicle-caused mortality occurs. This positive effect
is somewhat confounded, however, because there is a possibility that wildlife
will be diverted by the fence into the hamlet of Lake Louise where increased
encounters with humans could result. In addition, the fence end where Segment
B construction will stop near Lake Louise will be vulnerable to high vehicle/wildlife
collisions. Decisions about additional fencing at the hamlet of Lake Louise
influences the magnitude of the Project's positive effect on wildlife mortality
for a number of species, particularly grizzly bear and black bear.
Fish and fish Habitat
Any effects that the Project may have on fish and fish habitat are expected
to be of low magnitude because of the implementation of mitigations that will
be applied during construction and operations. Those mitigations include no
net loss of fish habitat from construction, and water quality protection from
sediment caused by erosion and runoff, spills, or salt from road maintenance
activities.
Air Quality
The Project is expected to result in a low magnitude increase in air
emissions during construction. During highway operations, changed
vehicle movement patterns are expected to result in a low magnitude
reduction in CO emissions, although there will be a low to moderate
magnitude increase in NOx emissions. No change to particulate
emissions is expected during operations.
Noise
Changes in noise levels as a result of the Project will be of low
magnitude, both during construction and operations. Equipment will
create noise in localized areas where construction is occurring.
minor, likely undetectable increase in noise levels will occur from
increasing traffic, but the variability in noise levels will be less
because the higher level of service will reduce stop and go traffic.
Terrain, Soils and Vegetation
The twinning of Phase IIIB will result in relatively limited additional
disturbance to terrain, soils and vegetation. The area does not have
high potential for rare plant species or communities, wetlands have
largely been avoided by adjusting the project alignment, and slope
stability can be addressed through appropriate construction and
stabilization techniques. Site-specific reclamation plans will be
required that address the specific challenges of this Project, including
shortage of topsoil, climate, and potential for introduction of invasive
species. During operations, salt management will need to be
addressed to minimize the effects of salt deposition and runoff into
wetlands.